Starting methods for generator/motor units employed in pumped-storage stations

Arrangements which must be made for starting reversible pumped-storage plant in the pumping mode are reviewed, and the alternative starting methods are discussed. It is necessary to study the starting process in detail, together with the effect this has on the power system, because of the capacity of large pumped-storage plant, with the requirement that the machines be started during periods of low demand. The method chosen must be technically sound, reliable and economic. Two starting methods are considered in detail: asynchronous starting and synchronous starting. Disturbances imposed on the power system by the starting process are particularly important in asynchronous starting. The method discussed is related principally to the Korndorfer procedure. The effect on starting performance of varying the system constraints, together with the effect of other criteria, is examined. Theoretical predictions are compared in specific cases with test results obtained on conventional hydroelectric plant relating to both asynchronous and synchronous starting, to verify the representation employed. Typical theoretical results relating to 2 × 150MW and 4 × 300MW schemes are given.