An Antioffset Electric Vehicle Wireless Charging System Based on Dual Coupled Antiparallel Coils

Abstract

Wireless power transfer (WPT) has the advantages of safety, convenience and freedom from the impact of the environment. Misalignment tolerance is a major issue for the electric vehicle wireless charging system. In this letter, a WPT system with anti-offset characteristic is proposed based on dual coupled transmitting coils with antiparallel windings, forming the inductor-capacitor-capacitor-series (LCC-S) topology. The T-shaped equivalent circuit is developed to obtain the decoupling circuit. Based on the misalignment tolerant characteristic of the antiparallel windings, the two transmitting coils are designed to have the same coil structure with antiparallel windings, leading to the same variation trend of the coupling between the two transmitting coils and the receiving coil and the opposite influence on the output. Therefore, the output voltage can be stable within a certain misalignment range. An experimental prototype is built to verify the effectiveness of the proposal. The experimental results show that the output voltage can remain stable within the range of −150 mm to 150 mm in the horizontal direction and 80 mm to 160 mm in the vertical direction.