Capacity configuration of battery energy storage as an alternative to thermal power units for frequency regulation

Traditional frequency regulation units rarely achieve real-time output equal to the theoretical values because of their inherent characteristics, leading to operation out of the economic zone. It is hard for these units to meet the demands of maintaining power system frequency stability with rapid development of grid involving renewable resources. Battery energy storage system(BESS) has advantages of fast response and precise tracking, providing a new frequency regulation method. On the basis of the use of energy storage for frequency regulation, the capacity configuration of BESS is made as an alternative to generator with the same capacity for the frequency regulation. A capacity control strategy for the energy storage has also been proposed. Exemplar calculations and comparative analysis are conducted to verify the feasibility of proposed capacity configuration methods and the reliability of the energy storage system for regulation.