Droop Calculator and Unit Performance Evaluation

SAR-003-TRE-001 March 31, 2009

Sydney Niemeyer

Grid Nominal Frequency 60.00000 Hz Unit Limiting Factor CompensationTurbine Capability 745.00000 MW Throttle Pressure Decay Rated Throttle Pressure 2400

Droop Setting 5.00% 3.00000 0.4826 P.U. Performance 1.0514Deadband Setting 0.03600 Hz PSIG Change/MW change

Hz Span 2.96400 Hz Resource Accounting for Resource Limiting Factor

Frequency Grid Frequency Minimum Minimum Limiting Ideal Ideal Minimum Standard Minimum StandardDeviation Frequency Response Performance Performance Factor Performance Performance Performance Performance

Hz Hz MW Droop % 5.00% Droop % Compensation adj for limiting factor Droop % MW Droop %

“FR Unit ST1” – Excel Sheet Name

Frequency Response for Unit Steam Turbine 1

-0.10200 59.89800 16.58907 7.63455% 12.441802 10.17939% -2.485 14.104 8.97978% 10.578 11.97304%-0.10100 59.89900 16.33772 7.67600% 12.253289 10.23467% -2.448 13.890 9.02854% 10.418 12.03805%-0.10000 59.90000 16.08637 7.71875% 12.064777 10.29167% -2.410 13.677 9.07882% 10.257 12.10510%-0.09900 59.90100 15.83502 7.76286% 11.876265 10.35048% -2.372 13.463 9.13070% 10.097 12.17427%-0.09800 59.90200 15.58367 7.80839% 11.687753 10.41118% -2.335 13.249 9.18425% 9.937 12.24567%-0.09700 59.90300 15.33232 7.85541% 11.499241 10.47388% -2.297 13.035 9.23956% 9.777 12.31942%-0.09600 59.90400 15.08097 7.90400% 11.310729 10.53867% -2.259 12.822 9.29671% 9.616 12.39562%-0.09500 59.90500 14.82962 7.95424% 11.122217 10.60565% -2.222 12.608 9.35580% 9.456 12.47440%-0.09400 59.90600 14.57827 8.00621% 10.933704 10.67494% -2.184 12.394 9.41693% 9.296 12.55591%-0.09300 59.90700 14.32692 8.06000% 10.745192 10.74667% -2.146 12.181 9.48020% 9.135 12.64027%-0.09200 59.90800 14.07557 8.11571% 10.55668 10.82095% -2.109 11.967 9.54573% 8.975 12.72764%

Enter “yellow” data to recalculate for unit to be evaluated.

Frequency ResponseBased on

Droop Setting and Deadband Setting

-1000.00

-800.00

-600.00

-400.00

-200.00

0.00

200.00

400.00

600.00

800.00

1000.00

57.00 57.50 58.00 58.50 59.00 59.50 60.00 60.50 61.00 61.50 62.00 62.50 63.00

Hz

MW

Ch

ang

e

Droop Setting 5.00% Ideal Performance adj for limiting factor Minimum Standard Performance MW

Deadband Setting

0.03600 Hz

745.00000Capability (MW)

“Chart FR ST1 MW full scale” – Excel Sheet Name

Frequency Response for Unit Steam Turbine 1

Frequency ResponseBased On

Droop Setting and Deadband

-150.00

-100.00

-50.00

0.00

50.00

100.00

150.00

59.50 59.55 59.60 59.65 59.70 59.75 59.80 59.85 59.90 59.95 60.00 60.05 60.10 60.15 60.20 60.25 60.30 60.35 60.40 60.45 60.50

Hz

MW

Ch

ang

e

Droop Setting 5.00% Ideal Performance adj for limiting factor Minimum Standard Performance Droop %

Deadband Setting

0.03600 Hz

745.00000Capability (MW)

“Chart FR ST1 MW small scale” – Excel Sheet Name

Frequency Response for Unit Steam Turbine 1

Frequency ResponseBased On

Droop Setting and Deadband

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

20.0%

57.00 57.50 58.00 58.50 59.00 59.50 60.00 60.50 61.00 61.50 62.00 62.50 63.00

Hz

Dro

op

Droop Setting 5.00% Ideal Performance Droop % Minimum Standard Performance Droop %

