A tariff based inductive power controller for charging electric vehicles (EVs)

As EVs are becoming increasing popular, the focus is to implement both efficient and cost effective power interfaces for charging EVs. This paper proposes a new power controller for charging EVs using Inductive Power Transfer (IPT) technology. The proposed control philosophy allows for charging multiple EVs while sharing power capability of the charging system according to tariff and without any direct communication. The controller utilizes two distinct jitters of frequency to convey information with regard to tariff for charging and power capability of the supply. Tariff for charging is varied with the demand for power, and EVs are allowed to be charged in accordance with their purchasing power and urgency. Moreover, the controller facilitates operation of the IPT charging system at tuned frequency and minimizes VAR consumption. The validity of the tariff based power control philosophy is demonstrated through simulated results of a 3 kW bi-directional IPT system that is capable of charging 3 EVs. Results convincingly indicate that proposed controller is attractive for charging bays where multiple EVs are charged, and also applicable for both wired and wireless charging systems as well as vehicle-to-grid (V2G) applications.