Inverter Technology Engineering Research Center of Beijing, North China University of Technology, Beijing 100144, China

Reliability and economy are two important references for capacity configuration of islanded microgrids with photovoltaic (PV) and energy storage systems (ESSs). However, it is hard to achieve the optimum simultaneously. In order to coordinate the contradiction, a capacity configuration method of islanded microgrids with PV and ESS considering reliability and economy is proposed. This method evaluates and analyzes the reliability and economy from two aspects of capacity and power by using the probability, frequency and duration indices. Then, configuration schemes of different load points integrated into the microgrid with PV and ESS are compared and studied.The results show that under a certain energy storage configuration, the increase of PV capacity can optimize the probability indices, but the frequency and duration indices show non-monotone performance. A reasonable energy storage configuration can further optimize the probability indices and lower or flatten the impact of the average interruption frequency index on microgrids. Installing a microgrid at a location with lower load level can achieve the best compromise between the reliability and the total cost.