Modeling of electric vehicle loads applicable to power system quasi-steady state analysis

Electric vehicles (EVs) are new power loads of power systems. It is important to model the charging process of EVs in power system numerical simulation. This paper proposes a methodology for modeling of EV loads applicable to power flow calculation and other quasi-steady state analysis. The numerical methodology of EV load modeling is expounded from the DC and the AC side of charging EVs. In the DC side, the constant current and the constant voltage charging processes are considered. In the AC side, the changes of the charging efficiency and power factor versus the AC frequency and voltage are analyzed. Based on the current EV market status and the development trends, four types of EV load models are calculated using this methodology. The EV load modeling methodology considers EV quantities, initial state-of-charge distributions, load change processes during charging and the effect of grid side parameters.