Electric vehicle permanent-magnet synchronous motor stator asymmetry fault diagnosis method

Abstract

The invention discloses an electric vehicle permanent-magnet synchronous motor stator asymmetry fault diagnosis method. Fault diagnosis on a permanent-magnet synchronous motor is carried out and the severity of a fault occurring in the motor is determined by fusing wavelet transform and a support vector machine system. A faulty resistor is connected in series to any phase to form a faulty phase; a motor stator three-phase winding current signal is collected; the collected current signal is processed by means of wavelet de-noising, and the characteristic quantity of the processed signal is extracted; the extracted characteristic quantity is input to a support vector machine system, and the output of the support vector machine system is set; and finally, the stator asymmetry fault of the permanent-magnet synchronous motor is diagnosed, and the severity of the stator asymmetry fault is determined. The electric vehicle permanent-magnet synchronous motor stator asymmetry fault diagnosis method of the invention has the advantages of accurate and effective diagnosis result, high diagnosis accuracy, and high operability.

Description

technical field [0001] The invention relates to a fault diagnosis method for an asymmetrical stator of a permanent magnet synchronous motor of an electric vehicle, and belongs to the technical field of state detection and fault diagnosis of a driving motor. Background technique [0002] The driving motor is the core equipment of electric vehicles and the source of power for vehicles. Its reliability directly affects the driving safety of electric vehicles. Compared with traditional electric excitation motors, permanent magnet synchronous motors are Small size, compact structure, reliable operation, low noise and other characteristics, in line with the best application indicators of electric vehicle drive motors, is the best choice for electric vehicle drive motors, not only that, its application range is extremely wide, almost throughout aerospace, military industry , automotive industry, industrial and agricultural production and various fields of daily life. [0003] The ...

AI Technical Summary

Problems solved by technology

[0003] The permanent magnet synchronous motor for driving electric vehicles is a new type of motor. Its operating environment is complex, frequent starting, acceleration and deceleration, emergency braking, continuous high-speed operation, and bumps and vibrations, etc., are not conducive to the safe operation of the motor. It induces stator short-circuit faults, rotor eccentric faults, rotor bearing faults, etc. in the drive motor, which seriously affects the reliability and safety of the drive motor operation; in addition, because the rotor permanent magnet replaces the excitation winding on the rotor, the rotor demagnetization fault is a permanent magnet The unique fault type of synchronous motor; if the fault in the electric vehicle drive motor cannot be found and dealt with in time, the fault will be further expanded and may cause the drive motor to stop, affecting the normal operation of the vehicle and endangering the life safety of the drivers and passengers

[0004] In the previous literature, the research on the fault diagnosis of permanent magnet synchronous motors for electric vehicles is more focused on the most frequent faults of permanent magnet synchronous motors, stator winding inter-turn short circuit faults and permanent magnet faults, which are unique to permanent magnet synchronous motors. Therefore, the study of permanent magnet synchronous motor stator asymmetric fault is ignored; in fact, the operating environment of permanent magnet synchronous motor for driving electric vehicles is complex and the operation is frequent, and stator asymmetric fault is also a relatively common problem of permanent magnet synchronous motor. Faults; faults such as damaged insulation of stator windings, short circuits of stator windings (including inter-turn, inter-strand, phase-to-phase short circuits), iron core short circuits and other faults will cause asymmetric operation of the stator; in addition, the motor load is asymmetrical and the power supply is asymmetrical And the short-circuit fault of the power supply is also the cause of the asymmetric operation of the motor; therefore, when the stator asymmetric fault occurs, timely diagnosis of the fault is also particularly important for the safety of electric vehicles

Images