An Analysis for the Imperial Irrigation District...Imperial Irrigation District RAMON MIRAGE S.C.E....
Transcript of An Analysis for the Imperial Irrigation District...Imperial Irrigation District RAMON MIRAGE S.C.E....
Transitional Cluster Study
PDS Consulting, PLC Tempe AZ 85282
An Analysis for the Imperial Irrigation District
~ FINAL REPORT~ 01-28-2010
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
i
EXECUTIVE SUMMARY
This section provides a summary of the transitional cluster study results for integrating about 2183 MW of generation resources to the Imperial Irrigation District (IID) transmission system. Detailed study results can be found in the subsequent sections of the report. Disclaimer
This report does not constitute an offer of transmission service nor confer upon the Interconnection Customer, any right to receive transmission service from IID. IID and its neighboring interconnected utilities may not have the Available Transmission Capacity to deliver to any customer or Point of Delivery. It must also be noted that the study results for the analysis presented in this report are highly dependent upon the data provided by the interconnection customers such as machine models, points of interconnection and timing of proposed projects. Any modification to the data provided in the interconnection application invalidates the results of this study. Although IID will share the study results with the other neighboring utilities, at this time the impact of the proposed generation projects on the affected systems are unknown.
Overview
IID is currently processing a large volume of active Interconnection Requests (IRs). IID clustered all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These proposed projects plan to deliver power to IID and other neighboring utilities in the 2010-2015 timeframe. Specifically, the Cluster Study contained the following active interconnection requests:
Project Code Capacity Point of Interconn. In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-3 36.1 MW ―EO‖ 92 kV line 11/01/2011 A-4 225 MW Midway 230 kV 05/01/2014 A-5 55 MW Niland 161 kV 01/01/2010 A-6 99 MW Plaster City 92 kV 12/31/2011 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
ii
A-8 80 MW ―N‖ line 1 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-11 130 MW ―R‖ line 09/01/2011 A-12 250 MW ―L‖ line 2 09/01/2011 A-13 50 MW ―L‖ line 12/01/2011 A-14-1 25 MW ―L‖ line 3 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012
To determine the impact of the proposed projects on the IID Transmission System and the neighboring transmission systems, IID contracted with PDS Consulting, PLC (PDS) to perform the Cluster Study. The Cluster Study was conducted using Western Electricity Coordination Council’s (WECC) approved heavy summer and light winter power flow models with detailed IID system representation incorporated. Studies performed included power flow, transient stability, post transient stability and short circuit analyses. PDS performed the transient and post-transient analyses portions of the Cluster Study while IID Transmission Planning conducted the power flow and short circuit analyses. Study Approach In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. For projects with different phases of implementation, the entire project output was considered operational in the year in which the first phase commences operation. Table I depicts the projects in each group and the WECC base model used for studying the group.
Group Projects WECC Base Model
2010
A-5 (55 MW) 2010 heavy summer and light winter models
2011
A-3 (36.1 MW), A-6 (99 MW), A-8 (80 MW), A-9 (100 MW), A-11 (130 MW), A-12 (250 MW) & A-13 (50 MW)
2011 heavy summer and 2010 light winter models
2012
A-1-1 (70 MW), A-1-2 (70 MW), A-1-3 (70 MW), A-7-1 (47 MW), A-7-2 (47 MW), A-10-1 (200 MW), A-10-2 (200 MW), A-14-1 (25 MW), A-14-2 (50 MW) , A-14-3 (50 MW) & A-15 (119 MW)
2012 heavy summer and 2013 light winter models
1 Project A-8 was connected to the IID ―KN‖ line between Midway and Coachella Valley Substations in lieu
of the requested ―N‖ line due to capacity limitation and huge cost of upgrading the ―N‖ line. 2 Due to capacity limitations on the ―L‖ line, A-12 was connected to the proposed Bannister to Dixieland
230 kV line. 3 A-14 was connected to Bannister via a radial 230 kV line
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iii
2014
A-2-4 (70 MW) A-2-5 (70 MW) & A-2-6 (70 MW) & A-4 (225 MW)
2014 heavy summer and 2013 light winter models
TABLE I: Grouping of Projects for Transitional Cluster Study
The output from all the generation projects in each group were dispatched and delivered as indicated in each project’s interconnection application. Power flow, transient stability, post-transient stability, and short circuit analyses were conducted on each group. The adequacy of the study results were evaluated using WECC/NERC reliability and the IID planning standards. Impacts of each group to the IID system were determined and mitigation plans recommended. The mitigation plans were designed to ensure cost is contained and development is coordinated with IID future transmission plan objectives.
IID Transmission System Impacts The studies described in this report showed that the interconnection of proposed generation projects created new transmission overloads under normal operating conditions as well as single and credible double element outage conditions. In particular, the addition of the Group 2010 Cluster projects caused two (2) IID transmission facilities to overload under single element outage conditions. The interconnection of the Group 2011 Cluster projects caused ten (10) transmission facilities to overload under single element outages and another eight (8) facilities to overload during double element outages. In some instances the proposed point of interconnection of some of the projects were modified in order to minimize the impact of the projects on the existing transmission system. The detail impact of each cluster group can be found in the ―Study Results‖ section of each cluster group study. The addition of the proposed projects also had some impact on the voltage performance of the IID transmission system. The post-transient stability analysis showed that the interconnection of the proposed project caused the reactive margins at most of the IID buses monitored to shrink marginally. Each project would therefore be expected to ensure at a minimum zero reactive power exchange between its project and the IID transmission system at the point of interconnection. The study showed that a minimum of 632 MVAR of reactive power resources (a combination of controllable and non-controllable shunt capacitors) would be needed to maintain acceptable voltage performance on the IID transmission system. The results of the transient stability analysis showed that system performance was significantly impacted following the addition of the cluster projects. In particular, the addition of the Group 2011 cluster projects caused self-sustaining system swings and WECC system performance criteria violations. With the observed system performance criteria violations in 2011 resolved, subsequent cluster project additions in 2012 and 2014 resulted in a well-damped transient stability performance with no performance criteria violations. The short circuit analysis showed that the interconnection of the proposed cluster projects would cause forty-one (41) IID breakers to exceed their interrupting capabilities.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iv
Recommended Mitigation Plan, Cost and Construction Timelines To mitigate the identified impacts to IID transmission system following the addition of the cluster projects, IID developed an iterative process that ensured that any mitigation plan designed meets the following objectives:
It ensures that WECC/NERC reliability standards are met
It fits into IID long term transmission expansion plans
It is cost effective. Based on these objectives, the mitigation plan provided in TABLES II-V portions of which is depicted graphically in FIGURE I, is recommended as the appropriate transmission network reinforcements needed for resolving the identified thermal and transient stability criteria violations attributable to the cluster projects. It is estimated that the recommended network upgrades and its implementation would cost $ 507 Million (2009 Dollars). This estimate excludes a direct assignment cost of $ 133 Million (2009 Dollars) for interconnecting the proposed projects to the IID transmission system. The estimated construction timelines for each of the upgrades is provided in TABLES II-V.
FIGURE I: Recommended Major Transmission Network Upgrades
S.C.E.DEVERS
ECSS
AVE 58
MIDWAY
I.V. SUB.
COACHELLA VALLEY
BANNISTER SS
NILAND
HIGHLINE
DROP 4
DIXIELAND
Transitional Cluster Study
Imperial Irrigation District
RAMON
MIRAGES.C.E.
IID I.V. SUB.
30 mo.
24 mo.
36 mo.
36 mo
30 mo. 30 mo.
Proposed Major Transmission Network Upgrades
to Blythe
to Blythe
to Palo Verde
to North Gila
to Pilot Knob
CC - Existing single161kV line upgraded to double circuit
230kV
DD - Existing 161/92kV line upgraded to double circuit
230kV
AA - New double circuit 230kV line using new ROW
BB - New single circuit 230kV line using new ROW
LEGEND
500kV line
230kV line
Proposed 230kV line upgrade
Existing 230kV Switching Stations
New 230kV Switching Stations
161kV line
Proposed 161kV line upgrade
92kV line
Proposed 92kV line upgrade
to La Rosita (CFE)
to Miguel (SDG&E)
36 mo.
24 mo.
CC
AA
BB
EE
DD
AA
New
230/161 KV
225MVAIID Approved Project
30 mo.
30 m
o.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
i
TABLE II: Recommended Mitigation Plan & Associated Cost for Group 2010 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate ($
M i l l ion)
Construction
Tim e L ines
(M onths) Notes
AVENUE 58 – JEFERSON 92 KV LINEN. LA QUINTA – AVENUE 42 92 KV LINE
"CD"132 MVA 127%
Rebuild line using 191 MVA, 900 MCM
ACSS ConductorIID Budget 18
N. LA QUINTA – AVENUE 42 92 KV LINE
"CD"AVENUE 58 – JEFERSON 92 KV LINE 132 MVA 126%
Rebuild line using 191 MVA, 900 MCM
ACSS ConductorIID Budget 18
MIDWAY #1 230/92 KV TRANSFORMER MIDWAY #2 230/92 KV TRANSFORMER 300 MVA 150% 12
MIDWAY #2 230/92 KV TRANSFORMER MIDWAY #1 230/92 KV TRANSFORMER 300 MVA 150% 12
RAMON – MIRAGE 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 118%Upgrade 0.1 miles to 2-1033.5
ACSS/TW conductor 0.18 18
CVSUB – JACKSON 92 KV LINE 132 MVA 121% 9.27 24
EDOM – RAMON 92 KV LINE 91 MVA 133% IID Budget 12
CITAP1 – COACHELA 92 KV LINE 152 MVA 115%
CITAP1- VANBUREN 92 KV LINE 152 MVA 115%
CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112%
CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112%
AVENUE 58 161/92 KV TRANSFORMER COACHELLA 161/92 KV TRANSFORMER 125 MVA 113%Replace unit with 225 MVA 161/92 kV
transformerIID Budget 24
Though overloads are due to Group
2010 Cluster projects, IID has aplanned budget for this upgrade
COACHELLA - DEVERS 230 KV LINE RAMON - MIRAGE 230 KV LINE 389 MVA 112% 23.00
CV - RAMON 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 109% 23.00
Install 104.4 MVAR capacitor banks 3.41
0.50
247.92
Network Upgrades Attributable to Group 2010 Cluster Pro jects
These transmission lines
share the same tower and
needed to be upgraded at the
Upgrade transmission line to 779 MVA,
2-1033 MCM ACSR30
Existing Transm ission System Upgrades
These network upgrades are not
due to the addition of the cluster
projects. However, the upgrades
are needed prior to the
integration of the proposed
projects. IID have some of the
upgrades already planned and
budgeted.
Implement Remedial Action Scheme
to trip generation at Midway 92 kV
Rebuild transmission lines using 191
MVA, 900 MCM ACSS Conductor
CVSUB - COACHELLA #1 &2 92 KV LINES
AVENUE 58 – JEFERSON 92 KV &
AVENUE 58 - AVENUE 48 92 KV LINES
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
ii
TABLE III: Recommended Mitigation Plan & Associated Cost for Group 2011 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate
($ M i l l ion)
Construction
Tim e L ines
(M onths)
Notes
NONE N/A N/A N/A
40 Breaker Replacements at El Centro 92 kV
switching station 13.60 12 Short Circuit Study
ELCENTSW – IMPERIAL VALLEY 230 KV LINE 370 MVA 148%
Rebuild line using 786 MVA, 2-1033 MCM
ACSS Conductor and also rebuild the ECSS
230.
58.94 30 None
ELCENTSW 230/92 KV TRANSFORMER 332 MVA 114%
USNAF – ELTERMIN 92 KV LINE 132 MVA 112%
USNAF – DIXIELAN 92 KV LINE 132 MVA 112%
COACHELLA 161/92 KV TRANSFORMER AVENUE 58 161/92 KV TRANSFORMER 125 MVA 178% Replace CV transformer with 300 MVA rating 8.32 24 None
DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 147%
DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 147%
DIXPRI – DIXPRI2 92 KV LINE 132 MVA 147%
RTAP2 – RTP1 92 KV LINE 57 MVA 149%
RTP1 – DIXIELAND 92 KV LINE 51 MVA 102%
RAMON 230/92 KV TRANSFORMER 225 MVA 142%
N. VIEW – AVE42 92 KV LINE 132 MVA 137%
N. VIEW – RAMON 92 KV LINE 132 MVA 132%
AVE42 – FRANWAY 92 KV LINE 132 MVA 130%
FRANWAY – EDOM 92 KV LINE 132 MVA 128%
COACHELA #1 230/92 KV TRANSFORMER 150 MVA 116%
COACHELA #1 230/92 KV TRANSFORMER 150 MVA 116%
ELCENTSW 161/92 KV TRANSFORMER
COACHELA – DEVERS 230 KV & MIRAGE –
RAMON 230 KV LINES 125 MVA 112%
New 230 kV substation at Dixieland 20.77
332 MVA 230/92 kV transformer at Dixieland
and a transmission line (circuit #1) from
Dixieland to IID's Imperial Valley Switching
Station
IID Budget
New 92 kV line from Avenue 58 to Coachella
through Kohl Ranch (KM line)9.15 24
New 230 kV line (circuit #2) from Dixieland
to Imperial Valley Sw. Station28.28 24
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24
New 19-mile, 786 MVA, 2-1033 MCM bundled
230 kV line from Highline to El Centro. Install
Remedial Action Scheme (RAS) to mitigate
the marginal transmission overloads.
Upgrade Highline Sub., Upgrade "E" line 3.4
miles.
Rebuild "R" line uisng 191 MVA, 900 MCM
ACSS Conductor from Dixieland to Anza and
to Central
36
30
None
DIXIELAND – IMPERIAL VALLEY 230 KV LINE
IMPERIAL VALLEY – EL CENTRO 230 KV LINE
New Network faci l i ties for In tegrating Group 2011 Cluster Pro jects
24
Network Upgrades Attributable to Group 2011 Cluster Pro jects
47.08
32.59
New 22-mile, 786 MVA, 2-1033 MCM ACSR
bundled 230 kV line from Dixieland to El
Centro. Rebuild 9-mile El Centro to L-TAPA-12
161 kV line using double circuit 554 MVA,
1033 ACSR conductor
52.80
NONE N/A N/A N/A
These projects are needed in
order to integrate Group 2011 Cluster Projecs in Dixieland area.
None
None
DIXIELAND 230/92 KV TRANSFORMER
COACHELA – DEVERS 230 KV &
COACHELA – RAMON 230 KV LINES 30
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iii
TABLE IV: Recommended Mitigation Plan & Associated Cost for Group 2012 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate ($
M i l l ion)
Construction
Tim e L ines
(M onths) Notes
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24 None
One Breaker replacement at
Coachella Valley 92 kV substation 0.13 N/A
Installation cost for
replacing the breaker
New 8.5-mile 230 kV line from Midway
– Hudson RanchIID Budget 24
Upgrade Midway 230 kV Substation 10.41 30
New 24-mile 230 kV line from Hudson
Ranch to Bannister44.70 30
Rebuild "L" line between Bannister
and A121P tap and BTAP-DTP 15.5
miles with 2 circuits of 2-1033 ACSR
35.65 36
Install 225 MVA, 230/161 kV
transformer and build Bannister
substation
21.37 30
AVE48 – AVE58 92 KV LINE AVE58 – JEFERSN 92 KV LINE 132 MVA 121%Reconductor line using 191 MVA, 900
MCM ACSS 92 kV Conductor5.85 18 None
RTAP2 – RTP3ANZA 92 KV LINE RTP3ANZA– RTP5DSTS 92 KV LINE 91 MVA 126%Rebuild line using 191 MVA, 900 MCM
ACSS 92 kV Conductor6.21 30 None
NILAND – COACHELA 161 KV LINE 165 MVA 119%
RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 122%
RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 116%
RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 111%
COACHELA – MIDWAY 230 KV &
COACHELA– A-8 230 KV LINES
Implement a Remedial Action Scheme
to trip generation at MidwayN/A
NORMAL OPERATIONS (N-0)
12Already included in 2011
Budget
165 MVA 103%
None N/A N/A N/A
None
Network Upgrades Attributable to Group 2012 Cluster Pro jects
A-13 (POI) – AVENUE 58 161 KV LINE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iv
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
v
TABLE V: Recommended Mitigation Plan & Associated Cost for Group 2014 Cluster Projects
Overloaded Facilities Critical OutageApplicable
RatingsLoadings Recommended Mitigation
Cost Estimate
($ Million)
Construction Time
Lines (Months)Notes
Implement Breaker-and-one half
configuration at Coachella Valley
substation
13.49 18
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24
RAMON 230/92 KV TRANSFORMER 225 MVA 132%
Install a second 225 MVA transformer at
Ramon8.35 24
N. VIEW – AVE42 92 KV LINE 132 MVA 121%
N. VIEW – RAMON 92 KV LINE 132 MVA 116%
AVE42 – FRANWAY 92 KV LINE 132 MVA 114%
FRANWAY – EDOM 92 KV LINE 132 MVA 112%
24
None
Network Upgrades Attributable to Group 2014 Cluster Projects
COACHELA – DEVERS 230 KV &
COACHELA– RAMON KV LINES Rebuild lines using 191 MVA, 900
ACSS Conductor
5.39
6.65
NONE N/A N/A N/A
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
vi
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
i
TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................... i STUDY OVERVIEW ..................................................................................................... 1 STUDY METHODOLOGY AND EVALUATED CRITERIA ............................................. 2
Power Flow Analysis ................................................................................................................................................. 3 Transient Stability Analysis..................................................................................................................................... 3 Post-Transient Stability Analysis .......................................................................................................................... 6 Short Circuit Analysis ................................................................................................................................................ 7
GROUP 2010 CLUSTER STUDY ................................................................................. 8 A.1 INTRODUCTION .................................................................................................... 9 A.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................... 9
A.2.1 Base Case Assumptions ............................................................................................................................. 9 A.2.2 Base Cases Studied ................................................................................................................................... 10 A.2.3 Load and Resources ................................................................................................................................... 10 A.2.4 Dynamic Models ........................................................................................................................................... 11 A.2.5 Short Circuit Data ......................................................................................................................................... 11
A.3 STUDY RESULTS ................................................................................................ 12 A.3.1 Power Flow Analysis Findings ................................................................................................................ 12
A.3.1.1 Heavy Summer Pre-Cluster Base Case .................................................................................. 12 A.3.1.2 Heavy Summer Post-Cluster Base Case ................................................................................ 12 A.3.1.3 Light Winter Pre-Cluster Base Case .......................................................................................... 15 A.3.1.4 Light Winter Post-Cluster Base Case........................................................................................ 15
A.3.2 Transient Stability Analysis Findings ................................................................................................... 17 A.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 18 A.3.4 Short Circuit Analysis Findings ............................................................................................................... 18
A.4 MITIGATION PLANS ............................................................................................ 19 A.4.1 Mitigation Plans for Existing Overloads .............................................................................................. 19 A.4.2 Mitigation Plans for Overloads Caused by Group 2010 Cluster Projects .............................. 21
A.5 COST AND CONSTRUCTION TIMELINES .......................................................... 21 GROUP 2011 CLUSTER STUDY ............................................................................... 37 B.1 INTRODUCTION .................................................................................................. 38 B.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................. 38
B.2.1 Base Case Assumptions ........................................................................................................................... 38 B.2.2 Base Cases Studied ................................................................................................................................... 39 B.2.3 Load and Resources ................................................................................................................................... 40 B.2.4 Dynamic Models ........................................................................................................................................... 40 B.2.5 Short Circuit Data ......................................................................................................................................... 41
B.3 STUDY RESULTS ................................................................................................ 42 B.3.1 Power Flow Analysis Findings ................................................................................................................ 42
B.3.1.1 Heavy Summer Pre-Cluster Base Case .................................................................................. 42 B.3.1.2 Heavy Summer Post-Cluster Base Case ................................................................................ 42 B.3.1.3 Light Winter Pre-Cluster Base Case .......................................................................................... 45 B.3.1.4 Light Winter Post-Cluster Base Case........................................................................................ 46
B.3.2 Transient Stability Analysis Findings ................................................................................................... 48 B.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 49 B.3.4 Short Circuit Analysis Findings ............................................................................................................... 49
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
ii
B.4 MITIGATION PLANS ............................................................................................ 50 B.4.1 Mitigation Plans for Overloads Caused by Group 2011 Cluster Study ................................... 50
B.5 COST AND CONSTRUCTION TIMELINES .......................................................... 51 GROUP 2012 CLUSTER STUDY ............................................................................... 78 C.1 INTRODUCTION .................................................................................................. 79 C.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ................................. 79
C.2.1 Base Case Assumptions ........................................................................................................................... 79 C.2.2 Base Cases Studied ................................................................................................................................... 80 C.2.3 Load and Resources ................................................................................................................................... 81 C.2.4 Dynamic Models ........................................................................................................................................... 81 C.2.5 Short Circuit Data ......................................................................................................................................... 82
C.3 STUDY RESULTS ................................................................................................ 83 C.3.1 Power Flow Analysis Findings ................................................................................................................ 83
C.3.1.1 Heavy Summer Pre-Cluster Base Case .............................................................................. 83 C.3.1.2 Heavy Summer Post-Cluster Base Case ............................................................................ 83 C.3.1.3 Light Winter Pre-Cluster Base Case ..................................................................................... 85 C.3.1.4 Light Winter Post-Cluster Base Case ................................................................................... 86
C.3.2 Transient Stability Analysis Findings ................................................................................................... 88 C.3.3 Post-Transient Stability Analysis Findings ......................................................................................... 89 C.3.4 Short Circuit Analysis Findings ............................................................................................................... 89
C.4 MITIGATION PLANS ............................................................................................ 90 C.4.1 Mitigation Plans for Overloads Caused by Group 2012 Cluster Study ................................... 90
C.5 COST AND COSTRUCTION TIMELINES ............................................................. 91 GROUP 2014 CLUSTER STUDY ............................................................................. 115 D.1 INTRODUCTION ................................................................................................ 116 D.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS ............................... 116
D.2.1 Base Case Assumptions ......................................................................................................................... 116 D.2.2 Base Cases Studied ................................................................................................................................. 117 D.2.3 Load and Resources ................................................................................................................................. 118 D.2.4 Dynamic Models ......................................................................................................................................... 118 D.2.5 Short Circuit Data ....................................................................................................................................... 118
D.3 STUDY RESULTS .............................................................................................. 119 D.3.1 Power Flow Analysis Findings .............................................................................................................. 119
D.3.1.1 Heavy Summer Pre-Cluster Base Case ............................................................................ 119 D.3.1.2 Heavy Summer Post-Cluster Base Case .......................................................................... 119 D.3.1.3 Light Winter Pre-Cluster Base Case ................................................................................... 121 D.3.1.4 Light Winter Post-Cluster Base Case ................................................................................. 122
D.3.2 Transient Stability Analysis Findings ................................................................................................. 124 D.3.3 Post-Transient Stability Analysis Findings ....................................................................................... 124 D.3.4 Short Circuit Analysis Findings ............................................................................................................. 125
D.4 MITIGATION PLANS .......................................................................................... 126 D.4.1 Mitigation Plans for Overloads Caused by Group 2014 Cluster Study ................................. 126
D.5 COST AND CONSTRUCTION TIMELINES ........................................................ 126
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iii
LIST OF APPENDICES
Group 2010 Cluster Study Appendix A1 – Power Flow Maps Appendix A2 – Summary of Power Flow Analysis Results Appendix A3 – Heavy Summer Post-Transient Stability Analysis Results Group 2011 Cluster Study Appendix B1 – Power Flow Maps Appendix B2 – Summary of Power Flow Analysis Results Appendix B3 – Heavy Summer Post-Transient Stability Analysis Results Group 2012 Cluster Study Appendix C1 – Power Flow Maps Appendix C2 – Summary of Power Flow Analysis Results Appendix C3 – Heavy Summer Post-Transient Stability Analysis Results Group 2014 Cluster Study Appendix D1 – Power Flow Maps Appendix D2 – Summary of Power Flow Analysis Results Appendix D3 – Heavy Summer Post-Transient Stability Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
iv
LIST OF ATTACHMENTS Attachment A – Group 2010 Cluster Study Transient Stability Plots Attachment B – Group 2011 Cluster Study Transient Stability Plots Attachment C – Group 2012 Cluster Study Transient Stability Plots Attachment D – Group 2014 Cluster Study Transient Stability Plots
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
1
STUDY OVERVIEW
Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These proposed projects plan to deliver power to IID and other neighboring utilities in the 2010-2015 timeframe. The Cluster Study contained the following active interconnection requests:
Project Code Capacity Point of Interconn. In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-3 36.1 MW ―EO‖ 92 kV line 11/01/2011 A-4 225 MW Midway 230 kV 05/01/2014 A-5 55 MW Niland 161 kV 01/01/2010 A-6 99 MW Plaster City 92 kV 12/31/2011 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013 A-8 80 MW ―N‖ line 4 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-11 130 MW ―R‖ line 09/01/2011 A-12 250 MW ―L‖ line 5 09/01/2011 A-13 50 MW ―L‖ line 12/01/2011 A-14-1 25 MW ―L‖ line 6 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012
To determine the impact of the proposed projects on the IID electric system and the neighboring transmission systems, IID contracted with PDS Consulting, PLC (PDS) to perform the Cluster Study. The Cluster Study was conducted using Western Electricity Coordination Council’s (WECC) approved heavy summer and light winter power flow models with detailed IID system representation incorporated. Studies performed included power flow, transient stability, post transient stability and short circuit analyses.
