Transformer and home energy management systems to lessen electrical vehicle impact on the grid

This study discusses how increased deployment of electric vehicles (EVs) acts as a catalyst for development of transformer and home energy management systems in order to reduce the impact of EV battery charging on distribution transformers. The analysis uses actual load consumption data from Austin, Texas, during a typical summer day. It also considers a case of high-density penetration of electric vehicle in line with plans announced as part of Austin´s Pecan Street smart grid initiative. The presented discussion describes first that because of air conditioner use, both during day and at night, power consumption remains relatively constant throughout the day, which creates issues even when considering charging EVs at night. In particular, the analysis anticipates that in such areas with high density of EVs and where air conditioner load is also present at night, distribution transformer life may be reduced unless EV charging is managed adequately.