Centralize control power sharing scheme of parallel connected inverters for microgrids

This paper presents a new control scheme that permits arbitrary power sharing between parallel inverters connected to a microgrid operating in island mode. The scheme processes the active and reactive output power information from all the inverters in a central controller that calculates the set-points for each inverter, based on the desired ratios of their output powers. This necessitates adjustment of the inverters' terminal voltages (phase and magnitude) relative to the voltage at the common ac bus. The power-sharing scheme is validated using MATLAB/Simulink simulation from three three-phase parallel inverters connected to a number of passive loads.