Belief Reliability Modeling and Assessment Method for IGBTs

In current IGBT reliability assessment methods, there is a lack of modeling for overstress failures and insufficient consideration of epistemic uncertainty. To address this, this paper proposes a novel reliability assessment method based on belief reliability theory and uncertainty theory. By establishing an IGBT reliability domain model and an external-stress model, a margin-evaluation framework integrating multi-operating-condition characteristics is constructed. Furthermore, a first-order information-based belief reliability calculation algorithm is developed. This method, for the first time, incorporates overstress failures into a quantitative assessment framework and overcomes the inaccuracy of traditional methods under small-sample testing scenarios, providing a technical basis for IGBT device selection and operational reliability assurance in power electronic systems.