An Inquiry into Adjustable Speed Operation of a Pumped Hydro Plant Part 1 - Machine Design and Performance

Abstract

The possibility of variable speed operation of a pumped hydro plant is proposed by providing an asynchronous tie between the hydro site and main ac grid. Variable speed operation results in a substantial improvement in system efficiency and improved system performance, as well as new flexibility in hydro plant siting and machine design. The problems associated with applying conventional synchronous generator technology to adjustable speed are evaluated and problem areas are identified.