Integration of plug-in electric vehicle charging and wind energy scheduling on electricity grid

Plug-in electric vehicles (PEVs) and wind energy are both key new energy technologies. However, they also bring challenges to the operation of the electricity grid. Charging a large number of PEVs requires a lot of grid energy, and scheduling wind energy is not trivial because of the intermittency. In this paper we propose a hierarchical control algorithm which integrates PEV charging and wind energy scheduling. It explores the controllable nature of PEV charging to accommodate the intermittent wind energy. The algorithm consists of three levels: the top-level controller solves the hourly scheduling of wind energy (and conventional generation) through an optimization problem, the middle-level controller determines sub-hourly scheduling of PEV charging to achieve load following, and the bottom-level controller uses grid frequency deviation as the feedback cue to control PEV charging in real time. The integrated controller achieves multiple goals, including optimal electricity cost, replacing fossil fuel generation by wind energy, reducing ancillary service by controlled PHV charging, and improving the quality of electricity service.