A Double Helix Flux Pipe-Based Inductive Link for Wireless Charging of Electric Vehicles

This paper presents a novel inductive link for wireless power transfer (WPT) system of electric vehicles (EVs). The WPT technology uses an alternating magnetic field to transfer electric power through space. The use of the WPT technology for charging electric vehicle provides an excellent alternative to the existing plug-in charging technology. It has been reported that the inductive link using planar coils such as the circular and rectangular coil are capable of transferring a high power with high efficiency. However, they have a poor tolerance for lateral misalignment, thus their power transfer efficiency decreases significantly with the misalignment. Due to the poor misalignment performance of the planar coil topology, extensive studies have been carried out on the flux pipe topology due to their excellent misalignment tolerance. To address this, in this paper, a novel inductive link using double helix flux pipe topology is proposed. The performances of the inductive link using the proposed double helix flux pipe are analyzed and compared with inductive links using conventional flux pipe. The proposed model has excellent characteristics in terms of the power transfer efficiency and tolerance against misalignments. The proposed model is capable of transferring over 1.6 kW of power with a coil-to-coil efficiency of over 98.5% at a load resistance of 20 Ω.