A Power Sharing Control Method for Microgrid Consisting of Capacitive-coupling and Inductive-coupling Inverter

Inverters play an important role in integrating distributed generators and regulating power flow of a microgrid (MG). Capacitive-coupling inverter (CCI) has been developed to enhance reactive power conditioning with a low operation voltage. Its power control range and characteristics are different from a conventional inductive-coupling inverter (ICI). Control of parallel-connected CCI and ICI in a MG is investigated in this paper. In order to fully utilize power control capability of each type of inverter, power sharing algorithm between them is studied for minimizing total inverter rating. A power reference determination method is therefore proposed and embedded in hierarchical control framework of the microgrid. Results indicate that inverter rating is reduced by combining CCI and ICI. Droop control is used as primary control method for each inverter. Simulation results are provided to show the validity of the proposed method.