Module 4: Operating Period - Electric Reliability Council ... Period Emergency Operation Conditions...

Module 4: Operating PeriodModule 4: Operating Period

Module 4: The Operating Period

Course Modules:

Nodal Market Overview

Day-Ahead Operations

Module 1

Module 2 Day Ahead Operations

Adjustment Period

Module 2

Module 3

Operating Period

Emergency Operation Conditions

Module 4

Module 5

Performance MonitoringModule 6

Slide 2

Module Objectives

Upon completion of this module, you will be able to:

• Identify timeline & processes of Real-Time Operations

Explain Real Time Network Security Analysis &• Explain Real-Time Network Security Analysis &Security Constrained Economic Dispatch

Describe Load Frequency Control functions• Describe Load Frequency Control functions

• Explain Generation Ancillary Services deployments

• Explain Controllable Load & associated QSE responses

D ib b i R l Ti i i f ti

Slide 3

• Describe basic Real-Time pricing functions

Timeline

When does the Operating Period occur?

Slide 4

The Operating Period

1 Preparing for Real-Time Operations

2 SCED Energy Dispatch

p g p

3 Ancillary Service Deployment

4 Forced Outage Detection

5 ERCOT / Resource Communications

Slide 5

Generation Resource Settlement6

Real-Time Data Exchange



p g p




Slide 6


ERCOT’s Role

ERCOT Real-Time Operations:

Matches Generation to Load• Resource OutagesResource Outages• Tracking Load• Energy Offer Curves &

Output SchedulesManages reliability of transmission system

• Transmission Outages• Weather Dynamic Ratings• Flow Constraints

Slide 7

• Flow Constraints• Voltage Control

Hourly Postings

At the beginning of each hour, ERCOT posts:posts:

• Changes in ERCOT system conditions• Updated system-wide Load Forecasts• Updated system-wide Load Forecasts• Updated Distribution factors• RMR deployments from the last hourp y• System demand, by Settlement Interval

Information is posted to the Market

Slide 8

Information System.

Impacts to QSEs

Information posted hourly to the MIS may impact QSEs in determining:determining:

• Resource offers and commitments• Capacity needs• Capacity needs• Obligation to provide MWs in Real-Time

Slide 9

Real-Time Data Exchange

Real-time data exchange between ERCOT and QSEs is required to maintain Real Time Operationsrequired to maintain Real-Time Operations.

Telemetry transmitted every 2 or 4 seconds via ICCP.

ICCPICCP

Slide 10

ATTACHMENT – ICCP Quality Codes

ICCP Quality Codes identify the source and quality of telemetry to QSEstelemetry to QSEs.

Normal SourceNormal SourceNormal SourceNormal Source

Current SourceCurrent Source

QualityQuality

N l V lN l V l

Slide 11

Normal ValueNormal Value

The AS Capacity Monitor

Inputs:AS Schedules & Responsibilities,

AS Capacity Monitor

Responsibilities, and Resource Net Power Limits

AS Capacity Monitor

Outputs:Regulation, RRS, & NSRS C it I f

Slide 12

NSRS Capacity Info

AS Capacity Output

Posted to the Market Information System:R i R C it• Responsive Reserve Capacity

• Non-Spinning Reserve Capacity • Amount of un-deployed Regulation Capacity• Amount of un-deployed Regulation Capacity

Slide 13

RT Energy Availability

Posted to the Market Information System:SCED U R• SCED Up Reserve• With Energy Offer Curves• Without Energy Offer Curves• Without Energy Offer Curves

• SCED Down Reserve• With Energy Offer Curvesgy• Without Energy Offer Curves

ERCOT uses Real-Time Energy Availability data for planning

Slide 14

Availability data for planning

Insufficient AS Capacity Scenario

Q: What happens if a Forced Outage impacts a QSE’s Ancillary Serviceimpacts a QSE’s Ancillary Service Obligations?

A:A:

AncillaryService

Slide 15

Obligation

Insufficient AS Capacity Scenario, cont’d

QSE Actions to Resolve a Reg-Up DeficitQSE Actions to Resolve a Reg-Up Deficit

Obtain from existing Resource

1

Impact

• Able to switch toanother of QSE’sanother of QSE s existing resources

• Cost change may be minimal

Slide 16


QSE Actions to Resolve a Reg-Up DeficitQSE Actions to Resolve a Reg-Up Deficit

Obtain from other QSEs


2ERCOT must approve theapprove the substitution

Impact

• Affects AS trade with QSE

• Able to switch toanother of QSE’s with QSE

• Private arrangement with another QSE determines cost

another of QSE s existing resources


Slide 17


QSE Actions to Resolve a Reg-Up Deficit

Notify ERCOT of inabilityto meet obligation

Obtain from other QSEs


3

Impact

• Affects AS trade with QSE

• Able to switch toanother of QSE’s

• ERCOT chooses replacement optionwith QSE

• Private arrangement with another QSE determines cost

another of QSE s existing resources


replacement option• Cost depends on

SASM

Slide 18

SCED Energy Dispatch



p g p




Slide 19


Overview

OffersOffers Real-Time OperationsContingenciesContingencies

PricingPricing

ContingenciesContingencies

Real-TimeNetworkSecurityAnalysis

Topology &EquipmentTopology &Equipment

PricingPricingSecurity-

ConstrainedEconomicDispatchAnalysisEquipmentEquipment

DispatchInstructions


Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 20

LimitCalculator

LimitCalculator

Forced Outage Detection


Real-Time Network Security Analysis


PricingPricing








Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 21

LimitCalculator

LimitCalculator



Telemetry Accuracy

OffersOffersContingenciesContingencies ?

