Observed Harmonic Levels on the Low Voltage Grid during EV DC Fast Charging

Abstract

The paper contains a set of observations on the fast charging of electric vehicles (EV’s) on Swedish low voltage networks in rural/commercial and urban areas. The emphasis of the study has been to analyze the impact of EV charging on the electric grid and particularly on the observed waveform distortion. The paper focuses on the observation of harmonics on the grid and the variation in the observed harmonics with time as the charging current increases from a small value associated with limiting the inrush current, to the value required by the EV’s for the fast charging of the battery pack. Observations from a bus charging station at Gothenburg are also discussed.