Effects of secondary leakage inductance on the LLC resonant converter - Part i: Transformer voltage gain and efficiency

Mostafa Noah, Tomohide Shirakawa, Kazuhiro Umetani, Jun Imaoka, Masayoshi Yamamoto, Eiji Hiraki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

Minimizing the transformer magnetizing inductance is essential for the soft switching operation of the LLC resonant converter, despite the fact that it results in higher values of magnetizing current, which deteriorates the converter efficiency. Furthermore, it is a well-known practice to utilize the transformer leakage as an inductive component in the resonant tank to improve the power destiny. This paper reveals that the transformer voltage gain can be improved when the transformer leakage inductance in concentrated on the secondary side to avoid the voltage drop inflicted by the relatively large value of the magnetizing current (im), especially at light load condition. The theoretical discussion relies on the asymmetry of the EI core by placing the secondary winding in a close contact with the magnetic core and placing the primary winding in the vicinity of the air gap. Moreover, noise absorber had been utilized to control the leakage inductance value. The proposed transformer design maximizes the value of the secondary leakage inductance and minimizes the primary leakage inductance. Alongside with the theoretical discussion, experimental tests had been conducted to evaluate the proposed method using a 390V-12V, 220W LLC resonant converter.

Original languageEnglish
Title of host publication34th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2019
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages780-786
Number of pages7
ISBN (Electronic)9781538683309
DOIs
Publication statusPublished - May 24 2019
Event34th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2019 - Anaheim, United States
Duration: Mar 17 2019Mar 21 2019

Publication series

NameConference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC
Volume2019-March

Conference

Conference34th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2019
CountryUnited States
CityAnaheim
Period3/17/193/21/19

Keywords

  • Dc/dc converter
  • Leakage inductance
  • LLC resonant converter
  • Magnetic cores
  • Soft switching converters
  • Transformer

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Effects of secondary leakage inductance on the LLC resonant converter - Part i: Transformer voltage gain and efficiency'. Together they form a unique fingerprint.

  • Cite this

    Noah, M., Shirakawa, T., Umetani, K., Imaoka, J., Yamamoto, M., & Hiraki, E. (2019). Effects of secondary leakage inductance on the LLC resonant converter - Part i: Transformer voltage gain and efficiency. In 34th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2019 (pp. 780-786). [8721980] (Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC; Vol. 2019-March). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/APEC.2019.8721980