Path Operator Task Force Recommendation

WECC Standing Committee Meetings October, 2014

Objective of the Presentation

• Discuss common misconceptions with the whitepaper

• Describe what the POTF recommendation is really about

• Lay out the POTF roadmap • Frequently Asked Questions • Discuss the vote • Question & Answer

Common Misconceptions With the POTF Recommendation

The POTF recommendation is: • Not eliminating Paths • Not eliminating nomograms • Not ignoring stability limitations • Not eliminating Path Transfer Capability for the planning

horizon or the operations horizon • Not mandating the use of RTCA or any other real-time

tool • Not requiring changes to current contracts • Not an overnight change

What the POTF Recommendation Really Is About

• Allows flexibility to create Operating Plans to address reliability concerns without being boxed in by the “Path SOL” and the associated 30 minute mitigation requirement. – The West is bound by TOP-007-WECC-1. Paths on the list

must have “Path SOLs” – “Path SOLs” on the list must be mitigated within 30 min

(forces drastic action even when drastic action is unwarranted)

– TOPs are required to manage reliability by the Path definition in TOP-007-WECC-1 regardless of availability of better alternatives

What the POTF Recommendation Really Is About

TOPs are expected to meet pre- and post- contingency system performance as defined by applicable Reliability Criteria (NERC, WECC, Peak SOL Methodology). This means: • Operating within all stability limits • Operating within applicable Facility Ratings pre- and post-

Contingency • Operating within applicable bus voltage limits pre- and post-

Contingency In the POTF world, this is accomplished by operating to prior studied conditions or by continuously studying/assessing the system based on the most up-to-date information.

What the POTF Recommendation Really Is About

• Delineates the “commercial” from the “reliability”

• Aligns with NERC/FERC expectations – Aligns with 9/13/12 Gerry Cauley (NERC CEO)

letter to WECC – Aligns with NERC approved MOD-001-2 R1 – Aligns with FERC NOPR for TOP/IRO standards – Aligns with NERC SOL Whitepaper

Core Concept – Distinguishing “SOL” from “TTC”

Path TTC: • Not an SOL • Respects SOLs • Respects 3-phase Rating

process, commercial issues, contracts, and allocations

SOLs: • Facility Ratings • Voltage limits • Stability limits These are observed pre- and post-Contingency

“Path SOL”

Example – Current Paradigm • Path “X” comprised of 4 lines

between two TOP Areas • Prior transfer simulations show

that at 1000 MW of N>S transfer on Path X, the loss green line causes blue line to reach its emergency Facility Rating. (Contingent and monitored elements not confined to Path Facilities)

• 1000 MW is the “thermally limited Path SOL”.

• TTC & SOL are the same • Path X SOL of 1000 MW is a real-

time operating limit.

TOP Area “A”

TOP Area “B”

1000 MW N>S is the “thermally limited Path SOL”

Example – POTF Paradigm (TTC) TTC Determination • Prior transfer simulations show that

at 1000 MW of N>S transfer on Path X, the loss green line causes blue line to reach its emergency Facility Rating.

• 1000 MW is the amount of power that can be reliably transferred from TOP Area “A” to TOP Area “B”. By NERC definition, this is Total Transfer Capability.

• TOP sets TTC=1000 MW. • TTC respects the Facility Ratings and

voltage limits in the pre- and post-Contingency states.

TOP Area “A”

TOP Area “B”

1000 MW N>S is the Path TTC

Example – POTF Paradigm (SOL) • All BES Facilities have a family of

Facility Ratings (normal and emergency). These are SOLs.

• Each BES bus has pre- and post-Contingency voltage limits. These are also SOLs.

• Studies have shown there are no stability issues for this interface.

• The expectation is to operate within Facility Ratings and voltage limits (SOLs) pre- and post-Contingency.

• How a TOP accomplishes that is up to them.

• There is no need to establish a unique Path SOL.

TOP Area “A”

TOP Area “B”

POTF Roadmap

• SDT to initiate the SAR for retiring TOP-007-WECC-1 (up to 18 month process) – Options under consideration for R2

• Peak to revise the RC’s SOL Methodology to better align with the POTF concept

• Path participants (TO/TOP/TSP/RC) develop implementation plans as necessary on a path-by-path basis

What About the Path Operator?

