A Statistical Approach on the Stator Current Performance Analysis Under Balanced, Unbalanced and Interturn Fault Condition of Three Phase Induction Motor

Squirrel cage induction motors are the standard machinery widely used in industries. Early detection of the fault either in stator winding or rotor side is essential due to technical and economic issues. In this paper, a statistical approach using a box plot has been found to be an efficient tool to analyse induction motor stator current in different conditions. The three-phase stator current values are considered the input of the proposed method for fault detection. The whole technique has been implemented under the MATLAB environment. The assessment of the proposed scheme is carried out through several laboratory experiments by creating artificial inter-turn faults under balanced and unbalanced conditions. It has been observed that the Interquartile range (IQR) -based diagnosis technique is found satisfactory in extracting the degree of unbalanced introduced in the motor current due to inter-turn stator winding fault in one of the phases, even in the presence of unbalanced three-phase supply voltage.