PricingPricing


=?Real-TimeNetworkSecurityAnalysis



ConstrainedEconomicDispatch

=AnalysisEquipmentEquipment



Dispatch

ResourceLimit

ResourceLimit

Telemetry

Slide 22



LimitCalculator

LimitCalculator

Telemetry Data

ContingenciesContingenciesOffersOffersR l Ti D tContingenciesContingencies

PricingPricing

Real-Time Data:

• Resource StatusReal-TimeNetworkSecurityAnalysis




• Resource Limits• Ancillary Service data• Ramp rate dataAnalysisEquipmentEquipment



DispatchRamp rate data

Sent every 2-4 seconds in Real-Time

ResourceLimit

ResourceLimit

Telemetry

Slide 23

LimitCalculator

LimitCalculator



Constraints

OffersOffersContingenciesContingencies

PricingPricingReal-TimeNetworkSecurityAnalysis






Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 24

LimitCalculator

LimitCalculator



State Estimator

OffersOffers State EstimatorContingenciesContingencies

PricingPricing





Real-TimeNetworkSecurityAnalysisEquipmentEquipment



DispatchAnalysis

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 25



LimitCalculator

LimitCalculator

Topology Consistency Analyzer

OffersOffersTopology Consistency AnalyzerContingenciesContingencies

PricingPricing





Topology &EquipmentTopology &Equipment Analysis



DispatchEquipmentEquipment

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 26

LimitCalculator

LimitCalculator



Security Constrained Economic Dispatch

Real-Time OperationsOffersOffersContingenciesContingencies

PricingPricing








Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 27

LimitCalculator

LimitCalculator



Resource Limit Calculator


PricingPricing








Dispatch

ResourceLimit

TelemetryTelemetry

Slide 28

LimitCalculator



Current Telemetry

HSL

Telemetered by the QSE every

CurrentTelemetryy

few secondsTelemetry

Slide 29

LSL

The Ancillary Service Schedule

Telemetered to ERCOT in Real-Time.• Identifies current Ancillary Service commitments• Identifies current Ancillary Service commitments

• By AS Type• By Resourcey esou ce

AncillaryServiceSchedule

AncillaryServiceSchedule

AncillaryServiceAncillary

ServiceAncillaryScheduleScheduleServiceScheduleService

Schedule

Slide 30

Generation Resource Limits

HSLReg-Up,

RRS & Non-SpinHASL

RRS & Non-Spin

Derived from the Resource’s Ancillary

CurrentTelemetryResource s Ancillary

Service ScheduleTelemetry

LASLReg-Down

Slide 31

LSL

HASL

HASL = Current HSL – AS Schedule (Telemetered by

Reg-Up,RRS & Non-Spin

HSL

Schedule (Telemetered by QSE)

HASLRRS & Non-Spin

Resource Limits Calculator calculates Current

TelemetryHASL from QSE’s telemetered values

Telemetry

LASLReg-Down

Slide 32

LSL

LASL

LASL = Current LSL + AS Schedule (Telemetered by


HSL

Schedule (Telemetered by QSE)

HASLRRS & Non-Spin

CurrentTelemetryTelemetry

LASLReg-Down

Slide 33

LSL

Ramp Rates

SCED-Up Ramp Rate = ERCOT Registered Up Ramp


HSL

ERCOT-Registered Up Ramp Rate – AS Reg-Up Commitments

HASL

HDL

RRS & Non-Spin

Commitments

SCED-Down Ramp Rate =

HDL

CurrentTelemetrySCED-Down Ramp Rate =

ERCOT-Registered Down Ramp Rate – AS Reg-Down

LDL

Telemetry

p gCommitments LASL

Reg-Down

Slide 34

LSL

HDL & LDL

HDL = Current Telemetry + (Ramp Rate * 5 min )


HSL

(Ramp Rate * 5 min.)

HDL ≤ HASL

HASL

HDL

RRS & Non-Spin

HDL ≤ HASL

CBase Point

Region

HDL

CurrentTelemetryLDL = Current Telemetry -

(Ramp Rate * 5 min.)

g

LDL

Telemetry

LDL ≥ LASLLASL

Reg-Down

Slide 35

LSL

Impacts of Regulation

HDL

3 MW/ i 5 i 15 MW

+15 MW

3 MW/min * 5 min = 15 MW

Current

5 minutes

Current Operating

Point

Slide 36

Impacts of Regulation, cont’d

Reserved for(3 MW/ i 5 i ) 10 MW for

10 MWReg-Up

(3 MW/min * 5 min) – 10 MW = 5 MW

+5 MW

HDL

Current

5 minutes

Current Operating

Point

Slide 37


Reg–Up RequirementReg Up Requirementincreased to 15 Mw

What is the HDL?

