An Evaluation on Thermal Performance Improvements for SiC Power Module Integrated with Vapor Chamber in MMC

In this article, the improvements in thermal performances of the SiC power module integrated with vapor chamber (VC) under modular multilevel converters (MMCs) working conditions are evaluated for the first time. The copper baseplate of the SiC power module is replaced by a VC with the same size, which has the advantages of good temperature uniformity, excellent thermal conductivity, compactness, flexible design, high integration, and low cost. The FEM simulation results show that the hotspot temperature, maximum temperature difference among the chips, and low-frequency temperature swing (TS $_{L}$ ) can be significantly reduced. Then, the well-designed VC is customized and integrated with the SiC power module. Finally, the advantages of VC in improving the thermal performances of power modules in SiC-MMC are validated by the comparative experiment. The experimental results show that the local over-temperature and thermal unbalance of the power module in SiC-MMC can be significantly mitigated.