Three-Winding-Coupled-Inductor-Based Bidirectional Soft-Switching Series-Resonant Converter with Sine-Wave Modulation

This article proposes a three-winding-coupled-inductor-based bidirectional series resonant converter (TWCI BSRC) with a sine-wave modulation (SWM) method and low magnetic component count. The resonant current is constantly a sine-wave, which can reduce current harmonics and simplify ZVS analysis. During a wide voltage range, load-independent voltage gain is achieved with the proposed SWM. In addition, the drive logic for primary and secondary switches is the same, only two sets of PWM signals are needed, and all switches allow zero voltage switching (ZVS) over the entire load range. The drive logic under bidirectional power directions is also identical. Besides, a magnetic integration structure is proposed, where two boost inductors, a high-frequency transformer and a resonant inductor can be integrated into a coupled inductor, and thus fewer magnetic components are required. The operational principle and performance of the presented converter are verified by experiments on a 1 kW prototype.