Probabilisitic Sizing of PV Generation on Commercial Parking Lot with PEVs to Avoid Transformer Aging

This paper presents an analytical method for sizing photovoltaic (PV) generation aiming at reducing transformer hottest-spot temperature and loss-of-life due to overloaded operation with the connection of plug-in electric vehicles. The study considers a commercial building with 8 electric vehicles charging stations supplied by a 75 kVA transformer. The methodology uses Monte Carlo simulation in order to consider data uncertainties, and simulations are performed based on real ambient temperature and irradiance data from Austin, Texas. The results show the connection of eight Level 2 charging stations is enough to make transformer operate overloaded for several hours and suffer premature aging in some scenarios. Also, the installation of PV generation with penetration level of 39.6% is enough to make transformer operate under the recommended temperature levels without suffering premature aging, even when operating overloaded for few hours.