Induction motor broken rotor bars detection using fuzzy logic: experimental research

This paper proposes a new automated practical method for the diagnosis and detection of broken rotor bars in induction motor. This method uses only one stator current sensor. It is based in spectral analysis of stator current envelope (SCE) obtained via Hilbert transform. According to the fault diagnosis objective, two features are selected from the SCE spectrum: the amplitude of the 2 sf harmonic ( s is the slip and f the fundamental harmonic) representing the broken bars defect and the DC value. These features will be used as inputs of fuzzy logic block, where the decision about the state of rotor is made. The results obtained are very satisfactory and the diagnostic system is capable to detect the correct number of broken bars.