Frequency Optimization for Inductive Power Transfer Based on AC Resistance Evaluation of Litz-wire

Jiangtao Liu, Qijun Deng, Dariusz Czarkowski, Marian K. Kazimierczuk, Hong Zhou, Wenshan Hu

Research output: Contribution to journalArticle

Abstract

A coil with a high quality factor (Q) is desired to obtain a high efficiency for inductive power transfer (IPT). Q is proportional to the coil inductance and operating frequency, while inversely proportional to the coil resistance which increases with the raising of the frequency. An optimized frequency exists to obtain the maximum efficiency. Eddy currents and resulting AC resistance in Litz-wire coils are attributed to magnetic field. Especially, the induction component of the AC resistance is approximately proportional to the squared magnetic field where the coil exposed to. FEA simulations are conducted and surface integral method are employed to obtain the squared field. Additionally, the volume integral method is proposed to evaluate the overall effect of the field on the induction resistance. The optimized frequency for maximum efficiency is obtained based on the squared field calculation and resulting AC resistance evaluation. Sample prototype coils are manufactured to verify the resistance analysis methods. An IPT system is built employing these coils. Experiments show that the IPT system obtains the highest efficiency at frequencies closed to the predicted optimized ones

Original languageEnglish (US)
JournalIEEE Transactions on Power Electronics
DOIs
StateAccepted/In press - May 21 2018

Fingerprint

Wire
Magnetic fields
Eddy currents
Inductance
Finite element method
Experiments

Keywords

  • Atmospheric modeling
  • Bars
  • Ferrites
  • Immune system
  • induction acresistance
  • Inductive power transfer
  • Litz-wire
  • Magnetic fields
  • optimized frequency
  • proximity effect
  • Resistance
  • skin effect
  • Spirals

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Frequency Optimization for Inductive Power Transfer Based on AC Resistance Evaluation of Litz-wire. / Liu, Jiangtao; Deng, Qijun; Czarkowski, Dariusz; Kazimierczuk, Marian K.; Zhou, Hong; Hu, Wenshan.

In: IEEE Transactions on Power Electronics, 21.05.2018.

Research output: Contribution to journalArticle

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