Current Operating

Point5 minutes

Slide 38


Reserved for 15 MW

Reg Up?

Reg-Up

Current Operating

Point5 minutes

Slide 39

Load Resource Limits

HSL = MPCReg Down

LoadLoad Resources

HASLg

mpt

ion

Current Load

NormalLoadFluctuationDerived from the

Resource’s Ancillary ng C

onsu

mLASL

TelemetryResource s Ancillary

Service ScheduleIn

crea

sin

LASLReg Up

ResponsiveNon-Spin

Slide 40

LSL = LPCp

0

LASL

HSL = MPCReg DownLoad Resources

HASLg

LASL = Current LSL + AS Schedule (Telemetered by

Current Load

( yQSE)

LASL

Telemetry

LASLReg Up

ResponsiveNon-Spin

Slide 41

LSL = LPCp

HASL


HASLg

HASL = Current HSL – AS Schedule (Telemetered by

Current Load

( yQSE)

LASL

Telemetry

LASLReg Up

ResponsiveNon-Spin

Slide 42

LSL = LPCp

Load Fluctuation


HASLg

Normal Load fluctuation occurs between HASL &

Current Load

LASL

LASL

Telemetry

LASLReg Up

ResponsiveNon-Spin

Slide 43

LSL = LPCp

Generation Resource Example

HSL (100 MW)

G ti R

50 MW

Generation Resource

LSL (15 MW)5 minutes

Slide 44

5 minutes

Generation Resource Example, cont’d

HASL = HSL (100 MW)

HASL/LASL

50 MW

HASL/LASL = HSL/LSL ± AS Schedule

HASL = 100 MW – 0 MW = 100 MW = HSL

LASL 15 MW + 0 MW

5 minutesLASL = LSL (15 MW)

LASL = 15 MW + 0 MW = 15 MW = LSL

Slide 45

5 minutes (15 MW)


HASL = HSL (100 MW)

HDL (75 MW)HDL/LDL

50 MW

HDL/LDL = (Unit Ramp Rate x Interval Duration)+ Current Operating Point

LDL (25 MW)

+ Current Operating Point

HDL = (+5 MW/min x 5 min) + 50 MW = 75 MW

5 minutes

LDL (25 MW)

LASL = LSL (15 MW)

LDL = (-5 MW/min x 5 min) + 50 MW = 25 MW

Slide 46

5 minutes (15 MW)


HSL (100 MW)Reg-Up10 MW

50 MW

LSL (15 MW)5 minutes

Slide 47

5 minutes



HASL (90 MW)( )

HASL = 100 MW 10 MW

50 MW

HASL = 100 MW – 10 MW = 90 MW


Slide 48

5 minutes (15 MW)



HASL (90 MW)( )

SCED Ramp Rate

50 MW

HDL (65 MW)SCED Ramp Rate = Unit Ramp Rate± (Regulation Up/Down÷ SCED interval)

LDL (25 MW)

SCED interval)

SCED Up Ramp Rate= 5 MW / min

(10 MW ÷ 5 i t )

5 minutes

LDL (25 MW)

LASL = LSL (15 MW)

- (10 MW ÷ 5 minutes)= 3 MW / min

HDL = (+3 MW/min x 5 min) +

Slide 49

5 minutes (15 MW)50 MW = 65 MW



RRS15 MW

50 MW

5 minutes

LSL (15 MW)

Slide 50

5 minutes



RRS15 MWHASL (75 MW)

HASL = 100 MW 25 MW

50 MW

HASL = 100 MW – 25 MW = 75 MW


Slide 51

5 minutes (15 MW)



SCED Ramp-Up Rate


SCED Ramp-Up Rate= 5 MW / min- (10 MW÷ 5 minutes)

HDL (65 MW)

50 MW5 minutes)= 3 MW / min

HDL = (+3 MW/min x 5 min) LDL (25 MW)+ 50 MW = 65 MW

5 minutes

LDL (25 MW)

LASL = LSL (15 MW)

Slide 52

5 minutes (15 MW)




65 MW


Slide 53

5 minutes (15 MW)



SCED Ramp-Up Rate

RRS15 MWHASL (75 MW)HDL (80 MW?)

SCED Ramp-Up Rate= 5 MW / min- (10 MW÷ 5 minutes)

65 MW

5 minutes)= 3 MW / min

HDL = (+3 MW/min x 5 min) + 65 MW = 80 MW?


Slide 54

5 minutes (15 MW)



Which one’s correct?

RRS15 MWHDL = HASL (75 MW)Which one’s correct?

HDL = (+3 MW/min x 5 min) + 65 MW = 80 MW?

65 MW

OR

= HASL, whichever is less.

So HDL = HASL = 75MW?


Slide 55

5 minutes (15 MW)

Scenarios

Resource Load Calculator

Slide 56

Scenario


RRS20 MW

Generation Resource

Current OperatingP i t

Reg up Req 5 MWReg Down Req 0 MWRes Rsv Req 20 MW Point

(Varies)Res Rsv Req 20 MWHSL 100 MWLSL 15 MWR R

5 minutes

LSL (15 MW)

Ramp Rates:Up 2 MW/MinDown 4 MW/Min

Slide 57

5 minutesCurrent OperatingPoint A variable

Scenario


What are the HDL


What are the HDLand LDL if the Operating Point is: Current

Operating1. 70 MW?

