Reliability assessment of adjustable speed drives using state Markov models

The aim of this paper is to overview fault tolerant power architectures for adjustable speed drives (ASD). Here, our goal is to assess the reliability of ASD provided in transportation systems. A Markov model is derived for each architecture. As the inverter is the least reliable component of ASD, a special stress is put to model it for reliability assessment. Each model consists of building blocks developed for power switches and isolation switches. The assessment results allow comparing studied drives particularly from dynamic reliability point of view taking into account operating conditions of the system. This point will be developed in future work.