Research on Equivalent Reliability for Press Pack IGBT in Hybrid HVDC Circuit Breaker

Abstract

The Direct Current Circuit Breaker (DCCB) is vital to isolate the fault lines and interrupt current in the Voltage Source Converter High Voltage Direct Current (VSC-HVDC). The Press Pack IGBT in the hybrid DCCB is a key to conduct current, transfer and break fault current. Considering the working condition of the hybrid HVDC circuit breaker, current was chosen as the stress to perform simulated working condition test. This paper first analyzes the working process of the hybrid DC circuit breaker, and proposes a test method for the simulated working condition of Press Pack IGBT to research the reliability under overheating and over-current failure. Then the paper explains the generation of the test equivalent current waveform. Based on the assumption that the device lifetime distribution conforms to the exponential distribution, the relationship between the current level and the average life was proposed so that the reliability of the device can be evaluated in the presence of different current stress conditions.