Study On Fault Rules And Fault Tolerant Control Of The Electric Drive System Based On The EMT

The electric drive system is highly integrated with electrical and automation technology.It has been widely used in new energy vehicles.However,due to the complexity of the system and the reliability of electrical components,the failure rate of the system is obviously higher than that of the traditional vehicle system,and the reliability of the system is lower than that of the traditional system.In the actual operation of the system,to ensure the reliability and stability of the work is the key to stable operation of the system.So it has certain theoretical significance and practical value to research the fault rule and fault tolerant control of electric drive system.In this thesis,firstly,the structure and fault of electric drive system based on EMT are classified and summarized,according to its working principle,the fault tree model of EMT electric drive system is set up.At the same time,the faults of the EMT electric drive of the ten pure electric bus in Wuhan and the mileage when the faults occurred were statistic,the distribution relationship of the system failure probability density and the failure rate with the mileages according to the car reliability theory was obtained.Then,based on the law of failure and the fault tree model,the fault diagnosis and fault tolerant control of EMT electric drive system was studied.Finally,the fault diagnosis model is established,and the function of fault diagnosis and fault tolerant control is realized by analog input signal.The research on the subject is mainly reflected in the following aspects:(1)The development and research status of fault rule and fault tolerant control of electric drive system are analyzed,and it provide theoretical direction and foundation for the following research contents and work;(2)According to the basic composition and working principle of EMT electric drive system,all faults are classified,and the fault tree model of the system is established.The faults of the EMT electric drive of the ten pure electric bus in Wuhan and the mileage when the faults occurred were statistic,the distribution relationship of the system failure probability density and the failure rate with the mileages according to the car reliability theory was obtained;(3)Research on fault diagnosis and fault tolerant control of system control signal,input signal,component and system self-diagnosis,according to the fault tree model and fault distribution law.(4)The model of fault diagnosis and fault tolerant control of EMT electric drive system is established by the stateflow module in simulink.In order to realize the function of fault diagnosis and fault-tolerant control system,the actual input data is simulated by the input analog vector signal,and the correctness of the model is verified.