Design and testing of a back-to-back starting system for pumped storage hydrogenerators at Mt. Elbert Powerplant

The design and testing of a back-to-back starting system for pumped storage hydrogenerators is described. Marginal reliability of the existing static starting system adversely affected availability of the two 170000 hp pumps. An alternative method of starting a unit in the pump mode was needed to increase plant availability and to provide interim starting capability for a planned static starter replacement. A back-to-back starting system that allows one unit, operating in generate mode, to synchronously start the other unit as a motor was designed. Field testing demonstrated the viability of back-to-back starting of the pumped storage units.>