Leveraging Grid-Forming Inverters for Enhanced EV Charging Station and Grid Interactions

The increasing use of renewable energy sources to supply electrical power to the future grid causes the grid to be more prone to changes in frequency and voltage due to load or generation disturbances. Utilizing the electric vehicles inside the parking lots as an energy source is an economical solution to support grids’ frequency and voltage with an ever-increasing number of electric vehicles (EVs) in the upcoming years. However, integrating these parking lots as EV charging stations into the grid to consider both the grid-side requirement and the situation of the EVs inside the parking lot is challenging. This paper proposes an algorithm to integrate the EV parking lots with the grid using a grid-forming inverter to consider both the power capability of the grid and other generation sources as well as the status of the EV inside the parking lot. Based on the departures or arrivals in the parking lot and the available SOC of the parking lot as well as the data received from the other generation sources of the grid, the proposed algorithm regulates the power injected to the grid by the grid-forming inverter interacting with DC charging station formed by the parking lot. The simulation result shows the ability of the proposed algorithm to regulate the power drawn from EVs according to the capacity of other generation resources and the available SOC of the EV parking lot, thus enabling an enhanced grid interaction of the EV parking lots as an auxiliary source for grid services.