Grid-Forming Inverters for Grid-Connected Microgrids: Developing “good citizens” to ensure the continued flow of stable, reliable power

Abstract

The electric power grid is in transition. For nearly 150 years it has supplied power to homes and industrial loads from synchronous generators (SGs) situated in large, centrally located stations. Today, we have more and more renewable energy sources—photovoltaic (PV) solar and wind—connected to the grid by power electronic inverters. These inverter-based resources (IBRs) do not have the same characteristics as SGs, such as inertia and high fault current. This mismatch has not been a problem until now. Inverters have assumed that the grid is strong and will provide a stable and clean voltage and that they are able to inject real power into the grid without undue impact on its operation.