Capacity optimization of a stand-alone microgrid system using charged system search algorithm

This paper proposes a novel method to solve the optimal capacity allocation problem for a stand-alone microgrid system. The stand-alone microgrid is usually found on offshore islands or in the areas where electric power cannot be delivered by the utility electric companies. Traditionally, the loads in a stand-alone microgrid are mainly supplied electric power from diesel generators. With continuing the development of renewable energy, the photovoltaic, wind turbine generator and battery energy storage system are integrated into stand-alone microgrid that reduces generation cost, mitigates environment emission and increases generation efficiency. To determine the complicated optimization problem, a combination of Monte Carlo simulation and charged system search algorithm is used in this paper. The proposed scheme comprises both the inner loop to determine the hourly schedule of distributed energy resources and outer loop to optimize the capacity of distributed energy resources in life cycle. The proposed method is tested on a stand-alone microgrid system in Taiwan. To verify the feasibility of the proposed method, comparisons are made to the differential evolution and particle swarm optimization approaches.