Extremum co-energy principle for analyzing AC current distribution in parallel-Connected wires of high-Frequency power inductors

Tomohide Shirakawa, Genki Yamasaki, Kazuhiro Umetani, Eiji Hiraki

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Inductor winding is often comprised of parallel-connected wires to suppress copper loss. However, in high-frequency inductors, the proximity effect can cause concentrated AC current distribution, hindering the suppression of the copper loss. Therefore, optimization of the physical inductor structure requires predicting the AC current distribution caused by the proximity effect. Certainly, simulators have been commonly employed for predicting the AC current distribution. However, simple analytical methods are also required for efficient design or invention of inductor structures that have more uniform AC current distribution among the parallel-connected wires. The paper proposes a novel simple analysis method for AC current distribution in parallel-connected wires of high-frequency inductors. The proposed method is based on a novel insight that AC current is distributed to give an extremum of the magnetic co-energy contributed by the AC flux under the given total AC current. Analysis of basic inductor structures revealed that the proposed method can derive the AC current distribution by straightforward calculation. In addition, experiments supported the analysis results. Consequently, the proposed method is suggested to be promising for developing inductor structures with less copper loss.

Original languageEnglish
Pages (from-to)35-42
Number of pages8
JournalIEEJ Journal of Industry Applications
Volume7
Issue number1
DOIs
Publication statusPublished - Jan 1 2018

Fingerprint

Power inductors
Wire
Copper
Patents and inventions
Simulators
Fluxes
Experiments

Keywords

  • AC current distribution
  • Inductor
  • Magnetic circuit
  • Magnetic co-energy

ASJC Scopus subject areas

  • Automotive Engineering
  • Energy Engineering and Power Technology
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

Cite this

Extremum co-energy principle for analyzing AC current distribution in parallel-Connected wires of high-Frequency power inductors. / Shirakawa, Tomohide; Yamasaki, Genki; Umetani, Kazuhiro; Hiraki, Eiji.

In: IEEJ Journal of Industry Applications, Vol. 7, No. 1, 01.01.2018, p. 35-42.

Research output: Contribution to journalArticle

@article{a8dbfaabeeef4c3e955401dc20198bb7,
title = "Extremum co-energy principle for analyzing AC current distribution in parallel-Connected wires of high-Frequency power inductors",
abstract = "Inductor winding is often comprised of parallel-connected wires to suppress copper loss. However, in high-frequency inductors, the proximity effect can cause concentrated AC current distribution, hindering the suppression of the copper loss. Therefore, optimization of the physical inductor structure requires predicting the AC current distribution caused by the proximity effect. Certainly, simulators have been commonly employed for predicting the AC current distribution. However, simple analytical methods are also required for efficient design or invention of inductor structures that have more uniform AC current distribution among the parallel-connected wires. The paper proposes a novel simple analysis method for AC current distribution in parallel-connected wires of high-frequency inductors. The proposed method is based on a novel insight that AC current is distributed to give an extremum of the magnetic co-energy contributed by the AC flux under the given total AC current. Analysis of basic inductor structures revealed that the proposed method can derive the AC current distribution by straightforward calculation. In addition, experiments supported the analysis results. Consequently, the proposed method is suggested to be promising for developing inductor structures with less copper loss.",
keywords = "AC current distribution, Inductor, Magnetic circuit, Magnetic co-energy",
author = "Tomohide Shirakawa and Genki Yamasaki and Kazuhiro Umetani and Eiji Hiraki",
year = "2018",
month = "1",
day = "1",
doi = "10.1541/ieejjia.7.35",
language = "English",
volume = "7",
pages = "35--42",
journal = "IEEJ Journal of Industry Applications",
issn = "2187-1094",
publisher = "The Institute of Electrical Engineers of Japan",
number = "1",

}

TY - JOUR

T1 - Extremum co-energy principle for analyzing AC current distribution in parallel-Connected wires of high-Frequency power inductors

AU - Shirakawa, Tomohide

AU - Yamasaki, Genki

AU - Umetani, Kazuhiro

AU - Hiraki, Eiji

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Inductor winding is often comprised of parallel-connected wires to suppress copper loss. However, in high-frequency inductors, the proximity effect can cause concentrated AC current distribution, hindering the suppression of the copper loss. Therefore, optimization of the physical inductor structure requires predicting the AC current distribution caused by the proximity effect. Certainly, simulators have been commonly employed for predicting the AC current distribution. However, simple analytical methods are also required for efficient design or invention of inductor structures that have more uniform AC current distribution among the parallel-connected wires. The paper proposes a novel simple analysis method for AC current distribution in parallel-connected wires of high-frequency inductors. The proposed method is based on a novel insight that AC current is distributed to give an extremum of the magnetic co-energy contributed by the AC flux under the given total AC current. Analysis of basic inductor structures revealed that the proposed method can derive the AC current distribution by straightforward calculation. In addition, experiments supported the analysis results. Consequently, the proposed method is suggested to be promising for developing inductor structures with less copper loss.

AB - Inductor winding is often comprised of parallel-connected wires to suppress copper loss. However, in high-frequency inductors, the proximity effect can cause concentrated AC current distribution, hindering the suppression of the copper loss. Therefore, optimization of the physical inductor structure requires predicting the AC current distribution caused by the proximity effect. Certainly, simulators have been commonly employed for predicting the AC current distribution. However, simple analytical methods are also required for efficient design or invention of inductor structures that have more uniform AC current distribution among the parallel-connected wires. The paper proposes a novel simple analysis method for AC current distribution in parallel-connected wires of high-frequency inductors. The proposed method is based on a novel insight that AC current is distributed to give an extremum of the magnetic co-energy contributed by the AC flux under the given total AC current. Analysis of basic inductor structures revealed that the proposed method can derive the AC current distribution by straightforward calculation. In addition, experiments supported the analysis results. Consequently, the proposed method is suggested to be promising for developing inductor structures with less copper loss.

KW - AC current distribution

KW - Inductor

KW - Magnetic circuit

KW - Magnetic co-energy

UR - http://www.scopus.com/inward/record.url?scp=85041961049&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85041961049&partnerID=8YFLogxK

U2 - 10.1541/ieejjia.7.35

DO - 10.1541/ieejjia.7.35

M3 - Article

VL - 7

SP - 35

EP - 42

JO - IEEJ Journal of Industry Applications

JF - IEEJ Journal of Industry Applications

SN - 2187-1094

IS - 1

ER -