scholarly journals Dependence of the spectral components of the stator current on damage in the electric motor

2021 ◽  
Vol 2094 (4) ◽  
pp. 042051
Author(s):  
P N Charikov ◽  
A G Afanasenko
Keyword(s):  
Service Life ◽  
Electric Motor ◽  
Technical Condition ◽  
Timely Manner ◽  
Stator Current ◽  
Asynchronous Electric Drive ◽  
Squirrel Cage ◽  
Spectral Components ◽  
Wear And Tear ◽  
Cage Rotor

Abstract Safety and fail-safety of production processes largely depend on the technical condition of machine assemblies that play a key role in production. The main drive mechanism of machine assemblies is an asynchronous electric drive with a squirrel-cage rotor. Damage to any part of the electric motor reduces the performance and service life of the machine. Malfunctions resulting from normal wear and tear, errors in maintenance and design, harmful environmental influences and other factors must be identified and eliminated in a timely manner. In this regard, the analysis of the condition of the electric motor and the prediction of damage plays a major role in increasing the reliability and increasing the service life of the equipment. This article will consider the regularities of the spectral components of the stator current of an electric motor from the mode of failure.

An AChBKr315M2BU3 induction variable-frequency electric motor with a squirrel-cage rotor

2007 ◽  
Vol 78 (6) ◽  
pp. 291-293
Author(s):  
M. F. Zapadnya ◽  
O. V. Martynov ◽  
S. V. Piskunov ◽  
S. A. Chizhov
Keyword(s):  
Electric Motor ◽  
Variable Frequency ◽  
Squirrel Cage ◽  
Cage Rotor

scholarly journals Studying and Simulating the Influence of the Rotor Fault on Stator Current

2020 ◽  
Vol 17 (1) ◽  
pp. 17-21
Author(s):  
Katalin Ágoston
Keyword(s):  
Equivalent Circuit ◽  
Frequency Spectrum ◽  
Induction Motors ◽  
Signature Analysis ◽  
Stator Current ◽  
Motor Current ◽  
Squirrel Cage ◽  
Motor Current Signature Analysis ◽  
Cage Rotor ◽  
Current Signature

AbstractThis paper presents fault detection techniques, especially the motor current signature analysis (MCSA) which consists of the phase current measurement of the electrical motor’s stator and/or rotor. The motor current signature analysis consists in determining the frequency spectrum (FFT) of the stator current signal and evaluating the relative amplitude of the current harmonics. Sideband frequencies appear in the frequency spectrum of the current, corresponding to each fault. The broken bar is a frequent fault in induction motors with squirrel-cage rotor. It is presented the equivalent circuit for induction motors and the equivalence between the squirrel-cage rotor and the rotor windings. It is also presented an equivalent circuit model for induction motors with squirrel cage rotor, and based on this a Simulink model was developed. It is shown how a broken rotor bar influences the magnetic field around the rotor and through this the stator current. This modification is highlighted through the developed model.

scholarly journals Research of current distribution by phases in asynchronous electric motor with a combined winding

2022 ◽  
Vol 23 (5) ◽  
pp. 150-159
Author(s):  
K. V. Martynov ◽  
L. A. Panteleeva ◽  
D. A. Vasiliev ◽  
E. V. Dresvyannikova
Keyword(s):  
Electric Motor ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Experimental Sample ◽  
Energy Characteristics ◽  
The Real ◽  
Squirrel Cage ◽  
Three Phase ◽  
Cage Rotor ◽  
Asynchronous Electric Motor

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.

scholarly journals The experimental identification method of the dynamic efficiency for frequency regulation algorithms of AEDs

2021 ◽  
Vol 12 (1) ◽  
pp. 59 ◽  
Author(s):  
Vladimir L. Kodkin ◽  
Aleksandr S. Anikin
Keyword(s):  
Control Method ◽  
Frequency Control ◽  
Reference Signal ◽  
Frequency Regulation ◽  
Current Feedback ◽  
Electric Drives ◽  
Stator Current ◽  
Asynchronous Electric Drive ◽  
Input Side ◽  
Mechanical Moment

The article proposes and substantiates a method for studying the dynamics of an asynchronous electric drives with frequency control from the input side of the signal for setting the speed of rotation of the electric motor. In this method, a constant speed reference signal is added to a harmonic variable frequency signal. The set of amplitude changes and phase shifts of velocity oscillations are the initial data for identifying the dynamics of the studied control method. The logic of this method is determined by the previously obtained nonlinear transfer function of the link that forms the mechanical moment in the asynchronous electric drive with frequency control. Experiments have shown the dynamic benefits of the drive with positive stator current feedback.

