A Stepwise Coordinated Primary Frequency Regulation Strategy Considering Renewable Energy Sources and Energy Storage Systems

Primary frequency regulation is an important issue to ensure frequency stability in power systems and the control strategy will become more flexible with the integration of renewable energy sources (RESs) and energy storage systems (ESSs). In order to realize fast frequency recovery in power systems, a strategy which cooperates with RESs and ESSs for primary frequency regulation is proposed in this paper. The proposed method utilizes the difference of response time and regulating capacity of RESs and ESSs in frequency characteristics to build a stepwise frequency support strategy. Different stations assume the active power deficiency in power systems in sequence and the system frequency recovery speed is faster comparing with the traditional primary frequency regulation by adjusting synchronous generators only. The effectiveness of proposed coordinated strategy is demonstrated by simulation results in MATLAB/Simulink.