Magnetic Design and Experimental Evaluation of a Commercially available Single Integrated Transformer in Three-phase LLC converter

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

Research output: Contribution to journalArticle

8 Citations (Scopus)


Multi-phase topologies are preferably employed in power conversion systems to lessen the per phase circuit current, conduction losses, devices thermal stresses, and to reduce the output current ripples. Multi-phase LLC resonant dc/dc converter usually possess a number of magnetic cores equal to the number of phases. These magnetic cores are the major contributors to supply volume, weight, and size. For these reasons, circuit designers tend to select the topologies that have a minimal number of magnetic cores. In this paper, the authors aim to promote the industrial applications of the three-phase LLC resonant converter by integrating three transformers into a single, commercially available, magnetic core to reduce the volume, weight, and cost of the power converter. A comprehensive magnetic analysis for the three-phase integrated transformer is conducted. FEM Simulation and experimental tests are carried out to validate the proper operation of the integrated transformer utilized in a 390/12V-500W prototype. Furthermore, the power losses distribution has been presented. The proposed integrated transformer has been proven efficient, and it realized a uniform thermal distribution along the core compared to the three discrete transformers.

Original languageEnglish
JournalIEEE Transactions on Industry Applications
Publication statusAccepted/In press - Jul 14 2018



  • dc/dc converter
  • Ferrite magnetic cores
  • Magnetic cores
  • Soft switching converters
  • Three-phase LLC resonant converter
  • Transformer design

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

Cite this