SPP REPORT ON TLR EVENTS FROM FEBRUARY 13 MARCH 4, 2002

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Edward Richard
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1 SPP REPORT ON TLR EVENTS FROM FEBRUARY 13 MARCH 4, 2002 On seven occasions between February 13 and March 4, 2002, SPP initiated a TLR on the MorStiSooNor flow gate, #5067, that included firm service curtailments. In response to NERC reporting requirements, SPP prepared a report on these events addressing thirteen bullet points associated with an initial investigation. The following is the report submitted by SPP for the February 13-March 4 MorStiSooNor TLR events addressing each of those points. 1. Description of purpose/cause of curtailment The purpose of these TLRs initiated by SPP between February 13, 2002 and March 4, 2002 was to relieve the Morrison Tap-Stillwater 138 kv line (Monitored Element) of excessive flows that would have resulted from an unexpected loss of the Spring Creek- Northwest 345 kv line (Contingency Element). This facility is modeled as a flow gate labeled MorStiSooNor (flow gate # 5067) in the IDC for which an Outage Transfer Distribution Factor is calculated based on the loss of the Contingency Element. 2. Facility/flow gate limitations and flows at the time the TLR was initiated. The Monitored Element has an emergency rating of 191 MVA based on a wave trap limitation. In each of the TLR events, the calculated post-contingency flow on the Monitored Element had either exceeded, or was expected to exceed, the 191 MVA line rating. 3. TLR levels, timing and relief requested amounts Attachment A contains the NERC TLR Procedure Logs for the February 13-March 4 TLR events on the MorStiSooNor flow gate. These logs contain timing of TLR actions, TLR levels, and the number, priority and amount of curtailments. All times are in CST. Please note that the log for February 27 indicates that while a TLR was issued, the NNL calculation within the IDC was not functioning during the event. The NNL responsibility for OG&E was estimated based on previous experience with this flowgate. Estimates indicated that WFEC s NNL responsibility was less than 1 MW. Since this was an estimate and it was very small, WFEC was not requested to provide NNL relief during this event. 4. Transmission and Generation outages or changes from prediction that may have contributed. On January 30, 2002 a major ice storm hit south central Kansas and north central Oklahoma. Ice accumulations of 6 inches were recorded in some areas of this region. The electric systems of American Electric Power (AEP), Oklahoma Gas & Electric (OG&E), Western Farmers Electric Cooperative (WFEC) and Westar (WR) suffered significant damage resulting in numerous transmission line outages. During the TLR events covered in this report, kv lines and as many as kv lines in this area were out-of-service due to the ice storm. These lines are listed in Attachment B.

2 SPP Report on TLR Events on February 13-March 4, 2002 Most of these facilities were in an area north and west of a line running from Oklahoma City, OK to Tulsa, OK. This area is shown in a map in Attachment C. Three of the 345 kv lines terminated at OG&E s Woodring substation and included a major tie to Westar to the north and a critical line to OG&E s Sooner Plant (1,020 MW of generating capacity) to the east. Approximately 650 structures were down in these three lines alone. With the Sooner-Woodring line out, Sooner s only remaining 345 kv outlet was the Sooner-Spring Creek-Northwest 345 kv line. A 336 MW IPP, OneOk, is located at the Spring Creek station. Given this configuration, if the Spring Creek- Northwest 345 kv line trips, all of the Sooner generation and the OneOk generation is rerouted to the 138 kv system around Sooner. This system is not capable of handling this amount of generation with all 138 kv lines in the area in-service. With several 138 kv facilities in the area out-of-service, overloading is exacerbated. OneOk has a firm point-to-point transmission reservation out of OG&E, but since the bulk of OG&E s generation is south of the MorStiSooNor flowgate, the impact of this transaction on the flow gate is less than the 5% threshold according to TDF calculations by the IDC. Therefore any transaction utilizing this reservation does not show up in the IDC Adjust Lists. However, OneOk is included in the list of generators impacting the flowgate more than 5% in the Control Area NNL Responsibility table in the IDC. Thus whenever OneOk utilizes its firm service reservation, the post-contingency flow on the flowgate is projected to exceed the rating of the monitored element forcing a Level 5 TLR. 5. Procedures implemented prior to curtailment. Recognizing the situation, OG&E shut down Sooner 2 prior to February 13 in an effort to limit loading on the flowgate. A scheduled maintenance outage for Sooner 2 was subsequently accelerated in order to take advantage of this forced reduction. The output of Sooner 1 is adjusted continuously to maintain flow gate loading below its rating. 6. Complete Transaction Curtailment lists & comparison to IDC Transaction Lists both before and after curtailment. Attachment D contains the Congestion Management Reports including the initial and subsequent TLR Level 5 curtailment lists and the control area NNL responsibilities issued by the IDC for relief on the MorStiSooNor flow gate for the events of February 13 through March Known transactions not in the IDC & actions taken. SPP assumed that all transactions were in the IDC and was not aware of any transactions flowing that were not in the IDC. 8. SCIS or other system messages No additional messaging for this TLR was posted other than that through the IDC. SPP 2 4/12/02

