Probabilistic Method for Assessing the System-wide Impact of Electric Vehicle Charging on Distribution System Assets

Electric vehicle charging represents a significant step increase in customer demand, which may impact the thermal loading of distribution system assets. Research up to this point has mainly focused on advanced detailed analysis and various control schemes to help mitigate the effect of electric vehicle charging on distribution systems. Many of these efforts are based on probabilistic models and methods that can be difficult to apply to a large number of system assets such as a utility's fleet of distribution transformers, which can number in the hundreds of thousands. This work provides a novel and simple closed-form, therefore fast, method for determining demand probability of electric vehicle charging for a given point in time. The likelihood of impact can then be quickly assigned to each asset in the system, based on specific customer and loading information, and aggregated to examine the impacts across the fleet of distribution system assets. The overall impact to system assets can then be readily evaluated as a function of changes in electric vehicle adoption, changing customer behaviors, or other considerations.