Rotor winding asymmetry is one of the leading causes of induction motor failure. For the purpose of detection of rotor fault, many diagnostic methods have been developed so far. Among them, the most widely used in industry are vibration monitoring and current signature analysis.
The above mentioned methods rely on measurement of motor current and vibration for detecting fault in the rotor. However, effects seen in the motor current and the motor vibration are consequences of change in magnetic field due to broken or faulty rotor bar and therefore are less sensitive to rotor fault. This often leads to misinterpretation of results since the method relies on secondary symptoms for detection and not the root of the problem. In other words, in terms of the condition monitoring of electric machine, such as electric motor and electric generator, the electric machine's condition inferred from the measurement of the current or vibration of the electric machine is often unreliable.
Additionally, the above mentioned methods, for carrying out measurements, require sensors and other equipment which are often cumbersome to use, and are expensive. Moreover, these sensors have to be installed inside terminal box of the motor, which is often time consuming and requires the motor to be shut down. Further, improper installation of sensors can result in damage to the motor, faulty monitoring.
Therefore, in light of the above discussion, there is a need for a system and method that solves the problems mentioned above.