Islanded operation of microgrids with inverter connected renewable energy resources

This paper contains a control scheme for power sharing in islanded microgrids with inverter-sourced distributed energy resources that combines robust control and droop control. As the load within the microgrid changes, the inverter-sourced generators share the change in the load; this paper shows that the uncontrolled load sharing among the generators will be arbitrary and methods such as droop control achieve a regulated change. This paper includes a background on control schemes for power sharing and highlights the difficulty in exact reactive power sharing. The performance of the proposed controller is demonstrated using a test microgrid system