Against the shortcomings of intermittency and instability of photovoltaic power generation in microgrids

a hybrid energy storage system composed of vanadium redox batteries(VRB) and super capacitors(SC) is utilized to smooth out the power fluctuations in standalone microgrids

thus to improve the power supply reliability of standalone microgrids. Considering the capacity allocation problem of the hybrid energy storage system

a multi-objective hybrid energy storage system capacity optimization model that minimizes the average annual cost of the hybrid energy storage system and the load shortage rate is developed. Aiming at the poor local search ability of the conventional elite non-dominated solution sorting genetic algorithm(NSGA-Ⅱ) algorithm for solving the multi-objective optimization problem

an NSGA-Ⅱ algorithm based on the improved elite retention strategy is proposed. By introducing a new fitness function

the algorithm is sorted and reasonably retains the elite individuals

so it improves the optimization effect

thus to enhance the local search ability

continuously approach the Pareto true frontier

and obtain better capacity configuration solutions. Finally

the rationality of the proposed method is verified by arithmetic examples.