Electric vehicle charging measurements in the Nordic environment - charging profile dependence on ambient temperature

Abstract

This paper aims at providing further understanding of electric vehicle (EV) charging in a cold environment by providing an overview of laboratory tests conducted for several EVs. The paper describes the laboratory test process and the main findings of the laboratory measurements. The measurement results and stochastic load modeling show that the energy demand increases significantly over wintertime charging sessions. The increased energy demand also increases peak loads in the distribution networks. In Nordic distribution grids, EV charging peak loads often overlap baseload peaks, creating incentives to manage charging in a smart way. The increased energy content and additional preheating power cause a need to rethink smart charging applications. As the main outcome of the paper, the laboratory routine is described with the measurement results of four EVs and one plugin hybrid electric vehicle (PHEV). As the main result, the study shows that the temperature dependence is among the key variables to be added to the stochastic EV charging load modeling in cold environment areas.