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Operations Reports

Daily Grid Operations Report
09/03/2008

Peak Load 49263
Peak Hour 17
Planned Peak 52239
Planned Peak Hour 17

Constraints Encountered During the Day

Start Constraint Reason
00:15 OOME Horse Hollow down Loss of San Angelo Red Creek 345/138kV autotransformer #2 overloads San Angelo Red Creed 345/138kV autotransformer #1 - 108% of 280 MVA rating.
00:15 OOME Capricorn Ridge down Base case overload on Menard autotransformer - 104% of 42 MVA rating.
00:15 OOME Callahan down Base case overload on Menard autotransformer - 104% of 42 MVA rating.
00:15 OOME Buffalo Gap down Loss of San Angelo Red Creek 345/138kV autotransformer #2 overloads San Angelo Red Creed 345/138kV autotransformer #1 - 108% of 280 MVA rating.
01:00 OOMC/OOME Ferguson Loss of Menard - Gillespie 138kV overloads Menard 138/69kV autotransformer #1 - 108% of 46 MVA rating.
10:00 OOMC Colorado Bend Loss of STP - Blessing 345kV overloads Columbus - Stafford 69kV - 107% of 38 MVA rating. 
11:00 North - South OC1 North - South limit 647, actual 465 - 72%.  Loss of Temple Pecan Creek - Tradinghouse and Temple Switch - Lake Creek 345kV overloads Brownwood Switch - Goldthwaite 138kV - 107% of 143 MVA rating.
11:15 North - Houston OC1 North - Houston limit 2985, actual 2985 - 100%.  Loss of King - Kuykendahl - Roans Prairie and Jewett - Tomball 345kV overloads Gibbons Creek - Obrien 345kV - 101% of 1487 MVA rating.
12:30 OOME Stryker up Loss of Elkton - Tricorner & Martin Lake 345kV overloads Tyler Northeast - Delek POI 138kV - 105% of 248 MVA rating.
13:00 Fleet up in Houston Zone North - Houston limit 3163, actual 3558 - 112%.  Loss of King - Kuykendahl - Roans Prairie and Jewett - Tomball 345kV overloads Gibbons Creek - Obrien 345kV - 115% of 1470 MVA rating.
14:15 OOME Laredo up  Laredo Import limit 350, actual 330 - 94%
19:15 OOME Monticello down Monticello SES - Allen Switch & Sulphur Springs Switch 345kV overloads Farmerville TU - Royse Switch 345kV - 126% of 1072 MVA.

Other Notable Events

Start End Event
00:15 24:00 Alert Level Yellow Elevated
04:25 04:45 Deployed 458 MW of Responsive Reserve Service from actual adjusted Responsive Reserve of 4894 MW with an obligation of 2300 MW when frequency dropped to 59.882 HZ when XXXX tripped with 618 MW.  ERCOT load 33364.
13:16 14:16 Emergency notice issued due to a potential voltage collapse in the Houston area with the loss of double circuit Jewett - TH Wharton and Tomball 345KV.