Detection of Rotor Bar Faults by Using Stator Current Envelope

The paper presents detection of rotor bar faults at steady state operation in squirrel cage induction motor by using stator current envelope. Three different rotor faults and healthy motor conditions were investigated in experiments. One of the stator currents has been used in the investigation of effects of rotor faults on the current envelope. The ratios of fluctuation of the envelope were used as feature of fault conditions for diagnosis. In the literature a lot of studies are available about diagnosis and detection rotor many different analysis and feature extraction methods such as motor current signature analysis (MCSA), fast Fourier transform (FFT). Unlike the literature, in the present study the stator current envelopes are used. The use of the current envelope does not affect the performance of the fault detection, while requiring much less computation and low cost in implementation, which would make it easier to implement in embedded systems for condition monitoring of motor.