Evaluation and implementation of a system to eliminate arbitrary load effects in current-based monitoring of induction machines

Diagnosis of rotor asymmetries in induction motors based on the transient extraction of fault components using filtering techniques

“…A high resolution implies a long sampling interval, and this is only possible if the machine works strictly in steady state. Load or voltage fluctuations cause uncertainty in the frequencies of the fault components [11,14]; subsequently, the fault harmonics can be confused with harmonics with similar frequencies caused by other phenomena. This means that the reliability of the diagnosis also reduces when the uniformity of the machine regime decreases.…”

“…-According to the physical quantity analysed for monitoring the rotor condition; diagnosis methods based on the measurement of vibrations [3], fluxes on search coils [4], axial flux on coils concentric with the shaft [5], air-gap torque [6], instantaneous power [7], residual voltages during the disconnection [8] or stator currents [1,[9][10][11] have been proposed; the methods based on the measurement of the stator current have drawn most of the attention in the industrial environment, since this signal can be obtained directly from the already existing current transformers, avoiding the installation of any specific probe or any interruption on the operation of the machine.…”

Detection of Rotor Bar Faults in Field Oriented Controlled Induction Motors

“…This method is based on the principle of monitoring the frequency components of the monitored signal via FFT analysis. The traditional MCSA method is especially successful for motors operating under a constant load torque, speed and voltage [10]. However, it is insufficient for systems operating under variable loads such as compressors, freight lifts, etc.…”

Reliable detection of broken rotor bars in induction motors via MUSIC and ZSC methods

“…This is due to the keyrole played by those electrical machines in manufacturing and industrial production processes [4]. Moreover, recent works have shown that the fault detection is not always straightforward, and special cases should also be considered [5]- [8]. Furthermore, it is not enough to detect a fault but also to determine its severity with accuracy and, if possible, to predict and plan a reliable maintenance strategy [1], [4].…”