Broken rotor bar detection using the full spectrum applied to the induction motor starting currents

Reliable detection of broken rotor bars through the analysis of sidebands around the fundamental component of the stator current at steady state is difficult when the motor operates at no-load or low load. In this work it is proposed to monitor the time evolution of the high frequency sequence components associated with broken rotor bars during the starting transient. Through simulations, the behavior of these components is analyzed for balanced and unbalanced power supply conditions, with and without harmonic distortion. The strategy proved to be independent of these conditions.