4 Project A-8 was connected to the IID ―KN‖ line in lieu of the requested ―N‖ line interconnected due to
capacity limitation and huge cost of upgrading the ―N‖ line. 5 Due to capacity limitations on the ―L‖ line, A-12 was connected to Dixieland 230 kV via a radial 13-mile
1033 MCM ACSR bundle 230 kV conductor. 6 A-14 was connected to Bannister via a radial 230 kV line
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
2
PDS performed the transient and post-transient analyses portions of the Cluster Study while IID Transmission Planning conducted the power flow and short circuit analyses. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. For projects with different phases of implementation, the entire project output was considered operational in the year in which the first phase commences operation. Table 1 depicts the projects in each group and the WECC base model used for studying the group. The study description, methodology and findings of each group are provided in this report. For example, Group 2010 Cluster Study of this report details the study findings of projects in Group 2010.
Group Projects WECC Base Model
2010
A-5 (55 MW) 2010 heavy summer and light winter models
2011
A-3 (36.1 MW), A-6 (99 MW), A-8 (80 MW), A-9 (100 MW), A-11 (130 MW), A-12 (250 MW) & A-13 (50 MW)
2011 heavy summer and 2010 light winter models
2012
A-1-1 (70 MW), A-1-2 (70 MW), A-1-3 (70 MW), A-7-1 (47 MW), A-7-2 (47 MW), A-10-1 (200 MW), A-10-2 (200 MW), A-14-1 (25 MW), A-14-2 (50 MW) , A-14-3 (50 MW) & A-15 (119 MW)
2012 heavy summer and 2013 light winter models
2014
A-2-4 (70 MW) A-2-5 (70 MW) & A-2-6 (70 MW) & A-4 (225 MW)
2014 heavy summer and 2013 light winter models
Table 1: Groupings of Projects for Transitional Cluster Study
The output from all the generation projects in each group were dispatched and delivered as indicated in each project’s interconnection application. IID and its neighboring interconnected utilities may not have the Available Transmission Capacity to deliver to any customer or Point of Delivery.
STUDY METHODOLOGY AND EVALUATED CRITERIA In performing the analyses, the proposed projects were grouped according to each project’s in-service year. Two operating conditions (heavy summer and light winter) were studied for each cluster group independent of the season that a project plans to start commercial operation. This enabled IID to determine the impact of the group as a whole and facilitated cost sharing for mitigating the identified impact. The analyses performed in this study included power flow, transient stability, post-transient stability and short circuit. This section provides a summary of the methods and the evaluation criteria used for analyzing the results of the studies.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
3
Power Flow Analysis
Power flow analysis was conducted on all the pre- and post-cluster base cases developed for the Cluster Study. Power flow analysis considers a snapshot in time where tap changing transformers, Static Var Devices (SVD) and phase-shifters have had time to adjust. In addition, a swing generator balances generation and load (plus losses) on the system during each contingency scenario. The power flow analysis was conducted with version 16 of General Electric’s PSLF software. Power flow results were monitored and reported for the IID and the neighboring control areas. Thermal and voltage performance of the system was evaluated under normal (N-0), single element outage (N-1) and select double element outage (N-2) conditions. Thermal loadings were reported when a modeled transmission component is loaded to 100% or more of its continuous MVA rating (as provided in the power flow database). Transmission voltage violations for N-0 conditions were reported when per unit voltages were less than 0.95 or greater than 1.05. Transmission voltage violations following N-1 or N-2 outage were reported when per unit voltage was less than 0.90 or greater than 1.05. Additionally, voltage deviations between the pre- and post-contingency conditions were recorded whenever these deviations were greater than 5% for single contingencies and 10% for double contingencies. In summary, the following WECC/NERC reliability criteria were used to assess the adequacy of the power flow study results:
Pre-disturbance bus voltage must be between 0.95 per unit and 1.05 per unit. (an IID-specific requirement)
Allowable voltage deviation of five (5) percent for N-1 Contingencies (deviation from pre-disturbance voltage).
Allowable voltage deviation of ten (10) percent for N-2 contingencies (deviation from pre-disturbance voltage).
Post-transient bus voltage must be at least 0.90 per unit (an IID-specific requirement)
Pre- and post-disturbance loading to remain within the emergency ratings of all equipment and line conductors. The emergency ratings are determined by the owner/operator of each equipment item.
As applied in the analysis, all tables and results for loading criteria were based on the normal or continuous rating (Rating 1) for all lines in service conditions and the emergency rating (Rating 2) for outage conditions. Transient Stability Analysis Transient stability analysis is a time-based simulation that assesses the performance of the power system shortly before, during, and after a contingency. Transient stability studies were performed on both the pre- and post-cluster base cases to verify the stability of the system following a system fault.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
4
Transient stability analysis was performed based on WECC Disturbance-Performance Criteria for selected system contingencies using version 16 of General Electric’s PSLF software. Transient stability contingencies were simulated for 10 seconds, excluding one (1) second of pre-disturbance data. All simulated faults, unless specified, were assumed to be three-phase with a 4 cycle breaker clearing time. System damping was assessed visually with the aid of stability plots. Selected critical contingencies were simulated. Provided below are the outages simulated.
Imperial Valley-Miguel 500 kV line outage
Palo Verde-Devers 500 kV line outage
N. Gila-Imperial Valley 500 kV line outage
Imperial Valley-El Centro 230 kV line outage
Ramon–Mirage 230 kV line outage
Coachella –Devers 500 kV line outage
ELSTM2 and REPU2 generator outages
Ramon –Mirage 230 kV and Coachella – Devers 230 kV lines outage
Imperial Valley–El Centro #1 &2 230 kV lines (Group 2014 Cluster Study only)
Imperial Valley–Dixieland #1 &2 230 kV lines (Group 2014 Cluster Study only) The following WECC transient voltage dip and transient frequency criteria were used to evaluate the impact of the project. A summary of the transient stability analysis evaluation criteria is provided in Table 2 and depicted graphically in Figure 1.
WECC transient voltage dip criteria: The transient voltage dip must not exceed 25% at load buses or 30% at non-load buses for N-1 contingency. For N-2 contingency, the transient voltage dip must not exceed 30% at any bus. The maximum duration of the voltage dip of 20% at load buses must not exceed 20 cycles for N-1 contingency or 40 cycles for N-2 contingency.
WECC transient frequency criteria: The minimum transient frequency for N-1 contingency is 59.6 Hz; if below 59.6 Hz, the duration must not exceed 6 cycles at load bus. For N-2 contingencies, the minimum transient frequency is 59.0 Hz; if below 59.0 Hz, the duration should not exceed 6 cycles at load bus.
The following parameters were plotted on the stability plots:
Bus Voltage Bus voltage plots provide a means of detecting out-of-step conditions and are useful to assess the magnitude and duration of post disturbance voltage dips and peak-to-peak voltage oscillations. The voltage plots also indicate system damping response and the expected bus voltage following the disturbance.
Bus Frequency Bus frequency plots provide expected magnitude and duration of post-disturbance frequency swings as well as indicating possible over-frequency or under-frequency conditions.
Six (6) critical buses which provide a representative illustration of the transmission system performance following each of the critical outages studied were monitored. The
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
5
monitored buses included: COACHELLA 230 kV, RAMON 230 kV, EL CENTRO 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVENUE 42 92 kV.
NERC and WECC Categories
Outage Frequency Associated with the Performance Category (outage/year)
Transient Voltage Dip Standard
Minimum Transient Frequency Standard
Post Transient Voltage Deviation Standard
A System normal
Not Applicable Nothing in addition to NERC
B One element out-of-service
0.33
Not to exceed 25% at load buses or 30% at non-load buses. Not to exceed 20% for more than 20 cycles at load buses.
Not below 59.6Hz for 6 cycles or more at a load bus.
Not to exceed 5% at any bus.
C Two or more elements out-of-service
0.033 – 0.33
Not to exceed 30% at any bus. Not to exceed 20% for more than 40 cycles at load buses.
Not below 59.0Hz for 6 cycles or more at a load bus.
Not to exceed 10% at any bus.
D Extreme multiple-element outages
< 0.033 Nothing in addition to NERC
Table 2: Stability and Post-transient Analysis Evaluation Criteria
Figure 1: Graphical Representation of Stability Analysis Evaluation Criteria
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
6
Post-Transient Stability Analysis
Post-transient stability analysis was performed on selected buses in the IID transmission system following selected critical outages. Governor power flow tools were used for the analysis. For each bus assessed, a synchronous condenser was modeled to extract reactive power till voltage collapse occurs. The maximum reactive power consumed prior to the voltage collapse is determined. The post-transient stability analysis related assumptions made are:
Loads were modeled as constant MVA during the post-transient time frame
Reactive power output of the system swing generator was limited to its maximum capability.
No manual operator intervention was allowed to increase generator MVAR flow.
Remedial actions such as generator dropping, load shedding or blocking of automatic generator control were not considered for single outages.
The list outages simulated and the buses monitored are provided below.
Imperial Valley-Miguel 500 kV line outage
Palo Verde-Devers 500 kV line outage
N. Gila-Imperial Valley 500 kV line outage
N. Laquinta–Avenue 42 92 kV line outage
Imperial Valley-El Centro 230 kV line outage
Ramon–Mirage 230 kV line outage
Coachella –Devers 230 kV line outage
ELSTM2 and REPU2 generator outages
Imperial Valley–El Centro #1 &2 230 kV lines (Group 2014 Cluster Study only)
Imperial Valley–Dixieland #1 &2 230 kV lines (Group 2014 Cluster Study only) The monitored buses included:
Avenue 58 161 kV
Coachella Valley 161 kV
N. Laquinta 92 kV
Coachella Valley 92 kV
Midway 92 kV
Niland 92 kV
El Centro 92 kV
Calexico 92 kV
Pilot Knob 92 kV
Dixieland 92 kV
For post-transient stability, positive reactive margin must be achieved at all buses. For IID transmission system the post-transient stability analysis evaluated criteria used are:
Minimum reactive power margin at any bus following N-1 outage is 100 MVAR
Minimum reactive power margin at any bus following N-2 outage is 50 MVAR
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
7
Short Circuit Analysis
Short circuit analysis was performed to determine the impact of the addition of the transitional cluster projects on selected IID substation breaker duties. The analysis was performed by the IID Planning Department using the ASPEN program and the machine data contained in the cluster project’s interconnection application. Fault duties were calculated for both single-phase -to- ground and three-phase faults at the selected substation buses prior to and after the interconnection of each cluster group. The incremental fault duties due to transitional cluster projects were calculated. The fault contributions from the cluster projects were compared to the available margins of the vicinity breakers to determine if a breaker’s interrupting capabilities is exceeded following the addition of the cluster projects.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 5063764
8
GROUP 2010 CLUSTER STUDY
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 9
A.1 INTRODUCTION
Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned interconnection points in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2010 Cluster Study. The Group 2010 Cluster Study contains one (1) proposed generation project, a 55 MW photovoltaic solar project with planned interconnection at IID’s Niland 161 kV substation. This proposed 55 MW generation project is referred to as ―Project A-5‖ per this analysis. The output of Project A-5 is planned to be delivered to the Mirage/Devers 230 kV with the Los Angeles Department of Water and Power (LADWP) Balancing Authority as the receiving entity. The planned in-service date of Project A-5 is January 2010.
The Group 2010 Cluster Study was conducted using approved WECC 2010 heavy summer and light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions.
A.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS
A.2.1 Base Case Assumptions
The Group 2010 Cluster Study was conducted using the following WECC approved power flow models as the starting base cases:
Heavy summer . . . . 10hs2sa.sav ………...Approved 10/05/2007
Light winter . . . . . . 10lw1a1.sav…………Approved 07/13/2009
Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2010 Cluster projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2010 when the Group 2010 Cluster projects plan to commence operations. While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2010 projects interconnection points.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 10
A.2.2 Base Cases Studied
Two pre-cluster base cases were developed for the Group 2010 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two (2) post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2010 Cluster projects. The output of the Group 2010 Cluster projects which consisted of only Project A-5 was scheduled to LADWP Balancing Authority. The four (4) base cases developed and used for studying the impact of the Group 2010 Cluster Projects are summarized in Table A-1.
Season PSLF Case Name Description
2010 Heavy Summer 2010 HS Pre-Cluster Planned IID heavy summer configuration without the Group 2010 Cluster projects
2010 Heavy Summer 2010 HS Post-Cluster Planned IID heavy summer configuration with Group 2010 Cluster projects modeled and dispatched
2010 Light Winter 2010 LW Pre-Cluster Planned IID light winter configuration without the Group 2010 Cluster projects
2010 Light Winter 2010 LW Post-Cluster Planned IID light winter configuration with Group 2010 Cluster projects modeled and dispatched
Table A-1: Study Base Cases-Group 2010 Cluster Study
A.2.3 Load and Resources The IID load (including parasitic loads at the new power plants) and Resources for the four base cases studied are provided in Table A-2. Table A-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flow for the receiving entity for the Group 2010 projects power output is highlighted in Table A-2.
Load & Resources 2010 HS
Pre-Cluster 2010 HS
Post-Cluster 2010 LW
Pre-Cluster 2010 LW Post-Cluster
Load (MW) 1041 1041 227 227
Load (MVAR) 397 397 59 59
Losses (MW) 49 50 35 36
Losses (MVAR) 224 234 127 145
Interchange (MW) 32 23 542 597
Total IID Shunts (MVAR) 510 520 121 131
IID Generation (MW) 1058 1114 803 860
IID Generation (MVAR) 104 101 67 68
LADWP Interchange (MW) 1817 1872 109 54
Table A-2: Summary of Load and Resources
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 11
A.2.4 Dynamic Models
Dynamic data files ―10hs2s1.dyd‖ and ―10lw11.dyd‖ developed for use with WECC power flow models ―10hs2sa.sav― and ―10lw1a1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2010 Cluster Study were user written algorithms provided by the owner of Project A-5 as contained in the interconnection application.
A.2.5 Short Circuit Data
The machine data used for the Group 2010 Cluster Study short circuit analysis was contained in the Project A-5 interconnection application.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 12
A.3 STUDY RESULTS
This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases.
A.3.1 Power Flow Analysis Findings
This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.
A.3.1.1 Heavy Summer Pre-Cluster Base Case The pre-cluster base case was used as a benchmark for the analysis. Pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2010 Cluster projects during the heavy summer operating condition can be found at Appendix A1, Figure A1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case included:
N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix A2, Table A2-1.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
Nine (9) IID transmission facilities were found to be overloaded following selected double element (N-2) outages. Summary of the pre-project overloads can be found at Appendix A2. Table A2-2.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer pre-cluster base case were 49 MW
A.3.1.2 Heavy Summer Post-Cluster Base Case In the Post-cluster analysis, the Group 2010 Cluster projects were dispatched and delivered to LADWP Balancing Authority. Compared to the Pre-cluster base case, the addition of the Group 2010 Cluster projects showed approximately the same voltage and thermal loadings as noted in the Pre-cluster under normal operating conditions. The impact of the Group 2010 Cluster Projects to IID system losses during heavy summer operating condition was about 1 MW. The heavy summer post-cluster power flow map can be found at Appendix A, Figure A2-2.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 13
To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table A-3. Table A-3 highlights the magnitude (not direction) of power flows on the selected transmission facilities.
Element (unit of measure) 2010 HS
Pre-Cluster 2010 HS
Post-Cluster
El Centro 161/230 kV Transformer (MW) 31 22
El Centro 230/92 kV Transformer (MW) 35 25
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 107 111
Niland 161/92 kV Transformer Circuit 1 (MW) 13 3
Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 95 87
Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 250 261
Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 125 131
Niland-Blythe 161 kV Line (MW) 92 80
Niland-Blythe 161 kV Line (MVAR) 29 26
Imperial Valley-El Centro SW 230 kV (MW) 66 46
Imperial Valley-El Centro SW 230 kV (MVAR) 14 13
Mirage-Ramon 230 kV Line (MW) 120 130
Mirage-Ramon 230 kV Line (MVAR) 40 41
Coachella-Devers 230 kV Line (MW) 16 24
Coachella-Devers 230 kV Line (MVAR) 34 34
Path 42 (MW) 136 154
Path 42 (MVAR) 63 65
Path 46 (MW) 5846 5898
Path 49 (MW) 5285 5296
SCIT (MW) 11739 11799
Table A-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2010 Cluster project on the IID and the interconnected transmission systems are also detailed. It must however be noted that for screening purposes IID typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes. N-0 findings
No transmission facility overload was identified during normal operating conditions
N-1 findings
Five (5) IID transmission facilities were overloaded following selected single element (N-1) outages. Four (4) out of the 5 transmission facility overloads were existing overloads which persisted following the integration of the Group 2010
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 14
cluster projects. However, the integration of the Group 2010 Cluster projects caused the existing N-1 contingency overload on the AVENUE 58 92/161 kV transformer to exacerbate up to 8%. A summary of the transmission facility overloads following single element outages is provided in Appendix A2, Table A2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table A-4.
No bus voltage deviation violation was observed following the selected single element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
AVENUE 58 – JEFERSON 92 KV LINE 132 MVA N.LAQUIN – AVENUE 42 92 KV LINE 127% 127%
N.LAQUIN – AVENUE 42 92 KV LINE 132 MVA JEFERSON – AVENUE58 92 KV LINE 126% 126%
AVENUE 58 161/92 KV TRANSFORMER
125 MVA CVSUB161 161/92 KV TRANSFORMER
105% 113%
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA MIDWAY #2 230/92 KV TRANSFORMER
150% 150%
MIDWAY #2 230/92 KV TRANSFORMER
300 MVA MIDWAY #1 230/92 KV TRANSFORMER
150% 150%
Table A-4: Single Element Outage Transmission Facility Overloads
N-2 findings
Nine (9) IID transmission facilities were overloaded following selected double element (N-2) outages. All the overloads were existing overloads that persisted or exacerbated following the integration of the Group 2010 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix A2, Table A2-2. Provided in Table A-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.
No bus voltage deviation violation was observed following the selected double element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
CVSUB – JACKSON 92 KV LINE 132 MVA
CVSUB – COACHELA #1 &2 92 KV LINES
121% 121%
AVENUE 58 161/92 KV TRANSFORMER
125 MVA 131% 133%
EDOM – RAMON 92 KV LINE 91 MVA 133% 126%
AVE58– JEFERSON 92 KV LINE 132 MVA AVE42 – N.LAQUIN 92 KV & AVE42- SHIELDS 92 KV LINES
131% 131%
N.LAQUIN – AVENUE 42 92 KV LINE 132 MVA
AVE58 – JEFFERSN 92 KV & AVE58 - AVE48 92 KV LINES
130% 130%
CITAP1 – COACHELA 92 KV LINE 152 MVA 115% 117%
CITAP1- VANBUREN 92 KV LINE 152 MVA 115% 117%
CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112% 114%
CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112% 114%
Table A-5: Double Element Outage Transmission Facility Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 15
Losses
IID system losses in the heavy summer post-cluster base case were 50 MW
A.3.1.3 Light Winter Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for the analysis. Key findings from the power flow analysis using the light winter pre-cluster base case are:
N-0 Findings
No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2010 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix A, Figure A3.
N-1 Findings
Three (3) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. A summary of the power flow analysis results can be found at Appendix A2, Table A2-3.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
No transmission facility overload was identified following selected double element (N-2) outages.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer pre-project case were 35 MW
A.3.1.4 Light Winter Post-Cluster Base Case
In the post-cluster analysis, the Group 2010 Cluster projects were dispatched and delivered to LADWP Balancing Authority. Compared to the Pre-cluster base case, the addition of the Group 2010 Cluster projects showed approximately the same voltage and thermal loadings as noted in the Pre-cluster under normal operations. The impact of the Group 2010 Cluster Projects to IID system losses was about 1 MW. The light summer post-cluster power flow map can be found at Appendix A, Figure A1-4.
To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table A-6. Table A-6 highlights the magnitude (not direction) of the power flow on the selected transmission facilities.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 16
Element (unit of measure) 2010 LW
Pre-Cluster 2010 LW
Post-Cluster
El Centro 161/230 kV Transformer (MW) 47 56
El Centro 230/92 kV Transformer (MW) 90 100
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 37 42
Niland 161/92 kV Transformer Circuit 1 (MW) 7 18
Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 12 19
Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 106 116
Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 53 58
Niland-Blythe 161 kV Line (MW) 79 67
Niland-Blythe 161 kV Line (MVAR) 18 16
Imperial Valley-El Centro SW 230 kV (MW) 138 159
Imperial Valley-El Centro SW 230 kV (MVAR) 10 9
Mirage-Ramon 230 kV Line (MW) 298 309
Mirage-Ramon 230 kV Line (MVAR) 1 1
Coachella-Devers 230 kV Line (MW) 193 200
Coachella-Devers 230 kV Line (MVAR) 31 32
Path 42 (MW) 489 507
Path 42 (MVAR) 36 41
Path 46 (MW) 5054 5106
Path 49 (MW) 3608 3609
SCIT (MW) 4250 4305
Table A-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Three (3) out of the 4 transmission facility overloads were existing overloads which persisted or exacerbated following the addition of the Group 2010 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix A2, Table A2-3. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table A-7.
No bus voltage deviation violation was observed following the selected single element outages.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 17
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
RAMON – MIRAGE 230 KV LINE 389 MVA COACHELA – DEVERS 230 KV LINE 118% 123%
COACHELA – DEVERS 230 KV LINE 389 MVA RAMON – MIRAGE 230 KV LINE 107% 112%
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA MIDWAY #2 230/92 KV TRANSFORMER
149% 149%
MIDWAY #2 230/92 KV TRANSFORMER
300 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 149%
Table A-7: Single Element Outage Transmission Facility Overloads
N-2 Findings
No transmission facility overload was identified following selected double element (N-2) outages.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer post-cluster base case were 36 MW
A.3.2 Transient Stability Analysis Findings
Stable and adequately damped transient stability performances were achieved following most of the outages simulated. A visual look at the stability plots (both bus voltage and frequency) for the Path 42 outage (with RAS), Mirage- Ramon 230 kV line outage and the Coachella – Devers 230 kV line outage reveals that the system swings following the three outages are self-sustaining and not adequately damped. However no transient voltage dip violation or transient frequency violation was observed following any of the three outages. The system performance following any of the three outages was not due to the integration of the Group 2010 Cluster projects but rather the large angular difference created between the IID and SCE transmission systems following each of the 3 outages. Key findings from the transient stability analysis using both the heavy summer and light winter pre- and post-cluster base cases are:
No transient voltage dip violations were observed per WECC/NERC transient voltage dip for all the outages simulated.
