Cooperative control strategy for frequency regulation of wind-pumped storage system considering wind speed partition

Abstract

In order to solve the problem of system inertia reduction and frequency response degradation caused by large-scale wind power interconnection, a strategy is proposed. This strategy incorporates a joint system model composed of doubly-fed wind turbine (DFWT) and variable speed pumped storage (VSPS), utilizing a fuzzy controller to dynamically determine the virtual inertia coefficient of the wind-pumped storage system based on the frequency state of the system, and adjusts the frequency-regulation participation factor of the DFWT in real time according to the operating conditions of it. The simulation results show that the proposed strategy can not only significantly improve the frequency nadir, speed up the system frequency and each generating unit in the system to restore to steady state, but also avoid the second frequency drop (SFD) caused by the wind farm out of primary frequency regulation (PFR), and improve the stability of the system frequency.