Role looks different for each Path Operator, but generally includes today: • Performing studies to establish Path SOL • Developing Path Operating Procedures • Handling allocations • Mitigating Path SOL exceedances in real-time

operations

Implementation Plans

• In response to the SAR and the RC SOL Methodology changes, entities may need to develop an implementation plan

• Entities may need to revisit: – Who will calculate TTC? – Who will determine and distribute allocations? – Contracts and agreements – existing ones OK? Is there a

need for new ones? • Much of this may already be covered in existing agreements All of this may be needed anyway to ensure coordination in preparation for MOD-001-2.

FAQ

Lots of people are not clear how to implement this – what group ensures that the transition to the new paradigm is well planned and well executed? • The SDT will implement the SAR process • Peak will ensure changes to the SOL Methodology are

socialized – training, rollout, etc. • Path participants need to address the changes on a path-

by-path basis • Is there value in having a core team to shepherd the

industry through this multi-year transition?

FAQ

What are the legacy processes and/or documents that refer to Path Operators that will need to be reviewed and updated? What is the process to uncover those documents and/or processes? • One is the UFMP – are there others? • WECC RE will need to review WECC documents • Path participants, and the industry at large (including the RC),

may need to review their own documents and processes in response to standards and SOL Methodology changes

• There is no prescriptive formula, rather this review will happen on a Path-by-Path basis

FAQ

Under the new paradigm, can I still operate to “Path SOLs”? • Yes, you can operate the system the same way

you do today. • But, you can’t call Path TTC an SOL. Paths do

not have uniquely monitored SOLs unless they have a stability limit.

Why a Vote?

A few realities: 1. Anyone can initiate a SAR for anything at any

time 2. Peak Reliability will need to align its SOL

Methodology to the NERC SOL Whitepaper Why do we need to “vote”? What are we actually voting on?

Why do we need a Vote?

• WECC Regional Entity wants to gauge the breadth of support for retiring TOP-007-WECC-1 before moving forward with the SAR

What is the Vote?

Motion: • Resolved, that the WECC PCC Endorse the Path

Operator Task Force Whitepaper “A New Paradigm for Path Operations”

What does Endorsement mean? • POTF is seeking general concurrence with the direction of the “new

paradigm” • Support for moving forward with the POTF Roadmap • We are at the beginning of a multi-year industry transition, no over-

night changes

Questions?

Path Operator Task Force Recommendation Background

WECC Standing Committee Meetings October, 2014

Issues Covered

• TTC vs. SOL • Review NERC SOL Whitepaper concepts • NERC Approved MOD-001-2 R1 • Review RC SOL Methodology concepts • FERC NOPR Items • Gerry Cauley 9/13/12 letter to WECC

TTC vs. SOL

“What is an SOL?” “What is not an SOL, but is rather a TTC?”

• These two questions underpin the POTF

recommendation. • This is a common area of misunderstanding in the

POTF whitepaper. • Why? Because it’s different from what we’ve

always known.

TTC vs. SOL

• Operational Transfer Capability (OTC) – Thermally limited OTC – Voltage limited OTC – Voltage or Transient Stability limited OTC

• OTC is a marriage of what we know today as “TTC” and “SOL” – It’s what we have always known – In its day, it was good for reliability

TTC vs. SOL • Pivotal decision: replace “OTC” with “SOL” • Terms changed, but function didn’t…the “Path SOL” is still a

marriage of TTC and SOL. • Regarding the OTC concept, NERC distinguished the “O –

operational” from the “TC – transfer capability”, but the we didn’t.

• Why a pivotal decision? What an entity regards as “an SOL” has significant reliability and compliance implications

• Except for “stability limited Paths”, POTF believes we have been calculating a TTC and calling it an SOL.

• We have been calling things “an SOL” that shouldn’t be called SOLs.

TTC vs. SOL

• NERC definition of Total Transfer Capability – The amount of electric power that can be moved

or transferred reliably from one area to another area of the interconnected transmission systems by way of all transmission lines (or paths) between those areas under specified system conditions.