No transient frequency criteria violations were observed for all the outages simulated.
Transient voltage and frequency plots at selected critical buses following each of the critical outages studied can be found in Attachment B. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 18
A.3.3 Post-Transient Stability Analysis Findings
Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, for most of the outages simulated using both the pre- and post-cluster base cases, the reactive margins at the N. LAQUIN 92 kV and MIDWAY 92 kV buses were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2010 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix A3.
A.3.4 Short Circuit Analysis Findings
The results of the Group 2010 Cluster Short Circuit Analysis is provided in Table A-8. The maximum incremental fault duty was 2,887 A. The available margins at the vicinity breakers indicate that the interconnection of the Group 2010 Cluster projects will not cause any IID breaker to exceed its interruption capabilities.
Table A-8: Summary of Short Circuit Analysis Results
Bus Name IID Substation Name kV
Breaker
Rating
(A)
Pre- Cluster Max
(3LG, 1LG) Fault
Current (A)
Available
Margins
(A)
Post-Cluster
Max (3LG, 1LG)
Fault Current (A)
Project
Contribution
(A)
AVE-52 AVE. 52 92 40,000 15,044 24,956 16,249 1,205
AVE.42 N.BUS AVE. 42 92 40,000 14,391 25,609 14,942 551
AVE48 AVE. 48 92 40,000 10,701 29,300 11,025 325
AVE58-161KV AVE. 58 161 40,000 5,931 34,069 8,817 2,887
AVE58-92 AVE. 58 92 40,000 12,778 27,222 13,413 635
CARREON CARREON 92 40,000 10,888 29,112 11,175 287
COACHELA COACHELLA SW STA 92 22,000 19,173 2,827 20,386 1,213
CV-161 COACHELLA VALLEY 161 40,000 6,834 33,166 7,054 220
CV-92 COACHELLA VALLEY 92 40,000 21,947 18,053 22,559 612
EDOM EDOM 92 40,000 10,952 29,048 11,906 954
FRANCES WAY- FRANCES WAY 92 40,000 9,523 30,477 9,887 364
JACKSON JACKSON 92 31,500 10,140 21,360 10,384 244
JEFFERSON92 JEFFERSON 92 40,000 8,681 31,319 9,687 1,006
LAQUINTA92 LA QUINTA 92 40,000 8,982 31,018 9,679 697
MARSHALL MARSHALL 92 40,000 8,519 31,481 9,301 782
MONROE MONROE 92 40,000 11,900 28,100 12,290 391
N. LA QUINTA NORTH LA QUINTA 92 40,000 9,808 30,192 10,562 754
NEW MECCA NEW MECCA 92 40,000 5,775 34,225 5,883 109
NILAND NILAND 92 40,000 13,682 26,318 13,804 122
NILAND NILAND 161 40,000 7,350 32,650 7,614 264
NORTHVIEW NORTH VIEW 92 40,000 10,752 29,248 11,037 285
RAMON RAMON 92 40,000 13,647 26,353 13,885 238
SHADOW HILLS SHADOW HILLS 92 40,000 12,106 27,894 13,306 1,200
SHIELDS SHIELDS 92 64,000 12,574 51,426 13,081 507
VANBUREN VAN BUREN 92 40,000 12,513 27,487 13,810 1,297
Group 2010 Cluster Projects: Short Circuit Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 19
A.4 MITIGATION PLANS
This section details the recommended transmission upgrade projects required to mitigate both existing and new overloads created following the integration of the Group 2010 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified. Post-transient stability analysis of the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix A3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the system was found to be stable and adequately damped with no WECC/NERC criteria violations.
A.4.1 Mitigation Plans for Existing Overloads
Table A-9 details the existing transmission facility overloads and the associated recommended mitigation plans.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 20
Worst Outage Overloaded Facility
Applicable
Rating
Pre- Cluster
Loadings Recommended Mitigation Notes
SINGLE ELEMENT OUTAGE (N-1)
N.LAQUIN – AVENUE 42 92 KV LINE
AVENUE 58 – JEFERSON 92 KV LINE
132 MVA 127% Rebuild line using 191 MVA, 900 MCM ACSS Conductor
Existing transmission facility overloads not attributable to Group 2010 Cluster Study.
JEFERSON – AVENUE58 92 KV LINE
N.LAQUIN – AVENUE 42 92 KV LINE
132 MVA 126% Rebuild line using 191 MVA, 900 MCM ACSS Conductor
MIDWAY #2 230/92 KV TRANSFORMER
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA 150% Utilize existing Remedial Action Scheme to trip generation at Midway 92 kV MIDWAY #1 230/92 KV
TRANSFORMER MIDWAY #2 230/92 KV TRANSFORMER
300 MVA 150%
COACHELA – DEVERS 230 KV LINE
RAMON – MIRAGE 230 KV LINE
389 MVA 118% Upgrade 0.1 miles to 2-1033.5 ACSS/TW conductor
DOUBLE ELEMENT OUTAGES (N-2)
CVSUB – COACHELA #1 &2 92 KV LINES
CVSUB – JACKSON 92 KV LINE
132 MVA 121%
Rebuild transmission lines using 191 MVA, 900 MCM ACSS Conductor
Existing transmission facility overloads not attributable to Group 2010 Cluster Study.
EDOM – RAMON 92 KV LINE
91 MVA 133%
AVE58 – JEFFERSN 92 KV & AVE58 – AVE48 92 KV LINES
CITAP1 – COACHELA 92 KV LINE
152 MVA 115%
CITAP1- VANBUREN 92 KV LINE
152 MVA 115%
CMTAP2 – VANBUREN 92 KV LINE
132 MVA 112%
CMTAP2 – SHAHILLS 92 KV LINE
123 MVA 112%
Table A-9: Recommended Mitigation Plans for Existing Transmission Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 21
A.4.2 Mitigation Plans for Overloads Caused by Group 2010 Cluster Projects
Table A-9 depicts overloads attributable solely to the integration of the Group 2010 Cluster Projects and their associated recommended mitigation plans. It should be noted the addition of the Group 2010 Cluster projects also caused existing transmission overloads to exacerbate. A.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2010 Cluster Projects is $ 67.3 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table A-10.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 22
Worst Outage Overloaded Facility
Applicable
Rating
Post- Cluster
Loadings Recommended Mitigation Notes
SINGLE ELEMENT OUTAGE (N-1)
CVSUB161 161/92 KV TRANSFORMER
AVENUE 58 161/92 KV TRANSFORMER
125 MVA 113% Replace unit with 225 MVA 161/92 kV transformer
Overloads attributable solely to the Group 2010 Cluster project RAMON – MIRAGE 230 KV LINE
COACHELA – DEVERS 230 KV LINE
389 MVA 112% Upgrade transmission line to 779 MVA, 2-1033 MCM ACSR
Table A-9: Recommended Mitigation Plans Group 2010 Cluster Projects
Table A-10: Recommended Mitigation Plan & Associated Cost for Group 2010 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate ($
M i l l ion)
Construction
Tim e L ines
(M onths) Notes
AVENUE 58 – JEFERSON 92 KV LINEN. LA QUINTA – AVENUE 42 92 KV LINE
"CD"132 MVA 127%
Rebuild line using 191 MVA, 900 MCM
ACSS ConductorIID Budget 18
N. LA QUINTA – AVENUE 42 92 KV LINE
"CD"AVENUE 58 – JEFERSON 92 KV LINE 132 MVA 126%
Rebuild line using 191 MVA, 900 MCM
ACSS ConductorIID Budget 18
MIDWAY #1 230/92 KV TRANSFORMER MIDWAY #2 230/92 KV TRANSFORMER 300 MVA 150% 12
MIDWAY #2 230/92 KV TRANSFORMER MIDWAY #1 230/92 KV TRANSFORMER 300 MVA 150% 12
RAMON – MIRAGE 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 118%Upgrade 0.1 miles to 2-1033.5
ACSS/TW conductor 0.18 18
CVSUB – JACKSON 92 KV LINE 132 MVA 121% 9.27 24
EDOM – RAMON 92 KV LINE 91 MVA 133% IID Budget 12
CITAP1 – COACHELA 92 KV LINE 152 MVA 115%
CITAP1- VANBUREN 92 KV LINE 152 MVA 115%
CMTAP2 – VANBUREN 92 KV LINE 132 MVA 112%
CMTAP2 – SHAHILLS 92 KV LINE 123 MVA 112%
AVENUE 58 161/92 KV TRANSFORMER COACHELLA 161/92 KV TRANSFORMER 125 MVA 113%Replace unit with 225 MVA 161/92 kV
transformerIID Budget 24
Though overloads are due to Group
2010 Cluster projects, IID has aplanned budget for this upgrade
COACHELLA - DEVERS 230 KV LINE RAMON - MIRAGE 230 KV LINE 389 MVA 112% 23.00
CV - RAMON 230 KV LINE COACHELLA - DEVERS 230 KV LINE 389 MVA 109% 23.00
Install 104.4 MVAR capacitor banks 3.41
0.50
247.92
Network Upgrades Attributable to Group 2010 Cluster Pro jects
These transmission lines
share the same tower and
needed to be upgraded at the
Upgrade transmission line to 779 MVA,
2-1033 MCM ACSR30
Existing Transm ission System Upgrades
These network upgrades are not
due to the addition of the cluster
projects. However, the upgrades
are needed prior to the
integration of the proposed
projects. IID have some of the
upgrades already planned and
budgeted.
Implement Remedial Action Scheme
to trip generation at Midway 92 kV
Rebuild transmission lines using 191
MVA, 900 MCM ACSS Conductor
CVSUB - COACHELLA #1 &2 92 KV LINES
AVENUE 58 – JEFERSON 92 KV &
AVENUE 58 - AVENUE 48 92 KV LINES
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 23
Appendix A1
Power flow Maps: Group 2010 Cluster Study
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 24
Figure A1-1: Power flow Map—2010 Heavy Summer Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 25
Figure A1-2: Power flow Map—2010 Heavy Summer Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 26
Figure A1-3: Power flow Map—2010 Light Winter Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 27
Figure A 1-4: Power flow Map—2010 Light Winter Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 28
Appendix A2
Summary of Power Flow Analysis Results: Group 2010 Cluster Study
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 29
Table A2-1: Summary of 2010 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-Cluster Outage description
8279 CVSUB 92 8312 COACHELA 92 1 Line 8 155 B92_L002 105% 103% Line CVSUB 92.0 to COACHELA 92.0 Circuit 2
8279 CVSUB 92 8312 COACHELA 92 2 Line 8 155 B92_L001 105% 103% Line CVSUB 92.0 to COACHELA 92.0 Circuit 1
8279 CVSUB 92 8312 COACHELA 92 2 Line 8 155 B92_L024A 105% 103% Line CVSUB 92.0 to AVE 52 92.0 Circuit 1
8281 AVE58 92 8285 JEFERSN 92 1 Line 8 132 B92_L014 127% 127% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
8285 JEFERSN 92 8354 MARSHALL 92 1 Line 8 132 B92_L014 102% 102% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
8292 N.LAQUIN 92 8309 AVE42 92 1 Line 8 132 B92_L007 126% 126% Line AVE58 92.0 to JEFERSN 92.0 Circuit 1
8311 COACHELA 230 8695 RAMON 230 1 Line 8 389 line_221 110% 110% line DEVERS to MIRAGE 230 ck 1
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B230_T003 101% 104% Tran RAMON92 92.00 .0to RAMON230 230.00 Circuit 1
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B161_T001 105% 113% Tran CVSUB 92.00 to CVSUB161 161.00 Circuit 1
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 B92_L008 100% 104% Line AVE58 92.0 to COACHELA 92.0 Circuit 1
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 150% 150% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 150% 150% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
Summary of 2010 Heavy Summer Power Flow Analaysis Results--Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 30
Table A2-2: Summary of 2010 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-Cluster Outage description
8279 CVSUB 92 8349 JACKSON 92 1 Line 8 132 C92_L012 121% 121% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES
8281 AVE58 92 8285 JEFERSN 92 1 Line 8 132 C92_L014 131% 131% Loss of AVE42 - N.LAQ(CD) 92kV & AVE42 - SHIELDS(CS) 92kV LINES
8285 JEFERSN 92 8354 MARSHALL 92 1 Line 8 132 C92_L014 105% 105% Loss of AVE42 - N.LAQ(CD) 92kV & AVE42 - SHIELDS(CS) 92kV LINES
8292 N.LAQUIN 92 8309 AVE42 92 1 Line 8 132 C92_L013 130% 130% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES
8301 CITAP1 92 8312 COACHELA 92 1 Line 8 152 C92_L013 115% 117% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92 kV LINES
8301 CITAP1 92 8389 VANBUREN 92 1 Line 8 152 C92_L013 115% 117% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES
8302 CARREON 92 8308 CITP4 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES
8304 CITP2 92 8308 CITP4 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES
8304 CITP2 92 8349 JACKSON 92 1 Line 8 132 C92_L012 103% 102% Loss of CVSUB - COACHELLA(CL) 92kV CK1 & CVSUB - COACHELLA 92kV LINES
8307 CMTAP2 92 8389 VANBUREN 92 1 Line 8 132 C92_L013 112% 114% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 - AVE48(CS) 92kV LINES
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T001 102% 101% Tran CVSUB 92.00 - COACHELA 230.00 CK1 & CK2
8330 EDOM 92 8640 RAMON92 92 1 Line 8 91 C230_T001 133% 126% Tran CVSUB 92.00 - COACHELA 230.00 CK1 & CK2
8309 AVE42 92 8406 SHAHILLS 92 1 Line 8 132 C92_L013 101% 103% Loss of AVE58 - JEFFERSON(CD) 92kV & AVE58 to AVE48(CS) 92 kV LINES
8406 SHAHILLS 92 8307 CMTAP2 92 1 Line 8 132 C92_L013 112% 114% Loss of AVE58 - JEFFERSON(CD)92kV & AVE58 - AVE48(CS) 92kV LINES
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L010 103% 106% Loss of AVE58 - RTP5DSTS(R)92kV & Ave 58 - COACHELLA 92 kV LINES
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L012 131% 133% Loss of CVSUB - COACHELLA(CL)92kV CK1 & CVSUB - COACHELLA 92kV LINES
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L014 107% 109% Loss of AVE42 - N.LAQ(CD)92kV & AVE42 - SHIELDS(CS)92kV LINES
8281 AVE58 92 8805 AV58 161 1 Tran 8 125 C92_L020 98% 102% Loss of AVE42 - MONROE(CW)92kV & AVE42 - SHAHILLS(CI)92kV LINES
Summary of 2010 Heavy Summer Power Flow Analysis Results--N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 31
Table A2-3: Summary of 2010 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-Cluster Outage description
8311 COACHELA230 8695 RAMON 230 1 Line 8 389 B230_L001 106% 109% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1
8311 COACHELA230 24804 DEVERS 230 1 Line 8 389 B230_L003 107% 112% Line RAMON230 230.0 to MIRAGE 230.0 Circuit 1
8695 RAMON 230 24806 MIRAGE 230 1 Line 8 389 B230_L001 118% 123% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
Summary of 2010 Light Winter Power Flow Analysis Results--Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 32
Appendix A3
Heavy Summer Post-Transient Stability Analysis Results: Group 2010 Cluster Study
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 33
Table A3-1: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/ mitigation
N.LAQUIN-AVE42 92 kV LINE
8805 AV58 161 kV 182 180 140
8808 CVSUB161 161 kV 174 172 198
8292 N.LAQUIN 92 kV 59 59 57
8312 COACHELA 92 kV 212 209 219
8700 MIDWAY 92 kV 100 100 96
8361 NILAND 92 kV 251 252 250
8335 ELSTEAMP 92 kV 442 441 437
8397 CLX92 92 kV 261 262 259
8369 PILOTKNB 92 kV 177 177 176
8319 DIXIELAN 92 kV 215 215 213
ELSTM 2 & REPU 2 GENERATOR OUTAGE
8805 AV58 161 kV 212 211 207
8808 CVSUB161 161 kV 231 229 222
8292 N.LAQUIN 92 kV 159 159 159
8312 COACHELA 92 kV 241 241 241
8700 MIDWAY 92 kV 103 103 99
8361 NILAND 92 kV 248 249 246
8335 ELSTEAMP 92 kV 414 414 409
8397 CLX92 92 kV 242 243 240
8369 PILOTKNB 92 kV 177 176 175
8319 DIXIELAN 92 kV 204 204 202
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 34
Table A3-2: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
PALO VERDE - DEVERS kV LINE
8805 AV58 161 kV 198 196 192
8808 CVSUB161 161 kV 216 213 205
8292 N.LAQUIN 92 kV 148 147 147
8312 COACHELA 92 kV 215 213 228
8700 MIDWAY 92 kV 96 96 92
8361 NILAND 92 kV 250 251 248
8335 ELSTEAMP 92 kV 445 456 452
8397 CLX92 92 kV 261 261 258
8369 PILOTKNB 92 kV 177 177 176
8319 DIXIELAN 92 kV 216 216 214
N.GILA-IMPERIAL VALLEY 500 kV LINE
8805 AV58 161 kV 206 206 201
8808 CVSUB161 161 kV 223 223 215
8292 N.LAQUIN 92 kV 150 151 151
8312 COACHELA 92 kV 223 224 224
8700 MIDWAY 92 kV 92 93 89
8361 NILAND 92 kV 251 252 248
8335 ELSTEAMP 92 kV 434 432 438
8397 CLX92 92 kV 253 253 250
8369 PILOTKNB 92 kV 177 177 176
8319 DIXIELAN 92 kV 213 212 210
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 35
Table A3-3: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
IMPERIAL VALLEY - MIGUEL kV LINE
8805 AV58 161 kV 204 202 198
8808 CVSUB161 161 kV 223 220 212
8292 N.LAQUIN 92 kV 153 152 152
8312 COACHELA 92 kV 232 232 232
8700 MIDWAY 92 kV 100 100 95
8361 NILAND 92 kV 254 254 252
8335 ELSTEAMP 92 kV 450 460 457
8397 CLX92 92 kV 263 264 261
8369 PILOTKNB 92 kV 178 178 177
8319 DIXIELAN 92 kV 218 218 215
IMPERIAL VALLEY – ELCENTRO 230 kV LINE
8805 AV58 161 kV 212 210 206
8808 CVSUB161 161 kV 231 229 221
8292 N.LAQUIN 92 kV 158 158 158
8312 COACHELA 92 kV 242 231 242
8700 MIDWAY 92 kV 103 103 99
8361 NILAND 92 kV 257 258 256
8335 ELSTEAMP 92 kV 458 467 452
8397 CLX92 92 kV 266 267 264
8369 PILOTKNB 92 kV 178 178 177
8319 DIXIELAN 92 kV 220 220 218
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 36
Table A3-4: Summary of 2010 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
RAMON – MIRAGE 230 kV LINE
8805 AV58 161 kV 138 139 124
8808 CVSUB161 161 kV 142 143 128
8292 N.LAQUIN 92 kV 104 105 97
8312 COACHELA 92 kV 122 123 113
8700 MIDWAY 92 kV 70 70 62
8361 NILAND 92 kV 245 246 240
8335 ELSTEAMP 92 kV 430 430 410
8397 CLX92 92 kV 265 265 260
8369 PILOTKNB 92 kV 178 178 176
8319 DIXIELAN 92 kV 218 218 214
COACHELA – DEVERS 230 kV LINE
8805 AV58 161 kV 155 154 142
8808 CVSUB161 161 kV 158 156 144
8292 N.LAQUIN 92 kV 123 123 116
8312 COACHELA 92 kV 138 137 128
8700 MIDWAY 92 kV 64 64 58
8361 NILAND 92 kV 247 247 243
8335 ELSTEAMP 92 kV 437 436 428
8397 CLX92 92 kV 262 263 259
8369 PILOTKNB 92 kV 178 177 176
8319 DIXIELAN 92 kV 217 217 214
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 37
GROUP 2011 CLUSTER STUDY
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 38
B.1 INTRODUCTION
Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2011 Cluster Study. The Group 2011 Cluster Study contains seven proposed generation projects totaling 745.1 MW. Provided below are the projects and their interconnection information.
Project Code Capacity POI In-service Date A-3 36.1 MW “EO” 92 kV line 11/01/2011 A-6 99 MW Plaster City 92 kV 12/31/2011 A-8 80 MW “N” line 05/30/2011 A-9 100 MW Dixieland 230 kV 09/01/2011 A-11 130 MW “R” line 09/01/2011 A-12 250 MW “L” line 7 09/01/2011 A-13 50 MW “L” line 12/01/2011
The Group 2011 Cluster Study was conducted using approved WECC 2011 heavy summer and light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions. B.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS
B.2.1 Base Case Assumptions The Group 2011 Cluster Study was performed using the following WECC approved power flow models as the starting base cases:
Heavy summer . . . . 11hs1b.sav ………...Approved 01/12/2007
Light winter . . . . . . 10lw1a1.sav…………Approved 07/13/2009
Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2011 Cluster Projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2011
7 Due to capacity limitations on the ―L‖ line, A-12 was connected to Dixieland 230 kV via a radial 13-mile
1033 MCM ACSR bundle 230 kV conductor
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 39
when the Group 2011 Cluster projects plan to initiate operations. Group 2010 Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2011 were modeled in the pre-cluster base cases. The following 12 transmission projects which were recommended for upgrade as part of the Group 2010 Cluster Study were incorporated into the 2011 pre-cluster base cases:
AVENUE 58 – JEFERSON 92 kV line (191 MVA, 900 MCM ACSS)
N. LAQUIN – AVENUE 42 kV line (191 MVA, 900 MCM ACSS)
RAMON – MIRAGE 230 kV line (779 MVA, 2-1033 MCM ACSR)
CVSUB – JACKSON 92 kV line (191 MVA, 900 MCM ACSS)
EDOM – MIRAGE 92 kV line (191 MVA, 900 MCM ACSS)
CITAP1 – COACHELLA 92 kV line (191 MVA, 900 MCM ACSS)
CITAP1 – VANBUREN 92 kV line (191 MVA, 900 MCM ACSS)
CMTAP2 – VANBUREN 92 kV line (191 MVA, 900 MCM ACSS)
CMTAP2 – SHAHILLS 92 kV line (191 MVA, 900 MCM ACSS)
COACHELLA – DEVERS 230 kV line (779 MVA, 2-1033 MCM ACSR)
COACHELLA – RAMON 230 kV line (779 MVA, 2-1033 MCM ACSR)
AVENUE 58 161/92 kV transformer (250 MVA) While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2011 projects interconnection points.
B.2.2 Base Cases Studied
Two (2) pre-cluster base cases were developed for the Group 2011 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2011 Cluster projects. Due to the capacity of the IID ―N‖ line, Project A-8 was connected to the IID ―KN‖ line in lieu of the requested interconnection point of ―N‖ line. In order to integrate the Group 2011 cluster projects in the Dixieland area to the IID transmission system, the following transmission facilities were modeled in the post-project base case:
DIXIELAND 230/92 KV transformer (332 MVA)
DIXIELAND – IMPERIAL VALLEY 230 kV line (786 MVA, 1033 MCM ACSR). The output of the Group 2011 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. The four base cases developed and used for studying the impact of the Group 2010 Cluster Projects are summarized in Table B-1.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 40
Season PSLF Case Name Description
2011 Heavy Summer 2011 HS Pre-Cluster Planned IID heavy summer configuration without the Group 2011 Cluster projects
2011 Heavy Summer 2011 HS Post-Cluster Planned IID heavy summer configuration with Group 2011 Cluster projects modeled and dispatched
2011 Light Winter 2011 LW Pre-Cluster Planned IID light winter configuration without the Group 2011Cluster projects
2011 Light Winter 2011 LW Post-Cluster Planned IID light winter configuration with Group 2011 Cluster projects modeled and dispatched
Table B-1: Study Base Cases-Group 2011 Cluster Study
B.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table B-2. Table B-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2011 projects power outputs are highlighted in Table B-2.
