Abstract
Transient-based fault diagnosis in induction
motors has gained increasing attention over the recent
years. This is due to its ability to avoid eventual wrong
diagnostics of the conventional motor current signature
analysis in certain industrial situations (presence of load
toque oscillations, light loading conditions, and so on).
However, the application of these transient methodologies
requires the use of advanced signal processing tools. This
paper presents a detailed comparison between the two
main groups of transforms that are employed in transient
analysis: discrete and continuous. This paper does not
focus on trivial fault cases but on difficult real situations
where the application of the conventional methods often
leads to false diagnostics (outer bar breakages in double-
cage motors, motors with rotor axial duct influence, and
combined faults). Indeed, it is the first time that continuous
tools are applied to some of these controversial situations.
The results in this paper prove the special advantages of
the continuous transforms, tearing down some false myths
about their use.
