Improved Droop Control Strategy Based on Energy Storage Inverter in Microgrid System

In microgrid system, the droop control is often adopted in the energy storage device. Since the main control unit in microgrid mostly adopts droop control, energy storage system usually distributes load power evenly with it when it is operating. In this way, the essential function of "peak load shaving" of the energy storage system will be weakened, and the amplitude and frequency of output voltage will be in an "uncontrollable" state. In order to solve the mentioned problem, an improved droop control method for energy storage system is proposed in this paper. Adjusting the output power of energy storage system according to the change of voltage and frequency of AC bus. Finally, the "peak load shaving" of active power and the "on-demand supply" of reactive power in energy storage system are realized. Simulation results are provided to validate the proposed method.