Static Eccentricity Fault Analysis in Inverter Fed Induction Motor using Finite Element Method

Abstract

One of the common faults encountered in three phase induction motors (IM) is the eccentricity fault. In this work, a study on the electromagnetic characteristics of open-loop voltage source inverter fed IM is carried out for healthy and static eccentricity fault condition with the assistance of Finite Element Analysis. The importance of electromagnetic field analysis is it contains the data about the position of stator, rotor and mechanical parameters of IM. Thus the strategy of monitoring airgap magnetic fields and current are often used for the diagnosis of faults in IM. Detection of eccentricity fault at the incipient stage is difficult because the changes that the fault would introduce in the motor terminal quantities are negligible unless the severity is very high. A comparative study is carried out for healthy and eccentric fault motor with the help of ANSYS Maxwell Finite Element Analysis tool. Electromagnetic field parameters such as speed, current, flux distribution over the machine and in the air gap are analysed for healthy and faulty motor.