Analysis and Suppression Strategy of Transient Frequency Deviation by Soft Guide Vane Control in Hydro Turbine

Abstract

Abstract The hydro-dominant characteristic is notable after the asynchronous operation in Southwest China Power Grid which brings worse transient frequency deviation caused by water hammer effect. To prevent the possible cascading failure due to the worse transient frequency deviation in the secondary frequency regulation, the soft guide vane control law is proposed to suppress the water hammer effect in the transient regulation process based on the detailed turbine-penstock model. The discrete state space expression of the turbine-penstock model is built to simulate the regulation effect in the time domain and the PSO (Particle Swarm Optimization) algorithm is applied to optimize the soft guide vane control adjustment factor considering multi-object. Finally, the emergency AGC (Automatic Generation Control) adjustment in the single machine with load transmission system is conducted to verify the effect of transient frequency deviation suppression by optimized soft guide vane control.