The distributed energy storage system in microgrid has developed rapidly in recent years, which has significant ad-vantages in stabilizing energy fluctuations. However, in practical application, the energy balance of each subsystem in the distributed energy storage system will bring hidden dangers to the safe and reliable operation of microgrid. Therefore, this paper proposes an improved droop control based on model predictive control. In this paper, the power control instructions of each port in the distributed energy storage system are obtained by using the model prediction theory, taking the energy balance as the control objective and the nature of the energy storage elements as the constraints. According to the power instruction, the real-time updated droop coefficient is generated. Through the change of droop coefficient, the real-time power redistribution is carried out for each subsystem, so as to achieve the energy balance of each subsystem. Finally, the simulation results based on MATLAB / Simulink model are given to verify the feasibility of the proposed droop control based on model prediction.

Micro power grid; distributed energy storage system; weak communication network; model predictive control; droop control