Real-time coordination for grid-friendly community-level electric vehicle charging based on discrete state by enhanced hysteresis model incorporating electricity price
Zhiqiang Liu, Zhijun Qin
Abstract
The electrification of the transportation sector has been recognized as a major step to improve the flexibility of power grids, leading to a rapid increase of the scale of electric vehicles (EVs). However, the uncontrolled charging pattern of EVs in residential communities can cause a huge adverse impact on distribution systems. Existing research on EV charging coordination mainly focuses on continuous power control, whereas discrete charging state control gains little attention. To achieve coordination of EV charging based on discrete state control, an enhanced hysteresis model is proposed and combined with a prioritization method to form a real-time control strategy. First, to minimize the charging cost of individual EV owners, the enhanced hysteresis model is built. Second, to effectively respond to regulated signals from EV aggregators, a prioritization method is proposed to clarify the dispatch sequence of EVs. Third, the combination of the enhanced hysteresis model and the prioritization method is applied to form a real-time control strategy. The performance of the enhanced hysteresis model and the real-time control strategy is validated by comparison with existing work. Simulation results demonstrate that the proposed method is effective in load profile smoothing and charging cost reduction with a short computational time.