July 10, 2008

ROS

Early Delivery SystemsStatus – R6.3 2 Hour Test

John Dumas and Jeff Gilbertson

2TPTF7/8/2008 2

Agenda

• EDS 3– Release 5 & 6: SCED / LFC

• 2-Hour Total System Test Results

– Test Chronology

– LFC Review

– Constraints

– State Estimator

– System Items of Note

• Future of LFC and SCED Testing

3TPTF7/8/2008 3

• EDS 3– Release 5 & 6: SCED / LFC

• 2-Hour Total System Test Results

– Test Chronology

– LFC Review

– Constraints

– State Estimator

– System Items of Note

• Future of LFC and SCED Testing

Agenda

4TPTF7/8/2008 4

Test Chronology – June 25, 2008

08:00 Taylor Control Room Hotline announcement of EDS 3 LFC R6.3

2 Hour Test to Start at 11:00 09:00 ERCOT discontinues the use of Zonal Congestion Management

Techniques (No OC1s in effect at the time)10:50 Taylor Control Room Hotline announcement of EDS 3 LFC R6.3

2 Hour VDI effective Market Wide at 11:00 AM11:00 Taylor Control Room Issues first Zonal to Nodal Switching Order12:18 Last QSE Confirms Switch to Nodal12:18 – 12:47 ERCOT manages Grid Control via Nodal12:47 First QSE confirms switch back to Zonal13:37 Last QSE confirms switch back to Zonal14:40 ERCOT resumes the use of Zonal Congestion Management

Techniques15:00 VDI Ended

5TPTF7/8/2008 5

LFC CPS1 Scores

-200

-150

-100

-50

0

50

100

150

200

250

0900 0930 1000 1030 1100 1130 1200 1230 1300 1330 1400 1430 1500

CPS1 Score

Time

CPS1 During 6/25/08 EDS3 R6.3 Test

CPS1 - 1 Min.

CPS1 - 1 Hr.

First QSE switched to NodalAll QSEs on Nodal

First QSE switched back to ZonalAll QSEs back on Zonal

CPS1 Score (1 Min.) Average

All in Zonal (900-1106)

107.27

Transition to Nodal (1107-1217)

111.25

All in Nodal (1218-1247)

159.92

Transition to Zonal (1248-1337)

120.04

All in Zonal (1338-1530)

125.27

6TPTF7/8/2008 6

LFC Regulation, Total Load and Total Generation

37000

40000

43000

46000

49000

52000

55000

58000

-800

-600

-400

-200

0

200

400

600

800

1000

0900 0930 1000 1030 1100 1130 1200 1230 1300 1330 1400 1430 1500 1530

Time

Total Regulation Deployed in Zonal and Nodal and Total Load and Generation

Nodal Reg. Deployed

Zonal Reg. Deployed

Load

Generation

First QSE switched to Nodal All QSEs on NodalFirst QSE switched back to Zonal

All QSEs back on Zonal

7TPTF7/8/2008 7

LFC Transition Time and Nodal Operation Duration

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Fraction

Time

Fraction of the ERCOT Total Generation, Regulation Up Responsibility and Regulation Down Responsibility being Controlled by Nodal

Generation

Reg. Up

Reg. Down

8TPTF7/8/2008 8

Constraints

Nodal RTCA & Zonal RTCA showed the same contingency violations.

Constraints in effect from 9:30 and throughout the test:Austrop Transformer

Loss of #2 Austrop 345/138kV transformer overloads #1 Austrop 345/138kV transformerDue to Generation Topology

Brownwood SwitchLoss of 345kV Temple Switch to Lake Creek & Temple Pecan Creek to Tradinghouse double circuit overloads Brownwood Switch to Goldthwaite 138kV lineA CRE for the North to South (Zonal) corridor

9TPTF7/8/2008 9

State Estimator Convergence (15 MW/30 MVAR Mismatch Tolerance)

June 25th

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour Ending

Convergence

09:37 - Large change in breaker status that went from closed to open due to a QSE’s ICCP data failure, impacted hour ending 10.

10:30 - RTU went down impacting telemetry from 3 units, impacted hour ending 11.

10TPTF7/8/2008 10

Limits during test period 6/25, 11am – 1pm

GTBD within 2000-3000MW of HDL (plenty of room). LEL > LSL for all but four intervals of test – check your telemetered LEL and LSL

20000 MW

25000 MW

30000 MW

35000 MW

40000 MW

45000 MW

50000 MW

55000 MW

60000 MW

65000 MW

6/25/2008 10:00 6/25/2008 10:30 6/25/2008 11:00 6/25/2008 11:30 6/25/2008 12:00 6/25/2008 12:30 6/25/2008 13:00 6/25/2008 13:30

