Active and Reactive Power Distribution for Cascaded-H-Bridge Microinverters under Island Microgrid

Cascaded-H-Bridge inverter is a good candidate for distribute generators due to the low voltage stress devices required. Power sharing distribution and communication among different microinverter modules are two hot issues that has been solved by inverse-droop method. However, this method can just ensure the power sharing equally among different microinverter modules. In this paper, an improvement power distribution method based on droop control that adapts reactive power to change frequency is proposed. Compared with inverse-droop control method that utlizing power factor as feedback to change frequency, the proposed method can distribute the active and reactive power in a wide range. The feasibility of the proposed control method has been verified by the simulation and hardware experiment results.