Residential EV Charging Co-Simulation for Distribution Powerflow Impact Analysis

As electric vehicle (EV) adoption accelerates, residential charging will impact distribution grid infrastructure. These impacts must be quantified and compared to the case when smart charge management is implemented. This paper demonstrates a new co-simulation tool, EVI-DiST: Electric Vehicle Infrastructure-Distribution System Integration Tool which co-simulates EV charging and distribution feeder powerflow to determine distribution system impacts including transformer loading, line loading, and bus/node voltages. The tool allows easy comparison of different control mechanisms both with and without network communication and coordination among charging equipment. This study presents a demonstration of this tool using four real feeders and simulation of residential EV charging for a 2030 adoption scenario. This novel powerflow co-simulation analysis tool enabled rapid determination of impacts on feeder components and voltages. Findings were that near-term residential charging will cause some service and other network transformer overloads, but stay within line capacities and acceptable voltage ranges. Findings from the four sample feeders were that the TOU Random control was the most effective at reducing the number of transformers that were ever overloaded, while grid-aware controls, where EV charging limits are set in response to measured available transformer capacity, were effective at reducing overload durations.