The Dooms-Lexington 500-kV line in Virginia will begin an extended outage next month and through winter to accommodate a rebuild of the 40-mile span.
The rebuild (Regional Transmission Expansion Plan project b1908) was ordered to prevent overloads on the line following the retirements of Chesapeake Units 1-4 and Yorktown Unit 1 generators.
The line will be out of service from Sept. 8 through June 5, 2015, returning to service for summer 2015 and then going offline again from Sept. 7, 2015 through Dec. 31, 2015.
To avoid limiting the output of the Bath County pump storage hydro plant, a special protection scheme (SPS) will be armed as needed to trip the Bath County generating and pump units on the loss of the Bath County-Valley 500-kV line. An existing Bath County “thermal” SPS will continue to be used as needed.
The project will also cause a potential thermal constraint on Valley transformer 1 for loss of the Dooms-Valley or Cloverdale transformers. Low voltages are possible from the loss of Bath County-Valley.
PJM authorized continuing work through the winter to reduce the overall outage duration by at least six months and coordinate it with other RTEP outages: the Cloverdale-Lexington 500-kV line in 2016 (AEP); the Cunningham-Elmont 500-kV line in 2016/2017; the Dooms-Cunningham 500-kV line in 2018; and the Mt. Storm-Valley 500-kV line in 2019/2021.
PJM planners identified no reliability issues during the winter outage. The rebuild is expected to be completed by June 2016.
