An Analysis of the Electric Vehicle Charging Demand in Lanzhou (China)

The article proposes an approach to analyzing the demand for electricity required for charging electric vehicles. The approach is based on the sociological data on electric vehicle owners and their schedule of using electric vehicles. The approach is aimed at obtaining a reasonable estimate of the electrical grid load produced by electric vehicles. The approach is applied to the conditions of the Lanzhou city (China). The entire population of the city was divided into nine groups, and for each of them, a model of electric vehicle use for a week was proposed. The total number of electric vehicles was around 20500 units, and each owner had his or her own individual schedule of using the electric vehicle within the assumption’s characteristic of their group. This made it possible to predict the electric vehicle charging time for each individual in the group and, accordingly, obtain a schedule of electricity consumption at charging stations for the entire city of Lanzhou. An important result was the confirmation of a highly nonuniform consumption of electricity by electric vehicles: the peak power consumed by charging stations is eight times higher than its average value. With the high growth rates in the number of electric vehicles that are typical for China, this can create essential problems for the power grid.