Low-Cost Diagnosis of Rotor Asymmetries of Induction Machines at Very Low Slip With the Goertzel Algorithm Applied to the Rectified Current

Induction machines are essential components of many industrial installations and, therefore, their faults must be detected early. Fault detection using current spectrum analysis is attracting an increasing interest as a condition-based monitoring technique. However, its use to detect rotor asymmetries in high-power induction machines, which operate at very low slip, particularly challenging, due the closeness characteristic fault harmonics fundamental component, separated only few mHz. Their reliable harsh environments requires high spectral resolution, that is, long acquisition times and huge number samples, what hinders implementation on embedded, online devices with limited computing resources. To address this problem, paper presents novel combination diagnostic techniques, rectified signal, Goertzel algorithm signal processing tool. This unique allows for optimized ot algorithm, provides resolution full load range machine, computational cost negligible memory footprint. proposal validated experimentally diagnosis medium-voltage motor.