- By:
- Inoue, Shuntaro ; Aydin, Emrullah ; Mohammad, Mostak ; Onar, Omer C; Ozpineci, Burak
- Page Number:
- 1-6
- Book Title:
- 2026 IEEE Transportation Electrification Conference & Expo (ITEC) & Electric Aircraft Technologies Symposium (EATS) (ITEC+EATS)
- Publication Date:
- August 31, 2026
- Publisher Location:
- IEEE, New Jersey, United States of America
- Conference Name:
- 2026 IEEE Transportation Electrification Conference & Expo (ITEC) & Electric Aircraft Technologies Symposium (EATS) (ITEC+EATS)
- Conference Location:
- Novi, Michigan, United States of America
- Conference Sponsor:
- IEEE
- View DOI Listing:
- https://doi.org/10.1109/ITECEATS66641.2026.11592997
Abstract
High step-down isolated DC-DC conversion from an 800 V DC bus to low-voltage, high-current outputs is required in automotive auxiliary converters and data center power supplies. In such applications, conventional transformer-based converters require large turns ratios, which increase winding resistance, leakage inductance, and magnetic height. This paper proposes a novel low-profile three-phase matrix transformer that realizes a large effective voltage ratio through flux division among multiple secondary legs, without increasing the physical turns count of each winding. As a result, the proposed structure reduces copper usage and transformer height while preserving the voltage conversion capability of a conventional three-phase transformer. Finite element analysis shows that the proposed design reduces magnetic height by 27%, ferrite volume by 34%, and copper volume by 28%. Circuit-level simulations of an 800 V/12 V,3 kW CLLLC dual-active-bridge converter further show that the lower winding resistance reduces total system loss by 91% and increases DC-DC efficiency from 82.6% to 97.6% at 3 kW output.