Load & Resources 2011 HS
Pre-Cluster 2011 HS
Post-Cluster 2011 LW
Pre-Cluster 2011 LW Post-Cluster
Load (MW) 1065 1079 253 267
Load (MVAR) 410 419 73 81
Losses (MW) 57 77 41 62
Losses (MVAR) 299 562 218 531
Interchange (MW) 318 1041 803 1543
Total IID Shunts (MVAR) 596 750 231 497
IID Generation (MW) 1439 2197 1097 1872
IID Generation (MVAR) 126 216 77 120
SCE Interchange (MW) 7644 7980 320 656
SDG&E Interchange (MW) 2430 2759 1348 1676
Table B-2: Summary of Load and Resources
B.2.4 Dynamic Models
Dynamic data files ―11hs11.dyd‖ and ―10lw11.dyd‖ developed for use with WECC power flow models ―11hs1b.sav― and ―10lw1a1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2011 Cluster Study were user written algorithms and other dynamic data contained in each project’s interconnection application.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 41
B.2.5 Short Circuit Data
The machine data used for the Group 2011 Cluster Study short circuit analysis were contained in each project’s interconnection application.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 42
B.3 STUDY RESULTS
This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both Group 2011 Cluster Study pre- and post-cluster base cases.
B.3.1 Power Flow Analysis Findings
This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.
B.3.1.1 Heavy Summer Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2011 Cluster projects during the heavy summer operating condition can be found at Appendix B1, Figure B1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:
N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Two (3) IID transmission facilities were found overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix B2, Tables B2-1 and B2-2.
One (1) bus voltage deviation violation was observed following the selected single element outages. A summary of the bus voltage deviation violations using the 2011 heavy summer base cases can be found at Appendix B2, Table B2-3.
N-2 Findings
One (1) IID transmission facility was overloaded following selected double element (N-2) outages. Summary of the pre-project overloads can be found at Appendix B2. Tables B2-4.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer pre-cluster base case were 57 MW
B.3.1.2 Heavy Summer Post-Cluster Base Case
In the Post-cluster analysis, the 745 MW net Group 2011 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2011 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 43
2011 Cluster Projects to IID system losses was about 20 MW. The heavy summer post-cluster power flow map can be found at Appendix B1, Figure B1-2.
To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table B-3. Table B-3 highlights the magnitude (not direction) of flow.
Element (unit of measure) 2011 HS
Pre-Cluster 2011 HS
Post-Cluster
El Centro 161/230 kV Transformer (MW) 20 97
El Centro 230/92 kV Transformer (MW) 79 157
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 126 172 Niland 161/92 kV Transformer Circuit 1 (MW) 53 57
Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 60 103 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 376 620 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 189 311
Niland-Blythe 161 kV Line (MW) 66 33
Niland-Blythe 161 kV Line (MVAR) 25 9 Imperial Valley-El Centro SW 230 kV (MW) 98 254
Imperial Valley-El Centro SW 230 kV (MVAR) 18 1 Imperial Valley – Dixieland 230 kV (MW) N/A 285 Imperial Valley – Dixieland 230 kV (MVAR) N/A 58 Mirage-Ramon 230 kV Line (MW) 184 283 Mirage-Ramon 230 kV Line (MVAR) 27 44 Coachella-Devers 230 kV Line (MW) 123 215 Coachella-Devers 230 kV Line (MVAR) 25 30
Path 42 (MW) 306 496 Path 42 (MVAR) 49 78
Path 46 (MW) 6832 7178
Path 49 (MW) 6082 6011
SCIT (MW) 14754 15150
Table B-3: Comparison Flows on Critical Lines/Paths
Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2011 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.
N-0 Findings
No transmission facility overload was identified during normal operating conditions.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 44
N-1 Findings
Nine (9) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Three (3) out of the 9 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2011 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix B2, Table B2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-4.
Two (2) bus voltage deviation violations were observed following the selected single element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
DIXPRI1 – DIXPRI 92 KV LINE 132 MVA IMPERIAL VALLEY – ELCENTSW 230 KV LINE
20% 131%
DIXPRI2 – DIXIELAN 92 KV LINE 132 MVA 17% 128%
DIXPRI2 – DIXPRI 92 KV LINE 132 MVA 17% 128%
DIXIELAN – RTP1 92 KV LINE 51 MVA DIXIE230-DIXIELAN 230/92 KV TRANSFORMER
79% 145%
RTAP2 – RTP1 92 KV LINE 57 MVA DIXIE230 - IMPERIAL VALLEY 230 KV LINE
70% 149%
IMPERIAL VALLEY – ELCENTSW 230 KV LINE
370 MVA N. GILA – IMPERIAL VALLEY 500 KV LINE
110% 127%
CVSUB161 161/92 KV TRANSFORMER
125 MVA AVENUE 58 161/92 KV TRANSFORMER
118% 178%
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA MIDWAY #2 230/92 KV TRANSFORMER
149% 149%
MIDWAY #2 230/92 KV TRANSFORMER
300 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 149%
Table B-4: Single Element Outage Transmission Facility Overloads
N-2 Findings
Ten (10) IID transmission facilities were found to be overloaded following selected double element (N-2) outages. One (1) out of the10 overloads were existing overloads that persisted or exacerbated following the integration of the Group 2011 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix B2, Table B2-5. Provided in Table B-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.
No bus voltage deviation violation was observed following the selected double element outages.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 45
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
NILAND - CVSUB161 161 KV LINE 165 MVA
ELCENTSW –IMPERIAL VALLEY 230 kV & ELCENTSW – AVE58 KV 161 KV LINES
101% 133%
DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 24% 148%
DIXPRI2 – DIXIELAN 92 KV LINE 132 MVA 21% 145%
DIXPRI2 – DIXPRI 92 KV LINE 132 MVA 21% 145%
DIXIE230-DIXIELAN 230/92 KV TRANSFORMER
300 MVA N/A 119%
DIXIELAN – RTP1 92 KV LINE 51 MVA 118% 130%
CVSUB161 161/92 KV TRANSFORMER
125 MVA ELCENTSW – AVE58 161 KV & CVSUB – AVE58 161 KV LINES
99% 128%
DIXIELAN – RTP1 92 KV LINE 51 MVA 103% 138%
RTAP2 – RTP1 92 KV LINE 57 MVA 92% 123%
CVSUB – COACHELA #1 92 KV LINE 150 MVA RAMON – MIRAGE 230 KV & COACHELA – DEVERS 230 KV LINES (W/RAS)
85% 114%
CVSUB – COACHELA #2 92 KV LINE 150 MVA 85% 114%
Table B-5: Double Element Outage Transmission Facility Overloads
Losses
IID transmission system losses in the heavy summer post-cluster base case were 77 MW
B.3.1.3 Light Winter Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Key findings from the power flow analysis using the light winter pre-cluster base case are:
N-0 Findings
No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2011 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix B1, Figure B1-4.
N-1 Findings
Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the power flow analysis results can be found at Appendix B2, Table B2-6.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
Two (2) transmission facility overloads were identified following selected double element (N-2) outages. Summary of the power flow analysis results can be found at Appendix B2, Table B2-8.
No bus voltage deviation violation was identified following the selected double element outages.
Losses
IID system losses in the light winter pre-project case were 41 MW
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 46
B.3.1.4 Light Winter Post-Cluster Base Case In the Post-Cluster analysis, the 745 MW net Group 2011 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2011 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2011 Cluster Projects to IID system losses was about 21 MW. The light winter post-cluster power flow map can be found at Appendix B1, Figure B1-5.
To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table B-6. Table B-6 highlights the magnitude (not direction) of flow.
Element (unit of measure) 2011 LW
Pre-Cluster 2011 LW
Post-Cluster
El Centro 161/230 kV Transformer (MW) 71 144
El Centro 230/92 kV Transformer (MW) 141 194
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 48 87 Niland 161/92 kV Transformer Circuit 1 (MW) 16 17 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 45 95 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 139 349 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 70 179
Niland-Blythe 161 kV Line (MW) 54 25
Niland-Blythe 161 kV Line (MVAR) 17 8 Imperial Valley-El Centro SW 230 kV (MW) 212 338 Imperial Valley-El Centro SW 230 kV (MVAR) 19 1 Imperial Valley – Dixieland 230 kV (MW) N/A 347 Imperial Valley – Dixieland 230 kV (MVAR) N/A 76 Mirage-Ramon 230 kV Line (MW) 372 468
Mirage-Ramon 230 kV Line (MVAR) 16 7 Coachella-Devers 230 kV Line (MW) 272 355 Coachella-Devers 230 kV Line (MVAR) 33 31
Path 42 (MW) 642 818 Path 42 (MVAR) 31 72
Path 46 (MW) 5298 5610
Path 49 (MW) 3001 3521
SCIT (MW) 4503 4817
Table B-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings
No transmission facility overload was identified during normal operating conditions
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 47
N-1 Findings
Eleven (11) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 11 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2011 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix B2, Table B2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-7.
No bus voltage deviation violation was observed following the selected single element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA MIDWAY #2 230/92 KV TRANSFORMER
149% 148%
MIDWAY #2 230/92 KV TRANSFORMER
300 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 148%
ELCENTSW – IMPERIAL VALLEY 230 KV LINE
370 MVA
DIXIE230 – IMPERIAL VALLEY 230 KV LINE
57% 148%
ELCENTSW 230/92 KV TRANSFORMER
332 MVA 43% 114%
DIXIELAN – RTP1 92 KV LINE 51 MVA 28% 112%
USNAF – ELTERMIN 92 KV LINE 132 MVA 12% 112%
USNAF – DIXIELAN 92 KV LINE 132 MVA 11% 111%
DIXIE230 – DIXIELAN 230/92 KV TRANSFORMER
300 MVA
ELCENTSW – IMPERIAL VALLEY 230 KV LINE
N/A 139%
DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 12% 147%
DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 12% 147%
DIXPRI – DIXPRI2 92 KV LINE 132 MVA 12% 147%
Table B-7: Single Element Outage Transmission Facility Overloads
N-2 Findings
Nineteen (19) transmission facilities were overloaded following selected double element (N-2) outages. Two (2) out of the 19 overloaded facilities are attributable to the addition of the Group 2011 cluster projects. A summary of the transmission facility overloads following double element outages is provided in Appendix B2, Table B2-8. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table B-8.
Fifty-five (55) bus voltage deviation violations were observed following the selected double element outages. A summary of the bus voltage deviation violations following selected double element outages can be found at Appendix B2, Tables B2-9 and B2-10.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 48
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
USNAF – ELTERMIN 92 KV LINE 132 MVA
ELCENTSW – IMPERIAL VALLEY 230 KV & ELCENTSW – AVENUE 161 KV LINES
22% 121%
USNAF – DIXIELAN 92 KV LINE 132 MVA 21% 121%
DIXPRI1 – DIXPRI 92 KV LINE 370 MVA 14% 161%
DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 14% 160%
DIXPRI – DIXPRI2 92 KV LINE 132 MVA 14% 160%
DIXIE230 – DIXIELAN 230/92 KV TRANSFORMER
300 MVA N/A 147%
RAMON 230/92 KV TRANSFORMER 225 MVA
COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/ RAS)
98% 142%
N. VIEW – AVE42 92 KV LINE 132 MVA 91% 137%
N. VIEW – RAMON 92 KV LINE 132 MVA 88% 132%
AVE42 – FRANWAY 92 KV LINE 132 MVA 86% 130%
FRANWAY – EDOM 92 KV LINE 132 MVA 85% 128%
COACHELA #1 230/92 KV TRANSFORMER
150 MVA 85% 116%
COACHELA #1 230/92 KV TRANSFORMER
150 MVA 85% 116%
ELCENTSW 230/161 KV TRANSFORMER
225 MVA
COACHELA – DEVERS 230 KV & MIRAGE – RAMON 230 KV LINES (W/ RAS)
85% 119%
ELCENTSW – IMPERIAL VALLEY 230 KV LINE
370 MVA 126% 164%
ELCENTSW 161/92 KV TRANSFORMER
125 MVA 21% 112%
COACHELA 161/92 KV TRANSFORMER
225 MVA 116% 79&
DIXIELAN – RTP1 92 KV LINE 51 MVA 97% 163%
RTAP2 – RTP1 92 KV LINE 57 MVA 87% 146%
Table B-8: Double Element Outages Transmission Facility Overloads
Losses
IID system losses in the light winter post-cluster base case were 62 MW
B.3.2 Transient Stability Analysis Findings Stable and adequately damped transient stability performances were achieved following Six (6) out of the eight (8) critical outages simulated using both the pre- and post-cluster base cases. A visual look at the stability plots (both bus voltage and frequency) for the Mirage- Ramon 230 kV line outage and the Coachella – Devers 230 kV line outage reveals that the system swings following the two outages are self-sustaining and not adequately damped. The observed system swings following the two outages were pre-existing which exacerbated following the integration of the Group 2011 Cluster projects. There were also bus voltage criteria violations following the Path 42 outage (with RAS). These criteria violations are attributable to the integration of the Group 2011 Cluster projects. Key findings from the transient stability analysis using both the heavy summer and light winter pre- and post-cluster base cases are:
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 49
Transient voltage dip violations were observed per WECC/NERC transient voltage dip for the Path 42 outage (with RAS).
No transient frequency criteria violations were observed for all the outages simulated.
System swings following 2 out of the 8 outages were not adequately damped. Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment A. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV. With the implementation of all the IID system upgrades proposed to mitigate the mentioned unstable conditions on the 2011 scenario, stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases.
B.3.3 Post-Transient Stability Analysis Findings
Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, for 3 out of the 8 outages simulated using both the pre- and post-cluster base cases, the reactive margins at the N. LAQUIN 92 kV and MIDWAY 92 kV buses were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2011 Cluster Projects resulted in marginal reductions in the reactive power margins at some of the buses monitored. Other monitored buses recorded improvements following the addition of the Group 2011 Cluster projects. Detailed results of the post-transient stability analysis can be found at Appendix B3.
B.3.4 Short Circuit Analysis Findings
The results of the Group 2011 Cluster Short Circuit Analysis is provided in Table B-9. The maximum incremental fault duty following the integration of the Group 2011 Cluster projects was 14,909 A at the El Centro 230 kV switching station. The available margins at the vicinity breakers as depicted in Table B-9 indicate that the interconnection of the Group 2011 Cluster projects will cause the El Centro 92 kV breakers to be within 120 A of their interruption capabilities. While the Group 2011 Cluster projects contributed 7189 A to the fault duty at the El Centro 92 kV breakers, the available margins on the breakers are 7308 A. Thus, the 40, 000 A breakers at the El Centro 92 kV substation would have to be replaced with a 63, 000 A rated breakers. In all, there are 40 breakers at the El Centro 92 kV substation.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 50
Table B-9: Summary of Short Circuit Analysis Results
B.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2011 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix B2 for power flow results). The results of the post-transient stability analysis using the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix B3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the transmission system was found stable and adequately damped with no WECC/NERC criteria violations (See Attachment B). B.4.1 Mitigation Plans for Overloads Caused by Group 2011 Cluster Study To mitigate the both the N-1 and N-2 overloads attributable solely to the integration of the Group 2010 Cluster Projects, the following transmission facilities are recommended:
Bus Name IID Substation Name kV
Breaker
Rating
(A)
Pre- Cluster Max
(3LG, 1LG) Fault
Current (A)
Available
Margins
(A)
Post-Cluster
Max (3LG, 1LG)
Fault Current (A)
Project
Contribution
(A)
ATEN ATEN 92 40,000 15,442 24,558 17,956 2,514
AVE58-92 AVE. 58 92 40,000 13,413 26,587 14,547 1,133
BRAVO 92 KV. BRAVO 92 40,000 11,749 28,251 13,697 1,948
CALEXICO CALEXICO 92 40,000 10,147 29,853 11,424 1,277
CENTRAL CENTRAL 92 40,000 12,085 27,915 14,925 2,840
CLARK CLARK 92 40,000 14,661 25,339 16,829 2,168
COACHELA COACHELLA SW STA 92 22,000 20,386 1,614 21,633 1,247
CV-161 COACHELLA VALLEY 161 40,000 7,054 32,946 7,725 671
CV-230 COACHELLA VALLEY 230 40,000 15,392 24,608 17,605 2,213
CV-92 COACHELLA VALLEY 92 40,000 22,559 17,441 28,584 6,024
DAHLIA DAHLIA 92 64,000 14,629 49,371 16,839 2,210
DIXIE-PRISON DIXIELAND PRISON 92 40,000 7,027 32,973 13,543 6,516
DIXIELAND DIXIELAND 92 40,000 7,479 32,521 19,044 11,565
ELCENTSW EL CENTRO SW STA 92 40,000 32,692 7,308 39,881 7,189
ELCENTSW EL CENTRO SW STA 230 63,000 11,155 51,845 26,064 14,909
EUCLID EUCLID 92 64,000 15,794 48,206 18,449 2,655
GATEWAY-92 GATEWAY 92 40,000 9,363 30,637 11,319 1,956
HEBER HEBER 92 40,000 12,497 27,503 14,012 1,516
HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 12,463 7,537 13,974 1,511
HIGHLINE230 HIGHLINE 230 40,000 5,407 34,593 17,492 12,084
HIGHLINE92 HIGHLINE 92 40,000 10,762 29,238 20,391 9,629
HOLTVILLE HOLTVILLE 92 40,000 11,995 28,005 13,911 1,916
MIDWAY230 MIDWAY 230 40,000 7,967 32,033 13,758 5,791
MIDWAY92 MIDWAY 92 40,000 14,547 25,453 17,377 2,831
NAVY BASE NAVY BASE 92 40,000 9,734 30,266 13,877 4,143
PLASTER-CITY PLASTER CITY 92 40,000 5,410 34,590 9,548 4,138
TERMINAL 92 TERMINAL 92 37,000 23,568 13,433 30,257 6,690
Group 2011 Cluster Projects: Short Circuit Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 51
New 22-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission line from Dixieland to El Centro
New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV transmission line from Dixieland to Imperial Valley
Rebuild 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission lines from Highline to El Centro.
Rebuild the 18.1 miles El Centro - Imperial Valley 230 kV line using 786 MVA, 2-1033 MCM ACSR bundled transmission line.
Replace Coachella 161/92 kV transformer with a 250 MVA transformer.
Rebuild 1 mile DIXPRI1 –DIXPRI 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 2.5 mile DIXPRI2 –DIXIELAN 92 kV line to 191 MVA, 900 ACSS conductor
Rebuild 1-mile DIXPRI –DIXPRI2 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 7.4-mile DIXIELAN – RTP1 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 20-mile RTP1 – RTAP2 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild the 9-mile, 161 KV line section from ELCENTSW to L-TAPA-12 to double circuit 554 MVA, 1033 ACSR conductor.
New 332 MVA, 230/92 kV transformer at Dixieland.
New 8- mile CVSUB – KOHLRANCH - AVENUE 58 92 kV line to 191 MVA, 900 ACSS conductor
It is also recommended to interconnect Project A-12 to the proposed Dixieland 230 kV substation via a radial 13-mile line in lieu of the Customer’s requested interconnection point of ―L‖ line due to capacity and cost implications. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables B-10 & B-11. B.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2011 Cluster Projects is $ 258.7 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table B-12.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 52
Worst Outage Overloaded Facility
Applicable
Rating
Post- Cluster
Loadings Recommended Mitigation Notes
NORMAL CONDITION (N-0 )
ALL LINES IN SERVICE
N/A N/A N/A Interconnect A-8 to ―KN‖ line in lieu of ―N‖ line
Change of interconnection points results in increased reliability and reduced cost N/A N/A N/A
Interconnect A-12 to Dixieland 230 kV line in lieu of ―L‖ line
N/A N/A N/A New 332 MVA, 230/92 KV transformer at Dixieland
Needed in order to integrate projects in Dixieland area
N/A N/A N/A New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV line from Dixieland to Imperial Valley
N/A N/A N/A New 8-mile, 191 MVA, 900 MCM ACSS 92 kV line from Avenue 58 through Kohl Ranch to Coachella
Required to lower Coachella area 92 kV transmission line flows following single element outages
SINGLE ELEMENT OUTAGE (N-1)
DIXIELAND – IMPERIAL VALLEY 230 KV LINE
ELCENTSW – IMPERIAL VALLEY 230 KV LINE
370 MVA 148% Rebuild 18.1-mile line using 786 MVA, 2-1033 ACSR bundled 230 kV line and rebuild the ECSS 230
Other N-1 outages such as N. Gila- Imperial Valley 500 kV line caused this line to overload
ELCENTSW 230/92 KV TRANSFORMER
332 MVA 114% New 22-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV line from Dixieland to El Centro Rebuild 9-mile El Centro to L-TAPA-12 161 kV line using Double Circuit 554 MVA 1033 ASCR Conductor
Needed to close the loop and prevent the Dixieland area power from overloading the underlying system during outages
USNAF – ELTERMIN 92 KV LINE
132 MVA 112%
USNAF – DIXIELAN 92 KV LINE
132 MVA 112%
AVENUE 58 161/92 KV TRANSFORMER
COACHELLA 161/92 KV TRANSFORMER
125 MVA 178% Replace CV transformer with 300 MVA rating
None
IMPERIAL VALLEY – EL CENTRO 230 KV LINE
DIXPRI1 – DIXPRI 92 KV LINE
132 MVA 147% Rebuild 1-mile line using 191 MVA, 900 MCM ACSS Conductor
Several other N-1 & N-2 outages caused these lines to overload
DIXIELAN – DIXPRI2 92 KV LINE
132 MVA 147% Rebuild 2.5-mile line using 191 MVA, 900 MCM ACSS Conductor
DIXPRI – DIXPRI2 92 KV LINE
132 MVA 147% Rebuild 1-mile line using 191 MVA, 900 MCM ACSS Conductor
DIXIELAND 230/92 KV TRANSFORMER
RTAP2 – RTP1 92 KV LINE 57 MVA 149% Rebuild 20-mile line using 191 MVA, 900 MCM ACSS Conductor
RTP1 – DIXIELAND 92 KV LINE
51 MVA 102% Rebuild 7.4-mile line using 191 MVA, 900 MCM ACSS Conductor
Table B-10: Summary of Transmission Facility Overloads and Associated Mitigation Plan
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 53
Worst Outage Overloaded Facility
Applicable
Rating
Post- Cluster
Loadings Recommended Mitigation Notes
DOUBLE ELEMENT OUTAGES (N-2)
COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/ RAS)
RAMON 230/92 KV TRANSFORMER
225 MVA 142%
New 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV line from Highline to El Centro. Upgrade Highline Substation. Upgrade ―E‖ Line 3.4 Miles.
Need to mitigate for the observed several bus voltage deviation violations were observed
N. VIEW – AVE42 92 KV LINE
132 MVA 137%
N. VIEW – RAMON 92 KV LINE
132 MVA 132%
AVE42 – FRANWAY 92 KV LINE
132 MVA 130%
FRANWAY – EDOM 92 KV LINE
132 MVA 128%
COACHELA #1 230/92 KV TRANSFORMER
150 MVA 116%
COACHELA #1 230/92 KV TRANSFORMER
150 MVA 116%
COACHELA – DEVERS 230 KV & MIRAGE – RAMON 230 KV LINES (W/ RAS)
ELCENTSW 161/92 KV TRANSFORMER
125 MVA 112%
Transient stability performance of the transmission system following this outage was inadequately damped. There were transient stability criteria violations.
Table B-11: Summary of Transmission Facility Overloads and Associated Mitigation Plan (Continued)
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 54
Table B-12: Recommended Mitigation Plan & Associated Cost for Group 2011 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate
($ M i l l ion)
Construction
Tim e L ines
(M onths)
Notes
NONE N/A N/A N/A
40 Breaker Replacements at El Centro 92 kV
switching station 13.60 12 Short Circuit Study
ELCENTSW – IMPERIAL VALLEY 230 KV LINE 370 MVA 148%
Rebuild line using 786 MVA, 2-1033 MCM
ACSS Conductor and also rebuild the ECSS
230.
