An induction motor model including the first space harmonics for broken rotor bar diagnosis

This work presents a model of a three‐phase induction machine which includes the first space harmonics of the magnetomotive force. Special attention has been paid to the way of improving detection of broken rotor bars. This detection is based on the spectral analysis of the stator current. We show that it is essential to extend the analysis to the amplitudes of the side bands due to the space harmonics. This thorough method makes it possible to detect with a higher degree of accuracy the type and the importance of a defect in the rotor cage.