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. Their increased penetration coupled with uncoordinated charging could impact the distribution system in terms of unbalanced voltage and transformer overloading. Although PEV battery charging is increasing, impact on the distribution system is not fully investigated. This paper focuses on unbalanced voltage 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 levels at 10-80% are studied, unbalanced voltage is calculated, and transformer overloading is observed. 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.