Impact of electric vehicle loads on utility distribution network voltages

Abstract

This work evaluates the impact of electric vehicle loads (EVs) on utility distribution secondary networks and determines the factors affecting the network voltage quality. The study is conducted using two actual distribution circuits, residential and mix residential and industrial circuits. The study reveals the following. A distant secondary network experiences a greater steady-state voltage drop than a nearby secondary network. Location of EV loads relative to the service transformer affects the secondary voltage more significantly. An EV load installed on a distant load node from a service transformer causes comparatively higher undervoltage condition (about 1.5%) than an EV on a nearby load node from the service transformer (about 0.75%). Increasing the size of EV charger increases the severity of an undervoltage condition. A 240V/30A EV charging station causes undervoltage condition to double compared to that of a 240V/16A EV charger. Also installing an EV load adjacent to the existing EV load customer approximately doubles the undervoltage condition at the EV load nodes.