Islanded Microgrid Hybrid Energy Storage Reliability Analysis Strategy Using State Cluster Partitioning

Different topologies and operating states of hybrid energy storage systems have a great impact on the reliability of islanded microgrids, but there is a lack of quantitative evaluation methods. This paper proposes a reliability evaluation strategy of islanded microgrid based on hybrid energy storage systems and state cluster classification. Firstly, according to the topology of lithium battery and bidirectional DC/DC semi-active hybrid energy storage system, combined with Markov theory, the reliability model of 32 states is established, and the state probability of 4 operating modes is obtained after state summary. Then, based on the classification of state clusters of hybrid energy storage system, the reliability evaluation of islanded microgrid with hybrid energy sources is carried out by using minimum load reduction strategy to ensure the overall load power supply. Finally, a numerical example verifies that the state cluster classification reliability model of hybrid energy storage system can improve the reliability index of islanded microgrid compared with lithium battery energy storage system.