The impact of charging plug-in hybrid electric vehicles on residential distribution transformers

Plug-in hybrid electric vehicles are becoming more popular in smart grids. The batteries of these electric vehicles may be charged at home from a standard outlet. These extra electrical loads may have several adverse impacts on the distribution system. This paper proposes a comprehensive approach for evaluating the adverse impact of different levels of PHEV penetration on the loss of distribution transformers' life. The proposed method is applied to a sample distribution transformer supplying residential customers. Obtained results show that nighttime charging of PHEVs has the least adverse impact on the loss of transformers' life. This is while charging during evening peak hours can even cause a 900% increase in the transformer loss-of-life rate for a scenario with only 30% penetration of PHEVs.