Reliability Assessment of Multistate Degraded Systems: An Application to Power Electronic Systems

This article demonstrates the feasibility of using a multistate degraded system analysis for obtaining much more accuracy in reliability evaluation. The proposed method is capable of estimating system-level reliability, while mission profile and physics of failure of the system's items are taken into account. In addition, the self and mutual degradation effects of items on the operation of the global system have been considered. Not only does the proposed framework can be employed in determining the reliability of the degraded systems in terms of multistate functions, but also obtains the states of the systems by estimating the system state probabilities. As an application, a power electronic system containing three critical items has been studied. In this case study, two power semiconductors and a capacitor have been considered as three degradation processes and their aging effects on the useful lifetime estimation of the power electronic system has been discussed.