• TTC is a better fit for WECC Paths • Reliability Standards require operation within

SOLs…not within TTCs.

TTC vs. SOL • New paradigm => “Path SOL” re-categorized as “Path TTC”,

with stability caveat – Stability limits must be identified and operated within. Stability limits

may or may not line up with WECC Paths. • Path TTC is calculated the same Path SOLs are today, but this

will ultimately depend on the TOP’s TTC methodology under the new MOD-001-2

• Path TTCs can be thermally limited, voltage limited, or stability limited…just as Path SOLs are today

• SOLs are the Facility Ratings, voltage limits, and stability limits that the TTCs must respect for both the pre- and post-Contingency states

TTC vs. SOL

Path TTC: • Not an SOL • Respects SOLs • Respects 3-phase Rating

process, commercial issues, contracts, and allocations

SOLs: • Facility Ratings • Voltage limits • Stability limits These are observed pre- and post-Contingency

“Path SOL”

NERC SOL Whitepaper

• Critical that we understand this • Part of TOP/IRO SDT effort • “The NERC-defined term System Operating Limit (SOL) is used

extensively in the NERC Reliability Standards; however, there is much confusion with – and many widely varied interpretations and applications of – the SOL term. This whitepaper describes the Standard Drafting Team’s (SDT) intent with regard to the SOL concept and brings clarity and consistency to the notion of establishing SOLs, exceeding SOLs, and implementing Operating Plans to mitigate SOL exceedances.”

“Some have interpreted the language in approved FAC-011-2, Requirement R2 to imply that the objective is to perform prior studies to determine a specific MW flow value (SOL) that ensures operation within the criteria

specified in approved FAC-011-2, Requirement R2 sub-requirements, the assumption being that if the system is operated within this pre-determined

SOL value, then all of the pre- and post-Contingency requirements described in approved FAC-011-2, Requirement R2 will be met. The SDT believes this approach may not capture the complete intent of the SOL concept within

approved FAC-011-2, which is both: 1. Know the Facility Ratings, voltage limits, transient Stability limits, and

voltage Stability limits, and 2. Ensure that they are all observed in both the pre- and post-Contingency

state by performing a Real-time Assessment.”

NERC SOL Whitepaper

NERC SOL Whitepaper • “SOLs are based on Normal and Emergency (short-term) Facility

Ratings, voltage limits, transient Stability limits, and voltage Stability limits – any of which can be the most restrictive limit at any point in time pre- or post-Contingency.”

• “For example, if an area of the BES is at no risk of encroaching upon Stability or voltage limitations in the pre- or post-Contingency state, and the most restrictive limitations in that area are pre- or post-Contingency exceedance of Facility Ratings, then the thermal Facility Ratings in that area are the most limiting SOLs. Conversely, if an area is not at risk of instability and no Facilities are approaching their thermal Facility Ratings, but the area is prone to pre- or post-Contingency low voltage conditions, then the voltage limits in that area are the most limiting SOLs.

NERC SOL Whitepaper (key point) • “It is important to distinguish operating practices and

strategies from the SOL itself. As stated earlier, the SOL is based on the actual set of Facility Ratings, voltage limits, or Stability limits that are to be monitored for the pre- and post-Contingency state.”

• “How an entity remains within these SOLs can vary depending on the planning strategies, operating practices, and mechanisms employed by that entity. For example, one Transmission Operator may utilize line outage distribution factors or other similar calculations as a mechanism to ensure SOLs are not exceeded, while another may utilize advanced network applications to achieve the same reliability objective.”

NERC Approved MOD-001-2 R1

• New MOD-001-2 replaces: – MOD-028-2 – MOD-029-1a – MOD-030-2

R1. Each Transmission Operator that determines Total Flowgate Capability (TFC) or Total Transfer Capability (TTC) shall develop a

written methodology (or methodologies) for determining TFC or TTC values. The methodology (or methodologies) shall reflect the

Transmission Operator’s current practices for determining TFC or TTC values.