scholarly journals Model for Predicting Road Markings Service Life

2019 ◽  
Vol 14 (3) ◽  
pp. 341-359
Author(s):  
Dario Babić ◽  
Anđelko Ščukanec ◽  
Darko Babić ◽  
Mario Fiolić
Keyword(s):  
Service Life ◽  
Measuring Method ◽  
Timely Manner ◽  
Data Set ◽  
Winter Maintenance ◽  
The Road ◽  
Annual Average Daily Traffic ◽  
Dynamic Measuring ◽  
Road Marking ◽  
Life Prediction Model

Road markings provide drivers with the information necessary for their comfortable and safe journey. To achieve that, they must be visible in all driving conditions, which means that they have to be renewed and maintained in a timely manner. This research aims to develop a model for predicting the service life of paint, thermoplastic and agglomerate cold plastic road markings. The research comprised 5218.00 km (115 roads) of solvent-borne paint road markings, 579.00 km (30 roads) of thermoplastic and 4979.00 km (30 roads) of agglomerate cold plastic road markings. The retroreflectivity of road markings was measured two times (after renewal and after winter) using the dynamic measuring method. Service life prediction model was developed for each material based on factors such as initial retroreflectivity, road marking age and position, annual average daily traffic and winter maintenance activity of the road. Developed models were tested using a new data set, and all three models showed satisfactory accuracy. The application of the model enables road authorities to optimise road-marking maintenance activities, while at the same time, ensuring the level of visibility required by drivers.

Investigations on corrosion of aircrafts in the aspect of prolonged service life and operation driven by their technical condition

2012 ◽  
Vol 30 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Piotr Barszcz
Keyword(s):  
Service Life ◽  
Air Force ◽  
Atmospheric Corrosion ◽  
Protective Coatings ◽  
Technical Condition ◽  
Structural Components ◽  
Institute Of Technology ◽  
Corrosion Investigation ◽  
Prolonged Service ◽  
Research Studies

Research studies that are conducted by both the Air Force Institute of Technology (AFIT) and other domestic and foreign organizations indicate that investigations of corrosion phenomena present a very important factor with respect to prolongation of technical resources and operation of aircraft driven by their actual technical condition. The investigation of the corrosion degree and deterioration of protective coatings must be carried out in a systemic manner with thorough analysis of information that bring together the aircraft operation and the processes of corrosion and deterioration of protective coatings. The investigation must comprise measurements of the atmospheric corrosion in order to determine corrosive aggressiveness of the atmosphere and establish frequency and scope of corrosion inspection. Only the analysis of gathered information with its characteristics may guarantee safe operation of structural components of aircrafts according to their actual technical condition. This paper outlines the approach to corrosion investigation that is in place in AFIT.

scholarly journals Assessment of the technical condition of lift guides using a magnetic field

2021 ◽  
Vol 2130 (1) ◽  
pp. 012003
Author(s):  
P Lonkwic ◽  
T Krakowski ◽  
H Ruta
Keyword(s):  
Early Stage ◽  
Technical Condition ◽  
Operating Conditions ◽  
Measuring Head ◽  
Cross Sectional ◽  
Correct Operation ◽  
Emergency Braking ◽  
Wear And Tear ◽  
Equipment Failures ◽  
Novel Concept

Abstract The systems that monitor individual components of machines and devices are under constant development. The ability to detect damages at an early stage allows failures to be prevented, so any uncontrolled downtime can be predicted in a controlled manner. Continuous monitoring of technical condition is an activity that also helps to reduce the losses due to equipment failures. However, not all areas can be monitored continuously. Such areas include lift guides where wear and tear can occur naturally, i.e. through abrasion of the material layer due to interaction with moving guide shoes or after emergency braking. Emergency braking causes local damages to the guide through plastic deformation of its surface resulting from indentation of the knurled roller of the brake. Such places are cleaned mechanically, which results in local reduction of the cross-sectional area. In such a case, it is difficult to continuously assess the technical condition of guides due to the prevailing operating conditions. Therefore, a concept of a head enabling assessment of the technical condition of guides at every stage of their operation has been developed. This article presents the novel concept of a magnetic head used for assessing the technical condition of lift guide rails that are the running track of lifting equipment. The initial tests were performed on the original test setup. The concept of the developed measuring head was verified for correct operation on specially prepared flat bars with holes. The results obtained in the form of laboratory tests proved that the proposed measuring head concept can be applied to the measurements under real conditions.

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