Deadband Setting

0.03600

Hz

745.00000Capability (MW)

“Chart Droop ST1 MW full scale” – Excel Sheet Name

Frequency Droop for Unit Steam Turbine 1

Frequency ResponseBased On

Droop Setting and Deadband

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

20.0%

59.50 59.55 59.60 59.65 59.70 59.75 59.80 59.85 59.90 59.95 60.00 60.05 60.10 60.15 60.20 60.25 60.30 60.35 60.40 60.45 60.50

Hz

Dro

op

Droop Setting 5.00% Ideal Performance Droop % Minimum Standard Performance Droop %

Deadband Setting

0.03600

Hz

745.00000Capability (MW)

“Chart Droop ST1 MW small scale” – Excel Sheet Name

Frequency Droop for Unit Steam Turbine 1

Data Start 16-Dec-08 15:30:00 INTERVALData End 16-Dec-08 16:30:00 2s

Hz Unit 1 ST Net Gen Unit 1 ST HSL/HOL

15:30:00 60.026 109.2213669 74515:30:02 60.027 108.9745865 74515:30:04 60.027 108.9745865 74515:30:06 60.021 109.537384 74515:30:08 60.019 109.5387268 74515:30:10 60.02 109.8129654 74515:30:12 60.022 109.826683 74515:30:14 60.023 111.7465668 74515:30:16 60.026 110.7458801 74515:30:18 60.027 110.6958466 74515:30:20 60.029 110.6933441 74515:30:22 60.029 109.5965195 74515:30:24 60.029 109.5416794 74515:30:26 60.031 110.0872955 745

“Data” – Excel Sheet Name

AGC Scan Rate Data for Unit Steam Turbine 1

Row Number 15:45:10 60.019 129.1644897 745462 15:45:12 60.019 129.1638031 745463 15:45:14 60.02 130.2604523 745464 15:45:16 60.017 128.6702423 745465 15:45:18 60.018 129.9616089 745466 15:45:20 60.021 130.0261688 745467 15:45:22 60.017 130.3035736 745468 15:45:24 60.016 130.0432739 745469 15:45:26 60.015 130.0302582 745470 15:45:28 60.012 129.2070923 745471 15:45:30 60.01 129.7142792 745472 15:45:32 59.847 129.7396393 745473 15:45:34 59.726 142.352829 745474 15:45:36 59.728 154.2245483 745475 15:45:38 59.774 154.8181305 745476 15:45:40 59.819 160.0570831 745477 15:45:42 59.844 153.4647217 745478 15:45:44 59.852 153.1351013 745479 15:45:46 59.848 152.570282 745480 15:45:48 59.845 152.542038 745481 15:45:50 59.836 155.2823639 745482 15:45:52 59.833 157.6127319 745483 15:45:54 59.838 157.7292633 745484 15:45:56 59.839 159.6542969 745485 15:45:58 59.837 159.7505341 745486 15:46:00 59.841 161.6745758 745

“Data” – Excel Sheet Name

Determine t(0) – The beginning of the Event

The first scan of frequency that deviates from the normal trend. Determine “row” number of data.

(see slide 11)

Turbine Steam Valve Position Impacts Steam Pressure Drop on Steam Flow

From 60.00 Hz Ideal droop & db Ideal droop, db & LF Min PerformPre event MW Chg 0.00 0.00 0.00Post event MW chg 32.17 30.08 22.56Event Total Chg 32.17 30.08 22.56

Percent Valve Position 21.66%Throttle Pressure Impact 0.433222995

Throttle Pressure Impact 50% Load -4.819704 MWThrottle Pressure Impact @ Post Average Output -2.088007 MW

Takes into account the governor deadband at the starting frequency if starting frequency is above or below the deadband.

Calculate the effect of the steam valve opening on Steam Flow and Steam Pressure drop.

1: Determine valve opening (curve)

2: Determine Pressure Impact

3: Adjust Pressure Impact on Steam Flow and MW response.

