Fault Monitoring and Multilevel Protection Method for SiC-Based Medium-Voltage Hybrid Clamped Converter

SiC-based medium/high voltage converters face complex operating conditions and extremely severe electromagnetic-thermal coupling impact, which puts strict requirements on their safety and reliability. The rapid and accurate identification of faults and the execution of safe disposal procedures are critical prerequisites for ensuring the safety of SiC equipment. This paper proposes a fault monitoring and multilevel protection method for the medium/high-voltage four-level hybrid clamped converter. Firstly, potential faults that may arise during operation of SiC-based multilevel converters are analyzed, including overcurrent, overvoltage, and overheating. Then, a condition monitoring circuit design tailored for reliable operation in high-voltage and strong electromagnetic field environments is proposed. Furthermore, a multilevel fault protection methodology is developed. The experimental results show that the system can identify and protect the faults quickly and accurately, and is suitable for the safe fault protection for SiC-based medium-voltage converters.