A Novel Frequency Regulation Strategy with the Application of Energy Storage System for Large Scale Wind Power Integration

Abstract

Integration of large scale wind power is both economical and environmentally-friendly. However, stochasticity and intermittency of wind power bring new challenges to frequency stability issue of the wind power system. The frequency regulation capacity limitation of the power system is one of the most important reasons limiting integration capacity of wind power. The power output of energy storage system (ESS) can be regulated very rapidly. Hence, it is feasible and effective for ESS to participate in system frequency regulation. This will increase overall system frequency regulation capacity and thus helps accommodating more wind power integrated into the power grid. A novel strategy for ESS to participate in frequency regulation is proposed in this paper. The control strategy includes two stages: in the first stage, ESS regulates its power output based on the wind power prediction information, in the second stage, frequency feedback is used to regulate the ESS power output to further reduce steady state frequency deviation. Since the ESS power output can be regulated before the frequency deviation happens, the dynamic response speed of frequency regulation of ESS can be significantly improved. Besides, frequency deviation can be decreased thanks to the step command in the first stage. Simulation of a wind power system is performed in Real Time Digital Simualtor (RTDS) and the results show the effectiveness of the proposed method.