A proper diagnosis of the state of an induction motor is of great interest to industry given
the great importance of the extended use of this motor. Presently, the use of this motor driven by
a frequency converter is very widespread. However, operation by means of an inverter introduces
certain difficulties for a correct diagnosis, which results in a signal with higher harmonic content and
noise level, which makes it difficult to perform a correct diagnosis. To solve these problems, this
article proposes the use of a time-frequency technique known as Dragon Transform together with
the functional ANOVA statistical technique to carry out a proper diagnosis of the state of the motor
by working directly with the curves obtained from the application of the transform. A case study
is presented showing the good results obtained by applying the methodology in which the state of
the rotor bars of an inverter-fed motor is diagnosed considering three failure states and operating at
different load levels.
