Electric vehicles – effects on domestic low voltage networks

Abstract

Electric Vehicles (EV) charging from a domestic power socket are becoming increasingly popular due to their economic and environmental benefits. The large number of such vehicles presents a significant additional load on existing low voltage (LV) power distribution networks (PDN). Evaluating this impact is essential for distribution network operators (DNO) to ensure normal functioning of the distribution grid. This research uses predictions of EV development and penetration levels to create a stochastic model of aggregate charging demand in a neighbourhood. Combined with historic distribution substations data from the Milton Keynes, UK total loads on the distribution transformers are projected. The results show significant overloading can occur with uncoordinated charging with just 25% of EVs on the road. The traditional way to solve this problem would be upgrading the transformer; however, that could be avoided by implementing coordinated charging to redistribute the load.