Research of droop control strategy based on virtual impedance

In a parallelly operated system composed of multi distributed generations (DGs), traditional droop control is usually utilized for load distribution. This article introduces the basic principle which is based on the characteristics of the parallel inverters power droop, and analyzes the circulation phenomenon of parallel inverters in Micro-grids. Due to the influences of feeder impedances and local load, a larger power distribution error may be caused by traditional droop control; a new kind of droop control strategy which was based on virtual impedance was put forward to improve the unequal distribution of power by adjusting the droop parameters. Results of simulation and experiments show that the proposed control strategy is feasible.