A novel three-phase LLC resonant converter with integrated magnetics for lower turn-off losses and higher power density

Mostafa Noah, Shota Kimura, Shun Endo, Masayoshi Yamamoto, Jun Imaoka, Kazuhiro Umetani, Wilmar Martinez

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

24 Citations (Scopus)


The aim of this work is to present a novel topology of a three-phase LLC converter with integrated magnetics. The converter operation and the comprehensive theoretical analysis are presented; this analysis follows the first harmonic approximation (FHA) approach to simplify the system model. Usually, LLC converter achieves zero voltage switching (ZVS) as long as it working in the inductive region. Therefore, the turn off losses are considered as the main source of the switching losses in the converter. In this paper the design in optimized to minimize the switching losses. On the other hand, adapting three discrete transformer cores in this topology will definitely increase the size and volume of the converter. As a result, a novel magnetic integration concept is introduced where all magnetic components of the three-phases are advantageously combined into a single magnetic core to increase the converter power density. Finally, the experimental results are presented to verify the optimized design by showing a reduction in the turn-off losses and the effectiveness of adapting the proposed integrated transformer, in which an increment of 56% in the power density of the converter could be attained.
Original languageEnglish
Title of host publicationProceedings of the 2017 IEEE Applied Power Electronics Conference and Exposition, APEC 2017
Number of pages8
ISBN (Electronic)978-1-5090-5366-7
Publication statusPublished - 1 Mar 2017
MoE publication typeA4 Article in a conference publication
EventApplied Power Electronics Conference and Exposition - Tampa, United States
Duration: 26 Mar 201730 Mar 2017
Conference number: 32

Publication series

NameConference proceedings : IEEE Applied Power Electronics Conference and Exposition
ISSN (Print)1048-2334
ISSN (Electronic)2470-6647


ConferenceApplied Power Electronics Conference and Exposition
Abbreviated titleAPEC
Country/TerritoryUnited States


  • approximation theory
  • resonant power convertors
  • transformer cores
  • zero voltage switching
  • FHA approach
  • ZVS
  • converter power density
  • discrete transformer cores
  • first harmonic approximation approach
  • integrated magnetics
  • magnetic components
  • switching losses
  • three-phase LLC converter
  • turn off losses
  • Inductance
  • Magnetic cores
  • Magnetic resonance
  • Magnetic tunneling
  • Rectifiers
  • Three phase LLC resonant converter
  • optimization
  • steady state analysis


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