| Title |
High-Efficiency Dual-Transformer Resonant Converter with a Wide Input Voltage Range |
| Authors |
남주현(Ju Hyeon Nam) ; 정강률(Gang-Youl Jeong) |
| DOI |
https://doi.org/10.5370/KIEE.2025.74.11.1914 |
| Keywords |
Dual-transformer; LC or LLC series resonant circuit; Resonant inductance and capacitor; PFM control |
| Abstract |
This paper proposes a high-efficiency dual-transformer resonant converter with a wide input voltage range. High-efficiency is achieved using an LC or LLC series resonant circuit formed by the equivalent series resonant inductance from the dual-transformer and a resonant capacitor. The dual-transformer consists of two center-tapped transformers with primary windings in series and secondary windings in parallel. This setup increases effective input resistance, reduces secondary winding loss, and eases handling of high-voltage DC input. Secondary windings are wound in opposite orders on each transformer core to ensure coordinated operation and equalize effective resonant inductance in each mode, resulting in equal secondary current magnitudes. The paper presents the operating principles by mode, describes dual-transformer design and effects, and validates performance through experiments using a prototype designed based on these principles and the fundamental harmonic approximation. |