A Review on Control Strategies of Grid-connected Energy Storage Systems for Frequency Regulation

With the escalating ratio of renewable energy in the modern power system, the unpredictability and instability of renewable energy significantly impact the electricity reliability of the system. Simultaneously, the extensive integration of power electronic devices has resulted in increased damping and inertia losses within the power system, seriously affecting its frequency stability. Due to its shortcomings, such as long start-up times and slow frequency response, traditional frequency regulation units have been incapable of meeting the frequency regulation needs of new power systems. Therefore, Battery Energy Storage Systems (BESS), with their frequency support capability and fast response rate, have garnered considerable attention for application. The participation of BESS in the auxiliary market has also emerged as a key focus of research. This paper initially presents the grid-connected control strategy of BESS, subsequently analyzing the research status of BESS providing primary and secondary frequency regulation services in power systems, and offering prospects for further research trends.