Abstract:
IGBT overcurrent failure, which is one of the important factors harming VSC-HVDC safe operation, can easily lead to module explosion, water cooling system leakage and even the converter valve shutdown. Based on the structural characteristics and operating conditions of the module multilevel VSC-HVDC converter valve, the paper analyzes the characteristics of three types of IGBT overcurrent failures of the VSC-HVDC converter valve, including short-circuit overcurrent, pulse over current, as well as fly-wheeling diode overcurrent. According to the working principle and characteristics of the MMC converter valve, three IGBT protection schemes and their parameter configuration methods are put forward. The IGBT (
3300 V/
1500 A) adopted in a converter valve of ±420 kV/
1250 MW is used for overcurrent failure analysis and protection scheme verification, and the test results prove the correctness of the proposed overcurrent failure analysis method and the effectiveness of the overcurrent protection scheme.