Effect of the Misalignment Level on the Analyses of Current and Stray Flux Signals in Induction Motors

This paper studies the effect of different levels of misalignment between an induction motor and its driven load on stator current and stray flux signals. Both types of signals are captured both under starting and under steady-state and they are subsequently analyzed with signal processing tools that are suited to each regime. In the case of stray flux signals, they are captured with a triaxial flux sensor that enables the acquisition of both axial and radial components with enough resolution. The results show that the misalignment fault has a direct effect on the currents (both under starting and steady-state), while the effect on the stray fluxes is minor. This conclusion is coherent with those of other recent works and ratify the potential of the combined use of both quantities (currents and stray-fluxes) to discriminate between misalignments and other types of faults such as eccentricities.