Educational laboratory test benches for induction motor fault diagnosis training

This paper presents three educational test benches especially conceived to illustrate the operation of different induction motors fault diagnosis techniques, both conventional and recently developed approaches. These test benches are used within the context of two laboratory sessions of a subject dealing with predictive maintenance of electrical installations and machinery. During the laboratory sessions, the students must proceed to the integral application of the different condition monitoring techniques. The test benches enable a simple capture of the current signals in machines with rather different constructive characteristics as well as operating and fault conditions. Stationary current signals are later analyzed by using the Fast Fourier Transform (FFT)-conventional approach- whereas the startup current signals are processed using the Discrete Wavelet Transform (DWT)-modern transient-based approach. The obtained results serve to show the students the suitability and application scope of each particular technique with regards to the diagnosis of failures in electric induction motors.