Journal of Power Electronics

The Korean Institute of Power Electronics (전력전자학회)
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Highly effective leakage magnetic field suppression by using a reactive coil in perfectly aligned EV wireless charging systems

  • Zhu, Guodong (State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University) ;
  • Gao, Dawei (State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University)
  • Received : 2019.01.15
  • Accepted : 2019.07.24
  • Published : 2020.01.20
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Abstract

Using a reactive coil to suppress the leakage magnetic field (LMF) in wireless power transfer is practical, but the suppression capability reported in the literature is still limited. This paper proposes several methods for improving the suppression capability of this scheme. Three conditions are required to realize this goal, namely (1) a good LMF proportionality, (2) an equation regarding the LMF coefficients and mutual inductances, and (3) an equation regarding the impedance of the reactive coil loop. Coil geometry optimization is performed to meet condition (2), and coil reactance is compensated by a capacitor to meet condition (3). Given the trade-off between LMF suppression capability and efficiency, a control strategy based on a switching capacitor array is adopted. In the experiments, a 97.5% reduction in the LMF strength is achieved on the measurement point with slight effects on efficiency.

Keywords

Acknowledgement

This work is supported by the following programs: (1) International Science & Technology Cooperation Program of China under 2016YFE0102200 and (2) Beijing Natural Science Foundation (3172019).

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