A survey on time and frequency characteristics of induction motors with broken rotor bars in line-start and inverter-fed modes

• A comprehensive detailed electrical, magnetic and mechanical analysis of industrial induction motors under broken bars fault is provided in this work.
• Effects of line-start and inverter-fed modes, different load levels and various reference speeds is deeply investigated.
• Different fault indexes are intuitively compared and investigated based on their applicability via analytical and experimental results.
• Advantages and disadvantages of fault diagnosis procedures are identified and an appropriate global fault detection routine which is applicable at different operating conditions is proposed.

This paper deals with the comprehensive detailed concepts of the rotor broken bars fault in industrial induction motors. It reviews the most important and applicable techniques for fault detection, and addresses fault diagnosing procedures at different supply modes including line-start and inverter-fed modes. Moreover, new analytical and experimental aspects of fault are proposed using the time and frequency domain variations of the motor variables such as current, voltage, electromagnetic torque and speed. Since the faulty motor behavior cannot be correctly identified without considering the motor operating condition, and the capability of the previous fault indicators are studied deeply in order to investigate their applicability at different conditions. These conditions include various faults, load and reference speed levels and also fault location. All in all, a precise condition assessment of the rotor broken bar induction motors, suitable for industrial purposes, is presented considering motor supply and conditions changes.