PEV charging impact on residential distribution transformer life

Due to the characteristics of electric power generation, transmission and distribution in the U.S., experts have identified the local distribution network as a likely area to be adversely affected by unregulated PEV (Plug-in Electric Vehicle/Electric Vehicle) charging. This paper presents a study performed to assess the impact of PEV charging on a local distribution transformer. Due to the fact that transformer insulation life is mostly affected by the hot-spot winding temperature, a dynamic thermal model was used for prediction of the transformer hot-spot temperature with the information of power load and ambient temperature, thus the aging of insulation can be predicted. Then, with the results from a Monte Carlo-based mass simulation model for PEV energy consumption analysis, different charging scenarios were conducted to study the impact of PEV charging on transformer insulation life.