A Novel Approach for Eccentricity Fault Detection in Squirrel Cage Induction Motors

Subject Areas : Fault diagnosis and identification

Mehdi Ahmadi ¹ , Javad Poshtan ² , Seyed Mehdi MirImani ³

1 - PhD Student/Sharif University of Technology
2 - Associate Professor/Iran University of Science and Technology
3 - Asistant Professor Babol (Noshirvani) University of Technology [e-mail]

Received: 2012-06-11 Accepted : 2013-01-02 Published : 2013-03-01

Keywords: Finite Element Method, Induction Motors, static eccentricity detection, test coil,

Abstract :

In this paper, static eccentricity fault detection in induction motors is studied. Two dimensional finite element method (2D-FEM) is used for faultless and eccentric condition modeling in induction motors. Also current and speed signals are compared in two experimental and simulation cases for model validating. For fault detection, fast Fourier transform is used at first. In this method, high order harmonics with small amplitude can alarms the fault occurrence. For this reason, the fault detection process is difficult.To overcome these drawbacks, it is suggested that two test coils contrive around the air-gap. So, any changes in air-gap can be detected easily. Moreover this test coils are used in open circuit case. So, these test coils do not effect on motor dynamics. Also, the results show that modulated voltage can be alarm the fault occurrence, type and percent well.