1.1 Each methodology shall describe the method used to account for the following limitations in both the pre- and

post-contingency state: 1.1.1 Facility ratings;

1.1.2 System voltage limits; 1.1.3 Transient stability limits;

1.1.4 Voltage stability limits; and 1.1.5 Other System Operating Limits.

NERC Approved MOD-001-2 R1

NERC Approved MOD-001-2 R1 1.2 Each methodology shall describe the method used to account for

each of the following elements, provided such elements impact the determination of TFC or TTC: 1.2.1 The simulation of transfers performed through the

adjustment of generation, Load, or both; 1.2.2 Transmission topology, including, but not limited to,

additions and retirements; 1.2.3 Expected transmission uses; 1.2.4 Planned outages; 1.2.5 Parallel path (loop flow) adjustments; 1.2.6 Load forecast; and 1.2.7 Generator dispatch, including, but not limited to,

additions and retirements.

NERC Approved MOD-001-2 R1

1.3 Each methodology shall describe the process for including any reliability-related constraints that are requested to be included by another Transmission Operator, provided that (1) the request references this specific requirement, and (2) the requesting Transmission Operator includes those constraints in its TFC or TTC determination. 1.3.1 Each Transmission Operator that uses the

Flowgate Methodology shall include…

NERC Approved MOD-001-2 R1 1.3.2 Each Transmission Operator that uses the Area Interchange or

Rated System Path Methodology shall describe in its methodology the process it uses to account for requested constraints that have a five percent or greater distribution factor for a transfer between areas in the TTC determination; otherwise the requested constraint is not required to be included. When testing transfers involving the requesting Transmission Operator’s area, the requested constraint may be excluded.

1.3.3 A different method for determining whether requested constraints need to be included in the TFC or TTC determination may be used if agreed to by the Transmission Operators.

RC’s SOL Methodology

Why does the RC have one? • FAC-011 requirement for RCs What is it? • It is not a procedure. • It is a “rulebook” for the RC and for all TOPs

within the RC Area for establishing SOLs and IROLs.

RC’s SOL Methodology

It is a “rulebook” because of FAC-014… R1. The RC shall ensure that SOLs, including IROLs, for

its RC Area are established and that the SOLs (including IROLs) are consistent with its SOL Methodology.

R2. The TOPs shall establish SOLs (as directed by its RC)

for its portion of the RC Area that are consistent with its RC’s SOL Methodology.

RC’s SOL Methodology • “The ultimate task of TOPs and the RC is to continually assess and

evaluate projected system conditions as Real-time approaches with the objective of ensuring acceptable system performance in Real-time.”

• “In the Peak RC Area, the BES is expected to be operated such that acceptable system performance is being achieved in both the pre- and post-Contingency state, regardless of the tools TOPs have available.”

• “If any of the acceptable pre- or post-Contingency system performance criteria stipulated in this Methodology are not being met, an SOL is being exceeded.”

• “TOPs may use Real-time tools or rely on prior studies, provided that those studies demonstrate acceptable BES performance for the current or expected system conditions.”

RC’s SOL Methodology

SOL Methodology Item #3 p.6: 3. Pre-Contingency: Acceptable system performance for the

pre-Contingency state in the Operations Horizon is characterized by the following [NERC Standard FAC-011-2 R2.1]:

a. The BES shall demonstrate transient, dynamic and voltage stability. b. All Facilities shall be within their continuous Facility Ratings and

thermal limits (Refer to illustration in Appendix II). c. All Facilities shall be within their pre-contingency voltage limits. d. All Facilities shall be within their stability limits.

RC’s SOL Methodology SOL Methodology Item #4 p.6: 4. Post-Contingency [SCs]: Acceptable system performance for the post-

contingency state for Single Contingencies (SC) in the Operations Horizon is characterized by the following (NERC Standard FAC-011-2 R2.2):

a. The BES shall demonstrate transient, dynamic and voltage stability. b. All Facilities shall be within their applicable short-term Facility

Ratings and thermal limits. (Refer to illustration in Appendix II). c. All Facilities shall be within their post-contingency voltage limits. d. All Facilities shall be within their stability limits. e. Cascading or uncontrolled separation shall not occur.

