Hierarchical Voltage Cooperative Optimization of AC Microgrids Based on Model Predictive Control

A method for hierarchical voltage cooperative optimization using model predictive control (MPC) is proposed to enhance the dynamic response in an AC microgrid (MG). The method adopts a two-layer optimization strategy by minimizing predictive errors to reduce voltage fluctuations which hybrid PV-BESS system brings. In the inner-level, VSG-control is used as the primary control of distributed generation (DG). Further a secondary control action based on consistency ensures the voltage recovery and power average distribution. On this basis, the outer layer is a rolling optimization, and real-time reactive power is compensated by static var generator (SVG) whose controller is replaced by model predictive control (MPC) to prevent the further voltage drop. Meanwhile, the deviation of voltage and frequency can be eliminated gradually in the hierarchical voltage cooperative control using feedback correction, which ensures the stable operation of the MG. The efficiency of the proposed method is verified by discussion and analysis of the simulation results.