58.94 30 None
ELCENTSW 230/92 KV TRANSFORMER 332 MVA 114%
USNAF – ELTERMIN 92 KV LINE 132 MVA 112%
USNAF – DIXIELAN 92 KV LINE 132 MVA 112%
COACHELLA 161/92 KV TRANSFORMER AVENUE 58 161/92 KV TRANSFORMER 125 MVA 178% Replace CV transformer with 300 MVA rating 8.32 24 None
DIXPRI1 – DIXPRI 92 KV LINE 132 MVA 147%
DIXIELAN – DIXPRI2 92 KV LINE 132 MVA 147%
DIXPRI – DIXPRI2 92 KV LINE 132 MVA 147%
RTAP2 – RTP1 92 KV LINE 57 MVA 149%
RTP1 – DIXIELAND 92 KV LINE 51 MVA 102%
RAMON 230/92 KV TRANSFORMER 225 MVA 142%
N. VIEW – AVE42 92 KV LINE 132 MVA 137%
N. VIEW – RAMON 92 KV LINE 132 MVA 132%
AVE42 – FRANWAY 92 KV LINE 132 MVA 130%
FRANWAY – EDOM 92 KV LINE 132 MVA 128%
COACHELA #1 230/92 KV TRANSFORMER 150 MVA 116%
COACHELA #1 230/92 KV TRANSFORMER 150 MVA 116%
ELCENTSW 161/92 KV TRANSFORMER
COACHELA – DEVERS 230 KV & MIRAGE –
RAMON 230 KV LINES 125 MVA 112%
New 230 kV substation at Dixieland 20.77
332 MVA 230/92 kV transformer at Dixieland
and a transmission line (circuit #1) from
Dixieland to IID's Imperial Valley Switching
Station
IID Budget
New 92 kV line from Avenue 58 to Coachella
through Kohl Ranch (KM line)9.15 24
New 230 kV line (circuit #2) from Dixieland
to Imperial Valley Sw. Station28.28 24
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24
New 19-mile, 786 MVA, 2-1033 MCM bundled
230 kV line from Highline to El Centro. Install
Remedial Action Scheme (RAS) to mitigate
the marginal transmission overloads.
Upgrade Highline Sub., Upgrade "E" line 3.4
miles.
Rebuild "R" line uisng 191 MVA, 900 MCM
ACSS Conductor from Dixieland to Anza and
to Central
36
30
None
DIXIELAND – IMPERIAL VALLEY 230 KV LINE
IMPERIAL VALLEY – EL CENTRO 230 KV LINE
New Network faci l i ties for In tegrating Group 2011 Cluster Pro jects
24
Network Upgrades Attributable to Group 2011 Cluster Pro jects
47.08
32.59
New 22-mile, 786 MVA, 2-1033 MCM ACSR
bundled 230 kV line from Dixieland to El
Centro. Rebuild 9-mile El Centro to L-TAPA-12
161 kV line using double circuit 554 MVA,
1033 ACSR conductor
52.80
NONE N/A N/A N/A
These projects are needed in
order to integrate Group 2011 Cluster Projecs in Dixieland area.
None
None
DIXIELAND 230/92 KV TRANSFORMER
COACHELA – DEVERS 230 KV &
COACHELA – RAMON 230 KV LINES 30
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 55
Appendix B1
Power flow Maps
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 56
Figure B1-1: Power flow Map—2011 Heavy Summer Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 57
Figure B1-2: Power flow Map—2011 Heavy Summer Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 58
Figure B1-3: Power flow Map—2011 Heavy Summer Post-Cluster w/ Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 59
Figure B1-4: Power flow Map—2011 Light Winter Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 60
Figure B1-5: Power flow Map—2011 Light Winter Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 61
Figure B1-6: Power flow Map—2011 Light Winter Post-Cluster w/Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 62
Appendix B2
Summary of Power Flow Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 63
Table B2-1: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 149% 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 line_211 96% 111% 101% line PALOVRDE to DEVERS 500 ck 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_L005 86% 112% 101% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C010 73% 112% 101% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L031 88% 103% 100% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B161_T002 118% 178% 83% Tran AVE58 92.00 to AV58 161.00 Circuit 1
8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 line_211 N/A 110% 78% line PALOVRDE to DEVERS 500 ck 1
8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 B230_L004 N/A 104% 65% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_210 11% 117% 61% line N.GILA to IMPRLVLY 500 ck 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T101 20% 112% 61% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_210 8% 113% 59% line N.GILA to IMPRLVLY 500 ck 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_210 8% 113% 59% line N.GILA to IMPRLVLY 500 ck 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 16% 109% 58% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 16% 109% 58% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_206 9% 106% 58% line HASSYAMP to N.GILA 500 ck 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_206 6% 102% 55% line HASSYAMP to N.GILA 500 ck 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_206 6% 102% 55% line HASSYAMP to N.GILA 500 ck 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L055 44% 104% 54% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B161_L006 86% 106% 54% Line AV58 161.0 to CVSUB 161.0 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_L004 20% 131% 53% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 line_211 81% 119% 53% line PALOVRDE to DEVERS 500 ck 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L054 40% 102% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B92_L031 67% 106% 52% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 17% 128% 51% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 17% 128% 51% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C005 79% 145% 44% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B230_C005 70% 130% 44% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_211 107% 137% 44% line PALOVRDE to DEVERS 500 ck 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 line_211 96% 123% 44% line PALOVRDE to DEVERS 500 ck 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 B230_L004 63% 104% 42% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_L005 92% 125% 41% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_C010 79% 125% 41% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_C010 70% 112% 41% Line A-13-IP 161.0 to AVE58 161.0 Circuit 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_L005 82% 112% 41% Line AV58 161.0 to ELCENTSW 161.0 Circuit 1
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_L004 N/A 106% 40% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_207 90% 119% 40% line IMPRLVLY to MIGUEL 500 ck 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 line_207 81% 107% 40% line IMPRLVLY to MIGUEL 500 ck 1
Summary of 2011 Heavy Summer Power Flow Analysis Results--N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 64
Table B2-2: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads (Continued)
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_T002 98% 126% 40% Tran AVE58 92.00 to AV58 161.00 Circuit 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B161_T002 87% 113% 40% Tran AVE58 92.00 to AV58 161.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L031 88% 109% 38% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T003 86% 106% 37% Tran RAMON92 92.00 .0to RAMON230 230.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L004 82% 104% 37% Line CVSUB 92.0 to COLMAC 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L032A 83% 104% 37% Line NILAND 92.0 to CCAP 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T001 83% 102% 37% Tran CVSUB 92.00 to COACHELA 230.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T002 83% 102% 37% Tran CVSUB 92.00 to COACHELA 230.00 Circuit 2
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_231 84% 105% 37% line J.HINDS to EAGLEMTN 230 ck 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T101 90% 104% 36% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_265 84% 104% 36% line BLYTHESC to BLYTHE 161 ck 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L006 81% 102% 36% Line EDOM 92.0 to RAMON92 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C001 79% 167% 36% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 B230_C001 70% 149% 36% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L008 83% 103% 36% Line AVE58 92.0 to COACHELA 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L014 81% 103% 36% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 line_232 81% 102% 36% line J.HINDS to MIRAGE 230 ck 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_T004 82% 102% 36% Tran NILAND 161.00 to NILAND 92.00 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B161_L006 83% 102% 36% Line AV58 161.0 to CVSUB 161.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L003 81% 102% 36% Line CVSUB 92.0 to JACKSON 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L072 83% 105% 36% Line MW1TAP 92.0 to MIDWAY 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L071 82% 104% 36% Line MIDWAY 92.0 to VULCAN 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B92_L0070 82% 103% 36% Line MIDWAY 92.0 to MINPLNT 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_T005 82% 104% 35% Tran HIGHLINE 230.00 to HIGHLINE 92.00 Circuit 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_210 110% 127% 29% line N.GILA to IMPRLVLY 500 ck 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_206 80% 105% 26% line HASSYAMP to N.GILA 500 ck 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C001 27% 116% 12% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
Summary of 2011 Heavy Summer Power Flow Analysis Results--N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 65
Table B2-3: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8292 N.LAQUIN 92 8 B92_L014 5.1% 5.5% 4.3% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
8286 LAQUINTA 92 8 B92_L014 4.9% 5.3% 4.2% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
Summary of 2011 Heavy Summer Power Flow Analysis--N-1 Bus Voltage Deviation Violations
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 66
Table B2-4: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_L007 101% 133% 101% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8279 CVSUB 92 8311 COACHELA 230 1 Tran 8 150 230_L004 85% 114% 78% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8279 CVSUB 92 8311 COACHELA 230 2 Tran 8 150 230_L004 85% 114% 78% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 C161_L001 99% 128% 62% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L007 24% 148% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 125 C92_L013 76% 116% 55% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 21% 145% 54% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 21% 145% 54% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C92_L003 44% 104% 54% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L006 14% 103% 53% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C161_L001 103% 138% 42% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C161_L001 92% 123% 42% Loss of Transmission ELCENTSW to AVE58(L) 161kV & AVE58 to CVSUB(L)161kV
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L007 N/A 119% 42% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L007 118% 130% 40% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C230_L007 106% 117% 40% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T001 97% 111% 40% Tran CVSUB 92.00 to COACHELA 230.00 CK1 & CK2
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L001 82% 104% 37% Line HIGHLINE 230.0 to MIDWAY 230.0 Circuit 1&2
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L012 89% 110% 36% Loss of Transmission from CVSUB to COACHELLA(CL)92kV CK1 & from CVSUB to COACHEL
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L014 84% 103% 36% Loss of Transmission from AVE42 to N.LAQ(CD)92kV & from AVE42 to SHIELDS(CS)92kV
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C92_L020 82% 103% 36% Loss of Transmission from AVE42 to MONROE(CW)92kV & from AVE42 to SHAHILLS(CI)92
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_T002 89% 112% 36% Tran MIDWAY 230.00 to MIDWAY 92.00 Ck1 & CK2
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 C230_L006 48% 104% 20% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 C230_L007 41% 109% 14% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 C230_L007 36% 104% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
Summary of 2011 Heavy Summer Power Flow Analysis Results---N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 67
Table B2-5: Summary of 2011 Heavy Summer Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations
Summary of 2011 Heavy Summer Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-Cluster Post-Cluster w/
Mitigation Outage Description
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 68
Table B2-6: Summary of 2011 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage description
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 149% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_T101 N/A 107% 72% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_T101 10% 120% 63% Tran ELCENTSW 230.00 to ELSTEAMP 92.00 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L060 6% 107% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L060 6% 106% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L060 6% 106% 60% Line USGYPS 92.0 to DIXIELAN 92.0 Circuit 1
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 B230_L004 N/A 137% 59% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 line_210 6% 107% 56% line N.GILA to IMPRLVLY 500 ck 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_T004 8% 102% 55% Tran ELCENTSW 161.00 to ELCENTSW 230.00 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B230_L004 12% 147% 55% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 12% 147% 54% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B230_L004 12% 147% 54% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L055 17% 108% 54% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 B92_L054 17% 108% 54% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L055 17% 108% 53% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L055 17% 108% 53% Line USNAF 92.0 to ELTERMIN 92.0 Circuit 1
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 B92_L054 16% 108% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 B92_L054 16% 108% 53% Line USNAF 92.0 to DIXIELAN 92.0 Circuit 1
8332 ELCENTSW 230 8335 ELSTEAMP 92 1 Tran 8 332 B230_C001 43% 114% 46% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_210 98% 114% 24% line N.GILA to IMPRLVLY 500 ck 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C005 57% 133% 23% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 line_206 80% 102% 22% line HASSYAMP to N.GILA 500 ck 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B230_C001 57% 148% 20% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 B92_L058 57% 102% 19% Line DIXIELAN 92.0 to DIXPRI 92.0 Circuit 1
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 B230_C001 28% 112% 17% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 B230_L004 18% 103% 5% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 B230_L004 18% 102% 5% Line ELCENTSW 230.0 to IMPRLVLY 230.0 Circuit 1
8331 ELCENTSW 161 8335 ELSTEAMP 92 1 Tran 8 125 B230_T004 18% 102% 4% Tran ELCENTSW 161.00 to ELCENTSW 230.00 Circuit 1
8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 B230_C001 11% 111% 3% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 B230_C001 12% 112% 1% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
Summary of 2011 Light Winter Power Flow Analysis Results-- N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 69
Table B2-7: Summary of 2011 Light Winter Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
Summary of 2011 Light Winter Power Flow Analysis Results--N-1 Bus Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 70
Table B2-8: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8640 RAMON92 92 8695 RAMON 230 1 Tran 8 225 230_L004 98% 142% 89% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8289 N.VIEW 92 8309 AVE42 92 1 Line 8 132 230_L004 91% 137% 83% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8289 N.VIEW 92 8640 RAMON92 92 1 Line 8 132 230_L004 88% 132% 79% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8309 AVE42 92 8310 FRANWAY 92 1 Line 8 132 230_L004 86% 130% 78% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8310 FRANWAY 92 8330 EDOM 92 1 Line 8 132 230_L004 85% 128% 76% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L006 N/A 135% 74% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 230_L004 N/A 104% 63% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8330 EDOM 92 8640 RAMON92 92 1 Line 8 156 230_L004 69% 104% 62% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8335 ELSTEAMP 92 8720 WSTBIOTP 92 2 Line 8 132 C230_L006 81% 105% 61% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8074 DIXIE230 230 8319 DIXIELAN 92 1 Tran 8 300 C230_L007 N/A 147% 60% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L007 14% 161% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 14% 160% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L007 14% 160% 56% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C230_L006 16% 124% 55% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 230_L004 4% 110% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8943 DIXPRI1 92 8944 DIXPRI 92 1 Line 8 132 C92_L003 17% 108% 54% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 230_L004 4% 109% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 230_L004 4% 109% 54% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8319 DIXIELAN 92 8946 DIXPRI2 92 1 Line 8 132 C92_L003 17% 108% 53% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI
8944 DIXPRI 92 8946 DIXPRI2 92 1 Line 8 132 C92_L003 17% 108% 53% Loss of Transmission from ELTERMINAL to USNAF(LW)92kV & from ELTERMINAL to EUCLI
8331 ELCENTSW 161 8332 ELCENTSW 230 1 Tran 8 225 C230_L006 85% 119% 47% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 C230_L006 126% 164% 34% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8279 CVSUB 92 8311 COACHELA 230 1 Tran 8 150 230_L004 85% 116% 27% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8279 CVSUB 92 8311 COACHELA 230 2 Tran 8 150 230_L004 85% 116% 27% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8332 ELCENTSW 230 22356 IMPRLVLY 230 1 Line 8 370 230_L004 80% 121% 25% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8279 CVSUB 92 8311 COACHELA 230 1 Tran 8 150 C230_L006 87% 106% 21% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8279 CVSUB 92 8311 COACHELA 230 2 Tran 8 150 C230_L006 87% 106% 21% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8319 DIXIELAN 92 8974 RTP1 92 1 Line 8 51 C230_L006 97% 163% 10% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8376 RTAP2 92 8974 RTP1 92 1 Line 8 57 C230_L006 87% 146% 10% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8282 USNAF 92 8337 ELTERMIN 92 1 Line 8 132 C230_L007 22% 121% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8282 USNAF 92 8319 DIXIELAN 92 1 Line 8 132 C230_L007 21% 121% 9% Line ELSWITCH 230.0 to IVSUB 230kV & ELSWITCH to AVE58(L) 161kV
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 225 C230_L006 116% 79% 3% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
8331 ELCENTSW 161 8335 ELSTEAMP 92 1 Tran 8 125 C230_L006 21% 112% 2% W/RAS RAMON230 230.0 to MIRAGE & COACHELA 230.0 to DEVERS
Summary of 2011 Light Winter Power Flow Analysis Results--N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 71
Table B2-9: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
8311 COACHELA 230 8 230_L004 1.8% 17.1% 2.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8008 A-8-IP 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8630 A-8 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8699 MIDWAY 230 8 230_L004 2.1% 18.2% 1.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8700 MIDWAY 92 8 230_L004 1.9% 18.4% 1.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8678 HUDSONTA 230 8 230_L004 1.9% 18.6% 1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8675 HUDSON23 230 8 230_L004 1.8% 18.7% 1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8723 VULCAN 92 8 230_L004 1.1% 18.0% 1.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8673 EARTHE2 92 8 230_L004 0.9% 17.6% 1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8702 REG1EX 92 8 230_L004 0.8% 17.4% 1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8279 CVSUB 92 8 230_L004 -0.2% 14.7% 0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8732 COLMAC 92 8 230_L004 -0.2% 14.8% 0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8670 MW1TAP 92 8 230_L004 1.2% 19.2% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8355 MECCA 92 8 230_L004 -0.1% 11.5% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8393 KTP2 92 8 230_L004 -0.2% 12.2% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8807 AV58TP2 161 8 230_L004 -0.3% 11.8% 0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8385 THERMAL 92 8 230_L004 -0.3% 13.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8358 AVE 52 92 8 230_L004 -0.4% 14.4% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8312 COACHELA 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8306 CMTAP1 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8303 SKY VLY 92 8 230_L004 -0.4% 14.7% 0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8805 AV58 161 8 230_L004 -0.6% 12.0% 0.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8690 HIGHLINE 230 8 230_L004 1.8% 18.0% 0.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8691 HIGHLINE 92 8 230_L004 0.8% 17.0% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8912 GEM23 92 8 230_L004 0.8% 17.1% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8363 OASIS 92 8 230_L004 -1.0% 12.4% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8380 RTP6OASS 92 8 230_L004 -1.0% 12.4% 0.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8652 SIGCTAP 92 8 230_L004 0.7% 16.1% 0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8900 PRUETTAP 92 8 230_L004 0.7% 16.1% 0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8287 RTAP8 92 8 230_L004 -1.0% 14.4% 0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8960 SIGC92 92 8 230_L004 0.5% 15.1% 0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8301 CITAP1 92 8 230_L004 -1.2% 15.4% -0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8703 MINPLNT 92 8 230_L004 0.3% 20.1% -0.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
Summary of 2011 Light Winter Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 72
Table B2-10: Summary of 2011 Light Winter Power Flow Analysis Results— N-2 Bus Voltage Deviation Violations (Continued)
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
8311 COACHELA 230 8 230_L004 1.8% 17.1% 2.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8008 A-8-IP 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8630 A-8 230 8 230_L004 N/A 18.3% 1.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8281 AVE58 92 8 230_L004 -1.4% 14.1% -0.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8389 VANBUREN 92 8 230_L004 -1.6% 15.7% -0.5% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8285 JEFERSN 92 8 230_L004 -1.8% 14.8% -0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8349 JACKSON 92 8 230_L004 -1.7% 15.9% -0.6% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8307 CMTAP2 92 8 230_L004 -1.8% 15.8% -0.7% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8354 MARSHALL 92 8 230_L004 -2.0% 15.2% -0.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8304 CITP2 92 8 230_L004 -2.0% 16.0% -0.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8406 SHAHILLS 92 8 230_L004 -2.1% 16.0% -0.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8308 CITP4 92 8 230_L004 -2.2% 16.1% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8291 AVE48 92 8 230_L004 -2.2% 15.5% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8315 CWTAP2 92 8 230_L004 -2.2% 15.5% -1.0% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8302 CARREON 92 8 230_L004 -2.3% 16.1% -1.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8286 LAQUINTA 92 8 230_L004 -2.3% 15.6% -1.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8292 N.LAQUIN 92 8 230_L004 -2.3% 15.7% -1.2% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8357 MONROE 92 8 230_L004 -2.5% 16.2% -1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8316 SHIELDS 92 8 230_L004 -2.5% 16.0% -1.3% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8309 AVE42 92 8 230_L004 -2.6% 16.2% -1.4% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8289 N.VIEW 92 8 230_L004 -3.1% 16.4% -1.9% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8310 FRANWAY 92 8 230_L004 -3.4% 16.3% -2.1% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS8330 EDOM 92 8 230_L004 -4.0% 15.2% -2.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8640 RAMON92 92 8 230_L004 -4.0% 14.7% -2.8% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
Summary of 2011 Light Winter Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 73
Appendix B3
Heavy Summer Post-Transient Stability Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 74
Table B3-1: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/ mitigation
N.LAQUIN-AVE42 92 kV LINE
8805 AV58 161 kV 208 144 233
8808 CVSUB161 161 kV 212 178 238
8292 N.LAQUIN 92 kV 72 57 76
8312 COACHELA 92 kV 266 182 252
8700 MIDWAY 92 kV 120 122 201
8361 NILAND 92 kV 290 280 294
8335 ELSTEAMP 92 kV 485 529 658
8397 CLX92 92 kV 276 278 313
8369 PILOTKNB 92 kV 149 160 161
8319 DIXIELAN 92 kV 224 368 388
ELSTM 2 & REPU 2 GENERATOR OUTAGE
8805 AV58 161 kV 240 215 267
8808 CVSUB161 161 kV 254 244 284
8292 N.LAQUIN 92 kV 192 173 206
8312 COACHELA 92 kV 288 282 345
8700 MIDWAY 92 kV 123 127 206
8361 NILAND 92 kV 290 286 297
8335 ELSTEAMP 92 kV 459 522 651
8397 CLX92 92 kV 259 266 303
8369 PILOTKNB 92 kV 167 162 162
8319 DIXIELAN 92 kV 215 367 387
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 75
Table B3-2: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
PALO VERDE - DEVERS kV LINE
8805 AV58 161 kV 199 138 195
8808 CVSUB161 161 kV 212 160 208
8292 N.LAQUIN 92 kV 166 122 156
8312 COACHELA 92 kV 252 191 250
8700 MIDWAY 92 kV 117 108 163
8361 NILAND 92 kV 270 238 262
8335 ELSTEAMP 92 kV 450 436 546
8397 CLX92 92 kV 267 265 298
8369 PILOTKNB 92 kV 158 128 148
8319 DIXIELAN 92 kV 216 351 364
N.GILA-IMPERIAL VALLEY 500 kV LINE
8805 AV58 161 kV 212 212 270
8808 CVSUB161 161 kV 223 238 286
8292 N.LAQUIN 92 kV 166 168 206
8312 COACHELA 92 kV 232 265 346
8700 MIDWAY 92 kV 95 110 205
8361 NILAND 92 kV 264 273 295
8335 ELSTEAMP 92 kV 405 470 620
8397 CLX92 92 kV 241 249 297
8369 PILOTKNB 92 kV 132 163 163
8319 DIXIELAN 92 kV 203 325 368
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 76
Table B3-3: Summary of 2011 Heavy Summer Post-Transient Stability Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
IMPERIAL VALLEY - MIGUEL kV LINE
8805 AV58 161 kV 218 171 236
8808 CVSUB161 161 kV 232 195 239
8292 N.LAQUIN 92 kV 177 141 174
8312 COACHELA 92 kV 267 225 286
8700 MIDWAY 92 kV 114 107 177
8361 NILAND 92 kV 286 263 280
8335 ELSTEAMP 92 kV 485 498 607
8397 CLX92 92 kV 276 275 307
8369 PILOTKNB 92 kV 165 152 154
8319 DIXIELAN 92 kV 224 365 378
IMPERIAL VALLEY – ELCENTRO 230 kV LINE
8805 AV58 161 kV 237 206 259
8808 CVSUB161 161 kV 251 235 277
8292 N.LAQUIN 92 kV 190 167 200
8312 COACHELA 92 kV 285 272 337
8700 MIDWAY 92 kV 122 124 202
8361 NILAND 92 kV 295 285 297
8335 ELSTEAMP 92 kV 497 544 671
8397 CLX92 92 kV 279 281 315
8369 PILOTKNB 92 kV 167 161 142
8319 DIXIELAN 92 kV 228 372 390
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 77
Table B3-4: Summary of 2011 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
RAMON – MIRAGE 230 kV LINE
8805 AV58 161 kV 181 183 244
8808 CVSUB161 161 kV 187 199 261
8292 N.LAQUIN 92 kV 141 141 184
8312 COACHELA 92 kV 170 188 296
8700 MIDWAY 92 kV 95 97 198
8361 NILAND 92 kV 291 285 299
8335 ELSTEAMP 92 kV 495 533 652
8397 CLX92 92 kV 279 279 315
8369 PILOTKNB 92 kV 150 160 160
8319 DIXIELAN 92 kV 228 370 389
COACHELA – DEVERS 230 kV LINE
8805 AV58 161 kV 198 183 246
8808 CVSUB161 161 kV 202 197 261
8292 N.LAQUIN 92 kV 160 147 190
8312 COACHELA 92 kV 184 186 295
8700 MIDWAY 92 kV 88 88 191
8361 NILAND 92 kV 290 282 295
8335 ELSTEAMP 92 kV 494 528 645
8397 CLX92 92 kV 278 279 314
8369 PILOTKNB 92 kV 167 141 160
8319 DIXIELAN 92 kV 227 369 389
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 78
GROUP 2012 CLUSTER STUDY
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 79
C.1 INTRODUCTION
Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Transitional Cluster Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2012 Cluster Study. The Group 2012 Cluster Study contains eleven proposed generation projects totaling 948 MW. Provided below are the projects and their interconnection information.
