scholarly journals Determination of the Sufficient Inductance of AC Line Reactor at the Input of Frequency Converter

2019 ◽  
Vol 11 (1) ◽  
pp. 25-29 ◽  
Author(s):  
M Yu Pustovetov
Keyword(s):  
Steady State ◽  
Induction Motor ◽  
Induction Motors ◽  
Short Circuit ◽  
Frequency Converter ◽  
Steady State Mode ◽  
Peak Current ◽  
Stable Characteristic ◽  
Additional Charge

 This article discusses the problem of sufficient inductance of AC line reactor at the input of frequency converter. Author provided some simulations for frequency converter loaded by induction motors with different rated powers. For all induction motors the following characteristics of phase current consumed by frequency converter from the grid considered. Instantaneous peak current during the frequency acceleration of induction motor. Amplitude of the current in steady state mode after the end of induction motor acceleration. Instantaneous peak current during additional charge of DC-link capacitance through the shunting contact of charging resistance. Instantaneous peak current when charging DC-link capacitance through the charging resistance - the most stable characteristic, which is practically does not depend on the presence and nominal of the line reactor. It is advisable to demand to inductance of the line reactor, that is, to percent impedance or short-circuit voltage, %, that the considered in computational experiments peak and amplitude values of currents remain not higher than the last above mentioned. It can be stated that with the increase of induction motor rated power, the sufficient value of short-circuit voltage, %, also increases. 

scholarly journals The Application of the Bispectrum Analysis to Detect the Rotor Unbalance of the Induction Motor Supplied by the Mains and Frequency Converter

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 3009
Author(s):  
Pawel Ewert
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Induction Motor ◽  
Induction Motors ◽  
Frequency Converter ◽  
Experimental Tests ◽  
Test Mass ◽  
Mechanical Vibrations ◽  
Stator Current

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.

scholarly journals An analysis of inter-bar currents on a polyphase cage induction motor

2004 ◽  
Vol 15 (4) ◽  
pp. 476-484
Author(s):  
Renato Carlson ◽  
Cláudia A. da Silva ◽  
Nelson Sadowski ◽  
Michel Lajoie-Mazenc
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Induction Motor ◽  
Induction Motors ◽  
Short Circuit ◽  
Fundamental Component ◽  
Cage Induction Motor ◽  
Element Method

This work uses a methodology based on 2D-Finite Element Method (FEM) and on the Circuits Theory (Independent Currents Method) to analyze the inter-bar currents on the rotor of cage induction motors. The Multi-Slice Technique is used to consider the skewing effect. Three conditions are considered: one inter-bar resistance, two inter-bar resistances and three inter-bar resistances. The results show the distribution of currents in the rotor bars, short-circuit rings and transversal resistances at a given time. The fundamental component of the inter-bar and surrounding bar currents are shown to help understanding the phenomenon.

scholarly journals Identification of Inter-Turn Short-Circuits in Induction Motor Stator Winding Using Simulated Annealing

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 117
Author(s):  
Marcin Tomczyk ◽  
Ryszard Mielnik ◽  
Anna Plichta ◽  
Iwona Goldasz ◽  
Maciej Sułowicz
Keyword(s):  
Simulated Annealing ◽  
Induction Motor ◽  
Induction Motors ◽  
Early Stage ◽  
Dynamic Properties ◽  
Short Circuit ◽  
State Variables ◽  
Novel Approach ◽  
Short Circuits ◽  
Identification Processes

This paper presents a method of inter-turn short-circuit identification in induction motors during load current variations based on a hybrid analytic approach that combines the genetic algorithm and simulated annealing. With this approach, the essence of the method relies on determining the reference matrices and calculating the distance between the reference matric values and the test matrix. As a whole, it is a novel approach to the process of identifying faults in induction motors. Moreover, applying a discrete optimization algorithm to search for alternative solutions makes it possible to obtain the true minimal values of the matrices in the identification process. The effectiveness of the applied method in the monitoring and identification processes of the inter-turn short-circuit in the early stage of its creation was confirmed in tests carried out for several significant state variables describing physical magnitudes of the selected induction motor model. The need for identification of a particular fault is related to a gradual increase in its magnitude in the process of the induction motor’s exploitation. The occurrence of short-circuits complicates the dynamic properties of the measured diagnostic signals of the system to a great extent.

