An Approach to the Use of an External Magnetic Field As a Diagnostic Sign of an Asynchronous Motor Malfunction

2021 ◽  
Vol 64 (3) ◽  
pp. 18-23
Author(s):  
Ildar Yamansarin ◽  
◽  
Mikhail Salikov ◽  
Alexander Padeev ◽  
Dmitry Surkov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Technical Condition ◽  
Stator Winding ◽  
Electric Motors ◽  
Transform Method ◽  
Fast Fourier Transform Method ◽  
Measurement Location

The article deals with the issues related to the possibility of diagnosing the technical condition of an asyn-chronous electric motor by an external magnetic field. The justification of the problems associated with the di-agnosis of electric motors is given. The difficulties that arise when measuring the external magnetic field of electric motors, as well as the devices with which it is possible to carry out measurements, are described. The re-lationship between the EMF of the sensor and the external magnetic field is shown. The results of processing the EMF waveforms induced by an external magnetic field in an inductive sensor for various electric motors are presented. The processing was carried out by the fast Fourier transform method. The external magnetic field contains the first harmonic and various harmonics that are multiples of the combination of the stator teeth, or the sum of the stator and rotor teeth that fall on one pair of poles. The ratio of the amplitudes of the first and tooth harmonics is affected by the measurement location and the orientation of the sensor. Diagrams showing the ratio of the main and tooth harmonics at different points of the motor body are constructed. The depend-ences of the harmonic amplitudes on the magnitude of the magnetizing current of the stator are given. Changes in the amplitudes and spectrum of harmonics in the presence and absence of an inter-turn short circuit in the stator winding are shown. Diagrams of the circular external magnetic field for the main and higher harmonics are constructed. The study shows the possibility of using an external magnetic field to detect inter-turn short circuits of the stator winding.

Diagnosis of Asynchronous Motor with Inter Connective Circuit in Stator Winding

2021 ◽  
Vol 64 (1) ◽  
pp. 48-53
Author(s):  
Rauf Mustafayev ◽  
◽  
Diyar Akhmedov ◽  
Aslan Akhmedov ◽  
◽  
...  
Keyword(s):  
Induction Motor ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Rapid Assessment ◽  
Feature Space ◽  
Technical Condition ◽  
Angular Distance ◽  
Technical Diagnostics ◽  
Stator Winding ◽  
Mathematical Methods

The problems of applying the achievement of general technical diagnostics for the recognition and assessment of the technical state of the stator winding in the process of performing functional processes by an asynchronous motor are considered. It is proposed to use the informative parameters of vibration acceleration obtained from full-scale experiments carried out in idle and load modes of an asynchronous motor for diagnosing an intertuеrn short circuit that often occurs in the stator winding. It is shown that for recognizing a malfunction of the stator winding of an induction motor, mathematical methods of technical diagnostics are effective, in particular, the method of potential functions and the method of diagnostics based on the angular distance in the feature space. The sequence of methods, rapid assessment of the technical condition of the stator winding and the determination of the interturn short circuit at the initial stages of its occurrence during the operation of the induction motor is given.

scholarly journals Development of the software-hardware complex for diagnostics of inter-turn short circuits of stator windings of asynchronous motors

2021 ◽  
Vol 288 ◽  
pp. 01040
Author(s):  
Roman Dolgih ◽  
Ivan Suvorov ◽  
George Palkin ◽  
Sergey Kakaurov ◽  
Marina Morozova
Keyword(s):  
Short Circuit ◽  
Asynchronous Motor ◽  
Research Work ◽  
Technical Condition ◽  
Diagnostic Methods ◽  
Operating Voltage ◽  
Stator Winding ◽  
Stator Windings ◽  
Hardware Complex ◽  
Short Circuits

