ANINQUIRYINTOADJUSTABLE SPEEDOPERATION OFA PUMPEDHYDROPLANT PART1 - MACHINEDESIGNANDPERFORMANCE

Thepossibility ofvariable speedoper- ationofa pumpedhydroplantisproposed byproviding an asynchronous tiebetweenthehydrositeandmainac grid.Variable speedoperation resultsina substantial improvement in systemefficiency and improvedsystem performance, as wellas new flexibility inhydroplant sitingandmachinedesign.Theproblems associated with applyingconventional synchronous generator technology toadjustable speedare evaluated andproblemareas are identified.