Impact of plug in electric vehicle battery charging on a distribution system

Plug-in Electric Vehicles (PEV) battery chargers are mostly connected to the low-voltage grid for charging, hence their increased penetration coupled with uncoordinated charging could impact the distribution system in terms of voltage unbalance and transformer overloading. Although PEV battery charging is increasing, impact on the distribution system is not fully understood. This study focuses on voltage unbalance caused by uneven distribution of PEV penetration among the phases. Using real data provided by utility, a distribution system has been modeled and tested using MATLAB-SIMULINK. PEV penetration level at 10-80% is studied, voltage unbalance is calculated and transformer overloading is analyzed. In the simulations conducted without PEV penetration, the real data at intellirupters of the system were close to simulated system voltages and currents. As PEV adoption is expected to increase, the impact on the distribution system will increase. Coordinated or smart charging of PEVs will be essential for consumers and utilities