Diagnosis of low insulation fault in the starting transient of squirrel cage rotor induction motors using wavelet analysis

The objective of this work was to diagnose faults in squirrel-cage induction motors during the startup transient, by analyzing the stator current signal. To achieve this, low- and medium-voltage motors were modeled in Simulink using MATLAB. Previously, the fault due to low insulation was diagnosed through a static test. It was demonstrated that, during the startup transient, the low insulation fault manifests through a Daubechies wavelet analysis at level 8 of the current signal. The fault was identified in the detail levels 1, 2, 5, 6, 7, and 8, for both low-voltage and medium-voltage motors.