On the Sensitivity Analysis in Reliability Evaluation for Power Electronic Converters

Power electronic converters are essential in modern electrical and electronic applications, necessitating the study on power electronic reliability for dependable design and operation. In earlier research on power electronic reliability, the mission profiles have been mapped to thermal stresses and lifetimes, while its applications are generally focused on steady-state scenarios. It turns out to be time-consuming and inefficient to repeat the entire procedures for addressing the impact of stress variances or model uncertainties. In this context, this article defines the sensitivity for power electronic reliability and provides a sensitivity-based perspective on system optimization, where the concept is formulated through two steps, accounting for thermal stresses and lifetime, respectively. The applications of sensitivities for thermal stresses and lifetime are demonstrated, which serve as identifiers of critical factors and quantitative metrics of marginal performances. Upon this, possibilities are also emerging for enhancing the cost-effectiveness of reliability validations and encompassing model robustness into reliability analysis and prediction.