Diagnosis of Broken Rotor Bar Fault Extent in Three Phase Squirrel Cage Induction Motor

In this paper, the formative mechanism of the characteristic frequency components caused by broken bar in the stator current of the squirrel cage induction motor is first described. Then a simple way to calculate the amplitude of the characteristic frequency components caused by broken rotor bars is presented, and the indication on the fault extent based on the ratio of the amplitude of the characteristic frequency components to that of the fundamental component is constituted. Computation results indicate that the fault extent indication defined in this paper coincides with the simulation results.