The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Reduction of Leakage Magnetic Fields in Low Frequency WPT System Using Soft Magnetic Materials

연자성체를 이용한 저주파 무선전력전송 시스템의 누설 자기장 저감

  • Lee, In-Gon (Department of Information & Communication Engineering, Kongju National University) ;
  • Kim, Nam (Department of Information & Communication Engineering, Chungbook National University) ;
  • Cho, In-Kui (Radio Technology Research Department, ETRI) ;
  • Hong, Ic-Pyo (Department of Information & Communication Engineering, Kongju National University)
  • 이인곤 (공주대학교 정보통신공학부) ;
  • 김남 (충북대학교 정보통신공학부) ;
  • 조인귀 (한국전자통신연구원 전파기술연구부) ;
  • 홍익표 (공주대학교 정보통신공학부)
  • Received : 2016.10.05
  • Accepted : 2016.12.16
  • Published : 2017.01.31
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Abstract

This paper presents the electromagnetic shielding structure for low frequency wireless power transfer system with magnetic induction method using soft magnetic materials. Soft magnetic materials have advantages such as high permeability and low magnetic loss, but have undesirable effect of power loss by eddy current. To overcome this, we proposed the patterned soft magnetic material to suppress the eddy current path. For validity of this paper, we simulated the coil transfer efficiency and the radiated electromagnetic field, and fabricated the proposed structure using 79-permalloy. The measured results shows good agreements with the simulated results and reduction of the radiated electromagnetic field compared to commercial ferrite plate.

본 논문에서는 저주파 자기유도방식의 소형 단말기 충전 기술에 적용되고 있는 상용 코일에 적용 가능한 연자성체 기반 차폐구조를 설계하였다. 연자성 재료는 높은 투자율과 낮은 자기손실 특성 등 강점이 있는데 반해, 낮은 절연 특성으로 와전류에 의한 전력 손실이 큰 단점이 있다. 본 연구에서는 연자성 재료에 격자형태의 패턴을 구현하여 와전류 경로를 줄임으로써 전력 손실을 개선하였으며, 외부로 누설되는 자기장 저감 효과를 가진 차폐구조를 제안하였다. Qi 표준인 WPC 상용 A10 코일을 위한 연자성체 기반 차폐구조를 설계하였으며, 제작 및 측정을 통해 본 논문에서 제안한 구조가 효과적으로 누설 자기장을 저감할 수 있음을 확인하였다.

Keywords

References

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