Research On Fault Diagnosis Techonlogy Of PMSM For Electric Vehicle Based On Injection Method

In this paper,the main body faults of PMSM for electric vehicle drive are studied,and the problem of unstable fault characteristics of motor system,convergence of multiple faults and incompatibility of different fault diagnosis algorithms in complex environment is solved.Multi-fault diagnosis method for permanent magnet synchronous motor for electric vehicles with injection technology.The motor fault tree is established.The fault type and fault diagnosis mode of permanent magnet synchronous motor are analyzed.The fault generation mechanism of rotor demagnetization,rotor eccentricity and interturn short circuit is expounded.The finite element model of the permanent magnet synchronous belt fault of electric vehicle is established.The simulation research of the i njection fault diagnosis method is carried out.The fault characteristics which are independent of the motor working condition and can be distinguished by different faults are extracted,and the effectiveness of the diagnostic method is determined.feasibi lity.A motor fault diagnosis method based on injection technology is proposed for the working gap of electric motor.By injecting the rotary voltage signal,when the fault characteristic quantity I0·? /Vi is larger than the faultless motor,the diagnosis is the inter-turn short circuit fault.The d-axis current signal is injected,and the differential inductance L'd value is used to distinguish the rotor demagnetization and the rotor eccentricity fault.The L'd value is too large for the demagnetization fault,and the L'd value is small for the eccentric fault.Implement a method to achieve multiple troubleshooting purposes.The diagnostic method is robust,not sensitive to the environment and working conditions,low in diagnostic cost,and simple and effective in structure.The applicability of the injectable diagnostic method was studied.The finite element model of permanent magnet synchronous motor with different rotor structure and different pole slots is established.The simulation is carried o ut by the same injection method.It is found that the fault characteristics are obvious when the rotor structure and the pole slot are changed.The conclusion of judging the magnitude of the value determines the broad applicability of the injective diagnos tic strategy.A permanent magnet synchronous motor based on 8 poles and 36 slots of various faults was fabricated,and an experimental platform was built.For the four prototypes of faultless,rotor demagnetization,rotor eccentricity and interturn sho rt circuit,the rotating voltage signal and d-axis current signal were injected respectively to extract the fault feature quantity,and the feasibility of the injection diagnosis strategy was verified.