SUM_HEL

SUM_HSL

SUM_HASL

SUM_HDL

GTBD

SUM_LDL

SUM_LASL

SUM_LSL

SUM_LEL

11TPTF7/8/2008 11

Reference LMP, Max LMP, Min LMP

Two constraints implemented for entire test – limits not reached until halfway through test Reference LMPs steady increase from $95 to $122 Temporary Max/Min LMP reduction at 12:35; transformer constraint not at limit briefly

0

10000

20000

30000

40000

50000

60000

10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30

-1000

-500

0

500

1000

1500

2000

GTBD

MAX LMP

MIN LMP

REFERENCE_LMP

12TPTF7/8/2008 12

Distribution of Prices with Line Constraint (12:30)

288 of 433 (66%) Resource node LMPs at $109.11 Max $1,388; Min -$425

Distribution of LMPs 6/25 12:30

10 1 10 11 10 5 439

288

55

7728 MW

488 MW 2907 MW 930 MW

0 MW

150 MW

377 MW3944 MW

34016 MW

0 MW0

50

100

150

200

250

300

350

-$425 -$0

$105.25 $109.11 $226-$227

$246-$255

$260-$280

$414-$875

$911-$964

$1076-$1090

$1,388

LMP

# o

f R

eso

urc

e N

od

es a

t L

MP

MW

5000 MW

10000 MW

15000 MW

20000 MW

25000 MW

30000 MW

35000 MW

40000 MW

MW

of

Res

ou

rce

as L

MP

# Resources

MW

13TPTF7/8/2008 13

Reference LMP, GTBD, SPP, Zonal MCPE (6/25)

Reference LMP comparable to MCPE (Zonal MCPE same in all Zones throughout test) Maximum difference of $14 between LMP and MCPE at beginning of test Differences between LMP/SPP/MCPE $0-$10 throughout test, except for South Zone

$50.00

$100.00

$150.00

$200.00

$250.00

$300.00

$350.00

$400.00

10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30

MW

10000 MW

20000 MW

30000 MW

40000 MW

50000 MW

60000 MW

LZ-W

LZ-N

LZ-S

LZ-H

Ref LMP

Zonal

HB-W

HB-N

HB-S

HB-H

GTBD

14TPTF7/8/2008 14

System Items of Note

Permissive Control for UDBP was not in effectRLC p1 parameter set at 1.0 which affects operation below

the LSL (will change to 0.9)Regulation Reduction was in effect and will need further

tuning before next LFC testSCED issue identified and to be corrected before next test

(memory issue) No off cycle SCED runs executedCombined Cycle Configuration Validation Check was not

effect

15TPTF7/8/2008 15

Agenda

• EDS 2 – Release 3: Telemetry & State Estimator

• EDS 3– Release 5 & 6: SCED / LFC

• 2-Hour Total System Test Results

– Test Chronology

– LFC Review

– Constraints

– State Estimator

– System Items of Note

• Future of LFC and SCED Testing

16TPTF7/8/2008 16

Near-Term Future of State Estimator

• MW and MVar tolerance set to 15 on July 1 based on last ½ of June results (~91% Convergence)

• Staffing shift engineers in 24-hr incremental blocks in August to drive SE issues and build toward 24x7 real-time operations– ‘Blackout’ will be communicated to MPs and all efforts should be made

to keep systems running and accurate– On non-blackout dates ERCOT will continue to monitor 8x5

• These efforts will position ERCOT and MPs well for an 8-Hour LFC test in Mid-September– With or without CIM– A longer test is needed for MPs and ERCOT to tune their systems

17TPTF7/8/2008 17

8 Hour Test

Preparation activities for 8 Hour Test

ERCOT Publish LFC 2 Hour Test ReportResolve SCED memory issueFurther LFC tuning effortsWork with MP’s towards State Estimator and Telemetry Standard

complianceWorks with MP’s towards a 24 X 7 Nodal operation support (ICCP)Schedule LFC Phase 3 Test Work ShopSchedule Blackout Days for State Estimator convergence testingSchedule LFC 8 hour test

18TPTF7/8/2008 18

Near-Term Future of SCED

• ERCOT proposal for Real-Time submissions until re-plan is complete– ERCOT will continue to run SCED / Post Real-Time LMPs

• QSEs continue TPO submittals up to 30-days in advance– TPO’s should continue to cover 80-120% of cost– Min Energy / Startup Costs may be 0.00 since no DAM/RUC execution– FIP / FOP % must still continue to = 100% combined

• COP will only be required in the case of using an output schedule– Output schedules use the sustainable limits in the COP for validation– In this circumstance, COP’s updates are not required in Adjustment Period

– ICCP • ICCP must continue to be in place 24/7 to support State Estimator and basic SCED

input values – Basic data required include configuration, MW output, breaker status, HSL, LSL.– Ancillary Services not required (zero for AS Schedules and Responsibility)

• ICCP data quality must continue to be monitored and problems resolved• These are the ongoing requirements communicated to the market from November of

2007

– ERCOT will implement 24/7 constraint management in nodal systems starting 7/5