Multi-time Scale Reliability Analysis of IGBT Modules in Microgrid Converter

Distributed renewable energy in microgrid makes the converter play a crucial role in power conversion, transmission, and storage. Working under complex operating conditions, the core device of converters, insulated-gate bipolar transistor (IGBT), often withstands a large number of thermal cycling loads, and its performance will gradually degrade, eventually causing its failure. This paper proposes a specific method for reliability analysis of IGBT modules using Rainflow counting and Weibull distribution. Then, based on the three-phase AC converter topology of the microgrid, an electro-thermal coupling model is built to obtain the junction temperature fluctuation data. Finally, combined with the 2MW wind power generation system in the microgrid, reliability analysis at different time scales is carried out.