Simulation Analysis of Gear Local Fault by Drive Motor Stator Current Method Under the Inverter Environment

In order to overcome the harmonic interference existing in the motor stator current under the environment of variable frequency power supply, and improve the ability to identify the mechanical fault of the stator current analysis method, this paper will establish a simulation model for asynchronous motor driven gear fault diagnosis under MATLAB / SIMULINK enviroment, based on the analysis of the equations of motion of asynchronous motor and the torsional vibration mechanical model of the gearbox of the drive system. By comparing and analyzing the mechanical fault characteristics of the stator current before and after the inverter, it shows that there are a large number of inverting harmonics on the front and the back of the inverter, which can easily couple with the gear fault signal and reduce the fault recognition ability. However, the signal before the inverter has the characteristics of carrier frequency (power frequency) component stability, high harmonic frequency and adjustable frequency bandwidth. At present, it can be used as a mean of separating and diagnosing mechanical fault information in variable frequency environment.