Analysis of loss and temperature characteristics of high power contactless transformer due to high-frequency magnetic field fluctuations

Takuya Shimotsu, Keiichiro Kondo, Keigo Ukita

Research output: Contribution to journalArticle


In contactless power transformers, the electric power is transmitted at a high frequency. Therefore, the skin and proximity effects much increase the AC resistance. In this paper, the influence of the magnetic field and frequency on the equivalent resistance of the coils is evaluated. In addition, the iron loss characteristics are evaluated by considering the excitation voltage. The iron and copper losses due to the skin and proximity effects in a 300 kW CPT transformer were estimated. Based on the results, the temperature rise characteristics were predictively studied using heat equivalent circuits. The results of this study contribute to the thermal design efforts of high power contactless power transformer coils.

Original languageEnglish
Pages (from-to)350-357
Number of pages8
JournalIEEJ Transactions on Industry Applications
Issue number4
Publication statusPublished - 2017 Jan 1
Externally publishedYes



  • Contactless power transfer (CPT)
  • High power
  • Loss
  • Proximity effect
  • Skin effect
  • Temperature

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

Cite this