Up to 38% of asynchronous motor (AM) failures are caused by damage to the stator insulation. Despite the wide variety of methods, the reliability of determining the inter-turn short circuits of stator windings under operating voltage still remains at a low level. The existing methods for diagnostics of asynchronous motor failure of the interturn short circuit of stator winding have been examined. New diagnostic methods for individual parameters developed in the course of the previous study are described. A new diagnostic method is formulated, on the basis of which the research work is carried out. The method will allow us to constantly monitor the technical condition of the stator winding, and identify its damage at an early stage of their development. Diagnostics can be performed without dismantling the engine and without removing it from the working process. The microprocessor unit is implemented for diagnostics of the technical condition of AM introducing this method. Moreover, the software and hardware complex is implemented for diagnostics of the technical condition for AM. The results of experiments on a laboratory stand with inter-turn AM closures are presented, which confirm the higher reliability of monitoring.

scholarly journals Detection of Stator Winding Short Circuit Faults Through Magnetic Fields In Induction Motors

2021 ◽  
Vol 5 (1) ◽  
pp. 89-102
Author(s):  
Bima Rachmat Ah Ro Ufun ◽  
Iradiratu Diah Prahmana Karyatanti ◽  
Belly Yan Dewantara
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Induction Motor ◽  
Induction Motors ◽  
Short Circuit ◽  
Stator Winding ◽  
Transform Method ◽  
Average Percentage ◽  
Fast Fourier Transform Method ◽  
Short Circuit Fault

In applications in the industrial world, the use of induction motors has been widely used in operation because induction motors have many advantages, although they have many advantages, induction motors themselves also have disadvantages, namely having high starting currents. In many cases the damage to the induction motor, the damage to the stator due to a short circuit, is a frequent failure, this damage can cause considerable losses because the motor can stop operation So this research will discuss about the detection of short circuit faults in the stator winding through leaky flux using a flux sensor that is placed outside the motor and placed radially and using the Fast Fourier Transform (FFT) method. Damage to the short circuit is done by reconstructing the stator winding of the induction motor. There are two variations of short circuit damage, namely short circuit winding 1 to winding 3 and short circuit winding 2 to winding 10 on an induction motor. The short circuit data is then processed using the Fast Fourier Transform method which produces data in the form of voltage to frequency. The results of the percentage of success of short circuit fault detection seen from the loaders have an average percentage of 50%, at no load conditions can detect short circuit faults by 100%. In conditions of short circuit interruption 1-3 has a success percentage of 30% and short circuit fault 2-10 by 70%. The existence of this system is expected to be able to anticipate any damage that can cause considerable and fatal losses.

scholarly journals Imitation Modeling of an Inter-Turn Short Circuit of an Asynchronous Motor Stator Winding for Diagnostics of Auxiliary Electric Drives of Transport Infrastructure

2021 ◽  
Vol 23 (2) ◽  
pp. C65-C74
Author(s):  
Sergey Goolak ◽  
Juraj Gerlici ◽  
Oleg Gubarevych ◽  
Tomáš Lack ◽  
Mikhail Pustovetov
Keyword(s):  
Short Circuit ◽  
Asynchronous Motor ◽  
Ac Impedance ◽  
Transport Infrastructure ◽  
Stator Winding ◽  
New Approach ◽  
Electric Drives ◽  
Imitation Modeling ◽  
Asynchronous Motors ◽  
Diagnostic Complex

A scientific approach to calculating the parameters and characteristics of an asynchronous motor in the inter-turn short circuit mode in one phase of the stator is proposed to create the foundations of a diagnostic complex for assessing the condition of asynchronous motors of the transport infrastructure. This approach consists of the fact that in the model with which the research is carried out, it is proposed to take into account changes in the mutual inductance of the motor when the AC impedance of one of the stator phases changes. Using a new approach to modeling processes occurring in an asynchronous motor during the inter-turn short circuit in one phase of the stator, pulsations of the torque on the motor shaft were studied for different values of the AC impedance and resistance of one of the stator winding phases, which corresponds to varying degrees of the inter-turn short circuits.

