Optimization method for WT–PV reserve power and BESS capacity considering combined FR of WT–PV–BESS system

Renewable energy stations can weaken the impact of renewable energy interconnection and its fluctuations in grid frequency by reserving reserve power and equipping battery energy storage system (BESS) devices. Taking into account reserve power and meeting complete frequency constraints, it is urgent to solve how to reasonably allocate BESS capacity. Therefore, this paper proposes an optimization method for the wind turbine (WT) and photovoltaic (PV) reserve power and BESS capacity considering the combined frequency regulation (FR) of WT–PV–BESS. First, a system frequency response model is constructed for WT–PV–BESS to participate in FR, and an analytical formula for frequency deviation is derived considering WT–PV–BESS FR. Second, the BESS capacity configuration and WT–PV reserve power optimization model are constructed to optimize reserve power and configure BESS capacity with the objectives of the economic evaluation index and FR effect evaluation index. Finally, MATLAB/CPLEX is used to solve the optimization schemes for BESS capacity and reserve power in different scenarios. The simulation results show that the method achieves the optimal configuration of WT–PV reserve power and BESS capacity while maintaining system stability and economy.