Fault Diagnosis And Modeling For Traction Motor Of High Speed Train With Closed Loop Structure

As a symbol of Chinese technology,high-speed railway has aroused widespread international attention.Due to its quickness,convenience and environmental benefits,high-speed trains have become the first choice for public transport.So their security problems are closely related to the vital interests of the people.Traction motor is the core component of the whole traction system.Feedback control is also the actual demand of system operation.Therefore,the fault diagnosis technology of motor in closed-loop structure has important theoretical significance and application value.Based on CRH2 high-speed train,this paper focuses on the closed-loop control system of traction motor,mainly researches the technology of fault diagnosis and modeling.Firstly,for the inter-turn short circuit in one phase of stator windings of the traction motor under the open-loop structure,the physical mechanism of both the fault and the motor is analyzed.Then,a linear model of the motor with fault parameters in a rotating orthogonal coordinate system is established.According to the characteristics of fault model,a fault detection method based on multi-model matching is proposed.The simulation results not only verify the effectiveness of the fault detection method,but also prove the accuracy of the fault model.Secondly,based on the physical characteristics of each component,the transfer function models of the inverter and motor are built in a rotor field oriented controlled closed-loop system.Combined with the constant frequency ratio control and slip frequency control module,a third order linear model of the motor in closed-loop system is established.According to the virtual current technology,a fault injection method of traction motor is proposed.On this basis,a fault model with fault parameters under closed-loop structure is established.The simulation verifies the accuracy and effectiveness of the established health and fault model of traction motor in closed-loop control system.Finally,according to the characteristics of the closed-loop system model,a fault diagnosis method based on system residuals and multiple-model matching is proposed,which is proved to be effective by simulations.Furthermore,based on the theory of stability analysis,the fault diagnosis conditions of the closed-loop system are established.The simulation results verify the correctness of the diagnosable conditions.The influence of the introduced closed-loop structure on the fault diagnosis is also analyzed,which shows that the diagnosable conditions have a good reference value.