Diagnosis simulation of broken rotor bars in squirrel cage induction motor fed with variable frequency power

The previous methods on broken rotor bars fault diagnosis of squirrel cage induction motor (SCIM) were just for motors fed with industry frequency power supply. In this paper, a simulation modeling of SCIM supplied with variable frequency power is introduced, which respectively in normal condition and in broken rotor bars conditions. Through the comparison and analysis of the one-phase stator current spectrum and the three-phase average instantaneous power spectrum, it is concluded that the latter has the better resolution from spectrum with abundant harmonics, so it can be an advisable criterion for the broken bars fault diagnosis.