2. 60 MW?

p gPoint

3. 30 MW?

5 minutes

LSL (15 MW)

Slide 58

5 minutes

Scenario

HSL (100 MW)5 MW Reg-Up

What are the HDL

HASL (75 Mw)20 MW

70 MW

80 MwRRS

HASL (75 MW)

What are the HDLand LDL if the Operating Point is:

70 MW

1. 70 MW?

2. 60 MW?

50 Mw

3. 30 MW?

5 minutes

LSL (15 MW)

Slide 59

5 minutes

Scenario


What are the HDL

20 MW RRS

70 MwHASL (75 MW)


60 MW

1. 70 MW?

2. 60 MW?40 Mw

3. 30 MW?

5 minutes

LSL (15 MW)

Slide 60

5 minutes

Scenario


What are the HDL

20 MW RRSHASL (75 MW)


40 Mw1. 70 MW?

2. 60 MW?30 MW

40 Mw

LSL (15 Mw)10 Mw

3. 30 MW? LSL (15 MW)

5 min tes

Slide 61

5 minutes

Resource Limit Calculator: Conclusion

OffersOffers Real-Time OperationsOffersOffersContingenciesContingencies

Real-TimeNetworkSecurityTopology &Topology &


ConstrainedEconomicy

AnalysisEquipmentEquipment



Dispatch

Resource

TelemetryTelemetry

Slide 62

LimitCalculatorForced Outage

DetectionForced Outage

Detection

Offers

ConstraintsConstraintsOffers

ConstraintsConstraints







Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 63



LimitCalculator

LimitCalculator

Energy Offer Curves

OROR

Can be submitted any time before the Operating Hour for non-RUC-committed hours only.

Slide 64

Resource Status

Valid Resource Status Values:

• “ON” – online w EOC and w/o Regulation Serviceegu a o Se ce

• “ONREG” – online w EOC and providing Regulation Service

Slide 65

Output Schedules

Output Schedulep

MW

0 5 10 15 20 25 30minutes

• DSRs can submit Schedules any time before SCED.• Non-DSRs must submit before end of Adjustment

Slide 66

Non DSRs must submit before end of Adjustment Period.

Resource Status

Valid Resource Status Values for Output Schedules (“OS”):Output Schedules ( OS ):

• “ONOS” – online with OS and w/o O OS o e OS a d /oRegulation Service

“ONOSREG” online with OS• “ONOSREG” – online with OSand providing Regulation Service

• “ONTEST” – online with OS for testing

Slide 67

Generation to be Dispatched

ConstraintsConstraintsOffersOffers






Real-Time OperationsReal-Time Operations




Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 68

LimitCalculator

LimitCalculator



Execution

Real-Time OperationsConstraintsConstraints

OffersOffersConstraintsConstraints







Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 69

LimitCalculator

LimitCalculator



Frequency

5 min. 5 min.5 min.

SCED ExecutionsSCED Executions

ERCOT may execute SCED more oftenERCOT may execute SCED more often than the scheduled, 5-minute interval.

Slide 70

Failure

5 min.◄ LMP = $12/MWh

5 min.LMP = $10/MWh

5 min.LMP = $12/MWh

SCED ExecutionsSCED Executions FAILUREFAILURE

Slide 71

Failure, cont’d

During SCED failure, ERCOT may• Relax constraintsRelax constraints• Issue Emergency Basepoints• Issue Verbal Instructions

SCED

More on this in Module 5 of this course

QSEs must:QSEs must:• Follow verbal & electronic instructions• In lack of any guidanceIn lack of any guidance

– hold to previous interval basepoints

Slide 72

Output

ConstraintsConstraintsOffersOffersVia LFC:


PricingPricing

• Base Points

Via MIS:Real-TimeNetworkSecurityAnalysis




Via MIS:• LMPs• SCED Shadow Prices• Active TransmissionAnalysisEquipmentEquipment



Dispatch• Active Transmission Constraints

• Settlement Point

TelemetryTelemetryResource

LimitResource

Limit

Prices

Slide 73

LimitCalculator

LimitCalculator

Pricing Data

ConstraintsConstraintsOffersOffers


PricingReal-TimeNetworkSecurityAnalysis


PricingSecurity-


Real-Time OperationsReal-Time Operations




Dispatch

TelemetryTelemetryResource

LimitResource

Limit

Mockup of MIS display.

