The Capability of a Grid-Forming Inverter to Support Dynamic Microgrids with High Penetrations of Photovoltaics Systems

Grid-forming (GFM) inverters that support photovoltaic (PV) and dynamic microgrids, that expand and contract depending on available resources, must adapt. Unlike common micro grid approaches that require significant financial investments to maintain operations of a system of a set size, the approach presented here provides necessary resilience for a critical load at a reduced cost. To work, a GFM inverter must maintain appropriate voltage and frequency as the magnitude of PV output and loads change quickly during a switching event that acts to reduce the difference between generation and consumption. The simulation effort, described here, studies the potential capabilities of the GFM to support variable PV generation and fast changes in the microgrid's size that either increase or decrease the system's size. Simulations in MATLAB/Simulink showed that a GFM inverter can maintain a frequency around 60 Hz and voltage between 0.995 pu and 1.005 pu during variable PV generation output if microgrids change their size by opening and closing switches in order to maintain balanced operations.