Reliability model of bond wire fatigue for IGBT in MMC with system redundancy consideration

摘要

Reliability is a significant factor in the operation of the modular multilevel converter (MMC). Since the bond wire fatigue is one of the dominant failures of the insulated-gate bipolar transistor (IGBT) in the aging aspect, the wire bond lifetime related research has captured much attention in recent years. However, at system level, the redundancy of the system is seldom discussed in the reliability analysis of MMC. This paper proposes a reliability model for wire bond failure of IGBT with system redundancy consideration. The reliability model for IGBT at the component level is established based on the lifetime model. Also, the reliability model for the system with redundancy is built by the end-of-life cumulative distribution obtained from Monte Carlo method. The unreliability change of system level and component level are compared, and the influence of bridge arm redundancy on system reliability is also analyzed.