Model and harmonic control strategy of electric vehicle chargers connected with the power system

In order to promote new energy electric vehicles (EVs) it is necessary to build a large number of Evs charging stations. (EV) chargers are highly non-linear load in power systems, they present a potential problem to power system in the forms of excessive harmonic currents and poor power factor. In this paper, individual EV charger model has been set up on the basis of analyzing actual data from a demonstration station in Shen Zhen city. By using Matlab as a simulation tool, we analyzed harmonic current of individual EV charger and individual EV charging station meanwhile the model of V2G was also described. The results show that the 5,7 harmonic ratio is beyond the scope of the national harmonic standards when the EVs charging station connected to the power system. Some measures and harmonic control strategy to improve the loading factor of power systems have been proposed. The research methods and results can also be use for charger suppliers, design units, power grid companies, research institutes.