“Unit ST1 Event Perf” – Excel Sheet Name

Unit Steam Turbine 1 Event Performance – Deadband and Valve Opening Adjustment

t(0) 15:45:32 Hz MW Delta2 scan rate 60.0157 129.74 Pre average data -0.1787 HZ Change

t HZ Unit MW Output 59.8370 161.38 Post average data 31.6310 MW Change

T-60 sec 15:44:32 60.02 123.983

T-58 sec 15:44:34 60.02 123.970 MW Change 22.56 Minimum Expected MW changeT-56 sec 15:44:36 60.023 124.791 30.08 Expected MW change Adjusted for db and limiting factorT-54 sec 15:44:38 60.026 126.752 32.17 Ideal MW change based on droop setting and deadbandT-52 sec 15:44:40 60.028 127.124 31.63 Actual MW ChangeT-50 sec 15:44:42 60.03 127.143T-48 sec 15:44:44 60.029 127.418 Droop 9.84% Minimum Expected DroopT-46 sec 15:44:46 60.03 126.883 7.38% Expected Droop Adjusted for db and limiting factorT-44 sec 15:44:48 60.028 126.856 6.90% Ideal Droop based on droop setting and deadbandT-42 sec 15:44:50 60.026 127.952T-40 sec 15:44:52 60.028 128.555 7.02% Actual DroopT-38 sec 15:44:54 60.028 128.585T-36 sec 15:44:56 60.029 129.135 P.U. Performance 1.051 Resource Event PerformanceT-34 sec 15:44:58 60.031 129.162 T-32 sec 15:45:00 60.023 128.341T-30 sec 15:45:02 60.023 128.341 Unit Name: Unit 1 PerformanceT-28 sec 15:45:04 60.024 128.300 Tuesday, December 16, 2008T-26 sec 15:45:06 60.022 129.449T-24 sec 15:45:08 60.02 129.178T-22 sec 15:45:10 60.019 129.164 615.26 Spinning ReserveT-20 sec 15:45:12 60.019 129.164T-18 sec 15:45:14 60.02 130.260T-16 sec 15:45:16 60.017 128.670T-14 sec 15:45:18 60.018 129.962T-12 sec 15:45:20 60.021 130.026T-10 sec 15:45:22 60.017 130.304T-08 sec 15:45:24 60.016 130.043T-06 sec 15:45:26 60.015 130.030T-04 sec 15:45:28 60.012 129.207T-02 sec 15:45:30 60.01 129.714T+0 sec 15:45:32 59.847 129.740

=Data!B472

“Unit ST1 Event Perf” – Excel Sheet NameEdit formula in this cell to “row” number determined on slide 8.

Change name in this cell to official unit name…WAP G8

Table will be built, graph drawn and performance will be evaluated based on t(0) entry time.

Unit 1 Performance

59.70

59.72

59.74

59.76

59.78

59.80

59.82

59.84

59.86

59.88

59.90

59.92

59.94

59.96

59.98

60.00

60.02

60.04

60.06

60.08

60.10

15:44:32 15:44:42 15:44:52 15:45:02 15:45:12 15:45:22 15:45:32 15:45:42 15:45:52 15:46:02 15:46:12 15:46:22 15:46:32

Hz

120.0

123.0

126.0

129.0

132.0

135.0

138.0

141.0

144.0

147.0

150.0

153.0

156.0

159.0

162.0

165.0

168.0

171.0

174.0

177.0

180.0

MW

HZ Average Frequency Unit MW Output Event Average MW Minimum Expected MW change

Tuesday, December 16, 2008P.U. Performance 1.051

Expected MW Change

Actual MW Change

Minimum Expected MW Change

30.08

22.56

31.63

Spinning Reserve MW 615.26

Chart Unit ST1 Event Performance – Excel Sheet Name

P.U. Performance = Actual/Expected

Expected MW Change is adjusted for unit limiting factors (LF), Pressure change, valve opening, deadband, droop setting and HOL/HSL.

Improve Evaluation Data Resolution and update time

Small units will measure better with MW values that have higher resolution.

Scan and store data at AGC scan rate. Avoid data compression.

TRE and ERCOT have data at scan rate received and resolution transmitted.

Small governor deadbands tend to get unit moving in correct direction sooner improving performance.

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