3 SPP Report on TLR Events on February 13-March 4, State Estimator snapshots and security analysis including any contingency analysis or stability analysis along with any other recorded data indicating need for Transmission Loading Relief Attachment E contains screen prints of Flowgate Detail from the SPP EMS used to monitor post-contingency flows on the SPP flow gates. These particular prints were made as each TLR Level 5 was being taken. Only one of the prints, associated with the 1723 event on February 13, 2002, indicates that the flow gate loading was clearly beyond its emergency limit of 191 MVA. (The EMS time stamps are in CST.) This is because the TLR was not issued during this event until after the IPP s firm transaction had started to ramp in. Subsequent TLRs, except for the 0623 event on February 27, 2002, were declared in anticipation of the firm transaction starting thus preventing the overload of the flow gate and an emergency redispatch of generation in OG&E. The screen prints for February 13 contain some hand written values. This is because the display had not been updated to coincide with a change in the contingent element brought about by system topology following the ice storm. Note the change in the contingent element and the monitored element calculation between the screen prints taken on February 13 and those taken on February 15 which reflect the changes. Note also that the display became fully operational by the time the 0916 print was taken on the 15 th. Results from other periodic analyses of pre-contingency and post-contingency flows from the EMS can be found in the NERC TLR Procedure Logs in Attachment A. 10. ATC limitations before, during and after the TLR event. The MorStiSooNor flow gate had not experienced any heavy loading or low ATCs prior to the transmission outages caused by the ice storm. 11. Description of actions taken to avoid future curtailments Although there wasn t much that could have been done to prevent the ice storm related outages that brought on this series of Level 5 TLRs, OG&E, WFEC and Westar have done a commendable job of repairing and returning facilities to service. Work continues on a daily basis to ensure that all repairs are completed and the facilities returned to service before the summer peak season. 12. Re-dispatch actions taken. As mentioned previously OG&E assumed the burden of redispatching its Sooner generation to prevent overloading on the flow gate. This ultimately led to OG&E accelerating a maintenance outage on Sooner 2 to take advantage of the forced downtime. Additional redispatch action was not taken until the Level 5 TLRs were issued as covered in Item 13 below. 13. If firm transaction curtailment took place, description of Transactional Contribution Factor calculation and results as well as how necessary relief was obtained through network service and native load contribution. SPP used the Transactional Contribution Factor (TCF) calculation process explained in the Parallel Flow Calculation Procedure Reference Document to determine the amount of relief required by native load and network service. The actual calculation was SPP 3 4/12/02

