SOC Balancing Control Strategy of DC Microgrid Energy Storage System Based on Droop Control

In a distributed energy storage system (DESS), unbalanced state of charge (SoC) of each energy storage will cause one of the energy storage systems (ESSs) first discharge completely and then exit the system, thereby accelerating the discharge speed of the remaining ESS and shortening the service life of the whole system. Based on the SoC balancing, this paper introduces a droop control, in which, an acceleration coefficient is proposed to adjust the speed of current distribution rate. The proposed control strategy is able to accelerate the speed of the SoC balancing process and maintain optimal power quality. The correctness of this control strategy is verified by building a MATLAB/Simulink simulation model.