FEM based electromagnetic signature analysis of winding inter-turn short-circuit fault in inverter fed induction motor

The intent of this paper is to analyze the electromagnetic signature of stator winding inter-turn short-circuit fault in a closed loop speed controlled Induction Motor (IM) employing Finite Element Method. Stator winding short-circuit nearly covers 21% of faults in IM. Diagnosing the inter-turn fault at an incipient stage is one of the challenging task in the area of fault detection of IM to prevent crucial damages in industrial applications. Also detecting the faults in inverter fed IM under variable speed applications under varying load is one of the major issues in industrial drives. As the signatures of electromagnetic field contains the entire data in association with the location of rotor, stator and mechanical parts of the motor, a regular monitoring of fields in the airgap can be used to diagnose the inter-turn fault in the stator winding of IM. In this direction, an IM is modeled with several inter-turn fault severities like 30 turns, 15 turns, 5 turns & 1 turn short using ANSYS Maxwell FEA tool and coupled with ANSYS Simplorer for loading arrangements. The PWM inverter with closed loop speed controlled strategy is implemented in Matlab Simulink and co-simulated with ANSYS Simplorer to integrate all the components in one common simulation platform environment for accurate design & analysis for realistic simulation. Several electromagnetic variables like flux density, flux lines and airgap flux density distribution over the machine are analyzed. The spatial FFT spectrum of radial component of flux density in the airgap contains the information related to the diagnosis of inter-turn fault at the incipient stage.