Rotor fault diagnosis based on DC-side current and fusion algorithm for induction motors

The spectrum of DC-side current is analyzed for the rotor fault of induction motor driven by inverter and it is found that the fault specific frequency components are distributed in its low-frequency band and a few high-frequency bands.A fusion algorithm is proposed to improve the accuracy and reliability of rotor fault diagnosis,which applies Hilbert transform to convert the high-frequency signals to low-frequency signals and fuses them with the low-frequency signals to suppress the environmental noise and unrelated frequency components.The experimental results show that the rotor fault of induction motor is detected effectively.