| Title |
Switching Frequency Modulation for Light-Load Efficiency Enhancement in a DAB Converter Applied to an On-Board Charger |
| Authors |
Seong-Yong Hong ; Jong-Eun Byun ; Jae-Bum Lee |
| DOI |
https://doi.org/10.6113/TKPE.2026.31.1.9 |
| ISSN |
1229-2214(pISSN), 2288-6281(eISSN) |
| Keywords |
Electric vehicles(EVs); On-Board Charger(OBC); In-Cable Control Box(ICCB); Dual-Active Bridge(DAB) converter; Variable switching frequency modulation |
| Abstract |
Electric vehicle (EV) components have been widely investigated to address the environmental issues associated with these EVs. Among these EV components, the on-board charger (OBC), which is responsible for charging the main battery, is receiving increasing attention. In particular, the functionality of the in-cable control box profile, which is used in home charging environments as part of the OBC system, urgently needs enhancement. Recent design trends emphasize the importance of supporting bidirectional power flow and improving efficiency under light-load conditions. The dual active bridge (DAB) converter has become a widely adopted topology because of its bidirectional operation and galvanic isolation capabilities, allowing the aforementioned requirement to be met. However, conventional DAB converters face challenges in achieving zero-voltage switching (ZVS) on the secondary side under large input/output voltage differences or light-load conditions, leading to reduced efficiency. This study proposes a control method that increases the switching frequency (fS) under light-load conditions to improve ZVS performance and overall power conversion efficiency. The proposed method is validated by the development and experimental evaluation of a 10.9 kW prototype, which demonstrates reliable ZVS operation and improved efficiency under light-load conditions. |