Slide 74

LimitCalculator

LimitCalculator

SCED

The Texas Two Step

SCED

SCED executes twice each cycle.• Ensures competition• Reduces Market

Power

Slide 75

Power

SCED

The Texas Two Step

SCED

Constraints are classified as:• Competitive• Non-Competitive

Slide 76

SCED

The Texas Two Step$ / MWh

Step One• Uses Energy Offer Curves

for all On-Line Generation Reference LMPfor all On-Line Generation Resources

• Observes the limits of

Reference LMP

Competitive Constraints only

• Determines “Reference LMPs”Energy Offer Curve

MWSCED

Slide 77

SCED


Step Two• Observes limits of all Competitive

and Non-Competitive Constraints Reference LMPand Non-Competitive Constraints Reference LMP

Energy Offer CurveMW

SCED

Slide 78

SCED


Step Two• Observes limits of all Competitive

and Non-Competitive Constraints Reference LMP

MitigatedOffer cap

and Non-Competitive Constraints

• Energy Offer Curve for on-line Resource capped at Reference

Reference LMP

ppLMP from Step 1 or Mitigated Offer Cap (whichever is greater) Energy Offer Curve

MWSCED

Slide 79

Scenarios

Texas Two Step

Slide 80

SCED

So – What curve is applied to each of the MW levels?

$ / MWh“The Energy Offer Curve for any on-line Resource is capped at the greater

$

R f LMPis capped at the greater of the Reference LMPfrom Step 1 or the Mitigated Offer Cap”

Mitigated

Reference LMP

Mitigated Offer Cap” Offer cap


Slide 81

MWSegment: a b c d

SCED

So – What curve is applied to each of

$ / MWh

the MW levels?

$

R f LMP

“The Energy Offer Curve for any on-line Resource is capped at the greater

Mitigated

Reference LMPis capped at the greater of the Reference LMPfrom Step 1 or the Mitigated Offer Cap” Offer cap


Mitigated Offer Cap”

Slide 82

MWSegment: a b c d

SCED


$ / MWh

the MW levels?

$

R f LMP


Mitigated




Slide 83

MWSegment: a b c d

SCED


$ / MWh

the MW levels?

$

R f LMP


Mitigated




Slide 84

MWSegment: a b c d

SCED


$ / MWh

the MW levels?

$

R f LMP


Mitigated




Slide 85

MWSegment: a b c d

SCED

And… Why was each segment

$ / MWh

applicable?

$

R f LMP


Mitigated




Slide 86

MWSegment: a b c d

Base Point Deviation

Security-

Over-Generation

yConstrainedEconomicDispatch

DispatchDispatch

Under-Generation

?Dispatch

InstructionsDispatch

Instructions

?

Slide 87

Ancillary Service Deployment



p g p




Slide 88


Area Control Error

Measures the deviance (in MW) from System Scheduled FrequencyFrequency.

250(LFC attempts to maintain a zero average deviation.)

200150100

W)

500

-50

AC

E (M

W

ACE

+0 +5 +10 +15 +25 +20 +25 +30 +35 +40

-100-150-200

A ACE

Slide 89

+0 +5 +10 +15 +25 +20 +25 +30 +35 +40Seconds

Deployment

LFC Ancillary Service deploymentsU d t l d i ti f th• Used to resolve deviations from the Scheduled System Frequency• Reg-down when ACE is positiveeg do e C s pos e• Reg-up when ACE is negative• Responsive Reserve when Reg-up

alone can not correct negativeACE

Slide 90

Regulation Service

Ancillary Service that enables ERCOT to manage system frequency in Real-Timefrequency in Real-Time

• Responds to ERCOT control signals every 4 seconds• Resource can provide:esou ce ca p o de

• Regulation-Up• Regulation-Down

RegulationRegulationService

Slide 91

Regulation-Up

Capacity deployed when ACE is below zeroHASL b d R U R ibilit• HASL based on Reg-Up Responsibility

• Dispatched at the QSE level• QSE determines how to allocate• QSE determines how to allocate• Affected Resources will increase generation

RegReg UpUp

=RegReg--UpUp

=Slide 92

Regulation-Down

Capacity deployed when ACE is above zeroLASL b d R D R ibilit• LASL based on Reg-Down Responsibility

• Dispatched at the QSE level• QSE determines how to allocate• QSE determines how to allocate• Affected Resources will decrease generation

==Slide 93

RegReg--DownDown

Resource Participation Factor

Identifies which portion of Regulation Service is deployedO R b i• On a per-Resource basis

• Telemetered to ERCOT every 2 seconds• Input to Ancillary Service Capacity Monitor• Input to Ancillary Service Capacity Monitor• Used to calculate Base Point Deviation charges during

Settlement

Slide 94

Example 1

60.06160

60.04

60.02

60.00224 sec. 264 sec.

Target SCED Base Point140

120

UDBP59.98

59.96

59 94MW

uenc

y

100

80

System Actual Freq.

59.94

59.92

59.90

M

Freq

u

84 sec.

Frequency Thresholds

60

40

59.88

59.86

Thresholds

0 +50 +100 +150 +200 +250 +300

20

0

Slide 95

SCED interval (w. LFC every 2-4 seconds)

Example 2

160 60.06UDBP

140

120

60.04

60.02

60.00

UDBP

Target SCED Base Point100

80

59.98

59.96

59 94MW

uenc

y

244 sec.

60

40

59.94

59.92

59.90

M

Freq

u

84 sec. 184 sec.