Project Code Capacity POI In-service Date A-1-1 70 MW Midway 230 kV 07/01/2012 A-1-2 70 MW Midway 230 kV 11/01/2012 A-1-3 70 MW Midway 230 kV 04/01/2013 A-7-1 47 MW ―KS‖ 230 kV 07/01/2012 A-7-2 47 MW ―KS‖ 230 kV 10/01/2013 A-10-1 200 MW Dixieland 230 kV 06/01/2012 A-10-2 200 MW Dixieland 230 kV 07/01/2013 A-14-1 25 MW ―L‖ line 06/30/2012 A-14-2 50 MW ―L‖ line 12/31/2012 A-14-3 50 MW ―L‖ line 06/30/2013 A-15 119 MW Anza 92 kV 09/01/2012
The Group 2012 Cluster Study was conducted using approved WECC 2012 heavy summer and 2013 light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses for peak (heavy summer) and off-peak (light winter) conditions. C.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS
C.2.1 Base Case Assumptions
The Group 2012 Cluster Study was conducted using the following WECC approved power flow models as the starting base cases:
Heavy summer . . . . 12hs2a1.sav ………...Approved 11/14/2007
Light winter . . . . . . 13lw1sa1.sav…………Approved 01/07/2009
Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2012 Cluster Projects. Pre-cluster base cases were developed from
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 80
the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2012 when the Group 2012 Cluster projects plan to initiate operations. Group 2011 Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2012 were modeled in the pre-cluster base cases. The following 13 new and existing transmission projects which were recommended for upgrade as part of the Group 2011 Cluster Study were incorporated into the 2012 pre-cluster base cases:
New 22-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission line from Dixieland to El Centro
New 8-mile, 786 MVA, 1033 MCM ACSR bundled 230 kV transmission line from Dixieland to Imperial Valley
New 19-mile, 786 MVA, 2-1033 MCM ACSR bundled 230 kV transmission lines from Highline to El Centro.
Rebuild the 18.1 miles El Centro - Imperial Valley 230 kV line using 786 MVA, 2-1033 MCM ACSR bundled transmission line.
Replace Coachella 161/92 kV transformer with a 250 MVA transformer.
Rebuild 1 mile DIXPRI1 –DIXPRI 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 2.5 mile DIXPRI2 –DIXIELAN 92 kV line to 191 MVA, 900 ACSS conductor
Rebuild 1-mile DIXPRI –DIXPRI2 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 7.4-mile DIXIELAN – RTP1 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild 20-mile RTP1 – RTAP2 92 kV line using 191 MVA, 900 ACSS conductor
Rebuild the 9-mile, 161 KV line section from ELCENTSW to L-TAPA-12 to double circuit 554 MVA, 1033 ACSR conductor.
New 332 MVA, 230/92 kV transformer at Dixieland.
Rebuild 8- mile CVSUB – KOHLRANCH - AVENUE 58 92 kV line to 191 MVA, 900 ACSS conductor
While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2012 projects interconnection points. C.2.2 Base Cases Studied The two pre-cluster base cases developed for the Group 2012 Cluster Study were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2012 Cluster projects. The output of the Group 2012 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. In the heavy summer post-cluster base case, the net output
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 81
of the Group 2012 Cluster projects was 932 MW while the net output of the Group 2012 Cluster projects during the light winter operating condition was 948 MW. The four base cases developed and used for studying the impact of the Group 2012 Cluster Projects are summarized in Table C-1.
Season PSLF Case Name Description
2012 Heavy Summer 2012 HS Pre-Cluster Planned IID heavy summer configuration without the Group 2012 Cluster projects
2012 Heavy Summer 2012 HS Post-Cluster Planned IID heavy summer configuration with Group 2012 Cluster projects modeled and dispatched
2012 Light Winter 2012 LW Pre-Cluster Planned IID light winter configuration without the Group 2012 Cluster projects
2012 Light Winter 2012 LW Post-Cluster Planned IID light winter configuration with Group 2012 Cluster projects modeled and dispatched
Table C-1: Study Base Cases-Group 2012 Cluster Study
C.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table C-2. Table C-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2012 projects power outputs are highlighted in Table C-2.
Load & Resources 2012 HS
Pre-Cluster 2012 HS
Post-Cluster 2012LW
Pre-Cluster 2012 LW Post-Cluster
Load (MW) 1102 1118 282 298
Load (MVAR) 427 437 81 91
Losses (MW) 71 92 43 68
Losses (MVAR) 504 827 299 601
Interchange (MW) 1026 1936 1534 2452
Total IID Shunts (MVAR) 713 886 275 492
IID Generation (MW) 2200 3147 1859 2819
IID Generation (MVAR) 224 382 92 220
SCE Interchange (MW) 9690 9784 1522 1616
SDG&E Interchange (MW) 1631 2366 1831 2566
Table C-2: Summary of Load and Resources C.2.4 Dynamic Models Dynamic data files ―12hs21.dyd‖ and ―13lw1s1.dyd‖ developed for use with WECC power flow models ―12hs2a1.sav ― and ―13lw1sa1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2012 Cluster
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 82
Study were user written algorithms and other dynamic data contained in each project’s interconnection application. C.2.5 Short Circuit Data The machine data used for the Group 2012 Cluster Study short circuit analysis were contained in each project’s interconnection application.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 83
C.3 STUDY RESULTS This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases. C.3.1 Power Flow Analysis Findings This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.
C.3.1.1 Heavy Summer Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2012 Cluster projects during the heavy summer operating condition can be found at Appendix C1, Figure C1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:
N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. A summary of the transmission facility overloads is provided in Appendix C2, Table C2-1.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
One (1) IID transmission facility was overloaded following selected double element (N-2) outages. A summary of the transmission facility overloads is provided in Appendix C2, Table C2-3.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer pre-cluster base case were 71 MW
C.3.1.2 Heavy Summer Post-Cluster Base Case
In the Post-Cluster analysis, the 932 MW net Group 2012 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2012 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2012 Cluster Projects to IID system losses was about 21 MW. The heavy summer post-cluster power flow map can be found at Appendix C1, Figure C1-2.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 84
To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table C-3. Table C-3 highlights the magnitude (not direction) of flow.
Element (unit of measure) 2012 HS
Pre-Cluster 2012 HS
Post-Cluster
El Centro 161/230 kV Transformer (MW) 19 47
El Centro 230/92 kV Transformer (MW) 98 122
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 146 169 Niland 161/92 kV Transformer Circuit 1 (MW) 72 74 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 110 130 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 757 1097 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 380 551
Niland-Blythe 161 kV Line (MW) 29 6
Niland-Blythe 161 kV Line (MVAR) 10 3 Imperial Valley-El Centro SW Circuit 1 &2 230 kV (MW) 80 201 Imperial Valley-El Centro W Circuit 1&2 230 kV (MVAR) 60 72 Imperial Valley – Dixieland 230 kV (MW) 396 886 Imperial Valley – Dixieland 230 kV (MVAR) 19 70 Mirage-Ramon 230 kV Line (MW) 327 472 Mirage-Ramon 230 kV Line (MVAR) 42 50 Coachella-Devers 230 kV Line (MW) 186 293 Coachella-Devers 230 kV Line (MVAR) 38 61
Path 42 (MW) 512 761 Path 42 (MVAR) 79 132
Path 46 (MW) 6401 6668
Path 49 (MW) 5035 4964
SCIT (MW) 15137 15415
Table C-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2012 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.
N-0 Findings
One (1) transmission facility overload was identified during normal operating conditions. In particular, the line section from Project A-13 interconnection point to Avenue 58 161 kV substation (A-13-IP – AVE58 161 kV line) was overloaded up to 103% of the line’s rating under normal operating condition.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 85
N-1 Findings
Four (4) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 4 transmission facility overloads are attributable to the integration of the Group 2012 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix C2, Table C2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-4.
No bus voltage deviation violation was observed following the selected single element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
AVE48 – AVE58 92 KV LINE 132 MVA AVE58 – JEFERSN 92 KV LINE 92% 118%
RTAP2 – RTP3ANZA 92 KV LINE 91 MVA RTP3ANZA– RTP5DSTS 92 KV LINE 4% 122%
MIDWAY #1 230/92 KV TRANSFORMER
225 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 150%
MIDWAY #1 230/92 KV TRANSFORMER
225 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 150%
Table C-4: Single Element Outage Transmission Facility Overloads
N-2 Findings
Four (4) IID transmission facilities were overloaded following selected double element (N-2) outages. Three (3) out of the 4 transmission facility overloads were attributable to the integration of the Group 2012 Cluster projects. A summary of the transmission facility overloads following the double element outages is provided in Appendix C2, Tables C2-3. Provided in Table C-5 are the identified overloads which exceeded 110% of facility’s continuous rating and warrants mitigation.
No bus voltage deviation violation was observed following the selected double element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
NILAND – COACHELA 161 KV LINE 165 MVA
COACHELA – MIDWAY 230 KV & COACHELA – A-8 230 KV LINES
111% 119%
RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 70% 122%
RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 64% 116%
RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 60% 111%
Table C-5: Double Element Outage Transmission Facility Overloads
Losses
IID transmission system losses in the heavy summer post-cluster base case were 92 MW
C.3.1.3 Light Winter Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Key findings from the power flow analysis using the light winter pre-cluster base case are:
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 86
N-0 Findings
No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2012 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix C1, Figure C1-4.
N-1 Findings
Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the power flow analysis results can be found at Appendix C2, Table C2-5.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
No IID transmission facility overload was identified following selected double element (N-2) outages.
No bus voltage deviation violation was identified following the selected double element outages.
Losses
IID system losses in the light winter pre-project case were 43 MW
C.3.1.4 Light Winter Post-Cluster Base Case In the Post-cluster analysis, the 948 MW net Group 2012 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2012 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The addition of the Group 2012 Cluster Projects caused IID system losses to increase by 25 MW. The light winter post-cluster power flow map can be found at Appendix C1, Figure C1-5.
To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table C-6. Table C-6 highlights the magnitude (not direction) of the power flow on the selected facilities.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 87
Element (unit of measure) 2012 LW
Pre-Cluster 2012 LW
Post-Cluster
El Centro 161/230 kV Transformer (MW) 48 83
El Centro 230/92 kV Transformer (MW) 122 152
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 58 77 Niland 161/92 kV Transformer Circuit 1 (MW) 58 60
Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 59 73 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 582 848 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 292 426
Niland-Blythe 161 kV Line (MW) 48 71
Niland-Blythe 161 kV Line (MVAR) 7 14 Imperial Valley-El Centro SW #1 &2 230 kV (MW) 254 357
Imperial Valley-El Centro SW #1 &2 230 kV (MVAR) 49 68 Imperial Valley – Dixieland #1 &2 230 kV (MW) 536 1000 Imperial Valley – Dixieland #1 &2 230 kV (MVAR) 5 58 Mirage-Ramon 230 kV Line (MW) 383 564 Mirage-Ramon 230 kV Line (MVAR) 39 27 Coachella-Devers 230 kV Line (MW) 215 350 Coachella-Devers 230 kV Line (MVAR) 9 13
Path 42 (MW) 597 910 Path 42 (MVAR) 50 72
Path 46 (MW) 4209 4533
Path 49 (MW) 3472 3408
SCIT (MW) 5170 5504
Table C-6: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Three (3) IID transmission facilities were overloaded following selected single element (N-1) outages. Two (2) out of the 3 transmission facility overloads were existing overloads which persisted following the integration of the Group 2012 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix C2, Table C2-5. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-7.
No bus voltage deviation violation was identified following the selected single element outages.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 88
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
MIDWAY #1 230/92 KV TRANSFORMER
225 MVA MIDWAY #2 230/92 KV TRANSFORMER
148% 148%
MIDWAY #2 230/92 KV TRANSFORMER
225 MVA MIDWAY #1 230/92 KV TRANSFORMER
148% 148%
RTAP2 – RTP3ANZA 92 KV LINE 91 MVA RTP3ANZA– RTP5DSTS 92 KV LINE 4% 125%
Table C-7: Single Element Outage Transmission Facility Overloads
N-2 Findings
One (1) IID transmission facilities was overloaded following selected double element outages. The transmission facility overload is attributable to the addition of Group 2012 Cluster projects. A summary of the transmission facility overloads following double element outages is provided in Appendix C2, Table C2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table C-8.
No bus voltage deviation violation was observed following the selected double element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
RTAP2 – RTP3ANZA 92 KV LINE 91 MVA AVE58– RTP5DSTS 92 KV & AVE58 – COACHELA 92 KV LINES
5% 123%
Table C-8: Double Element Outages Transmission Facility Overloads
Losses
IID system losses in the light winter post-cluster base case were 68 MW
C.3.2 Transient Stability Analysis Findings
With the modeling of all the IID system upgrades proposed to mitigate the unstable conditions found for the scenario 2011, stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases. Key findings include:
No transient voltage dip violations were observed per WECC/NERC transient voltage dip for all the outages simulated.
No transient frequency criteria violations were observed for all the outages simulated.
Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment C. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 89
C.3.3 Post-Transient Stability Analysis Findings Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, the reactive power margins at the N. LAQUIN 92 kV bus following the outage of the N. LAQUIN – AVE42 92 kV line were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2012 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix C3. C.3.4 Short Circuit Analysis Findings The results of the Group 2012 Cluster Short Circuit Analysis is provided in Table C-9. The maximum incremental fault duty following the integration of the Group 2012 Cluster projects was 3,956 A at the Midway 230 kV substation. The available margins at the vicinity breakers as depicted in Table C-9 showed that the interconnection of the Group 2012 Cluster projects will cause the El Centro 92 kV and the Coachella Switching Station 92 kV breakers to exceed their interruption capabilities by 649 A and 31 A respectively. Therefore, the 40, 000 A breakers at the El Centro 92 kV substation and the 22,000 A breakers at Coachella 92 kV switching station would have to be replaced with a 63, 000 A and 40,000 A respectively rated breakers prior to the interconnection of the Group 2012 Cluster projects. There are forty (40) breakers with interruption capability of 40,000 A at the El Centro 92 kV substation and one (1) breaker with interruption capability of 22,000 A at Coachella Switching Station.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 90
Table C-9: Summary of the Short Circuit Analysis Results
C.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2012 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix C2 for power flow results). The results of the post-transient stability analysis using the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix C3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the system was found to be stable and adequately damped with no WECC/NERC criteria violations (See Attachment C). C.4.1 Mitigation Plans for Overloads Caused by Group 2012 Cluster Study The following transmission upgrade projects are recommended for mitigating the identified transmission overloads caused by the integration of the Group 2012 Cluster projects to the IID transmission system.
Bus Name IID Substation Name kV
Breaker
Rating
(A)
Pre- Cluster Max
(3LG, 1LG) Fault
Current (A)
Available
Margins
(A)
Post-Cluster
Max (3LG, 1LG)
Fault Current (A)
Project
Contribution
(A)
ANZA ANZA 92 30,000 3,019 26,981 6,553 3,534
CARREON CARREON 92 40,000 11,386 28,614 11,532 146
CENTRAL CENTRAL 92 40,000 14,925 25,075 15,114 190
CLARK CLARK 92 40,000 16,829 23,171 17,016 187
CLPT-PRISON CALIPATRIA PRISON 92 40,000 10,887 29,113 10,928 40
COACHELA COACHELLA SW STA 92 22,000 21,633 367 22,031 398
CV-161 COACHELLA VALLEY 161 40,000 7,725 32,275 8,044 319
CV-230 COACHELLA VALLEY 230 40,000 17,605 22,395 18,537 932
CV-92 COACHELLA VALLEY 92 40,000 28,584 11,417 29,739 1,155
DAHLIA DAHLIA 92 64,000 16,839 47,161 17,029 189
DESERT SHORE DESERT SHORES 92 40,000 4,129 35,871 5,266 1,137
DIXIE-PRISON DIXIELAND PRISON 92 40,000 13,543 26,457 13,974 430
DIXIELAND DIXIELAND 92 40,000 19,044 20,956 19,983 939
DROP4 DROP 4 92 40,000 14,757 25,243 14,847 90
ELCENTSW EL CENTRO SW STA 92 40,000 39,881 119 40,649 768
ELCENTSW EL CENTRO SW STA 161 16,000 10,305 5,695 10,933 628
ELCENTSW EL CENTRO SW STA 230 63,000 26,064 36,936 27,928 1,863
ELMORE-92 k (CALENERGY) ELMORE 92 31,500 7,107 24,393 7,169 62
EUCLID EUCLID 92 64,000 18,449 45,551 18,679 230
FRANCES WAY- FRANCES WAY 92 40,000 10,027 29,973 10,049 22
GATEWAY-92 GATEWAY 92 40,000 11,319 28,681 11,377 58
HEBER HEBER 92 40,000 14,012 25,988 14,117 105
HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 13,974 6,026 14,077 103
HIGHLINE230 HIGHLINE 230 40,000 17,492 22,508 19,697 2,206
HIGHLINE92 HIGHLINE 92 40,000 20,391 19,609 20,705 315
MIDWAY230 MIDWAY 230 40,000 13,758 26,242 17,713 3,956
MIDWAY92 MIDWAY 92 40,000 17,377 22,623 19,328 1,951
SANFELIP SAN FELIPE 92 10,000 2,188 7,813 2,888 701
SHIELDS SHIELDS 92 64,000 13,426 50,574 13,619 193
Group 2012 Cluster Projects: Short Circuit Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 91
Replace the existing Avenue 58 – Avenue 48 92 kV line with a 191 MVA, 900 MCM ACSS conductor
Rebuild the RTP3ANZA – RTP5DSTS 92 kV line with a 191 MVA, 900 MCM ACSS conductor
New 8.5-mile, 560 MVA, 2-1590 MCM ACSS bundled 230 kV line from Midway to Hudson Ranch
New 24-mile, 560 MVA, 2-1590 MCM ACSS bundled 230 kV line from Hudson Ranch to Banister
Replace the existing Avenue 58 – El Centro 161 kV line (24.5-mile Bannister to El Centro section) with 2-1033 MCM ACSR bundled 230 kV conductors. Terminate one circuit at El Centro. Extend the other circuit to Dixieland to from Bannister- Dixieland 230 kV line.