scholarly journals Application of Genetic Algorithm for Inter-Turn Short Circuit Detection in Stator Winding of Induction Motor

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8523
Author(s):  
Marcin Tomczyk ◽  
Ryszard Mielnik ◽  
Anna Plichta ◽  
Iwona Gołdasz ◽  
Maciej Sułowicz
Keyword(s):  
Genetic Algorithm ◽  
Induction Motor ◽  
Diagnostic Method ◽  
Induction Motors ◽  
Short Circuit ◽  
Experimental Tests ◽  
Stator Winding ◽  
Short Circuits ◽  
Cage Induction Motor ◽  
Industry Conditions

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.

Determination of the region of stability of the synchronous propulsion motor steady-state mode

2014 ◽  
Vol 85 (3) ◽  
pp. 150-155 ◽  
Author(s):  
A. I. Korshunov
Keyword(s):  
Steady State ◽  
Steady State Mode ◽  
Region Of Stability

Analysis of operating modes of squirrel-cage induction motors in the presence of damage to the rotor rods.

2020 ◽  
Vol 23 (2) ◽  
pp. 59-64
Author(s):  
E. NIEMTSEV ◽  
Keyword(s):  
Induction Motor ◽  
Induction Motors ◽  
Supply Voltage ◽  
Negative Impact ◽  
Short Circuit ◽  
Start Time ◽  
Software Environment ◽  
Engine Operation ◽  
Diagnostic Parameters ◽  
Emergency Situations

The article determines that the main faults in induction motors are damage to the stator and rotor windings, which occur due to changes and distortions in the shape and amplitude of the supply voltage, technological overheating of the windings, mechanical damage. These factors lead to accelerated wear of the insulation of the windings, structural components of the motors, increased values of power losses and the occurrence of pre-emergency and emergency situations. Among the specified diagnostic parameters of engine operation it is possible to consider separately existence of damages of cores of a short-circuited rotor which timely diagnostics demands removal of the engine in repair and will allow to avoid emergency situations with induction motors. To diagnose the control of the rotor rods are quite diverse: determining the amplitude-frequency spectrum of stator currents, detecting the presence of current ripples in an artificial short circuit in the stator winding, the use of diagnostic curves, the selection of appropriate harmonic oscillations in the vibration of the rotor. To reduce or eliminate the negative impact of various factors on the course of technological processes, the best approach at present is the use of tools and measures to diagnose the operation of engines using modeling methods. Based on the model of an induction motor with a short-circuited rotor created in the MATHCAD software environment, graphical dependences were obtained that reflect the change of the main parameters of the induction motor operation and allow to analyze their change during the modulation time. The presence of pulsations of regime parameters and aperiodic components caused by transients was shown. Studies of the process of starting the engine without load and under load showed an increase in start-up time, and the pulsating nature of the studied parameters is observed only in the initial section. The engine start time also increases in the presence of damaged rods in the short-circuited rotor. The pulsating nature of the main diagnostic parameters can be used as a criterion for determining the presence of damage in the short-circuited winding of the rotor of an induction motor.