RC’s SOL Methodology (stability)

• Item #35 – “TOPs shall establish SOLs to prevent unit/intra-area instability, inter-area instability, or tripping of critical BES Facilities due to out-of-step conditions.”

• Item #37 – “TOPs shall establish SOLs to prevent insufficiently damped system response as determined by the impacted TOP…”

• Item #38 – “To facilitate monitoring, TOPs shall communicate established transient stability limited SOLs as pre-Contingent MW flow limits on Transmission Paths/Interfaces…”

• Item #41 – “TOPs shall stress Transmission Paths/Interfaces or load areas to the reasonably expected maximum transfer conditions or area load levels to determine whether steady state voltage stability limits exist.”

FERC NOPR TOP/IRO • Para 59: In Order No. 693, the Commission directed NERC to develop requirements

for a minimum set of analytical tools (analysis and monitoring capabilities) to ensure that a reliability coordinator has the tools it needs to perform its functions. In its TOP Petition, NERC discusses the importance of analytical tools and real-time monitoring noting that, “[a]ccording to the August 2003 Blackout Report, a principal cause of the August 14, 2003 blackout was a lack of situational awareness, which was in turn the result of inadequate reliability tools.” We agree with NERC’s statement and believe this is an area of reliability that requires vigilance. Moreover, our view is reinforced by the 2011 Southwest Outage Blackout Report, which found that “[a]ffected TOP’s real-time tools are not adequate or, in one case, operational to provide the situational awareness necessary to identify contingencies and reliably operate their systems” and consequently recommended that “TOPs should take measures to ensure that their real-time tools are adequate, operational, and run frequently enough to provide their operators the situational awareness necessary to identify and plan for contingencies and reliably operate their systems.”

FERC NOPR TOP/IRO • Para 59: In Order No. 693, the Commission directed NERC to develop requirements

for a minimum set of analytical tools (analysis and monitoring capabilities) to ensure that a reliability coordinator has the tools it needs to perform its functions. In its TOP Petition, NERC discusses the importance of analytical tools and real-time monitoring noting that, “[a]ccording to the August 2003 Blackout Report, a principal cause of the August 14, 2003 blackout was a lack of situational awareness, which was in turn the result of inadequate reliability tools.” We agree with NERC’s statement and believe this is an area of reliability that requires vigilance. Moreover, our view is reinforced by the 2011 Southwest Outage Blackout Report, which found that “[a]ffected TOP’s real-time tools are not adequate or, in one case, operational to provide the situational awareness necessary to identify contingencies and reliably operate their systems” and consequently recommended that “TOPs should take measures to ensure that their real-time tools are adequate, operational, and run frequently enough to provide their operators the situational awareness necessary to identify and plan for contingencies and reliably operate their systems.”

FERC NOPR TOP/IRO • Para 42: Without a requirement to analyze and operate within all SOLs in

the proposed standards and by limiting non-IROL SOLs to only those identified by the transmission operator internal to its area, system reliability is reduced and negative consequences can occur outside of the transmission operator’s internal area.

• Para 74: …Should all transmission operators be required to run a real-time contingency analysis (RTCA) frequently, since the lack of such analysis can impair situational awareness substantially? Or is the value of such information outweighed for smaller entities with such limited facilities and operations that they generally can maintain similar reliability based on operator experience and judgment without any extra staffing and procedures needed to ensure that the RTCA’s informational inputs and modeling are valid and useful?

NERC Recommendation

From the 9/13/12 Letter From Gerry Cauley (NERC CEO) to Mark Maher (WECC CEO at the time):

Role of Path Operators (ORG3) “NERC is pleased to see that WECC is holding additional discussions to clarify the role of Path Operators, including the potential to implement contractual relationships and make use of RTCA and other tools to improve the accuracy of system operating limits. As these discussions continue NERC suggests that you also review the concept of Path Ratings and whether, as the Western Interconnection has become more highly interconnected, the Path Rating and Path Operator concept, along with the use of nomograms, still has merit for real-time operations. Other Interconnections do determine Flowgate limits for purposes of interchange scheduling, but rely more fully on RTCA for real-time operating reliability.”

Questions?