Improved droop control strategy based on voltage feedforward current compensation

In order to achieve the stable operation of different-capacity parallel distributed generators, this paper proposes an improved droop control strategy according to the control strategy of parallel synchronous generators. By the improved control strategy, the active power and reactive power of parallel distributed generators can be automatically allocated by ratio of distributed generators capacity, and the function of plug and play of the distributed generators in microgrids can be realized. It will improve the flexibility of distributed generator’s interconnection and solve the technological problem of different-capacity distributed generator interconnection. In addition, the proposed control strategy can keep unchanged while switching microgrid operation mode, realizing the smooth transition between grid mode and island mode, and improving the stability and reliability of microgrid. Simulation results verify that the improved droop control strategy can make the different-capacity parallel distributed generators work stably under static and transient operation