Impact of cost-based smart electric vehicle charging on urban low voltage power distribution networks

This paper introduces a probabilistic modelling approach, based on smart meter data and a novel agent-based electric vehicle (EV) simulator, to analyse the impact of various cost-based EV charging strategies on the power distribution network (PDN). We investigate the effects of a 40% EV adoption on three parts of the low voltage distribution network (LVDN) of Frederiksberg, a densely urbanised municipality in Denmark. Our findings indicate that especially cable and transformer overloading poses a challenge. However, the impact of EVs varies significantly between each LVDN area and charging scenario. Across scenarios and LVDNs, the share of cables facing congestion ranges between 5% and 60%. It is also revealed, that time-of-use (ToU)-based and single-day cost-minimised charging could be beneficial for LVDNs with moderate EV adoption rates. In contrast, multiple-day optimisation will likely lead to severe congestion, as such strategies concentrate demand on a single day that would otherwise be distributed over several days, thus raising concerns on how to prevent it. The wider implications of our study are that, while initial concerns have mainly been focused on congestion caused by uncontrolled charging during peak hours, a shift towards cost-based smart charging driven by a growing awareness of time-dependent electricity prices, could result in a sharp increase in charging synchronisation with undesirable implications for the PDN.