4 SPP Report on TLR Events on February 13-March 4, 2002 performed using the IDC. The results of the calculations are shown in Attachment D, the IDC Congestion Management Reports (CMR), for the events of February 13 March 4. In each report the Control Area NNL Responsibility table details the relief to be provided by NNL. The summary of all curtailments, NNL responsibilities and pointto-point service, can be found in the Next Hour Reallocation/Reload Report or the Current Hour Transactions Curtailment List of each Level 5A or 5B, respectively, CMR. For each event, results indicated that generators serving native load or providing network service in the OG&E, WFEC and WR control areas contributed to the postcontingency loading on the Monitored Element. The curtailment prescriptions for each TLR issuance on each day are summarized in Attachment F. The table indicates the time of issue, a breakdown of the relief and how much NNL relief was actually provided by each control area. Because the impacting generators in the WR control area were not on-line during these events, WR was relieved of any NNL responsibility. OG&E and WFEC provided the native load and network service relief assigned to them by redispatch as noted in the attachment. WFEC was not asked to provide NNL relief during the February 28 event due to oversight on the part of the SPP Reliability Authority. SPP 4 4/12/02

5 NERC TRANSMISSION LOADING RELIEF (TLR) PROCEDURE LOG FILE SAVED AS: O:\SECURITY\SECURITY DOCUMENTS\NERC TLR Log\SPP_2002 INCIDENT : SPP_ DATE: 2/13/2002 IMPACTED SECURITY COORDINATOR : SPP ID NO: 5067 I N I T I A L C O N D I T I O N S The Sooner-Woodring 345 kv and other 138 kv lines in the vicinity of Sooner remain out-of-service due the ice storm of January 30, 2002 Limiting Flowgate (LIMIT) Rating Contingent Flowgate (CONT.) ODF Morrison Tap - Stillwater 138 kv line 191 Sooner - Northwest 345 kv 45% TLR Levels Priorities NX Next Hour Market Service 0: TLR Incident Canceled NS Service over secondary receipt and delivery points 1. Notify Security Coordinators of potential problems. NH Hourly Service 2: Halt additional transactions that contribute to the overload ND Daily Service 3a and 3b: Curtail transactions using Non-firm Transmission Service NW Weekly Service 4. Reconfigure to continue firm transactions if needed. NM Monthly Service 5a and 5b: Curtail Transactions using Firm Transmission Service. NN Non-firm imports for native load and network customers from 6: Implement emergency procedures. non-designated network resources F Firm Service T L R A C T I O N S TLR 3,5 TLR 3,5 LIMIT CONT. LEVEL TIME Priority NO. TX MW Present Post-Cont. Present C O M M E N T S A B O U T A C T I O N S Curtail Curtail Flow Flow Flow 5B Issued TLR Level 5B, OG&E and WFEC redispatched generation to relieve flowgate loading Reissued TLR as Level 5A, released some redispatch OG&E and WFEC 5A A Reissued TLR Leve 5A, released additional redispatch Reissued TLR as Level 0

6 NERC TRANSMISSION LOADING RELIEF (TLR) PROCEDURE LOG FILE SAVED AS: O:\SECURITY\SECURITY DOCUMENTS\NERC TLR Log\SPP_2002 INCIDENT : SPP_ DATE: 2/15/2002 IMPACTED SECURITY COORDINATOR : SPP ID NO: 5067 I N I T I A L C O N D I T I O N S The Sooner-Woodring 345 kv and other 138 kv lines in the vicinity of Sooner remain out-of-service due the ice storm of January 30, 2002 Limiting Flowgate (LIMIT) Rating Contingent Flowgate (CONT.) ODF Morrison Tap - Stillwater 138 kv line 191 Sooner - Northwest 345 kv line 45% TLR Levels Priorities NX Next Hour Market Service 0: TLR Incident Canceled NS Service over secondary receipt and delivery points 1. Notify Security Coordinators of potential problems. NH Hourly Service 2: Halt additional transactions that contribute to the overload ND Daily Service 3a and 3b: Curtail transactions using Non-firm Transmission Service NW Weekly Service 4. Reconfigure to continue firm transactions if needed. NM Monthly Service 5a and 5b: Curtail Transactions using Firm Transmission Service. NN Non-firm imports for native load and network customers from 6: Implement emergency procedures. non-designated network resources F Firm Service T L R A C T I O N S TLR 3,5 TLR 3,5 LIMIT CONT. LEVEL TIME Priority NO. TX MW Present Post-Cont. Present C O M M E N T S A B O U T A C T I O N S Curtail Curtail Flow Flow Flow Issued TLR Level 5A, OG&E and WFEC redispatched generation to relieve flowgate loading in anticipation of firm transaction scheduled to start at A A Reissued TLR as Level 5A, redispatch held at previous hour's level Reissued TLR as Level 0 Issued TLR Level 5A, OG&E and WFEC redispatched generation to relieve flowgate loading in anticipation of firm transaction scheduled to start at A Reissued TLR as Level 0

