Seamless Transition Strategy for Micro-grid Inverter based on Improved Droop Control Strategy

摘要

Microgrid is a new way to solve current energy problems, such as environmental pollution and resource shortages, for using renewable energy effectively to improve power supply reliability and flexibility. Microgrid inverter has two working modes, on-grid mode and off-grid mode, and seamless transition between the two modes is the key to ensure continuous uninterrupted power supply. The focus of this paper is mainly to achieve the smooth transition from island mode to grid connected mode, to limit the abrupt and transient changes. To achieve this objective, an improved droop control method has been suggested. Voltage-control method based on droop control is used during both on-grid mode and off-grid mode to avoid the forced transition in traditional control strategies. Simulation results are presented using PLECS to validate the seamless transition between the two modes