Gearbox monitoring by using the stray flux in an induction machine based electromechanical system

The aim of this paper is to analyze experimentally the stray flux spectrum of a three phase induction machine in an electromechanical system, in order to show how it is influenced by the gearbox behavior. The mechanical monitoring in the electromechanical systems has been mainly studied using vibration signals. Recently, some works have been performed in order to monitor the mechanical part by using the stator current spectrum. In this paper the effect of the gearbox behavior is observed in the stray flux by using the spectral signature given by the stator current which is produced by the torsional vibrations induced by the gearbox in normal operation. This study is performed on two different induction machines (squirrel-cage and wound rotor) sharing the same mechanical system.