M'hamed Drif

Airgap-Eccentricity Fault Diagnosis, in Three-Phase Induction Motors, by the Complex Apparent Power Signature Analysis

This paper deals with the use of the signature analysis of the complex apparent power modulus as a new technique for the diagnostics of mixed airgap-eccentricity condition in operating three-phase squirrel-cage induction motors. First, a modeling and simulation study concerning the occurrence of airgap eccentricity in three-phase induction motors is presented. For that purpose, the winding function approach is considered. Then, both simulation and experimental results are presented to illustrate the effectiveness of the proposed approach. A suitable fault-severity factor is also proposed as an indicator of the condition of the machine.

Discriminating the Simultaneous Occurrence of Three-Phase Induction Motor Rotor Faults and Mechanical Load Oscillations by the Instantaneous Active and Reactive Power Media Signature Analyses

This paper deals with the use of the instantaneous active and reactive power signature analyses and their derived signals-the instantaneous power factor and phase angle - for discriminating broken rotor bars and airgap eccentricity conditions (rotor faults) from mechanical load oscillation effects in operating three-phase squirrel cage induction motors. Both simulation and experimental results are presented to show the effectiveness and the merits of the proposed approach that offers the possibility to distinguish between the three conditions by comparing the signature analyses of two different quantities for each abnormality condition.

Stator Fault Diagnostics in Squirrel Cage Three-Phase Induction Motor Drives Using the Instantaneous Active and Reactive Power Signature Analyses

In this paper, the instantaneous active and reactive power signature analyses are presented for stator fault diagnosis in operating squirrel cage three-phase induction motors either directly connected to the mains or fed from inverters. Both simulation and experimental results are presented to show the effectiveness and the merits of the proposed approach that offers the possibility to detect this type of fault and to discriminate it from other abnormality conditions responsible for the same motor behavior by comparing the signature analyses of the two considered quantities.

The Use of the Instantaneous-Reactive-Power Signature Analysis for Rotor-Cage-Fault Diagnostics in Three-Phase Induction Motors

In this paper, a new detection technique based on the instantaneous-reactive-power signature analysis is proposed for the diagnosis of rotor-cage faults (RCFs) in operating three-phase induction motors (IMs). This technique has been tested through the simulation of two different IMs using a mathematical model based on the winding-function approach. In order to demonstrate the capability of the proposed tool for rotor-condition monitoring, these simulations are complemented by the experimental results obtained from two IMs with several faulty rotors, powered from sinusoidal and nonsinusoidal supply voltages. The results obtained by the fast-Fourier-transform algorithm and the Welch method show the merits of the proposed approach for the detection of RCFs. A suitable fault-severity factor is also proposed as an indicator of the motor condition. Moreover, the inductive reactive effect of RCFs is underlined to demonstrate the effectiveness and convenience of this new technique for the diagnosis of RCFs in three-phase IMs.

Power Spectrum-Based Detection of Induction Motor Rotor Faults for Immunity to False Alarms

It has recently been shown that spectrum analysis of instantaneous power can provide sensitive online detection of rotor faults in induction motors compared with current, torque, speed, or vibration spectrum analysis. However, it was reported that monitoring of the twice slip frequency, 2sfs, components induced by the fundamental component can produce false rotor fault alarms due to asymmetry in the rotor or low frequency load oscillations. In this paper, the rotor fault components induced in the power spectrum by the stator fifth and seventh space harmonics are derived to evaluate their immunity to false alarms. It is shown that the (6 - 8s)fs component can provide reliable detection of rotor faults under cases where existing methods produce false alarms. An experimental study performed on custom built rotor samples shows that the new components are capable of detecting rotor faults immune to false alarms produced by rotor axial air ducts, rotor anisotropy, and low frequency load oscillations for cases where existing methods fail. The components derived in this paper can also be applied to vibration, speed, torque, or acoustic monitoring for reliable detection of rotor faults.

Airgap eccentricity fault diagnosis, in three-phase induction motors, by the complex apparent power signature analysis

This paper introduces the use of the complex apparent power signature analysis as a tool for the diagnostics of mixed airgap eccentricity condition in operating three-phase squirrel cage induction motors. Firstly, a modelling and simulation study concerning the occurrence of airgap eccentricity in three-phase induction motors is presented. For that purpose, the winding function approach is considered. Then, both simulation and experimental results are presented to illustrate the effectiveness of the proposed approach

On-line fault diagnostics in operating three-phase induction motors by the active and reactive power media

This paper deals with the use of the instantaneous active and reactive power signature analysis and their ratios for the diagnosis of airgap eccentricity and rotor cage fault conditions in operating three-phase induction motors. Both simulation and experimental results are presented to show the merits of the proposed approach that offers the possibility to distinguish between both fault conditions.

The instantaneous reactive power approach for rotor cage fault diagnosis in induction motor drives

In this paper a new detection technique based on the instantaneous reactive power signature analysis is proposed for the diagnosis of rotor cage faults in induction motors drives. Experimental tests were carried out on an induction motor with several faulty rotors and the obtained results corroborate the effectiveness of the instantaneous reactive power approach for the detection of broken rotor bars in inverter-fed induction motors. A suitable fault severity factor is also proposed as an indicator of the condition of the machine.

The instantaneous power factor approach for rotor cage faults diagnosis in three-phase induction motors

In this paper a new fault detection technique based on the instantaneous power factor signature analysis is proposed for the diagnosis of rotor cage faults in three-phase induction motors. A mathematical model based on the Winding Function Approach was used for the simulation of this type of fault and experimental tests were carried out on an induction motor with several faulty rotors. Both simulation and experimental results are presented to illustrate the effectiveness of the proposed approach. A suitable fault severity factor is also proposed as an indicator of the machine condition.

Rotor Cage Fault Diagnostics in Three-Phase Induction Motors, by the Instantaneous Phase-Angle Signature Analysis

Detection of broken rotor bars has long been an important but difficult job in the detection area of motor faults. The characteristic frequency components of a faulted rotor in the stator current spectrum are very close to the power frequency component but by far less in amplitude, which brings about great difficulty for accurate detection. In this paper a new detection method based on the instantaneous phase-angle signature analysis is proposed for the diagnosis of rotor cage faults in operating three-phase induction motors. For that purpose, a mathematical model based on the winding function approach is used in order to simulate this type of fault and experimental tests are carried out on an induction motor with several faulty rotors. Simulation and experimental results are presented to show the merits of this novel approach for the detection of cage induction motor broken rotor bars.