Impacts Analysis of Electric Vehicles Integration to the Residential Distribution Grid

The proliferation of Electric Vehicles (EVs) can cause vulnerability to the electric grid. This paper analyzes the EV integration impacts on the distribution grid that mainly consists of residential loads. The EV uncertainties are addressed by a comprehensive model using arrival time and miles traveled. The penetration of EV is modeled based on the maximum permissible number of customers that can be connected to each node of a representative residential feeder. The temporal power consumption of EVs is calculated by using their daily trip and capacity information which are measured by utilizing specific EV models. An IEEE 123 bus feeder is used for power flow simulation and the demonstration of different case studies. Results from the customer-oriented modeling presented here show that wide voltage deviations occur at local nodes with higher penetration of EVs and it also depends on the distance of the nodes from the substation. The coincidental peak can cause large voltage unbalance at the closer nodes and hourly voltage profiles can vary significantly based on this. While voltage deviation increases with higher EV penetration at the distant nodes, the closer nodes demonstrate insignificant change in voltage deviation for different levels of penetrations. The synergy between EV and grid modeling and the in-depth statistical analysis of voltage distribution at the local nodes are needed by the grid operators for higher EV integration in the future.