System Actual Freq. Frequency Thresholds

20

0

59.88

59.86

Thresholds

0 +50 +100 +150 +200 +250 +300

Slide 96

SCED interval (w. LFC every 2-4 seconds)

Responsive Reserve Service

Deployed when Reg-Up is insufficient to maintain system frequencyfrequency

• Must be deliverable 10 minutes from deployment• Ramps at Emergency Rate• Ramps at Emergency Rate• Releases additional capacity for immediate SCED

dispatch

RegReg--UpUp

• LFC will recall when frequency is acceptable

+ ResponsiveReserveService

Slide 97

Control-Block Status

QSE telemeters status when unit operators temporarily make Resource unavailable for regulationmake Resource unavailable for regulation

• Resource is removed from LFC consideration• ERCOT tracks how long the block is in place• ERCOT tracks how long the block is in place

Slide 98

Non-Spinning Reserve Service

Non-spin brings additional capacity online to:Off t i ffi i t it f di t h i th f t• Offset insufficient capacity for dispatch in the near future

• Address disturbance conditions • Minimize the prolonged use of Responsive Reserve• Minimize the prolonged use of Responsive Reserve

Non-SpinRReserveService

AS Capacity

Slide 99

AS Capacity Monitor

Deployment

ERCOT deploys Non-Spin from specific ResourcesS l t d b d i• Selected based on economics

• Each Resource deployed at 100% of Non-Spin.• Notice transmitted to QSEs via MMS• Notice transmitted to QSEs via MMS

• Amount of capacity to be deployed• Expected duration of deploymentp p y

Dispatch process depends on Resource p

type and current Status

Slide 100

Load Resource

When deployed:ERCOT t d l bl k• ERCOT must deploy as a block

• QSE must interrupt the requested energy within 30 minutes

100% ofNon-SpinR100% of

Reserved Capacity

ReserveService

Slide 101

Online Generation Resource

When deployed:ERCOT d t R ’ N S i AS S h d l• ERCOT updates Resource’s Non-Spin AS Schedule• Re-calculates HASL• Triggers SCED and dispatches new Base Points

DSR QSEs must update Output Schedule via Real-Time telemetry

• Triggers SCED and dispatches new Base Points• Updates Output Schedule

Schedule via Real Time telemetry

100% ofNon-SpinR

ONON100% of

Reserved Capacity

ReserveService

Slide 102

Recall

ERCOT recalls Non-Spin when conditions have passed

Resource Status prior to deployment

Recall Actionsy

Offline Generation QSE may ramp down to LSL and take off-line

O li G ti / N S i t d d HASL t dOnline Generation w/ Energy Offer Curve

Non-Spin restored and HASL re-computed; ramp down to new Base Point

Online Generation w/ Back out of Non-Spin incrementally at Output Schedule normal Ramp Rate

All Load Resources Must restore energy within 3 hours or replace with other non-committed Resource

Slide 103

replace with other non committed Resource

Voltage Support Service

Used to maintain system voltages within established levelsA d t il d i ERCOT O ti G id• As detailed in ERCOT Operating Guides.

S

Q

P

φ

Slide 104

Voltage Profiles

Describes bus voltages under normal conditions.D t i d b ERCOT & TSP• Determined by ERCOT & TSPs

• Measured at Gen Resource buses

Slide 105

TSP Responsibilities

TSPs are responsible for maintaining transmission system voltages in accordance with the published voltagesystem voltages in accordance with the published voltage profiles.

• If unable to maintain voltage must alert ERCOT who can• If unable to maintain voltage, must alert ERCOT who can then dispatch a Generation Resource to address the problem.

!V

!Mw

Slide 106

QSE Responsibilities

QSEs responsible for providing VSS must:• Operate with Resource’s AVR in voltage control mode• Operate with Resource s AVR in voltage control mode• Telemeter Real and Reactive Power to ERCOT• Inform ERCOT if Resource can not meet its voltage profileInform ERCOT if Resource can not meet its voltage profile.

Posted VoltageProfile

Posted VoltageProfile

Transmission Operator Generator Site Name High Side PTI Bus No Generator Unit Base KV On-Peak Off-Peak

Slide 107

TransOp Electric Generators Inc. 12345 GenInc 1 138 144 142.5

Generation Requirements

UnitReactive

MW

ReactiveLimit

MW

rM

Var .95

power factor

Slide 108

> 20 MVA

Compensation

Unit Reactive Limit

Paid

MW

Unit Reactive Limit

Not paid

MW

r

Lost OpportunityPayment

MVa

r (if Mw restricted)

Slide 109




p g p




Slide 110


Overview

Real-Time OperationsConstraintsConstraints

OffersOffersConstraintsConstraints







Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 111

LimitCalculator

LimitCalculator



Overview

ContingenciesContingenciesOffersOffersSCADA TelemetryContingenciesContingencies

PricingPricing

SCADA Telemetry• Provides breaker status and

output of Resources • Provides status of observable





• Provides status of observable Transmission Elements of the Network Operations Model