7 NERC TRANSMISSION LOADING RELIEF (TLR) PROCEDURE LOG FILE SAVED AS: O:\SECURITY\SECURITY DOCUMENTS\NERC TLR Log\SPP_2002 INCIDENT : SPP_ DATE: 2/27/2002 IMPACTED SECURITY COORDINATOR : SPP ID NO: 5067 I N I T I A L C O N D I T I O N S The Sooner-Woodring 345 kv and other 138 kv lines in the vicinity of Sooner remain out-of-service due the ice storm of January 30, 2002 Limiting Flowgate (LIMIT) Rating Contingent Flowgate (CONT.) ODF Morrison Tap-Stillwater 138kv line 191 Sooner-Northwest 345kv line 45% TLR Levels Priorities NX Next Hour Market Service 0: TLR Incident Canceled NS Service over secondary receipt and delivery points 1. Notify Security Coordinators of potential problems. NH Hourly Service 2: Halt additional transactions that contribute to the overload ND Daily Service 3a and 3b: Curtail transactions using Non-firm Transmission Service NW Weekly Service 4. Reconfigure to continue firm transactions if needed. NM Monthly Service 5a and 5b: Curtail Transactions using Firm Transmission Service. NN Non-firm imports for native load and network customers from 6: Implement emergency procedures. non-designated network resources F Firm Service T L R A C T I O N S TLR 3,5 TLR 3,5 LIMIT CONT. LEVEL TIME Priority NO. TX MW Present Post-Cont. Present C O M M E N T S A B O U T A C T I O N S Curtail Curtail Flow Flow Flow 5A , Issued TLR Level 5A, OG&E redispatched generation to relieve flowgate loading in anticipation of firm transaction scheduled to start at IDC did not provide NNL responsibilities, therefore redispatch amounts were estimated. 5A Reissued TLR Level 5A, OG&E continues to redispatch generation to relieve flowgate loading in anticipation of firm transaction scheduled to run at IDC did not provide NNL responsibilities, therefore redispatch amounts were estimated Reissued TLR as level 0

8 NERC TRANSMISSION LOADING RELIEF (TLR) PROCEDURE LOG FILE SAVED AS: O:\SECURITY\SECURITY DOCUMENTS\NERC TLR Log\SPP_2002 INCIDENT : SPP_ DATE: 2/28/2002 IMPACTED SECURITY COORDINATOR : SPP ID NO: 5067 I N I T I A L C O N D I T I O N S The Sooner-Woodring 345 kv and other 138 kv lines in the vicinity of Sooner remain out-of-service due the ice storm of January 30, 2002 Limiting Flowgate (LIMIT) Rating Contingent Flowgate (CONT.) ODF Morrison Tap - Stillwater 138 kv line 191 Sooner - Northwest 345 kv line 45% TLR Levels Priorities NX Next Hour Market Service 0: TLR Incident Canceled NS Service over secondary receipt and delivery points 1. Notify Security Coordinators of potential problems. NH Hourly Service 2: Halt additional transactions that contribute to the overload ND Daily Service 3a and 3b: Curtail transactions using Non-firm Transmission Service NW Weekly Service 4. Reconfigure to continue firm transactions if needed. NM Monthly Service 5a and 5b: Curtail Transactions using Firm Transmission Service. NN Non-firm imports for native load and network customers from 6: Implement emergency procedures. non-designated network resources F Firm Service T L R A C T I O N S TLR 3,5 TLR 3,5 LIMIT CONT. LEVEL TIME Priority NO. TX MW Present Post-Cont. Present C O M M E N T S A B O U T A C T I O N S Curtail Curtail Flow Flow Flow Issued TLR Level 5B, OG&E redispatching generation to relieve overload on 5B flowgate Reissued TLR as Level 0 5A 0809 Issued Preliminary TLR Level 5A 5A , Reissued TLR as Level 5A Final -- OKGE redispatched generation in anticipation of firm transaction scheduled to start at Reissued TLR as Level 0

