A model for coupling under coil misalignment for DD pads and circular pads of WPT system

Guangjie Ke, Qianhong Chen, Ligang Xu, Siu Chung Wong, Chi Kong Tse

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

9 Citations (Scopus)


The coupling coefficient of a transformer is a key parameter affecting the performance of a wireless power transmission system. Based on the magnetic reluctance model under aligned condition, this paper gives an effective method for calculating the null coupling position, as well as a practical and accurate model for finding the coupling coefficient under coil misalignment and varying air gap. The null coupling position is determined by the horizontal offset when the flux of opposite direction that is intersected with the receiving coil is cancelled out. An empirical formula is given to correct the null coupling position. Based on the physics of coupling under misaligned conditions, a practical model for coupling is constructed. Transformers with DD structure and typical circular structure are fabricated for verification. Experimental measurement validates the model.
Original languageEnglish
Title of host publicationECCE 2016 - IEEE Energy Conversion Congress and Exposition, Proceedings
ISBN (Electronic)9781509007370
Publication statusPublished - 1 Jan 2016
Event2016 IEEE Energy Conversion Congress and Exposition, ECCE 2016 - Milwaukee, United States
Duration: 18 Sep 201622 Sep 2016


Conference2016 IEEE Energy Conversion Congress and Exposition, ECCE 2016
Country/TerritoryUnited States


  • coupling coefficient
  • misalignment
  • null coupling position
  • Wireless power transfer

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology
  • Control and Optimization

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