Induction motor inter turn fault detection using infrared thermographic analysis

• Infrared thermography (IRT) is used to detect inter turn fault in induction motor.
• Transient rise in temperature during initial start of the motor is carried to detect inter turn fault.
• At steady thermal state, pseudo-coloring technique is proposed to extract hot region on the motor surface.
• Pseudo-coloring technique is in compliance with NETA thermographic standard.
• Comparative analysis has been carried under healthy and faulty conditions.

Induction motors are the most commonly used prime movers in industries. These are subjected to various environmental, thermal and load stresses that ultimately reduces the motor efficiency and later leads to failure. Inter turn fault is the second most commonly observed faults in the motors and is considered the most severe. It can lead to the failure of complete phase and can even cause accidents, if left undetected or untreated. This paper proposes an online and non invasive technique that uses infrared thermography, in order to detect the presence of inter turn fault in induction motor drive. Two methods have been proposed that detect the fault and estimate its severity. One method uses transient thermal monitoring during the start of motor and other applies pseudo coloring technique on infrared image of the motor, after it reaches a thermal steady state. The designed template for pseudo-coloring is in acquiescence with the InterNational Electrical Testing Association (NETA) thermographic standard. An index is proposed to assess the severity of the fault present in the motor.