Fault Diagnosis For Broken Rotor Bars In Converter-Fed Induction Motor

It is necessary to achieve the incipient fault diagnosis for broken rotor bars in converter-fed induction motor with high sensitivity and reliability. The expressions of the stator current (converter output current) sideband components derived from rotor broken fault and load fluctuation are deduced in detail, and analyzes thoroughly the impact to power supply current(converter input current) caused by broken rotor bar fault. In order to detect broken rotor fault in converter-fed induction motors at an earlier stage, the simulation of PWM-VSI variable-frequency control system which uses space vector transform technique with broken rotor bars are completed,as well as the corresponding experiments. Furthermore,the fault diagnosis for broken rotor bar is realized by using continuous subdivision Fourier transform and self-adaptive filter techniques. The simulation and experimental results demonstrate that it is effective.