scholarly journals Effects of the Slot Harmonics on the Stator Current in an Induction Motor with Bearing Fault

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xiangjin Song ◽  
Jingtao Hu ◽  
Hongyu Zhu ◽  
Jilong Zhang

Bearing faults are the most frequent faults of induction motors. The current spectrum analysis is an easy and popular method for the monitoring and detection of bearing faults. After a presentation of the existing fault models, this paper illustrates an analytical approach to evaluate the effects of the slot harmonics on the stator current in an induction motor with bearing fault. Simple and clear theoretical analysis results in some new current characteristic frequencies. Experimental tests with artificial bearing outer raceway fault are carried out by measuring stator current signals. The experimental results by spectral analysis of the stator current agree well with the theoretical inference.

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 3009
Author(s):  
Pawel Ewert

This article presents the effectiveness of bispectrum analysis for the detection of the rotor unbalance of an induction motor supplied by the mains and a frequency converter. Two diagnostic signals were analyzed, as well as the stator current and mechanical vibrations of the tested motors. The experimental tests were realized for two low-power induction motors, with one and two pole pairs, respectively. The unbalance was modeled using a test mass mounted on a specially prepared disc and directly on the rotor and the influence of this unbalance location was tested and discussed. The results of the bispectrum analysis are compared with results of Fourier transform and the effectiveness of unbalance detection are discussed and compared. The influence of the registration time of the analyzed signal on the quality of fault symptom analyses using both transforms was also tested. It is shown that the bispectrum analysis provides an increased number of fault symptoms in comparison with the classical spectral analysis as well as it is not sensitive to a shorter registration time of the diagnostic signals.


2014 ◽  
Vol 698 ◽  
pp. 83-89 ◽  
Author(s):  
Nail Safin ◽  
Vladimir Prakht ◽  
Vladimir Dmitrievskii

This paper deals with the possibilities of bearing fault diagnosis of induction motors by stator currents analysis based on Park’s vector approach. The main theoretical aspects, the experimental results and their analysis are presented. It is shown that preventive stator current diagnostics of induction motors based on Park’s vector allows us early detection of bearing defects in the inner and outer races. The current spectra additional harmonics appearing in the case of bearing damage are found.


2018 ◽  
Vol 27 (4) ◽  
pp. 1166-1173 ◽  
Author(s):  
I. Andrijauskas ◽  
M. Vaitkunas ◽  
R. Adaskevicius

2019 ◽  
Vol 9 (4) ◽  
pp. 616 ◽  
Author(s):  
Maciej Skowron ◽  
Marcin Wolkiewicz ◽  
Teresa Orlowska-Kowalska ◽  
Czeslaw Kowalski

Electrical winding faults, namely stator short-circuits and rotor bar damage, in total constitute around 50% of all faults of induction motors (IMs) applied in variable speed drives (VSD). In particular, the short circuits of stator windings are recognized as one of the most difficult failures to detect because their detection makes sense only at the initial stage of the damage. Well-known symptoms of stator and rotor winding failures can be visible in the stator current spectra; however, the detection and classification of motor windings faults usually require the knowledge of human experts. Nowadays, artificial intelligence methods are also used in fault recognition. This paper presents the results of experimental research on the application of the stator current symptoms of the converter-fed induction motor drive to electrical fault detection and classification using Kohonen neural networks. The experimental tests of a diagnostic setup based on a virtual measurement and data pre-processing system, designed in LabView, are described. It has been shown that the developed neural detectors and classifiers based on self-organizing Kohonen maps, trained with the instantaneous symmetrical components of the stator current spectra (ISCA), enable automatic distinguishing between the stator and rotor winding faults for supplying various voltage frequencies and load torque values.