Install a new 225 MVA, 230/161 kV transformer at Bannister
Implement a Special Protection System to trip generation at Midway 92 kV. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables C-10. C.5 COST AND COSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for mitigating the impact of the Group 2012 Cluster Projects is $ 127.6 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table C-11.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 92
Worst Outage Element (s) Overloaded Facility
Applicable
Rating
Post- Cluster
Loadings Recommended Mitigation Notes
NORMAL OPERATIONS (N-0 )
ALL LINES IN SERVICE A-13-IP – AVENUE 58 161 KV LINE
165 MVA 103%
New 8.5-mile , 230 kV line from Midway to Hudson Ranch using 560 MVA, 2-1590 MCM ACSS bundled conductors These new transmission
lines and interconnection points help to mitigate the costly upgrade of the Avenue 58 – El Centro 161 kV line. These upgrades also ameliorate the reliability of the entire transmission system following selected double element outages from Midway to SCE transmission system
New 24-mile 230 kV line from Hudson Ranch to Bannister using 560 MVA, 2-1590 MCM ACSS bundled conductors
Rebuild ―L‖ line between Bannister and A121P tap and BTAP-DTP 15.5 Miles with 2 circuits of 2-1033 ACSR
Install 225 MVA, 230/161 kV transformer at Bannister
Interconnect Project A-8 to Banister 230 kV substation
Interconnect Project A-12 to the new Bannister – Dixieland 230 kV line
Interconnect Project A-1 to Hudson Ranch 230 kV substation
SINGLE ELEMENT OUTAGE (N-1
AVE58 – JEFERSN 92 KV LINE AVE48 – AVE58 92 KV LINE 132 MVA 121% Reconductor the 6.5-mile using 191 MVA, 900 MCM ACSS 92 kV Conductor
None
RTP3ANZA– RTP5DSTS 92 KV LINE
RTAP2 – RTP3ANZA 92 KV LINE
91 MVA 126% Rebuild 6.9-mile line using 191 MVA, 900 MCM ACSS Conductor
DOUBLE ELEMENT OUTAGE (N-2)
COACHELA – MIDWAY 230 KV & COACHELA– A-8 230 KV LINES
NILAND – COACHELA 161 KV LINE
165 MVA 119%
Implement a Special Protection Scheme to trip generation at Midway 92 kV and the new cluster projects at Midway
None
RTP3ANZA – RTP4SLTN 92 KV LINE
132 MVA 122%
RTP4SLTN – RTP5DSTS 92 KV LINE
132 MVA 116%
RTP5DSTS – RTP6OASS 92 KV LINE
132 MVA 111%
Table C-10: Summary of Transmission Facility Overloads and Associated Mitigation Plan
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 93
Table C-11: Recommended Mitigation Plan & Associated Cost for Group 2012 Cluster Projects
Overloaded Faci l i ties Cri tica l OutageAppl icable
RatingsLoadings Recom m ended M itigation
Cost
Estim ate ($
M i l l ion)
Construction
Tim e L ines
(M onths) Notes
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24 None
One Breaker replacement at
Coachella Valley 92 kV substation 0.13 N/A
Installation cost for
replacing the breaker
New 8.5-mile 230 kV line from Midway
– Hudson RanchIID Budget 24
Upgrade Midway 230 kV Substation 10.41 30
New 24-mile 230 kV line from Hudson
Ranch to Bannister44.70 30
Rebuild "L" line between Bannister
and A121P tap and BTAP-DTP 15.5
miles with 2 circuits of 2-1033 ACSR
35.65 36
Install 225 MVA, 230/161 kV
transformer and build Bannister
substation
21.37 30
AVE48 – AVE58 92 KV LINE AVE58 – JEFERSN 92 KV LINE 132 MVA 121%Reconductor line using 191 MVA, 900
MCM ACSS 92 kV Conductor5.85 18 None
RTAP2 – RTP3ANZA 92 KV LINE RTP3ANZA– RTP5DSTS 92 KV LINE 91 MVA 126%Rebuild line using 191 MVA, 900 MCM
ACSS 92 kV Conductor6.21 30 None
NILAND – COACHELA 161 KV LINE 165 MVA 119%
RTP3ANZA – RTP4SLTN 92 KV LINE 132 MVA 122%
RTP4SLTN – RTP5DSTS 92 KV LINE 132 MVA 116%
RTP5DSTS – RTP6OASS 92 KV LINE 132 MVA 111%
COACHELA – MIDWAY 230 KV &
COACHELA– A-8 230 KV LINES
Implement a Remedial Action Scheme
to trip generation at MidwayN/A
NORMAL OPERATIONS (N-0)
12Already included in 2011
Budget
165 MVA 103%
None N/A N/A N/A
None
Network Upgrades Attributable to Group 2012 Cluster Pro jects
A-13 (POI) – AVENUE 58 161 KV LINE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 94
Appendix C1
Power flow Maps
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 95
Figure C1-1: Power flow Map—2012 Heavy Summer Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 96
Figure C1-2: Power flow Map—2012 Heavy Summer Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 97
Figure C1-3: Power flow Map—2012 Heavy Summer Post-Cluster w/ Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 98
Figure C1-4: Power flow Map—2012 Light Winter Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 99
Figure C1-5: Power flow Map—2012 Light Winter Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 100
Figure C1 6: Power flow Map—2012 Light Winter Post-Cluster w/Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 101
Appendix C2
Summary of Power Flow Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 102
Table C2-1: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8639 A-13-IP 161 8806 AV58TP1 161 1 Line 8 165 Base 65% 103% 71% No outage (N-0)
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 150% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 149% 150% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C005 60% 108% 112% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L031 100% 100% 108% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1
8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 B230_C005 55% 103% 106% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C017 53% 99% 104% Line COACHELA 230.0 to A-8 230.0 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_L007 53% 99% 104% Line COACHELA 230.0 to MIDWAY 230.0 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B161_C009 55% 104% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C009 101% 110% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C018 52% 97% 102% Line Midway 230.0 to A-8 230.0 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L030 94% 95% 102% Line NEW MECCA to AVE 52 92.0 Circuit 1
8074 DIXIE230 230 22356 IMPRLVLY 230 2 Line 8 786 B230_C001 57% 105% 87% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8279 CVSUB 92 8808 CVSUB161 161 1 Tran 8 250 B161_T002 83% 102% 73% Tran AVE58 92.00 to AV58 161.00 Circuit 1
8291 AVE48 92 8281 AVE58 92 1 Line 8 132 B92_L007 92% 118% 64% Line AVE58 92.0 to JEFERSN 92.0 Circuit 1
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L028 4% 122% 59% Line RTP3-ANZA 92.0 to Desert Shores 92.0 Circuit 1
Summary of 2012 Heavy Summer Power Flow Analysis Results-- N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 103
Table C2-2: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
Summary of 2012 Heavy Summer Power Flow Analysis--N-1 Voltage Deviation Violations
None
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 104
Table C2-3: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8291 AVE48 92 8281 AVE58 92 1 Line 8 132 C92_L020 81% 105% 69% Loss of Transmission from AVE42 to MONROE(CW)92kV & from AVE42 to SHAHILLS(CI)92
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 C230_C007 70% 122% 126% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_C007 111% 119% 126% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 C230_C008 67% 119% 123% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_C008 107% 115% 122% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit
8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 C230_C007 64% 116% 120% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 C230_C008 61% 112% 117% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit
8379 RTP5DSTS 92 8380 RTP6OASS 92 1 Line 8 132 C230_C007 60% 111% 115% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8379 RTP5DSTS 92 8380 RTP6OASS 92 1 Line 8 132 C230_C008 57% 108% 112% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit
8082 RKMTAP 92 8380 RTP6OASS 92 1 Line 8 132 C230_C007 48% 99% 103% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C92_L011A 93% 94% 101% Loss of Transmission from AVE58 to COACHELLA(R)92kV & from MECCA to COACHELLA(NE
8691 HIGHLINE 92 8093 HIGH161 161 1 Tran 8 125 C230_C007 53% 102% 99% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8301 CITAP1 92 8312 COACHELA 92 1 Line 8 191 C92_L013 93% 108% 71% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92
8301 CITAP1 92 8389 VANBUREN 92 1 Line 8 191 C92_L013 93% 108% 71% Loss of Transmission from AVE58 to JEFFERSON(CD)92kV & from AVE58 to AVE48(CS)92
8690 HIGHLINE 230 8105 A-7TAP1 230 1 Line 8 389 C230_C007 N/A 104% 55% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8105 A-7TAP1 230 8019 A-7 230 1 Line 8 393 C230_C007 N/A 103% 55% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C92_L010 16% 107% 52% Loss of Transmission from AVE58 TO RTP5DSTS(R)92kV & from Ave 58 to COACHELLA(R)
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C230_C007 104% 45% 25% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
Summary of 2012 Heavy Summer Power Flow Analysis Results---N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 105
Table C2-4: Summary of 2012 Heavy Summer Power Flow Analysis Results— N-2 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
Summary of 2012 Heavy Summer Power Flow Analysis Results--N-2 Bus Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 106
Table C2-5: Summary of 2012 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage description
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 148% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 148% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8074 DIXIE230 230 22356 IMPRLVLY 230 2 Line 8 786 B230_C001 67% 105% 106% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8695 RAMON 230 24806 MIRAGE 230 1 Line 8 779 B230_L001 77% 102% 93% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L028 4% 125% 61% Line RTP3-ANZA 92.0 to Desert Shores 92.0 Circuit 1
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 B92_L026 5% 123% 60% Line AVE58 92.0 to OASIS 92.0 Circuit 1
Summary of 2012 Light Winter Power Flow Analysis Results--N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 107
Table C2-6: Summary of 2012 Light Winter Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
Summary of 2012 Light Winter Power Flow Analysis Results-- N-1 Bus Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 108
Table C2-7: Summary of 2012 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8361 NILAND 92 8059 NILTAP92 92 1 Line 8 132 C230_C007 81% 79% 104% Line COACHELA to MIDWAY & COACHELLA TO A-8 230.0 Circuit
8361 NILAND 92 8059 NILTAP92 92 1 Line 8 132 C230_C008 78% 77% 101% Line COACHELA to MIDWAY & MIDWAY TO A-8 230.0 Circuit
8376 RTAP2 92 8377 RTP3ANZA 92 1 Line 8 91 C92_L010 5% 123% 60% Loss of Transmission from AVE58 TO RTP5DSTS(R)92kV & from Ave 58 to COACHELLA(R)
8690 HIGHLINE 230 8699 MIDWAY 230 2 Line 8 389 C230_L003 49% 104% 48% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1, COACHELA 230 to RAMON Circuit 1
Summary of 2012 Light Winter Power Flow Analysis Results--N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 109
Table C2-8: Summary of 2012 Light Winter Power Flow Analysis Results— N-2 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
Summary of 2012 Light Winter Power Flow Analysis Results--N-2 Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 110
Appendix C3
Heavy Summer Post-Transient Stability Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 111
Table C3-1: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/ mitigation
N.LAQUIN-AVE42 92 kV LINE
8805 AV58 161 kV 232 203 207
8808 CVSUB161 161 kV 276 243 248
8292 N.LAQUIN 92 kV 80 68 70
8312 COACHELA 92 kV 335 297 306
8700 MIDWAY 92 kV 207 234 243
8361 NILAND 92 kV 318 296 298
8335 ELSTEAMP 92 kV 707 637 643
8397 CLX92 92 kV 324 304 305
8369 PILOTKNB 92 kV 153 141 142
8319 DIXIELAN 92 kV 468 437 439
ELSTM 2 & REPU 2 GENERATOR OUTAGE
8805 AV58 161 kV 270 236 242
8808 CVSUB161 161 kV 302 271 277
8292 N.LAQUIN 92 kV 217 194 208
8312 COACHELA 92 kV 364 330 340
8700 MIDWAY 92 kV 211 238 247
8361 NILAND 92 kV 325 303 306
8335 ELSTEAMP 92 kV 697 641 647
8397 CLX92 92 kV 315 296 297
8369 PILOTKNB 92 kV 155 145 145
8319 DIXIELAN 92 kV 465 438 440
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 112
Table C3-2: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
PALO VERDE - DEVERS kV LINE
8805 AV58 161 kV 244 206 213
8808 CVSUB161 161 kV 272 237 243
8292 N.LAQUIN 92 kV 197 171 184
8312 COACHELA 92 kV 330 290 300
8700 MIDWAY 92 kV 195 224 234
8361 NILAND 92 kV 310 287 290
8335 ELSTEAMP 92 kV 690 617 625
8397 CLX92 92 kV 321 300 300
8369 PILOTKNB 92 kV 151 140 140
8319 DIXIELAN 92 kV 463 431 433
N.GILA-IMPERIAL VALLEY 500 kV LINE
8805 AV58 161 kV 280 246 252
8808 CVSUB161 161 kV 312 283 288
8292 N.LAQUIN 92 kV 224 203 216
8312 COACHELA 92 kV 377 345 354
8700 MIDWAY 92 kV 220 245 253
8361 NILAND 92 kV 334 316 318
8335 ELSTEAMP 92 kV 728 665 672
8397 CLX92 92 kV 326 308 309
8369 PILOTKNB 92 kV 162 154 154
8319 DIXIELAN 92 kV 471 440 443
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 113
Table C3-3: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
IMPERIAL VALLEY - MIGUEL kV LINE
8805 AV58 161 kV 244 198 205
8808 CVSUB161 161 kV 272 228 234
8292 N.LAQUIN 92 kV 197 164 177
8312 COACHELA 92 kV 330 279 288
8700 MIDWAY 92 kV 194 218 228
8361 NILAND 92 kV 310 278 281
8335 ELSTEAMP 92 kV 683 578 589
8397 CLX92 92 kV 321 296 297
8369 PILOTKNB 92 kV 150 136 137
8319 DIXIELAN 92 kV 461 422 424
IMPERIAL VALLEY – ELCENTRO 230 kV LINE
8805 AV58 161 kV 263 227 233
8808 CVSUB161 161 kV 293 261 266
8292 N.LAQUIN 92 kV 212 188 201
8312 COACHELA 92 kV 356 319 329
8700 MIDWAY 92 kV 208 235 244
8361 NILAND 92 kV 323 302 304
8335 ELSTEAMP 92 kV 718 653 660
8397 CLX92 92 kV 325 306 308
8369 PILOTKNB 92 kV 153 142 142
8319 DIXIELAN 92 kV 471 442 444
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 114
Table C3-4: Summary of 2012 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
RAMON – MIRAGE 230 kV LINE
8805 AV58 161 kV 245 229 236
8808 CVSUB161 161 kV 271 259 266
8292 N.LAQUIN 92 kV 189 182 195
8312 COACHELA 92 kV 300 293 302
8700 MIDWAY 92 kV 203 239 248
8361 NILAND 92 kV 324 309 311
8335 ELSTEAMP 92 kV 699 639 647
8397 CLX92 92 kV 326 309 309
8369 PILOTKNB 92 kV 151 137 137
8319 DIXIELAN 92 kV 471 444 446
COACHELA – DEVERS 230 kV LINE
8805 AV58 161 kV 250 215 222
8808 CVSUB161 161 kV 277 247 252
8292 N.LAQUIN 92 kV 201 176 189
8312 COACHELA 92 kV 324 291 301
8700 MIDWAY 92 kV 197 227 237
8361 NILAND 92 kV 319 296 299
8335 ELSTEAMP 92 kV 697 625 634
8397 CLX92 92 kV 324 303 305
8369 PILOTKNB 92 kV 152 139 139
8319 DIXIELAN 92 kV 468 435 438
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 115
GROUP 2014 CLUSTER STUDY
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 116
D.1 INTRODUCTION
Imperial Irrigation District (IID) is currently processing a large volume of active Interconnection Requests (IRs). IID has elected to cluster all pending IRs into a common Cluster System Impact Study (Cluster Study) group. About 2183 MW of proposed generation projects with planned Points of Interconnection (POI) in the IID service area were included in the Cluster Study. These projects plan to deliver power to IID and several IID neighboring utilities in the 2010-2015 timeframe. In conducting the Cluster Study, the proposed projects were grouped according to each project’s year of in-service. Projects with different phases of implementation were grouped in the year in which the first phase becomes operational. This section of the report details the study assumptions, methodology and results of Group 2014 Cluster Study. The Group 2014 Cluster Study contains four proposed generation projects totaling 435 MW. Provided below are the projects and their interconnection information.
Project Code Capacity POI In-service Date A-2-4 70 MW Midway 230 kV 04/01/2014 A-2-5 70 MW Midway 230 kV 01/01/2015 A-2-6 70 MW Midway 230 kV 10/01/2015 A-4 225 MW Midway 230 kV 05/01/2014
The Group 2014 Cluster Study was performed using approved WECC 2014 heavy summer and 2013 light winter power flow models. Studies performed included power flow, transient stability, post-transient stability and short circuit analyses. D.2 STUDY BASE CASE DESCRIPTION AND ASSUMPTIONS
D.2.1 Base Case Assumptions
The Group 2014 Cluster Study was conducted using the following WECC approved power flow models as the starting base cases:
Heavy summer . . . . 14hs2sa.sav ………...Approved 07/23/2008
Light winter . . . . . . 13lw1sa1.sav…………Approved 01/07/2009
Both power flow base cases were selected because they were the most recently developed and available base cases in the WECC library based on planned in-service dates of the Group 2014 Cluster Projects. Pre-cluster base cases were developed from the starting base cases by incorporating IID detailed system representation. IID system loads, resources, and topology were adjusted to reflect the conditions expected in 2014 when the Group 2014 Cluster projects plan to initiate operations. It was noted that existing generation resources at Imperial Valley were operating at a very low output level (78 MW) in the pre-cluster base case. The outputs of the Imperial Valley generation resources were maintained at the pre-cluster level. Cluster projects and other queued generation projects with planned interconnection to IID transmission system prior to summer 2014 were modeled in the pre-cluster base cases.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 117
The following new and existing transmission projects which were recommended for mitigating the Group 2012 Cluster projects impacts were incorporated into the 2014 pre-cluster base cases:
AVENUE 58 – AVENUE 48 92 kV line (191 MVA, 900 MCM ACSS)
RTP3ANZA – RTP5DSTS 92 kV line (191 MVA, 900 MCM ACSS )
New MIDWAY – HUDSON RANCH 230 KV LINE (560 MVA, 2-1590 MCM ACSS)
New HUDSON RANCH – BANNISTER 230 kV line (560 MVA, 2-1590 MCM ACSS)
New BANNISTER – EL CENTRO 230 kV line (786 MVA, 2-1033 MCM ACSR)
New BANNISTER – DIXIELAND 230 kV line (786 MVA, 2-1033 MCM ACSR)
New 225 MVA, 230/161 kV transformer at Bannister While it is impossible to study all IID transmission system flows and generation levels during all seasons, these two pre-cluster base cases represent extreme generation and transmission flows that will potentially expose any transmission constraints at the Group 2014 projects interconnection points. D.2.2 Base Cases Studied Two pre-cluster base cases were developed for the Group 2014 Cluster Study. The pre-cluster base cases were initially tested to ensure that all transmission facilities in IID control area are within their normal operating limits and this provided a benchmark for post-cluster evaluations. Two post-cluster base cases were developed from the pre-cluster base cases by modeling the Group 2014 Cluster projects. Project A-2 (which comprises of A-2-4, A-2-5 and A-2-6) was interconnected to Hudson Ranch 230 kV substation in lieu of Midway 230 kV substation due to the transmission reconfiguration recommended following the Group 2012 Cluster Study. The output of the Group 2014 Cluster projects were dispatched and scheduled according to the information provided on each projects interconnection application. The four base cases developed for studying the impact of the Group 2014 Cluster Projects are summarized in Table D-1.
Season PSLF Case Name Description
2014 Heavy Summer 2014 HS Pre-Cluster Planned IID heavy summer configuration without the Group 2014 Cluster projects
2014 Heavy Summer 2014 HS Post-Cluster Planned IID heavy summer configuration with Group 2014 Cluster projects modeled and dispatched
2014 Light Winter 2014 LW Pre-Cluster Planned IID light winter configuration without the Group 2014Cluster projects
2014 Light Winter 2014 LW Post-Cluster Planned IID light winter configuration with Group 2014 Cluster projects modeled and dispatched
Table D-1: Study Base Cases-Group 2014 Cluster Study
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 118
D.2.3 Load and Resources The IID load and Resources for the four base cases studied are provided in Table D-2. Table D-2 also depicts IID transmission system losses and area interchange flows for both pre- and post- cluster base cases. The area interchange flows for the receiving entities for the Group 2014 projects power outputs are highlighted in Table D-2.
Load & Resources 2014 HS
Pre-Cluster 2014 HS
Post-Cluster 2014LW
Pre-Cluster 2014 LW Post-Cluster
Load (MW) 1179 1195 311 326
Load (MVAR) 460 470 97 106
Losses (MW) 82 100 68 89
Losses (MVAR) 724 942 643 897
Interchange (MW) 1888 2287 2446 2854
Total IID Shunts (MVAR) 1059 1065 485 499
IID Generation (MW) 3149 3582 2825 3270
IID Generation (MVAR) 288 362 277 389
SCE Interchange (MW) 7937 8161 1616 1841
LADWP Interchange (MW) 1780 1984 189 21 Table D-2: Summary of Load and Resources
D.2.4 Dynamic Models Dynamic data files ―14hs2s1.dyd‖ and ―13lw1s1.dyd‖ developed for use with WECC power flow models ―14hs2sa.sav― and ―13lw1sa1.sav― respectively were used for the transient stability analysis. New ―motorw‖ data for the IID control area were created and added to the dynamic data files. The stability models used for the Group 2014 Cluster Study were user written algorithms and other dynamic data contained in each project’s interconnection application. D.2.5 Short Circuit Data The machine data used for the Group 2014 Cluster Study short circuit analysis were contained in each project’s interconnection application.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 119
D.3 STUDY RESULTS This section provides the results obtained by applying the stated study assumptions and the general study methodology. It illustrates the findings associated with the power flow, transient stability and post-transient stability analyses for both the pre- and post-cluster base cases. D.3.1 Power Flow Analysis Findings This section details the findings of the power flow analysis. WECC/NERC reliability criteria were used to assess the adequacy of the study results.
D.3.1.1 Heavy Summer Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. A pre-cluster power flow map that depicts the power flow distribution at the points of interconnections of the Group 2014 Cluster projects during the heavy summer operating condition can be found at Appendix D1, Figure D1-1. Key findings from the power flow analysis using the Heavy Summer Pre-cluster Base Case include:
N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. Summary of the pre-project overloaded facilities can be found at Appendix D2, Table D2-1.
Two (2) bus voltage deviation violations were observed following the selected single element outages. A summary of the voltage deviation violations can be found at Appendix D2, Table D2-2.
N-2 Findings
No IID transmission facility was overloaded following selected double element (N-2) outages.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID system losses in the heavy summer pre-cluster base case were 82 MW.
D.3.1.2 Heavy Summer Post-Cluster Base Case
In the Post-cluster analysis, the Group 2014 Cluster project’s output were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the integration of the Group 2014 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2014 Cluster Projects to IID system losses during heavy summer operating condition was about
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 120
18 MW. The heavy summer post-cluster power flow map can be found at Appendix D1, Figure D1-2.
To ease the comparison between pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in Table D-3. Table D-3 highlights the magnitude (not direction) of the power flow on the selected transmission facilities.
Element (unit of measure) 2014 HS
Pre-Cluster 2014 HS
Post-Cluster
El Centro 161/230 kV Transformer (MW) 69 63
El Centro 230/92 kV Transformer (MW) 150 142
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 130 135 Niland 161/92 kV Transformer Circuit 1 (MW) 53 59 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 114 117 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 578 703
Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 295 353
Niland-Blythe 161 kV Line (MW) 72 61
Niland-Blythe 161 kV Line (MVAR) 11 6 Imperial Valley-El Centro SW #1 &2 230 kV (MW) 422 546 Imperial Valley-El Centro SW #1 &2 230 kV (MVAR) 37 11 Imperial Valley – Dixieland #1 &2 230 kV (MW) 918 1016
Imperial Valley – Dixieland #1 &2 230 kV (MVAR) 58 30 Mirage-Ramon 230 kV Line (MW) 353 449 Mirage-Ramon 230 kV Line (MVAR) 67 19 Coachella-Devers 230 kV Line (MW) 223 301 Coachella-Devers 230 kV Line (MVAR) 1 24
Path 42 (MW) 575 747
Path 42 (MVAR) 62 25
Path 46 (MW) 8586 8833
Path 49 (MW) 6854 6870
SCIT (MW) 14645 14909
Table D-3: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the heavy summer post-cluster base case are provided below. A comparison of the impact of Group 2014 Cluster projects on the IID and the interconnected transmission systems are also detailed. It must however be noted that IID, for screening purposes, typically uses identical continuous and emergency ratings for its facilities. Typically 110% of continuous rating is an acceptable emergency rating for 30 minutes.
N-0 Findings
No transmission facility overload was identified during normal operating conditions.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 121
N-1 Findings
Three (3) IID transmission facilities were found to be overloaded following selected single element (N-1) outages. Two (2) out of the 3 transmission facility overloads were existing overloads which persisted following the integration of the Group 2014 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix D2, Table D2-1. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-4.
Two (2) bus voltage deviation violations were observed following the selected single element outages. The bus voltage violations were pre-existing violations which persisted following the interconnection and subsequent dispatch of the Group 2014 cluster projects. A summary of the voltage deviation violations can be found at Appendix D2, Table D2-2.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
MIDWAY #1 230/92 KV TRANSFORMER
300 MVA MIDWAY #2 230/92 KV TRANSFORMER
149% 149%
MIDWAY #2 230/92 KV TRANSFORMER
300 MVA MIDWAY #1 230/92 KV TRANSFORMER
149% 149%
IMPERIAL VALLEY – DIXIELAND #1 230 KV LINE
786 MVA IMPERIAL VALLEY – DIXIELAND #1 230 KV LINE
100% 111%
Table D-4: Single Element Outage Transmission Facility Overloads
N-2 findings
No transmission facility overload was identified following selected double element outages.
No bus voltage deviation violation was observed following the selected double element outages.
Losses
IID transmission system losses in the heavy summer post-cluster base case were 100 MW
D.3.1.3 Light Winter Pre-Cluster Base Case
The pre-cluster base case was used as a benchmark for post-cluster performance evaluations. Key findings from the power flow analysis using the light winter pre-cluster base case are:
N-0 Findings
No transmission facility overload was identified during normal operating conditions. The pre-cluster power flow map that depicts the power flow distribution at the point of interconnections of the Group 2014 Cluster projects during the light winter operating conditions with all transmission lines in-service can be found at Appendix D1, Figure D1-4.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 122
N-1 Findings
Two (2) IID transmission facilities were overloaded following selected single element (N-1) outages. A summary of the power flow analysis results can be found at Appendix D2, Table D2-5.
No bus voltage deviation violation was observed following the selected single element outages.
N-2 Findings
No transmission facility overloads was identified following selected double element (N-2) outages.
No bus voltage deviation violation was identified following the selected double element outages.
Losses
IID system losses in the light winter pre-project case were 68 MW
D.3.1.4 Light Winter Post-Cluster Base Case In the Post-Cluster analysis, the Group 2014 Cluster projects were dispatched and delivered as prescribed in each projects interconnection application. Compared to the Pre-cluster base case, the addition of the Group 2014 Cluster projects resulted in significant changes in voltage and thermal loadings under normal operations. The impact of the Group 2014 Cluster Projects to IID system losses during light winter operating condition was about 21 MW. The light winter post-cluster power flow map can be found at Appendix D1, Figure D1-5.
To ease the comparison between light winter pre- and post-cluster base cases, power flows on critical IID transmission lines and paths under normal operating conditions are highlighted in TableD-5. Table D-5 highlights the magnitude (not direction) of flow.
Element (unit of measure) 2014LW
Pre-Cluster 2014 LW
Post-Cluster
El Centro 161/230 kV Transformer (MW) 46 39
El Centro 230/92 kV Transformer (MW) 122 113
Avenue 58 161/92 kV Transformer Circuit 1 (MW) 49 53 Niland 161/92 kV Transformer Circuit 1 (MW) 68 73 Coachella Valley 92/161 kV Transformer Circuit 1 (MW) 63 64 Imperial Valley 500/230 kV Transformer Circuit 1 (MW) 885 999 Imperial Valley 500/230 kV Transformer Circuit 2 (MW) 444 501
Niland-Blythe 161 kV Line (MW) 80 93
Niland-Blythe 161 kV Line (MVAR) 10 14 Imperial Valley-El Centro SW 230 kV (MW) 454 557 Imperial Valley-El Centro SW 230 kV (MVAR) 54 31 Imperial Valley – Dixieland 230 kV (MW) 961 1059 Imperial Valley – Dixieland 230 kV (MVAR) 69 48
Mirage-Ramon 230 kV Line (MW) 513 524 Mirage-Ramon 230 kV Line (MVAR) 29 72 Coachella-Devers 230 kV Line (MW) 314 395 Coachella-Devers 230 kV Line (MVAR) 22 36
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 123
Path 42 (MW) 824 1004 Path 42 (MVAR) 74 154
Path 46 (MW) 4488 4739
Path 49 (MW) 3401 3399
SCIT (MW) 5411 5699
Table D-5: Comparison Flows on Critical Lines/Paths Key findings from the power flow analysis using the light winter post-cluster base case are: N-0 Findings
No transmission facility overload was identified during normal operating conditions
N-1 Findings
Four (4) IID transmission facilities were overloaded following selected single element (N-1) outages. Two (2) out of the 4 transmission facility overloads were existing overloads which persisted or exacerbated following the integration of the Group 2014 cluster projects. A summary of the transmission facility overloads following single element outages is provided in Appendix D2, Table D2-5. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-6.
