1.电力系统及发电设备控制和仿真国家重点实验室，清华大学，北京市 100084;2.国网北京市电力公司，北京市 100031
1.State Key Laboratory of Control and Simulation of Power System and Generation Equipments, Tsinghua University, Beijing 100084, China;2.State Grid Beijing Electric Power Company, Beijing 100031, China
This work is supported by State Grid Corporation of China (No. 5202011600UH).
To address the issue of state of charge (SOC) unbalance in cascaded battery energy storage system, this paper analyzes the boundary conditions of over-modulation with unity power factor for balancing control strategy when SOC is extremely imbalanced and proposes a novel balancing control strategy of SOC in phase with injection of reactive power. By superimposing the active and reactive voltage components to each H-bridge modulation signal and redistributing active power and reactive power, this strategy can ensure that the batteries with extreme SOC mainly exchange active power, while other batteries mainly exchange reactive power. Therefore, it can effectively reduce the modulation ratio of the batteries with extreme SOC, while slightly increase the modulation ratio of other batteries, and avoid over-modulation. Compared with the balancing control strategy with unity power factor, this strategy can fully coordinate the modulation ratio of each module by controlling the power factor angle and expand application scope of balancing control with bigger difference between SOC of each battery. The simulation results verify the correctness and effectiveness of the proposed control strategy.
CHEN Shuyu,LIU Wenhua,ZHAO Xianghua,et al.Balancing Control Strategy of State of Charge for Cascaded Battery Energy Storage System with Injection of Reactive Power[J/OL].Automation of Electric Power Systems,http://doi.org/10.7500/AEPS20190823004.