ELKHA ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 122
Author(s):  
Andri Pradipta ◽  
Santi Triwijaya ◽  
Mohamad Ridwan

Induction motors are widely used in industrial processes, vehicles and automation. Three-phase induction motors can be used for traction systems on electric locomotives. In this case, the speed control system is an important thing that must be applied to the propulsion system. This study aimed to test the indirect torque control for a Three-phase induction motor. A proportional integral (PI) controller was applied for speed controller. The indirect torque control system was modeled and simulated using PSIM software. According to the result, the control method showed a good performance. The speed could be maintained even the speed reference was changing or a load was applied. The steady state error of the speed response was just 0.1% with rise time around 0.06 s. The stator current went up to 39.5 A in starting condition. The stator current reached 12 A rms when the load of 10 Nm was applied. Then, the current rose to 15.7 A rms when the load was increased to 40 Nm and the current came down to 12.8 A rms when the load was decreased to 20 Nm.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8523
Author(s):  
Marcin Tomczyk ◽  
Ryszard Mielnik ◽  
Anna Plichta ◽  
Iwona Gołdasz ◽  
Maciej Sułowicz

This paper presents a new method of inter-turn short-circuit detection in cage induction motors. The method is based on experimental data recorded during load changes. Measured signals were analyzed using a genetic algorithm. This algorithm was next used in the diagnostics procedure. The correctness of fault detection was verified during experimental tests for various configurations of inter-turn short-circuits. The tests were run for several relevant diagnostic signals that contain symptoms of faults in an examined cage induction motor. The proposed algorithm of inter-turn short-circuit detection for various levels of winding damage and for various loads of the examined motor allows one to state the usefulness of this diagnostic method in normal industry conditions of motor exploitation.


2014 ◽  
Vol 1070-1072 ◽  
pp. 1187-1190 ◽  
Author(s):  
Nail R. Safin ◽  
Vladimir A. Prakht ◽  
Vladimir A. Dmitrievskii ◽  
Anton A. Dmitrievskii

The article is dedicated to investigate possibility of diagnostics bearing faults of induction motors by stator currents analysis. The main features of stator currents analysis are studied. The possibility of identifying air-gap eccentricity due to the working with damaged bearings by stator currents investigating is revealed. The recommendations of monitoring and configuration of a proper diagnosis of induction motor are provided.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1884 ◽  
Author(s):  
Rafia Nishat Toma ◽  
Alexander E. Prosvirin ◽  
Jong-Myon Kim

Efficient fault diagnosis of electrical and mechanical anomalies in induction motors (IMs) is challenging but necessary to ensure safety and economical operation in industries. Research has shown that bearing faults are the most frequently occurring faults in IMs. The vibration signals carry rich information about bearing health conditions and are commonly utilized for fault diagnosis in bearings. However, collecting these signals is expensive and sometimes impractical because it requires the use of external sensors. The external sensors demand enough space and are difficult to install in inaccessible sites. To overcome these disadvantages, motor current signal-based bearing fault diagnosis methods offer an attractive solution. As such, this paper proposes a hybrid motor-current data-driven approach that utilizes statistical features, genetic algorithm (GA) and machine learning models for bearing fault diagnosis. First, the statistical features are extracted from the motor current signals. Second, the GA is utilized to reduce the number of features and select the most important ones from the feature database. Finally, three different classification algorithms namely KNN, decision tree, and random forest, are trained and tested using these features in order to evaluate the bearing faults. This combination of techniques increases the accuracy and reduces the computational complexity. The experimental results show that the three classifiers achieve an accuracy of more than 97%. In addition, the evaluation parameters such as precision, F1-score, sensitivity, and specificity show better performance. Finally, to validate the efficiency of the proposed model, it is compared with some recently adopted techniques. The comparison results demonstrate that the suggested technique is promising for diagnosis of IM bearing faults.


Author(s):  
Mo. Suhel A. Shaikh ◽  
Rakesh Maurya

Abstract This paper deals with the performance analysis of different PWM techniques for three-phase and dual three-phase induction motors. In this paper, the dual three-phase induction motor is reconnected as a three-phase and six-phase winding configurations and its performances are investigated. The comparative evaluation for the aforesaid machine configurations are carried out in terms of quality of stator current waveform with different PWM techniques. Total harmonic distortion are obtained in terms of harmonic distortion factor for stator current. The theoretical findings are further verified through simulation and experimental results.


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