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Electronics and Telecommunications Research Institute (한국전자통신연구원)
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Investigation of the effects of common and separate ground systems in wireless power transfer

  • Park, Woocheon (Electronics and Telecommunications Research Institute) ;
  • Moon, Jung-Ick (Electronics and Telecommunications Research Institute) ;
  • Cho, In-kui (Electronics and Telecommunications Research Institute)
  • Received : 2020.07.14
  • Accepted : 2021.07.16
  • Published : 2022.04.10
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Abstract

This article presents an investigation of the effects on a grounding system of wireless power transfer (WPT) when transmitting over relatively far distances, that is, up to 1.25 m. Conventional two-coil WPT systems are sufficiently commercialized in strong coupling range, but it is important to accomplish the long-range WPT in weak coupling range for further various applications. This system depends on the coupling effect between the two coils that the grounds of the transmitting and receiving coils should be completely separated. However, when evaluating the performance of two-coil systems with the instrument consisting of two ports and one common ground, undesirable problems occur in weak coupling ranges, for example, obtaining disagreeable transmission efficiency and degrading system stability/reliability. We investigate the problems of the leakage power from common ground systems and provide a practical solution to obtain a reliable WPT system by using an isolation transformer. The usefulness of this approach is that it is possible to achieve the stability of the system with relatively far transmitting distances and to determine the exact transmission efficiency.

Keywords

Acknowledgement

This work was supported by the Institute of Information & Communications Technology Planning Evaluation (IITP) grant funded by the Korean government No. 2019-0-00007, "Magnetic Field Communication Technology Based on 10pT Class Magnetic Field for Middle and Long Range," and the Electronics and Telecommunications Research Institute funded by the Korean government under Grant 20ZH1141, "Study on 3D Communication Technology for Hyperconnectivity."

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