Research on Grid-Connection Failure Mechanisms and New Start-up Strategies of Pumped Storage Power Station Under Low Water Head

This paper investigates the grid-connection failure mechanisms and new start-up strategies of the pumped storage power station (PSPS) under low water head. Firstly, the simulation model of a PSPS is established for grid-connection under the low water head. Then, the cause of the gird-connection failure of a PSPS is analyzed. Finally, the two new start-up strategies are provided and verified. The results indicate that the simulation model of a PSPS is verified to be of high accuracy. There may be an unstable region in the small guide vane opening (GVO) in turbine operation, where the trajatory passes, and the speed of the pumped storage unit (PSU) will fluctuate greatly, resulting in grid-connection failure. The new start-up strategies can meet the requirements of grid-connection under extremely low water head, in which strategy 1 has a short time and strategy 2 is relatively stable.