SPP REPORT ON JULY 17, 2001 TLR EVENT On July 17, 2001, SPP initiated a TLR on the LacStiLacWgr flow gate, #5023, that proceeded to the point of firm curtailments. In response to NERC reporting requirements, SPP prepared a report on this event addressing thirteen bullet points associated with an initial investigation. The following is the report submitted by SPP for the July 17 LacStiLacWgr TLR event addressing each of those points. 1. Description of purpose/cause of curtailment The purpose of the TLR initiated by SPP on July 17, 2001 was to relieve the LaCygne- Stilwell 345 kV line (Monitored Element) of excessive south to north flows that would have resulted from an unexpected loss of the LaCygne-West Gardner 345 kV line (Contingency Element). This facility is modeled as a flow gate labeled “LacStiLacWgr” (flow gate # 5023) 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 had an emergency rating of 1243 MVA based on disconnect switches at the Stilwell line terminal. This rating is higher than that reported during previous TLR Level 5 events because KCPL discovered that the previous limiting factor, wave traps at both ends of the line, actually had a higher rating than they had been using. The post-contingency flow on the Monitored Element had exceeded 1300 MW prior to the time the TLR Level 5A was initiated. Loading at the time the TLR Level 5A was issued was 1329 MW as indicated in the NERC TLR Procedure Log, Attachment A, for the event. 3. TLR levels, timing and relief requested amounts Attachment A contains the NERC TLR Procedure Log for the July 17 TLR event on the LacStiLacWgr flow gate. This log contains timing of TLR actions, TLR levels, the number, priority and amount of curtailments. All times are in CST. 4. Transmission and Generation outages or changes from prediction that may have contributed. Abnormally heavy flows from the south to the north contributed significantly to the loading on the LacStiLacWgr flow gate. These heavy flows were caused by a combination of warm temperatures in the MAIN and MAPP regions and generation limitations north of the flow gate in the SPP, MAIN and MAPP regions. WR’s Jeffrey #1 Unit (744MW) was off-line due to a forced outage. This plant is located just northwest of the flow gate. Three generating units in MAIN were out-of-service due to forced outages (see table below) on the 17th. MAPP also reported three unit deratings just to the north of the flow gate at MEC’s Council Bluffs #3 (237 MW derate) and Louisa #1 (87 MW derate) and NPPD’s Cooper #1 (62 MW derate).