9 NERC TRANSMISSION LOADING RELIEF (TLR) PROCEDURE LOG FILE SAVED AS: O:\SECURITY\SECURITY DOCUMENTS\NERC TLR Log\SPP_2002 INCIDENT : SPP_ DATE: 3/4/2002 IMPACTED SECURITY COORDINATOR : SPP ID NO: 5067 I N I T I A L C O N D I T I O N S The Sooner-Woodring 345 kv and other 138 kv lines in the vicinity of Sooner remain out-of-service due the ice storm of January 30, 2002 Limiting Flowgate (LIMIT) Rating Contingent Flowgate (CONT.) ODF Morrison Tap-Stillwater 138kv line 191 Sooner-Northwest 345kv line 45% TLR Levels Priorities NX Next Hour Market Service 0: TLR Incident Canceled NS Service over secondary receipt and delivery points 1. Notify Security Coordinators of potential problems. NH Hourly Service 2: Halt additional transactions that contribute to the overload ND Daily Service 3a and 3b: Curtail transactions using Non-firm Transmission Service NW Weekly Service 4. Reconfigure to continue firm transactions if needed. NM Monthly Service 5a and 5b: Curtail Transactions using Firm Transmission Service. NN Non-firm imports for native load and network customers from 6: Implement emergency procedures. non-designated network resources F Firm Service T L R A C T I O N S TLR 3,5 TLR 3,5 LIMIT CONT. LEVEL TIME Priority NO. TX MW Present Post-Cont. Present C O M M E N T S A B O U T A C T I O N S Curtail Curtail Flow Flow Flow 5A Issued Preliminary TLR Level 5A in anticipation of firm transaction starting at Redispatch required to prevent flowgate overloading. 5A Reissued TLR as Level 5A Final, requested redispatch by OG&E and WFEC generation Reissued TLR as Level 0, EES curtailed transaction that was firm in SPP as non-firm transaction in EES for TLR on Weber-Richard flowgate. Issued TLR Level 5A in anticipation of firm transaction starting at OG&E and WFEC requested to redispatch to prevent flowgate overloading. 5A A Reissued TLR Level 5A, relieved some redispatch by OG&E and WFEC generation 5A Reissued TLR Level 5A, relieved additional redispatch by OG&E and WFEC generation Reissued TLR as Level 0, firm transaction scheduled to end at 1000

10 Transmission Line Outages Caused by the Ice Storm 345 kv Neosho-Rose Hill (WR) Woodring-Cimarron (OG&E) Woodring-Sooner (OG&E) Woodring-Wichita (OG&E/WR) 138 kv Altoona-Butler (WR) Clinton Junction-Weatherford Junction (CSWS) Cow Creek-Morrison Tap (OG&E) Dover-Okeene (WFEC) Hennessey-Dover (WFEC) Hydro-Weatherford (WFEC) Jensen Road-Weatherford Junction (CSWS) Otter-Woodring (OG&E) Sara-Cimarron (OG&E) Waukomis Tap-South 4 th Street (OG&E) Waukomis Tap-Woodring (OG&E) Woodring-Cottonwood Creek (OG&E)

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59 MorStiSooNor TLR NNL Relief Date Issue Relief NNL Relief Time Non-firm Firm NNL Total CA Contribution Provided 2/13/ : OG&E WFEC : OG&E WFEC : OG&E WFEC /15/2002 6: OG&E WFEC : OG&E WFEC : OG&E WFEC /27/02 1 8: OG&E : OG&E /28/2002 6: OG&E WFEC : OG&E WFEC /4/02 2 6: OG&E WFEC : OG&E WFEC : OG&E WFEC NNL responsibilities not calculated by the IDC 2 - Level 5 TLR initially issued at 0504 but reissued as a Level 0 at 0542 because of tag adjustments

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