Research on the application of all-SiC MOSFET devices in converters for rail transit

In the context of global climate change and energy structure transformation, the low-carbon development of rail transit systems has become a core issue within China’s national strategies. Policies such as China's <italic>Development Plan for a Modern Comprehensive Transportation System During 14th Five-Year Plan Period</italic> explicitly call for the upgrading of rail transit equipment towards electrification and intelligence. All-SiC MOSFET devices, with their excellent performance, have been recognized as critical to breaking through the energy efficiency bottleneck. This paper systematically analyzes the advantages and challenges of applying SiC devices in rail transit traction and auxiliary converter systems. Compared to traditional Si IGBTs, SiC devices significantly improve system energy efficiency and enable lightweight designs due to their reduced on-state voltage drop, as well as high-frequency and high-temperature resistance properties. The comprehensive benefits of SiC systems have been verified in metro systems across China, such as the Shenzhen Metro, particularly in harmonic suppression, dynamic response optimization, and thermal management simplification. However, issues such as high-temperature compatibility, drive design, electromagnetic interference, and insulation aging of SiC devices still need to be addressed. The research outcomes provide technical pathways and engineering references for the green development strategy of rail transit in China.