Research On Reliability Quantitative Evaluation Of Switched Reluctance Motor Drive

Switched reluctance motor(SRM)is a special motor with simple and robust structure,excellent control performance and high fault tolerance,which has been used in military,aerospace,automobile manufacturing and other fields at present.With the use and promotion of switched reluctance motor drive(SRD),its reliability is gradually coming into focus.Carrying out reliability research on SRD can help prevent the occurrence of system failure during operation,reduce unnecessary economic loss caused by system failure,and lower the maintenance cost in the later period,which is of great significance for the use and promotion of SRD.Markov model is selected to analyze the reliability of the system,considering the structure and operation characteristics of SRD,and a method of reliability evaluation and enhancement is proposed,whose main analysis steps and implementation process are presented as well.In this method,the reliability of the system is improved step by step in the order of system-module-component.This thesis includes reliability engineering introduction,SRD basic structure analysis,fault mode summary,systemlevel Markov model establishment,component importance analysis,vulnerable spot reliability evaluation,component reliability improvement and so on.The original SRD system is composed of a four-phase 8/6 structure SRM and the asymmetric half-bridge(AHB)power converter.Potential faults in the system can be summarized through fault mode analysis.The corresponding operation states of SRD under these faults,which are the basis of Markov reliability model,are determined by theoretical analysis,simulation and hardware experiment results.According to the characteristics of Markov model,the component importance analysis of SRD is carried out by using credible improvement potential(CIP)method,which help determine switch tubes and diodes as the key components that affect the reliability of SRD.Since switch tubes and diodes both belong to the converter,the converter is identified as the vulnerable spot in the system.The reliability evaluation and improvement of converter and the key components are carried out,and a new SRD system is constructed,whose reliability modeling and evaluation are carried out in subsequent chapters.By comparing the reliability evaluation results of the original system and the new system,the conclusion is drawn that this method can effectively enhance the reliability of the system and is not limited by the SRM structure.Therefore,this method has certain practicality and universality.Finally,the main work of this thesis is summarized,and the future research is proposed.