PJM on Wednesday ordered its second load-shed event since implementing Capacity Performance in 2015, less than two months after ordering the first. (See PJM Experiences First Load Shed in the CP Era.)

Both events were in the American Electric Power zone.

The July 18 event occurred on the border between West Virginia and Virginia, PJM spokesperson Jeff Shields said. An AEP equipment issue led to other equipment being taken out of service, which resulted in “severe” low voltages in the area around Bluefield and Princeton in West Virginia.

PJM called on AEP at 11:14 a.m. to reduce load in the area by 32 MW to return the voltages to acceptable levels. Keeping the voltages low would have risked “potential further voltage problems and equipment damage that could cause wider problems,” Shields said, but assured that didn’t include any potential for cascading outages.

The order lasted for 83 minutes until PJM canceled it at 12:37 p.m. after the equipment was returned to service. Approximately 13,000 customers were affected.

While both events trigger the significant performance-related bonuses and penalties introduced with CP, no resources were impacted by either incident. The May 29 event was caused by transmission equipment unexpectedly tripping offline in the area of several planned transmission line outages, causing constraints that had potential to cause a cascading outage. (See “Load Shed Details,” PJM Operating Committee Briefs: July 10, 2018.) Prior to these events, PJM last ordered load shedding during the 2013 heat wave.

PJM plans to review the most recent event at its Members Committee meeting on July 23.

— Rory D. Sweeney