Impact of PEV charging and rooftop PV penetration on distribution transformer life

As Plug-in Electric Vehicles (PEVs) take a greater share in the automobile market; their penetration levels may bring potential challenges to the electric utility especially at the distribution level. However with increasing penetration of rooftop photovoltaics (PVs) in residential networks, one major benefit is for rooftop PV units to counterbalance PEV loads, and hence normalize the useful life of distribution transformers. This effect has yet to be quantified in existing literature. This paper presents a study that evaluates the impact of PEV charging imposed on distribution transformer life, in the presence of rooftop PV units. The proposed methodology in this paper is applied to a real distribution system with various scenarios, including diversified PV and PEV penetration levels. Through deterministic and stochastic simulation, results reveal that distribution transformer increased loss-of-life (LOL), as a function of PEV charging, can be negated through the integration of distributed rooftop PV installation.