Evaluation of different broken bar fault diagnostic means in double-cage induction motors with FEM

The aim of the present paper is to compare and evaluate different diagnostic means for the identification of the broken bar fault in delta connected double-cage induction motors. The work is carried out with FEM. The motors are studied at nominal load as well as under low load operation. The traditionally used diagnostic means such as: the current, torque and apparent power waveforms´ spectrums are thoroughly studied with respect to prior work. Moreover, in this work the zero-sequence current spectrum is also investigated. The advantages and disadvantages of each diagnostic mean will be discussed and evaluated, offering an important insight of the broken bar fault diagnosis in the double-cage induction motor.