PCB Winding Coupled Inductor Design for SiC-Based Soft-Switching Three-Phase AC-DC Converter with Balance Technique

This paper explores PCB winding coupled inductor design for a SiC-based critical conduction mode soft-switching three-phase ac-dc converter with balance technique. Although using SiC devices with the soft-switching technique can achieve high power density and efficiency, high dv/dt over the system parasitic capacitance causes substantial common mode (CM) noise compared to Si devices. To reduce the CM noise, a balance technique is applied to the three-phase ac-dc converter creating a return path and adding inductors in the path. The inductors in the main circuit and the return path are coupled in one core and implemented with the PCB windings to enhance the CM noise reduction capability. A new PCB winding structure is introduced to minimize the winding loss and to have strong coupling between the main and additional inductors. Design considerations and the design process of the PCB winding coupled inductor are discussed in detail. The performance of the soft-switching three-phase acdc converter with the proposed PCB winding coupled inductor is experimentally verified with a SiC-based 25-kW laboratory prototype.