Diagnostics of Stator Winding Faults in a Three-Phase Asynchronous Motor Using Park’s Vector Analysis

Vestnik MEI ◽  
2021 ◽  
pp. 69-74
Author(s):  
Muhammad Deeb ◽  
◽  
Gassan Ibragim ◽  
Talal Assaf ◽  
◽  
...  
Keyword(s):  
Induction Motor ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Vector Model ◽  
Stator Winding ◽  
Stator Windings ◽  
Stator Current ◽  
Experimental Part ◽  
Three Phase ◽  
Short Circuit Fault

The study addresses the problem of detecting a short circuit fault in the three-phase induction motor winding by monitoring the stator current Park vector (Lissajous curves). Park's vector model is implemented using the Matlab software package. The experimental part of the study was carried out on an 11 kW three-phase induction motor. The Lissajous curves obtained for a healthy motor and a motor with short-circuited turns under various load conditions were compared with each other. The obtained results have demonstrated the effectiveness of the proposed method for detecting interturn short circuit faults in the three-phase stator windings of induction motors.

scholarly journals Method of condition monitoring of rotor windings of the medium voltage induction motors of power plant auxiliaries in start-up modes

Vestnik IGEU ◽  
2019 ◽  
pp. 31-44 ◽  
Author(s):  
E.M. Novoselov ◽  
D.A. Polkoshnikov ◽  
V.A. Savelyev ◽  
A.S. Strakhov ◽  
A.A. Skorobogatov
Keyword(s):  
Magnetic Field ◽  
Power Plant ◽  
External Magnetic Field ◽  
Software Package ◽  
Induction Motors ◽  
Electric Motors ◽  
Medium Voltage ◽  
Start Up ◽  
Rotor Winding ◽  
Start Ups

A promising method of monitoring rotor winding condition of induction electric motors ensuring higher reliability of their operation is spectral analysis of the external magnetic field signal. Modern methods of external magnetic field analysis use only the spectrum of this signal in the steady-state operation mode, which does not allow effective monitoring on a number of medium voltage electric motors of power plant auxiliaries operating with long start-ups (for example, machines with variable load, with a double squirrel cage, etc.). It is possible to evaluate the rotor winding condition of such machines in start-up modes, which means that an important task is to study the frequency-time spectra of the external magnetic field of the above-mentioned electric motors and to develop a method for monitoring the state of their rotor windings in the startup mode. In the study, the authors used two-dimensional models of two different types of motors representing drives of the mechanisms of draft systems at power stations. Both models are developed in the ANSYS software package. The calculation of the external magnetic field was carried out using the finite element method. The modelling was done for cases with or without defects. Signal processing was per-formed using the Fourier window transform method in the MatLab software package. Frequency-time spectra of the external magnetic field were built in the start-up mode on models of the investigated induction motors with the following defects: with dynamic eccentricity, with one broken bar of the rotor winding and without the indicated defects. The research results allowed us to develop a method for monitoring the rotor winding state of medium voltage electric motors of power plant auxiliaries operating with long start-ups. The method is based on detecting lower side frequencies of the fictitious rotor winding harmonics in the frequency-time spectrum during the startup. Their specific feature is «reflection» in the spectrum from the time axis. The developed method of monitoring rotor winding condition of the above-mentioned induction electric motors allows increasing the reliability of their operation by timely detection of faults in the rotor windings.

scholarly journals Procedure for Detection of Stator Inter-Turn Short Circuit in AC Machines Measuring the External Magnetic Field

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1132
Author(s):  
Remus Pusca ◽  
Raphael Romary ◽  
Ezzeddine Touti ◽  
Petru Livinti ◽  
Ilie Nuca ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Short Circuit ◽  
Physical Phenomenon ◽  
Invasive Procedure ◽  
Spectral Lines ◽  
Stator Windings ◽  
Non Invasive ◽  
Healthy State ◽  
Rotor Poles

This paper presents a non-invasive procedure to detect inter-turn short circuit faults in the stator windings of AC electrical machines. It proposes the use of the stray external magnetic field measured in the vicinity of the machine to determine stator faults. The originality introduced by this procedure is the analysis method presented in the paper, which when compared to usual diagnosis methods, does not require any data on the healthy state of the machine. The procedure uses the magnetic unbalance created by the rotor poles and the load variation in faulty cases. The presented method can be applied to induction and synchronous machines used as a motor or generator. It is based on the variation of sensitive spectral lines obtained from the external magnetic field when the load changes. Analytical relationships are developed in the paper to justify the proposed method and to explain the physical phenomenon. To illustrate these theoretical considerations, practical experiments are also presented.

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