Abstract
This article proposes a magnetic integration design for EV wireless power transfer (WPT) systems, where the compensation and transmitting coils overlap one on top of the other to share the ferrite layer without any decoupling consideration. The magnetic field generated by both the compensation and transmitting coils are exploited to transfer power. To this end, a compensation method is proposed to enable magnetic field enhancement without any reactive power flow between the compensation and the transmitting coils, and to achieve input zero phase angle and constant current output. In addition, an efficient finite element analysis-based coil optimization algorithm is proposed to improve the coil misalignment tolerance on the horizontal plane, in which a reversely connected inner coil is used to stabilize the system output under misalignment conditions. Analytical and simulation results confirm transmission flux density enhancement and reduced leakage field characteristics of the proposed coil design. Finally, a scaled-down WPT prototype is built and tested to verify the performance and effectiveness of the design. The proposed design achieves 91.17% efficiency and misalignment tolerance up to 200 mm in any XY-direction while maintaining the power transfer and its efficiency. The results of this work provide insights into magnetic integration design of high-order compensation topologies featuring higher compactness, less ferrite usage, magnetic field enhancement, and misalignment tolerance for WPT systems.
| Original language | English |
|---|---|
| Article number | 9186063 |
| Pages (from-to) | 3852-3867 |
| Number of pages | 16 |
| Journal | IEEE Transactions on Power Electronics |
| Volume | 36 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2021 |
Funding
Manuscript received April 5, 2020; revised July 21, 2020; accepted August 31, 2020. Date of publication September 3, 2020; date of current version November 20, 2020. This work was funded by the China Scholarship Council (Grant No. 201706700003) and the Major Program of the National Natural Science Foundation of China (Grant No. 51690181). Recommended for publication by Associate Editor C. K. Lee. (Corresponding author: Changsong Cai.) Pengcheng Zhang is with the State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300132, China, and also with the Georgia Institute of Technology, Atlanta, GA 30332 USA (e-mail: [email protected]).
Keywords
- Field enhancement
- high-order resonant network
- magnetic integration
- misalignment tolerance
- wireless charging
