T02.8 - Enhanced Cocharge Operation Scheme in Bidirectional PhaseShift Full-Bridge Converters with Eliminated Voltage Overshoot and Reduced Freewheeling Current

Tuesday, March 18, 2025

11:20 AM – 11:40 AM ET

Location: Level Three, A302

Technical Lecture Presenter(s)

Tien-Sheng Li (he/him/his)

Virginia Tech

Presentation Paper

Co-Author(s)

Minh Ngo, Masters

Virginia Polytechnic Institute and State University
Rolando Burgos

Virginia Polytechnic Institute and State University
DD

Dong Dong

Virginia Polytechnic Institute and State University

To achieve high power density and efficiency in an isolated bidirectional DC/DC converter, this paper employs a bidirectional phase-shift full bridge (PSFB). However, the PSFB converter exhibits significant voltage overshoot on the secondary side of the transformer, which increases the voltage stress on the secondary-side switches. Additionally, the large freewheeling current in the PSFB reduces the circuit's efficiency. This paper proposes a technique that eliminates voltage overshoot and reduces the freewheeling current. The circuit operation is analyzed and modeled to explain the principle of the proposed technique. A benchmark design is provided for comparison with previous methods. A preliminary experiment is conducted to demonstrate the feasibility and effectiveness of the proposed technique.