Study on Influence of "S" Shape Characteristics on Unit Performence in Pump-turbine Operation

During of the designing of a pump-turbine,the "S" shape performance on the turbine 4 quadrant diagram n_(11)-Q_(11)will deeply affect the daily operation of a pumped-storage power station.This article analyzes the courseof the "S"shape performance physically and its influence theoretically.The influence in the practical operation of a pumped-storage power station is described.Some ways to solve this problem are presented.