Study On The Reliability Of Switched Reluctance Motor Drive System

With excellent fault tolerance and high reliability, Switched Reluctance motor Drive system(SRD) has been widely applied in industrial production and national security. Along with the high priority of safety production and the severity of failure hazards, SRD reliability research has a more profound significance. However, current domestic and international SRD reliability research still remains in its infancy stage.This paper summarizes current research status of motor drive system reliability. Considering motor performance features and control strategy, reliability of SRD is analyzed both at system-level and component-level. The main contents are as follows:Reliability Block Diagram and Markov process were selected and compared for SRD reliability modeling under single switch chopping strategy. In Markov model, unique fault modes classification and summary methods were applied to fully take account of system control strategy; also multilevel fault modes analysis and system state assessment were conducted in consideration of system fault tolerance. Then state transition diagram and state probability matrix were given to provide SRD Markov model graphically and numerically. Finally, simulation and experiments were implemented to verify system state assessment results.Birnbaum’s measure and Credible Improvement Potential were applied, respectively, to measure component importance in RBD and Markov model. Results show that the Power Switch Msw is judged to be the most important component.Power Switch Msw and Mon transient power loss models were built based on component actual function. Then, electro-thermal simulation was implemented to analyze the junction temperature difference between Msw and Mon caused by control strategy. Also real-time predicted lifetime of the two switches was compared. Finally, conclusion further demonstrates that Msw is much weaker than Mon of the same phase due to the impact of control strategy.On this basis, summary of paper work is achieved, also future work assumption is provided.