Dispatch• ERCOT Operator may consult QSE or TSP regarding discrepancies

ResourceLimit

ResourceLimit

d sc epa c esTelemetry

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LimitCalculator

LimitCalculator



Overview

ContingenciesContingenciesOffersOffersForced Outage Detection

U l i ti t t l tContingenciesContingencies

PricingPricing

• Uses logic equations to translate breaker and switch status changes into Transmission Element status





changes




Dispatch

ResourceLimit

ResourceLimit

TelemetryTelemetry

Slide 113

LimitCalculator

LimitCalculator



Forced Outage Detection (FOD) PurposeD t t t t h b d i t d b k d• Detect status changes based on associated breaker and switch status changes for the following Transmission Facilities– Resources – Transmission lines – Transformers– Loads

Identif forced o tages of Transmission Facilities• Identify forced outages of Transmission Facilities• Produce alarms for ERCOT Operators in real-time at same

frequency as SCADA telemetry processing

Slide 114

q y y p g


Inputs and Detection


Breaker & Switch Status

Planned Outages

E i ti F

Planned

Existing Force Outages

Planned Resource Status

Network

Slide 115

Network Operations Model

Forced Outage Detection (continued)




Planned Outages Transmission Element Status

DetectionE i ti F

Planned

Detection




Network

Continued Alarming

Slide 116






Planned Outages Forced Outages Display

Transmission Element Status

DetectionE i ti F

Planned

Status Change & Forced

Detection




Network

Outage AlarmContinued Alarming

Slide 117



Transmission Element DetectionIs the Load Is the Resource on-line or off-Is the Autotransformer

Load

Is the Load energized or

de-energized?

Resource

Is the Resource on-line or off-line? Does the status match the Current Operating Plan?

Is the Autotransformer energized or

de-energized?

Load

C

ResourceO

Is the Line . . .Energized?

De-energized? Line CLine BO CO C

Line AOpen at one end?

Open at both ends?C OC O

Slide 118


Transmission Element Detectionf

Load Resource

It depends on the combination of breaker and switch statuses.Transmission Element detection figures this out!

Load

C

ResourceO

Line CLine BO CO C

Line A

C OC O

Slide 119


Unplanned Outages for QSE and TSP FacilitiesERCOT Operator is alerted of unplanned outagesERCOT Operator is alerted of unplanned outages

Unavoidable Extension1

Forced Outage2

Forced Extension3

Slide 120


Unplanned Outages for QSE and TSP FacilitiesERCOT Operator may request that QSE or TSPERCOT Operator may request that QSE or TSP• Correct the breaker and/or switch

status indication causing the alarmstatus indication causing the alarm

• Enter an Unavoidable Extension, Forced Outage or ForcedForced Outage or Forced Extension into the Outage Scheduler

Slide 121


Resource Status Deviations ERCOT Operator is notified of status deviations

1

ERCOT Operator is notified of status deviations for QSE Resources

FOD detects a deviation between telemetered Resource

2

FOD detects a deviation between telemetered Resource status and FOD calculated Resource status

After a configurable time into the Operating Hour FOD2 After a configurable time into the Operating Hour, FOD detects a deviation between planned resource status from COP and FOD calculated resource status.

Slide 122


Resource Status Deviations (continued)

Example:

• Planned resource status from COP is “ON” and• Planned resource status from COP is ON , and

• Next hour planned status is also “ON”, and

• Resource status calculated by FOD is “OFF”

FOD shall notify the ERCOT operator of an unexpected deviation from the operating plan

Slide 123

unexpected deviation from the operating plan.


Resource Status Deviations (continued)ERCOT Operator may verbally request that the responsibleERCOT Operator may verbally request that the responsible QSE

• Correct the breaker and/or switch status indication causing the alarm

• Correct the deviation between COP and the FOD calculated• Correct the deviation between COP and the FOD calculated status

Slide 124




p g p




Slide 125


Scenarios

Adjusting Resources

Slide 126

Adjusting Resources

Adjusting ResourcesAdjusting Resources• QSE is about to bring a Resource

On-LineOn-Line• Unit has DAM awarded energy and

ancillary services responsibilities.• COP reflects:

• Resource statuses• Limits• Resource Responsibilities

Slide 127

Adjusting Resources, cont’d

Initial values and desired end-points

Resource Parameters Starting Point Desired EndHSL 100 MW 100 MWLSL 10 MW 10 MWNormal Ramp Rate 5 MW/min 5 MW/minReg-Up AS Resource Responsibility 0 MW 10 MWReg-Down AS Resource Responsibility 0 MW 15 MWA d d E Off i th DAM 50 MWAwarded Energy Offer in the DAM 50 MWAwarded Reg-Up Offer in the DAM 10 MWAwarded Reg-Down Offer in the DAM 15 MWSCED Base Point 60 MW

Slide 128

SCED Base Point 60 MWCurrent Telemetry 60 MW


Parameter Values

SCED U R t

NormalR R t

Reg-Up Responsibility5 i-

SCED Up Rate

Ramp Rate 5 min

SCED Down Rate

NormalRamp Rate

Reg-Down Responsibility5 min-

Slide 129


Parameter Values

SCED U R t

5 MW/min10 MW5 min 3 MW/min- =

SCED Up Rate

5 min

SCED Down Rate

5 MW/min15 MW5 min

2 MW/min- =

Slide 130


Actions and Resource Changes

QSE Actions Resource Changes

SCED computes Base PointClose breaker


Unit is ramped to a value less than 90% LSL and stabilizes:HASL=HDL=LDL=LASL

Set Ramp Resource to stabilization level and ready HASL=HDL=LDL=LASL

Base Point = Current Telemetryfor dispatch

Resource Limit Calculator Enter desired Reg-Up and Reg Down AS Resource

Slide 131

computes HASL, HDL, LDL, LASLReg-Down AS Resource Responsibility in Real-Time


Actions and Resource Changes


SCED computes Base PointSet Ramp Resource above 90% LSL


Change to ONREG indicates On-Line Resource with Energy Offer Curve providing Regulation Service