Transient and Steady-State Measurement of Slip in Induction Motors

1971 ◽  
Vol 4 (7) ◽  
pp. 185-185
Author(s):  
D. W. H. Hampshire ◽  
C. Gould
Keyword(s):  
Steady State ◽  
Induction Motor ◽  
Induction Motors ◽  
Educational Measurement ◽  
Traditional Methods ◽  
State Measurement ◽  
Steady State Measurement ◽  
Transient And Steady State

The measurement of the slip of an induction motor is a common industrial and educational measurement. Traditional methods of slip measurement, of which some of the most common are outlined, tend to be either inaccurate or cumbersome. A recently developed instrument which may be used for both transient and steady-state measurements, is described, which is easy to use and accurate results are quickly obtained. It is not necessary to make any connections to the supply or to fit a transducer to the shaft of the machine.

scholarly journals Detection and Classification of Stator Short-Circuit Faults in Three-Phase Induction Motor

2020 ◽  
Vol 24 (3) ◽  
pp. 417-424
Author(s):  
A.I. Abdullateef ◽  
O.S. Fagbolagun ◽  
M.F. Sanusi ◽  
M.F. Akorede ◽  
M.A. Afolayan
Keyword(s):  
Wavelet Transform ◽  
Induction Motor ◽  
Euclidean Distance ◽  
Induction Motors ◽  
Short Circuit ◽  
Fault Classification ◽  
Discrete Wavelet ◽  
Machine Failure ◽  
Wavelet Energy

Induction motors are the backbone of the industries because they are easy to operate, rugged, economical and reliable. However, they are subjected to stator’s faults which damage the windings and consequently lead to machine failure and loss of revenue. Early detection and  classification of these faults are important for the effective operation of induction motors. Stators faults detection and classification based on  wavelet Transform was carried out in this study. The feature extraction of the acquired data was achieved using lifting decomposition and reconstruction scheme while Euclidean distance of the Wavelet energy was used to classify the faults. The Wavelet energies increased for all three conditions monitored, normal condition, inter-turn fault and phase-to-phase fault, as the frequency band of the signal decreases from D1 to A3. The deviations in the Euclidean Distance of the current of the Wavelet energy obtained for the phase-to-phase faults are 99.1909, 99.8239 and 87.9750 for phases A and B, A and C, B and C respectively. While that of the inter-turn faults in phases A, B and C are 77.5572, 61.6389 and 62.5581 respectively. Based on the Euclidean distances of the faults, Df and normal current signals, three classification points were set: K1 = 0.60 x 102, K2 = 0.80 x 102 and K3 = 1.00 x 102. For K2 ≥ Df ≥ K1 inter-turn faults is identified and for K3 ≥ Df ≥ K2 phase to phase fault identified. This will improve the induction motors stator’s fault diagnosis. Keywords: induction motor, stator fault classification, data acquisition system, Discrete Wavelet Transform

scholarly journals Automatic Temperature Regulation System of Locomotive Traction Induction Motors With Power Losses Minimization

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
A. S. Kosmodamianskiy ◽  
V. I. Vorobiev ◽  
A. A. Pugachev
Keyword(s):  
Induction Motor ◽  
Temperature Regulation ◽  
Induction Motors ◽  
Frequency Converter ◽  
Operating Mode ◽  
Regulation System ◽  
Air Cooling ◽  
Power Losses ◽  
Automatic Temperature ◽  
Stator Current

The air cooling systems are shown to be used to provide required temperature condition of traction induction motors on locomotives. The automatic temperature regulation system is developed for its using to solve such a task. Results of experimental investigation showed that the AO63-4 induction motor stator end winding on the side opposite to air supply is the most heated part of the induction motor. Based on the results of the research, it was used an aperiodic second-order transfer function for approximation of the thermal transient curves. The design of an induction motor control system maintaining operating mode with minimum of the stator current are considered. It is shown that the modes of minimum of the stator current and minimum of power losses are quite close to each other. The MatLab simulation results taking typical nonlinearities and iron power losses in an induction motor and conduction and commutation power losses in semiconductors of frequency converter into account are presented. It is shown that as a result of application of the suggested system the power losses reduction may be led up to 20 % relatively to classical scalar control.

Sign in / Sign up

Export Citation Format

Share Document