An Improved Droop Control Strategy of Distributed Energy Storage Systems in Microgrids

Load power balance between the distributed generations is an important issue in microgrid control. In order to achieve the power balance, droop control is considered to be an effective method due to the ability of plug and play. However, the traditional droop control strategy of the DC microgrid has the problems of low current sharing accuracy and voltage deviation. Aiming at this defect, an improved droop control strategy for the distributed energy storage system of microgrid is proposed. In this method, the state of charge (SOC) is estimated to realize the SOC balance in the discharge process. The simulation results show that the SOC values are balanced before the end of discharge, which verifies the effectiveness of the improved droop control strategy.