Harmonic research of electric vehicle fast chargers

Electric vehicle (EV) chargers may lead to power quality problems which mainly contain harmonic emission and voltage deviation. The fast chargers, as a kind of high-power power electronic component, will cause impact to power grid than generally chargers. This thesis is focused on the harmonics of EV fast charging stations which have operated already. Single set/multiple sets of electric vehicles as charging were measured on site. We simulated the situation of multiple chargers as charging simultaneously in the distribution network. The harmonic characteristics and influence of EV fast chargers on power grid harmonic is discussed. The testing result shows that, at present, most of the fast chargers models cannot reflect the actual charging harmonic characteristics. Furthermore, part of the harmonic current is beyond the requirements of relevant specifications as the normal operation of the electric vehicle fast charging station, which shall also cause larger harmonic pollution to the distribution network.