No bus voltage deviation violation was observed following the selected single element outages.
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
MIDWAY #1 230/92 KV TRANSFORMER
225 MVA MIDWAY #2 230/92 KV TRANSFORMER
148% 148%
MIDWAY #2 230/92 KV TRANSFORMER
225 MVA MIDWAY #1 230/92 KV TRANSFORMER
148% 148%
DIXIE230 – IMPERIAL VALLEY #2 230 KV LINE
786 MVA DIXIE230 – IMPERIAL VALLEY #1 230 KV LINE
105% 117%
RAMON – MIRAGE 230 KV LINE 779 MVA COACHELA – DEVERS 230 KV LINE 92% 114%
Table D-6: Single Element Outage Transmission Facility Overloads
N-2 Findings
Five (5) transmission facilities were overloaded following selected double element (N-2) outages. A summary of the transmission facility overloads following double element outages is provided in Appendix D2, Table D2-7. Overloads which exceeded 110% of facility’s continuous ratings and warrant mitigation are summarized in Table D-7.
No bus voltage deviation violation was observed following the selected double element outages.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 124
Overloaded Transmission Facility Applicable
Rating
Worst Outage Element(s) Loadings
Pre- Cluster
Post Cluster
RAMON 230/92 KV TRANSFORMER 225 MVA
COACHELA – DEVERS 230 KV & COACHELA – RAMON 230 KV LINES (W/RAS)
107% 132%
N. VIEW – AVE42 92 KV LINE 132 MVA 97% 121%
N. VIEW – RAMON 92 KV LINE 132 MVA 93% 116%
AVE42 – FRANWAY 92 KV LINE 132 MVA 92% 114%
FRANWAY – EDOM 92 KV LINE 132 MVA 90% 112%
Table D-7: Double Element Outages Transmission Facility Overloads
Losses
IID system losses in the light winter post-cluster base case were 89 MW
D.3.2 Transient Stability Analysis Findings
Stable and adequately damped transient stability performances were achieved following all of the critical outages simulated using both the pre- and post-cluster base cases. Key findings include:
No transient voltage dip violations were observed per WECC/NERC transient voltage dip for all the outages simulated.
No transient frequency criteria violations were observed for all the outages simulated.
Transient voltage and frequency plots at selected critical buses which provide a representative illustration of the transmission system response following each of the critical outages studied can be found in Attachment C. The critical buses monitored included: COACHELA 230 kV, RAMON 230 kV, ELCENTSW 161 kV, NILAND 161 kV, HIGHLINE 230 kV and AVE42 92 kV.
D.3.3 Post-Transient Stability Analysis Findings
Post-transient stability analysis was performed on the heavy summer pre- and post-cluster base cases. The post-transient stability analysis showed that for both cases and for all the outages simulated positive reactive margins were achieved at all the buses monitored. However, the reactive power margins at the N. LAQUIN 92 kV bus following the outage of the N. LAQUIN – AVE42 92 kV line were below IID’s acceptable minimum reactive margins. In general, the study showed that the integration of the Group 2014 Cluster Projects resulted in marginal reductions in the reactive power margins at most of the buses monitored. Detailed results of the post-transient stability analysis can be found at Appendix D3.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 125
D.3.4 Short Circuit Analysis Findings The results of the Group 2012 Cluster Short Circuit Analysis is provided in Table D-8. It was assumed in this analysis that the 40,000 A El Centro 92 kV breakers and the 22,000 A Breaker at Coachella Switching Station have been replaced with 63,000 A Breakers and 40,000 A Breaker respectively. The maximum incremental fault duty following the integration of the Group 2014 Cluster projects was 7,039 A at the Ramon 230 kV substation. The available margins at the vicinity breakers as depicted in Table D-8 indicate that the interconnection of the Group 2012 Cluster projects will not cause any IID breakers to exceed their interruption capabilities.
Table D-8: Summary of the Short Circuit Analysis Results
Bus Name IID Substation Name kV
Breaker
Rating
(A)
Pre- Cluster Max
(3LG, 1LG) Fault
Current (A)
Available
Margins
(A)
Post-Cluster
Max (3LG, 1LG)
Fault Current (A)
Project
Contribution
(A)
AVE-52 AVE. 52 92 40,000 17,293 22,707 17,857 564
AVE.42 N.BUS AVE. 42 92 40,000 15,243 24,757 17,053 1,810
AVE48 AVE. 48 92 40,000 11,871 28,129 12,648 776
AVE58-161KV AVE. 58 161 40,000 10,296 29,704 10,529 233
AVE58-92 AVE. 58 92 40,000 15,464 24,536 16,216 752
CARREON CARREON 92 40,000 11,532 28,468 12,304 772
COACHELA COACHELLA SW STA 92 40,000 22,031 17,970 22,635 605
COLMAC92 COLMAC 92 40,000 8,577 31,423 8,669 92
CV-161 COACHELLA VALLEY 161 40,000 8,044 31,956 8,244 200
CV-230 COACHELLA VALLEY 230 40,000 18,537 21,463 19,067 530
CV-92 COACHELLA VALLEY 92 40,000 29,739 10,261 30,740 1,001
EDOM EDOM 92 40,000 12,082 27,918 16,624 4,542
ELCENTSW EL CENTRO SW STA 92 63,000 40,649 22,351 40,756 108
ELCENTSW EL CENTRO SW STA 161 16,000 10,933 5,067 11,001 68
ELCENTSW EL CENTRO SW STA 230 63,000 27,928 35,073 28,470 542
FRANCES WAY- FRANCES WAY 92 40,000 10,049 29,951 11,534 1,485
HEBERSCE HGC PLANT (HEBER SCE) 92 20,000 14,077 5,923 14,097 20
HIGHLINE230 HIGHLINE 230 40,000 19,697 20,303 20,655 958
JACKSON JACKSON 92 31,500 10,757 20,743 11,289 532
JEFFERSON92 JEFFERSON 92 40,000 10,383 29,618 10,834 451
LAQUINTA92 LA QUINTA 92 40,000 10,084 29,916 10,659 575
MARSHALL MARSHALL 92 40,000 9,801 30,199 10,268 467
MIDWAY230 MIDWAY 230 40,000 17,713 22,287 21,071 3,358
MIDWAY92 MIDWAY 92 40,000 19,328 20,672 20,195 867
MONROE MONROE 92 40,000 12,664 27,336 13,725 1,061
N. LA QUINTA NORTH LA QUINTA 92 40,000 10,941 29,059 11,696 755
NILAND NILAND 92 40,000 15,489 24,511 15,641 152
NILAND NILAND 161 40,000 8,826 31,174 9,533 707
NORTHVIEW NORTH VIEW 92 40,000 11,244 28,756 13,030 1,786
RAMON RAMON 92 40,000 14,063 25,937 21,102 7,039
RAMON RAMON 230 40,000 25,710 14,290 26,335 626
SHADOW HILLS SHADOW HILLS 92 40,000 12,474 27,526 13,236 762
SHIELDS SHIELDS 92 64,000 13,619 50,381 14,925 1,306
VANBUREN VAN BUREN 92 40,000 12,808 27,192 13,451 644
Group 2014 Cluster Projects: Short Circuit Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 126
D.4 MITIGATION PLANS This section details the recommended transmission upgrade projects required to mitigate overloads created following the integration of the Group 2014 Cluster Projects. The recommended upgrades have been tested and found to mitigate all the overloads identified (See Appendix D2 for power flow results). The results of the post-transient stability analysis for the post-cluster base case with the recommended transmission plans incorporated can be found in Appendix D3. Similarly, transient stability analysis was performed on the post-cluster base case with the recommended transmission plans incorporated and the transmission system was found to be stable and adequately damped with no WECC/NERC criteria violations (See Attachment D).
D.4.1 Mitigation Plans for Overloads Caused by Group 2014 Cluster Study
The following transmission upgrade projects are recommended for mitigating the identified transmission overloads caused by the integration of the Group 2014 Cluster projects to the IID transmission system.
Construct 8-mile Dixieland – Imperial Valley 230 kV lines with a 887 MVA, 2-1033 MCM ACSS conductor
Construct 8-mile Ramon – Mirage 230 kV line with a 887 MVA, 2-1033 MCM ACSS conductor
Install a second 225 MVA 230/92 kV transformer at Ramon
Rebuild the 11.6-mile from Avenue 42 to N. view to Ramon using a 191 MVA, 900 MCM ACSS 92 kV conductor
Rebuild the 13.7-mile from Avenue 42 to Francis Way to Edom using a 191 MVA, 900 MCM ACSS 92 kV conductor
Implement Breaker-and-Half configuration at Coachella. Summary of the overloaded transmission facilities and the associated recommended transmission facilities are also provided in Tables D-9. D.5 COST AND CONSTRUCTION TIMELINES The estimated cost for the recommended network upgrades for the Group 2014 Cluster Projects is $ 37.3 Million. The detail network upgrade cost and the construction timelines for implementing the upgrades are provided in Table D-10.
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 127
Worst Outage Element (s) Overloaded Facility
Applicable
Rating
Post- Cluster
Loadings Recommended Mitigation Notes
NORMAL CONDITION (N-0)
ALL LINES IN SERVICE N/A N/A N/A Implement Breaker-and-Half Configuration at Coachella Valley
This will ensure that under double element outages of
Coachella – Devers & Coachella –Ramon 230 kV
lines, both Coachella 230/92 kV transformers will be in
service.
SINGLE ELEMENT (N-1 )
DIXIELAND – IMPERIAL VALLEY #1 230 KV LINE
DIXIELAND – IMPERIAL VALLEY #2 230 KV LINE
786 MVA 117% Construct the 8-mile Dixieland – Imperial Valley 230 kV lines using 887 MVA, 2-1033 MCM ACSS 230 kV Conductor
These lines have already been recommended for upgrades in 2010-2011. Build lines using higher ampacity conductors
DIXIELAND – IMPERIAL VALLEY #2 230 KV LINE
DIXIELAND – IMPERIAL VALLEY #1 230 KV LINE
786 MVA 117%
COACHELA – DEVERS 230 KV LINE
RAMON – MIRAGE 230 KV LINE
779 MVA 114%
Construct the 8-mile Ramon – Mirage 230 kV line using 887 MVA, 2-1033 MCM ACSS 230 kV Conductor
DOUBLE ELEMENT OUTAGE (N-2)
COACHELA – DEVERS 230 KV & COACHELA– RAMON 230 KV LINES (W/ RAS)
RAMON 230/92 KV TRANSFORMER
225 MVA 132% Install a second 225 MVA, 230/92 kV transformer at RAMON
None
N. VIEW – AVE42 92 KV LINE
132 MVA 121% Rebuild 11.6-mile line from Avenue 42- N. View - Ramon using 191 MVA, 900 ACSS 92 kV Conductor
None N. VIEW – RAMON 92 KV LINE
132 MVA 116%
AVE42 – FRANWAY 92 KV LINE
132 MVA 114% Rebuild 13.7-mile line from Avenue 42- Francis Way - Edom using 191 MVA, 900 ACSS92 kV Conductor
None FRANWAY – EDOM 92 KV LINE
132 MVA 112%
Table D-9: Summary of Transmission Facility Overloads and Associated Mitigation Plan
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 128
Table D-10: Recommended Mitigation Plan & Associated Cost for Group 2014 Cluster Projects
Overloaded Facilities Critical OutageApplicable
RatingsLoadings Recommended Mitigation
Cost Estimate
($ Million)
Construction Time
Lines (Months)Notes
Implement Breaker-and-one half
configuration at Coachella Valley
substation
13.49 18
Install 105 MVAR of reactive power
resources (Shunt capacitors)3.41 24
RAMON 230/92 KV TRANSFORMER 225 MVA 132%
Install a second 225 MVA transformer at
Ramon8.35 24
N. VIEW – AVE42 92 KV LINE 132 MVA 121%
N. VIEW – RAMON 92 KV LINE 132 MVA 116%
AVE42 – FRANWAY 92 KV LINE 132 MVA 114%
FRANWAY – EDOM 92 KV LINE 132 MVA 112%
24
None
Network Upgrades Attributable to Group 2014 Cluster Projects
COACHELA – DEVERS 230 KV &
COACHELA– RAMON KV LINES Rebuild lines using 191 MVA, 900
ACSS Conductor
5.39
6.65
NONE N/A N/A N/A
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 129
Appendix D1
Power flow Maps
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 130
Figure D1-1: Power flow Map—2014 Heavy Summer Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 131
Figure D1-2: Power flow Map—2014 Heavy Summer Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 132
Figure D1-3: Power flow Map—2014 Heavy Summer Post-Cluster w/ Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 133
Figure D1-4: Power flow Map—2014 Light Winter Pre-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 134
Figure D1 5: Power flow Map—2014 Light Winter Post-Cluster Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 135
Figure D1 6: Power flow Map—2014 Light Winter Post-Cluster w/Mitigation Base Case
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 136
Appendix D2
Summary of Power Flow Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 137
Table D2-1: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 149% 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 149% 149% 149% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L031 109% 109% 108% Line NILAND 92.0 to NEW MECCA 92.0 Circuit 1
8377 RTP3ANZA 92 8378 RTP4SLTN 92 1 Line 8 132 B230_C005 106% 108% 108% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 line_265 104% 104% 104% line BLYTHESC to BLYTHE 161 ck 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B161_C009 103% 104% 103% Line AV58TP1 161.0 to A-13-IP 161.0 Circuit 1
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 B92_L030 103% 103% 103% Line NEW MECCA to AVE 52 92.0 Circuit 1
8378 RTP4SLTN 92 8379 RTP5DSTS 92 1 Line 8 132 B230_C005 100% 102% 102% Tran DIXIE230 230.00 to DIXIELAN 92.00 Circuit 1
8074 DIXIE230 230 22356 IMPRLVLY 230 2 Line 8 786 B230_C001 100% 111% 98% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
Summary of 2014 Heavy Summer Power Flow Analysis Results-- N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 138
Table D2-2: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage Description
8286 LAQUINTA 92 8 B92_L014 5.42% 5.69% 5.71% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
8292 N.LAQUIN 92 8 B92_L014 5.63% 5.90% 5.93% Line N.LAQUIN 92.0 to AVE42 92.0 Circuit 1
Summary of 2014 Heavy Summer Power Flow Analysis--N-1 Voltage Deviation Violations
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 139
Table D2-3: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C92_L011A 102% 102% 102% Loss of Transmission from AVE58 to COACHELLA(R)92kV & from MECCA to COACHELLA(NE)
8359 NILAND 161 8808 CVSUB161 161 1 Line 8 165 C230_T001 102% 102% 99% Tran CVSUB 92.00 to COACHELA 230.00 CK1 & CK2
Summary of 2014 Heavy Summer Power Flow Analysis Results---N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 140
Table D2-4: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-2 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
Summary of 2014 Heavy Summer Power Flow Analysis Results--N-2 Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 141
Table D2-5: Summary of 2014 Light Winter Power Flow Analysis Results— N-1 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/MitigationOutage description
8699 MIDWAY 230 8700 MIDWAY 92 1 Tran 8 225 B230_T007 148% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 2
8699 MIDWAY 230 8700 MIDWAY 92 2 Tran 8 225 B230_T006 148% 148% 148% Tran MIDWAY 230.00 to MIDWAY 92.00 Circuit 1
8074 DIXIE230 230 22356 IMPRLVLY 230 2 Line 8 786 B230_C001 105% 117% 103% Line IMPRLVLY 230.0 to DIXIE230 230.0 Circuit 1
8695 RAMON 230 24806 MIRAGE 230 1 Line 8 779 B230_L001 92% 114% 72% Line COACHELA 230.0 to DEVERS 230.0 Circuit 1
Summary of 2014 Light Winter Power Flow Analysis Results--N-1 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 142
Table D2-6: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-1 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
Summary of 2014 Light Winter Power Flow Analysis Results-- N-1 Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 143
Table D2-7: Summary of 2014 Light Winter Power Flow Analysis Results— N-2 Thermal Overloads
From Name kV To Name kV ck Type Area Rated Mva Outage Pre-Cluster Post-ClusterPost-Cluster
w/ MitigationOutage Description
8640 RAMON92 92 8695 RAMON 230 1 Tran 8 225 230_L004 107% 132% 80% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8289 N.VIEW 92 8309 AVE42 92 1 Line 8 132 230_L004 97% 121% 100% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8289 N.VIEW 92 8640 RAMON92 92 1 Line 8 132 230_L004 93% 116% 97% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8309 AVE42 92 8310 FRANWAY 92 1 Line 8 132 230_L004 92% 114% 75% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
8310 FRANWAY 92 8330 EDOM 92 1 Line 8 132 230_L004 90% 112% 74% W/RAS LossofTransmission from Coachella to Devers & Coachella to Ramon (KN & KS
Summary of 2014 Light Winter Power Flow Analysis Results--N-2 Thermal Overloads
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 144
Table D2-8: Summary of 2014 Heavy Summer Power Flow Analysis Results— N-2 Voltage Deviation Violations
Bus Name kV Area Outage Pre-Cluster Post-ClusterPost-Cluster w/
MitigationOutage Description
Summary of 2014 Light Winter Power Flow Analysis Results--N-2 Voltage Deviation Violations
NONE
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 145
Appendix D3
Heavy Summer Post-Transient Stability Analysis Results
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 146
Table D3-1: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/ mitigation
N.LAQUIN-AVE42 92 kV LINE
8805 AV58 161 kV 168 175 221
8808 CVSUB161 161 kV 208 215 271
8292 N.LAQUIN 92 kV 64 67 70
8312 COACHELA 92 kV 291 216 339
8700 MIDWAY 92 kV 249 266 266
8361 NILAND 92 kV 317 309 327
8335 ELSTEAMP 92 kV 638 602 619
8397 CLX92 92 kV 305 287 288
8369 PILOTKNB 92 kV 158 172 172
8319 DIXIELAN 92 kV 366 303 304
ELSTM 2 & REPU 2 GENERATOR OUTAGE
8805 AV58 161 kV 241 244 262
8808 CVSUB161 161 kV 277 281 303
8292 N.LAQUIN 92 kV 201 207 232
8312 COACHELA 92 kV 324 330 381
8700 MIDWAY 92 kV 253 269 270
8361 NILAND 92 kV 322 313 331
8335 ELSTEAMP 92 kV 634 598 613
8397 CLX92 92 kV 296 278 279
8369 PILOTKNB 92 kV 160 155 155
8319 DIXIELAN 92 kV 367 303 305
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 147
Table D3-2: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
PALO VERDE – DEVERS 500 kV LINE
8805 AV58 161 kV 206 207 224
8808 CVSUB161 161 kV 237 239 260
8292 N.LAQUIN 92 kV 172 176 199
8312 COACHELA 92 kV 287 288 319
8700 MIDWAY 92 kV 236 253 253
8361 NILAND 92 kV 305 296 315
8335 ELSTEAMP 92 kV 610 577 596
8397 CLX92 92 kV 297 279 281
8369 PILOTKNB 92 kV 157 171 171
8319 DIXIELAN 92 kV 352 289 292
N.GILA-IMPERIAL VALLEY 500 kV LINE
8805 AV58 161 kV 252 259 276
8808 CVSUB161 161 kV 286 295 317
8292 N.LAQUIN 92 kV 207 217 241
8312 COACHELA 92 kV 333 356 392
8700 MIDWAY 92 kV 254 272 272
8361 NILAND 92 kV 321 315 335
8335 ELSTEAMP 92 kV 597 565 579
8397 CLX92 92 kV 292 275 276
8369 PILOTKNB 92 kV 184 163 181
8319 DIXIELAN 92 kV 345 283 283
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 148
Table D3-3: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
IMPERIAL VALLEY – MIGUEL 500 kV LINE
8805 AV58 161 kV 205 204 221
8808 CVSUB161 161 kV 237 236 258
8292 N.LAQUIN 92 kV 171 174 197
8312 COACHELA 92 kV 277 283 316
8700 MIDWAY 92 kV 233 249 250
8361 NILAND 92 kV 304 292 311
8335 ELSTEAMP 92 kV 585 545 568
8397 CLX92 92 kV 293 275 277
8369 PILOTKNB 92 kV 157 170 151
8319 DIXIELAN 92 kV 342 279 281
IMPERIAL VALLEY – ELCENTRO 230 kV LINE
8805 AV58 161 kV 234 236 254
8808 CVSUB161 161 kV 269 273 295
8292 N.LAQUIN 92 kV 196 201 226
8312 COACHELA 92 kV 326 322 365
8700 MIDWAY 92 kV 250 267 267
8361 NILAND 92 kV 323 316 334
8335 ELSTEAMP 92 kV 654 617 633
8397 CLX92 92 kV 308 289 291
8369 PILOTKNB 92 kV 176 172 154
8319 DIXIELAN 92 kV 371 308 309
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 149
Table D3-4: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
RAMON – MIRAGE 230 kV LINE
8805 AV58 161 kV 234 248 263
8808 CVSUB161 161 kV 267 283 300
8292 N.LAQUIN 92 kV 190 205 223
8312 COACHELA 92 kV 291 308 343
8700 MIDWAY 92 kV 254 274 275
8361 NILAND 92 kV 333 332 348
8335 ELSTEAMP 92 kV 651 621 635
8397 CLX92 92 kV 310 293 294
8369 PILOTKNB 92 kV 176 171 152
8319 DIXIELAN 92 kV 373 312 312
COACHELA – DEVERS 230 kV LINE
8805 AV58 161 kV 226 229 246
8808 CVSUB161 161 kV 260 264 285
8292 N.LAQUIN 92 kV 188 193 217
8312 COACHELA 92 kV 306 310 349
8700 MIDWAY 92 kV 245 263 263
8361 NILAND 92 kV 322 314 331
8335 ELSTEAMP 92 kV 641 603 619
8397 CLX92 92 kV 306 287 288
8369 PILOTKNB 92 kV 176 171 171
8319 DIXIELAN 92 kV 367 301 303
Imperial Irrigation District: Transitional Cluster Study Report
PDS Consulting, PLC 150
Table D3-5: Summary of 2014 Heavy Summer Post-Transient Stability Analysis Results (Continued)
Outage
Monitored Bus Reactive Power Margin (MVar)
Bus Number Bus Name Pre-Cluster Post-Cluster Post-Cluster w/mitigation
IMPERIAL VALLEY – ELCENTRO #1 &2 230 kV LINES
8805 AV58 161 kV 223 220 237
8808 CVSUB161 161 kV 258 255 276
8292 N.LAQUIN 92 kV 188 188 212
8312 COACHELA 92 kV 312 308 347
8700 MIDWAY 92 kV 242 256 256
8361 NILAND 92 kV 317 305 323
8335 ELSTEAMP 92 kV 606 566 583
8397 CLX92 92 kV 304 283 285
8369 PILOTKNB 92 kV 156 150 169
8319 DIXIELAN 92 kV 359 289 290
IMPERIAL VALLEY – DIXIELAND #1 &2 230 kV LINES
8805 AV58 161 kV 202 201 220
8808 CVSUB161 161 kV 234 232 255
8292 N.LAQUIN 92 kV 171 173 198
8312 COACHELA 92 kV 278 280 314
8700 MIDWAY 92 kV 230 247 248
8361 NILAND 92 kV 291 279 299
8335 ELSTEAMP 92 kV 432 407 429
8397 CLX92 92 kV 273 256 259
8369 PILOTKNB 92 kV 150 162 144
8319 DIXIELAN 92 kV 254 221 224