Probabilistic Modeling and Statistical Analysis of Aggregated Electric Vehicle Charging Station Load

The number of electric vehicles is increasing worldwide. The charging of a single electric vehicle can draw several kilowatts of power, and the aggregate effects of charging thousands of electric vehicles on electric power system infrastructure, operation, and planning must be considered. An important tool in studying the integration of electric vehicles and developing associated technologies and controls within the framework of the smart grid are probabilistic models of charging station load. This article identifies, evaluates, and proposes probabilistic models and analyzes the statistical characteristics of aggregated electric vehicle charging station load. A data-driven approach is taken, using measured time-stamped power consumption from charging stations to formulate and evaluate suitable parametric probabilistic models. The influence of time-of-use pricing on electric vehicle charging station load characteristics is also examined. Two data sets—one from Washington State, the other from San Diego, CA—each covering over 2 years, are used to create the models.