Designing collaborative working laboratory sessions for induction machine fault diagnosis learning

Abstract

In this paper, two laboratory sessions, specially designed to instruct students on the operational methodology of different induction motors fault diagnosis techniques, are presented and explained. The sessions are taught within the context of a subject dealing with predictive maintenance of electrical installations and machines. During the laboratory sessions, the students apply the different condition monitoring techniques, using special educational laboratory test benches built to this end. These test benches allow the students to easily capture the necessary current signals in motors with rather different constructive characteristics, operating conditions and faults. Next, the students must process the captured signals by using available software programs. While stationary current signals are analyzed using the Fast Fourier Transform (FFT) conventional diagnosis approach the startup current signals are processed using the Discrete Wavelet Transform (DWT) modern transient-based diagnosis method. The laboratory sessions have been developed from a collaborative perspective, so that the students are encouraged to work in groups in the experimental part with further collective discussion on their diagnostic conclusions, all within an open framework for information sharing.