Optimal charging of plug-in electric vehicles for a car park infrastructure

This paper proposes an intelligent workplace parking garage for plug-in hybrid electric vehicles (PHEVs). The system involves the developed smart power charging controller, a 75kW photovoltaic (PV) panel, a DC distribution bus and the AC utility grid. Stochastic models of the power demanded by PHEVs in the parking garage and output power of PV are presented. In order to limit the impact of PHEVs´ charging on the utility AC grid, a fuzzy logic power flow controller is designed. Based on their power requirements, PHEVs were classified into five charging priorities with different rates according to the developed controller. The charging rates depend on the predicted PV output power, the power demand by the PHEVs and the price of energy from the utility grid. The developed system can dramatically limit the impacts of PHEVs on the utility grid and reduce the charging cost. The system structure and the developed PHEVs smart charging algorithm are described. Moreover, a comparison between the impacts of the charging process of the PHEVs on the grid with/without the developed smart charging technique is presented and analyzed.