Abstract: Cascaded energy storage power conversion system is widely used in high voltage and large capacity

occasions，it plays a role of peak shaving and valley filling for power system，its control strategy directly affects the

performance and reliability of energy storage system. Therefore，in recent years，the research on the control strategy of cascade energy storage power conversion system attracts wide attention，and scholars at home and abroad did a lot of research on it，which can be divided into power control，balanced control and fault-tolerant control. According to these aspects，the control strategies of cascade energy storage power conversion system were classified，generalized and summarized ，its principles，characteristics and application conditions of different control strategies were analysed，and its development trend was discussed，so as to provide a reference for the research and engineering application of control strategy of cascade energy storage power conversion system.

    Key words: cascaded multilevel；energy storage；power conversion system（PCS）；control strategy