Insights on diagnostic signals in single-phase and three-phase induction motors in single-phasing fault

This work deals with novel diagnostic insights on induction machines of different types and in various conditions. Three main case-studies are analyzed: healthy three-phase machines, permanent-capacitor single-phase or split-phase machine (assimilated to a two phase machine), and three-phase machine in single-phasing fault (once in rotation, assimilated to a single phase machine). Three-phase machines with higher rated power are tested on-field, to have a comparison with the smaller laboratory ones. Time- and frequency-domain analyses are carried out on current, axial and radial stray flux signals. Highlighting was performed on a harmonic sideband in stray flux signals. Insights are carried out about classical motor current signature analysis technique that cannot be applied easily to permanent-capacitor machines. Considerations about the third harmonic in these conditions are then treated. Some observations on the torque signal in single-phasing machines are exposed as well.