Control Strategy of Seamless Operation Mode Switch for AC/DC Hybrid Microgrid

On the background of an AC/DC hybrid microgrid on a small island, operation mode of the microgrid was divided into diesel generator power supply independently, inverter power supply independently and compositive power supply according to the cooperation of the diesel generator and the interface inverter. Switch control strategy of the microgrid operation mode was proposed in this paper based on hierarchical control. System layer take microgrid energy management as the kernel and decide the microgrid operation mode based on operating datas. Equipment layer response to the instructions from system layer and adjust their work state as well as control method to achieve microgrid operation mode switch. For the case of diesel generator grid-connect to the inverter and off-grid, a seamless switch control method of the inverter controller was proposed and the validity of the method was verified by simulation and experiment test, providing reference for microgrid construction.