Abstract:
This paper proposes a method of multi-mode operation and switching scenarios for microgrid systems with flexible multi-state switches. Firstly, the system is divided into 320 operating modes based on the characteristics of communication mode, topology structure, and load state. Then, an in-depth analysis is conducted on the power transmission balance relationship and inherent switching logic under different operating modes. By applying control strategies, the active power control instructions for voltage source converters (VSC) in multi-mode operation are obtained, which achieves stable operation and seamless switching of the system, load balancing of the feeder lines, and automatic control of the main transformer overload. Finally, the reliability of the proposed control strategy is verified through simulations, and the influence of communication delay on distributed control is analyzed. The simulation results demonstrate that the proposed control strategy can ensure stable operation and flexible switching of AC/DC hybrid microgrid systems under different operating modes.