An improved droop control method for parallel operation of distributed generations in microgrid

In this paper, circulating current in voltage-source mode parallel operation of distributed generation in microgrid is modeled and analyzed. Then an improved droop control method, which combined the advantages of communication, is proposed in order to improve the power sharing performance and eliminate the circulating current of parallel operation. The proposed method inherits simplicity, robustness and expandability characteristic of traditional droop methods, and provides better voltage regulation and circulating current elimination through taking advantage of communication lines. Moreover, this method can achieve tight voltage regulation during both transient process and steady state in various load conditions. Finally simulation results from a four-inverter microgrid are presented, validating the performance of the proposed method.