Set Resource Status to ONREG

• Base Point movement restricted to Ramp Rate of Resource

Control Resource to Base Point of 60 MW;

LFC Actions

Slide 132

p• Updated Desired Base Point

provided as Reference

;Regulate around Base Point

Dispatch Communications

Dispatch CommunicationsERCOT sends electronic or verbal Dispatch instructionsERCOT sends electronic or verbal Dispatch instructions

• QSEs must:• Reply to electronic dispatch within one minute of receipt • Repeat verbal dispatch instructions back to ERCOT• Request clarification if instruction is not understood

Resources with ‘ONTEST’ Status are exempt from Dispatch Instructions.



Slide 133

InstructionsInstructions

Verbal Dispatch Checklist

ID of responsible Entity and instructing authorityS ifi R bj t f Di t h I t tiSpecific Resource subject of Dispatch InstructionSpecific action requiredC t ti l l t t f R th t bj tCurrent operating level or state of Resource that are subject to instructionOperating level or state to which such Resource(s) will beOperating level or state to which such Resource(s) will be dispatchedTime of notification of Dispatch InstructionTime at which QSE is required to initiate instructions Time at which QSE is required to complete instructions

Slide 134

Verbal Dispatch Instruction (VDI) reference number

Dispatch Conflicts

QSE may contest dispatch instructions that:Ri k d th t t f t b dil h• Risk undue threat to safety, bodily harm, or equipment damage

• Are not in compliance with Protocols• Are not in compliance with Protocols• Conflict with other instructions

When contested, QSE must notify ERCOT and work to resolutionwork to resolution.

ERCOT has final decision-

Slide 135

making authority.

Non-Compliance Resolution

If ERCOT & QSE fail to agree on resolution:B th id h ld d t h ibl• Both sides should document as much as possible.

• Resolve dispute Alternative Dispute Resolution.

Slide 136

Settlement Impacts



p g p




Slide 137


Overview

Real-Time Settlement P t & h b d 15 i S ttl t I t l• Payments & charges based on 15-min. Settlement Intervals

• QSE actions can’t affect past Settlement Intervals

15 min. 15 15 15 15 15 15 15

Hour 1 Hour 2

Slide 138

Scenarios

G ti S ttl t 60 MWGeneration Settlement 60 MW

G ti S ttl t 45 MWGeneration Settlement 45 MW

Slide 139

Generation Settlement: Scenario #1

Generation Settlement

For Hour Ending 11: {? MW


• DAM: Resource is struck for 50MW(No Ancillary Service awards)

{? MW

• Real-Time: 60MW generated for whole hour

Sold in DAM? MW

Real-TimeMetered

? MW

What is the QSE paid?

? MW

Slide 140



10 MWWhat is the QSE paid?


{+10 MWWhat is the QSE paid?

DAM

{Sold in DAM

50 MW

Real-TimeMetered60 MW

• Paid 50 MW at the DAM SPP

60 MWReal-Time• Paid 60 MW at Real-Time SPP

Ch d 50 MW t R l Ti SPP

Slide 141

• Charged 50 MW at Real-Time SPP



For Hour Ending 11:


• DAM: Resource is struck for 50MW(No Ancillary Service awards)

? MW}• Real-Time: 45MW generated for

whole hourSold in DAM? MW

Real-TimeMetered

? MW


? MW ? MW

Slide 142


Generation SettlementGeneration Settlement

What is the QSE paid?-5 MW}


DAMReal-TimeMetered45 MW

Sold in DAM

50 MW

• Paid 50 MW at the DAM SPP

45 MW50 MWReal-Time• Paid 45 MW at Real-Time SPP

Ch d 50 MW t R l Ti SPP

Slide 143

• Charged 50 MW at Real-Time SPP


Other considerations:

• Settlement intervals?

• Different SPPs?

• Ancillary Services?

Real-TimeSold in Sold in DAM

Real-TimeMetered45 MW

DAM50 MW

DAM50 MW

Metered60 MW

Slide 144

Course Summary

You should be able to:

Identif timeline & processes of Real Time Operations• Identify timeline & processes of Real-Time Operations

• Explain Real-Time Network Security Analysis &

Security Constrained Economic Dispatch

• Describe Load Frequency Control functions

• Explain Generation Ancillary Services deployments

• Explain Controllable Load & associated QSE• Explain Controllable Load & associated QSE

responses

Slide 145

• Describe basic Real-Time pricing functions

Module ConclusionModule Conclusion

Module 4: Operating Period - Electric Reliability Council ... Period Emergency Operation Conditions...

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