Breaking the boundary: A droop and master-slave hybrid control strategy for parallel inverters in islanded microgrids

The well-known droop control and master-slave control methods are two dominant coordinative control schemes for inverter interfacing parallel distributed energy resources (DERs) in islanded AC microgrids. However, both these two control methods have some drawbacks and inherent limitations in practical application. After analyzing their complementary strengths and weaknesses, this paper proposed a hybrid control strategy, which exploits advantages from both droop control and master-slave control methods. Firstly, the system configuration and control architecture are introduced. Then the control loop design and operation principles are discussed. Comparing to traditional methods, this proposed hybrid control strategy provides better flexibility, stronger reliability, ideal power sharing and voltage regulating performance. Finally, simulation results are presented to validate the advantages of this proposed strategy.