Study on characteristics of variable voltage and variable frequency motor with broken rotor bars

The induction motor is commonly operated at variable voltage and variable frequency state at present. The broken rotor bars fault is one common fault in the operation state. The electromagnetic and thermal characteristics of induction motor in broken rotor bar condition are very important fault characteristics. The electromagnetic field of induction motor at fault is analyzed by finite element method. Based on the results above, the temperature distribution and temperature rise of induction motor is analyzed in different broken rotor bar and typical area with maximal temperature rise is investigated too. At last, fault characteristics at broken rotor bar are obtained as a criterion for fault diagnosis.