scholarly journals Improving a model of the induction traction motor operation involving non-symmetric stator windings

2021 ◽  
Vol 4 (8(112)) ◽  
pp. 45-58
Author(s):  
Sergey Goolak ◽  
Borys Liubarskyi ◽  
Svitlana Sapronova ◽  
Viktor Tkachenko ◽  
Ievgen Riabov ◽  
...  

The analysis of operating conditions of induction traction motors as part of traction electric drives of electric locomotives reported here has revealed that they are powered by autonomous voltage inverters with asymmetric non-sinusoidal voltage. It was established that the induction motor operation may be accompanied by defects caused by the asymmetrical modes of the motor stator. A model of the induction motor has been proposed that takes into consideration changes in the values of mutual inductance of phases and complete inductance of the magnetization circuit due to changes in the geometric dimensions of the winding caused by a certain defect. An algorithm that considers the saturation of the magnetic circuit of the electric motor has been proposed. This approach to modeling an induction motor is important because if one of the stator's windings is damaged, its geometry changes. This leads to a change in the mutual inductance of phases and the complete inductance of the magnetization circuit. Existing approaches to modeling an induction motor do not make it possible to fully take into consideration these changes. The result of modeling is the determined starting characteristics for an intact and damaged engine. The comparison of modeling results for an intact engine with specifications has shown that the error in determining the controlled parameters did not exceed 5 %. The modeling results for the damaged engine demonstrated that the nature of change in the controlled parameters did not contradict the results reported by other authors. The discrepancy in determining the degree of change in the controlled parameters did not exceed 10 %. That indicates a high reliability of the modeling results. The proposed model of an induction electric motor could be used to investigate electromagnetic processes occurring in an electric motor during its operation as part of the traction drive of electric locomotives

2018 ◽  
Vol 58 ◽  
pp. 03016 ◽  
Author(s):  
I.V Naumov ◽  
N.V. Savina ◽  
M.V. Shevchenko

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.


2020 ◽  
Author(s):  
Pedro Cabral ◽  
Amel Adouni

Many industry applications required the use of the induction motors. In such envirenement the electrical machines are facing of many stressed operating conditions. One of the critical creteria which decide the choice of the induction motor is the thermal behaviour under different mode operation. In this paper a study of the thermal behavior of an induction motor is presented. In order to predict the temperature in the different machine components, a model based on the lumped parameter thermal network   has been developed. The geometry of the machine and the thermal properties of its various components are used to express the developed model. The joule and the iron losses are considering as the inputs. The proposed model is implemented and tested using MATLAB software. It is a simple model which could predict rapidly the different temperatures. Keywords: Induction motor, Thermal analysis, Lumped parameters thermal network, Modeling, Heat sources


Author(s):  
Sonong Sonong ◽  
Herman Nauwir ◽  
Muhammad Ruswandi Djalal

Electric motor is an electric machine that has a function as a converter of electrical energy into mechanical energy. Electric motors are widely used as movers because they are better in terms of technical and economical, but have disadvantages such as large initial currents so that they cannot last long, to overcome this can be used Y-utan star starting method both manually and automatically created in a panel box. In the operation and manufacture of a protection system for a 3 phase induction motor, some supporting equipment can be arranged in a panel box so that motor performance can be maximized. The results of this tool design are in the form of a panel box in which there are three types of circuits, namely: 3 phase induction motor operation circuit with the starting Y-∆ automatically, reversing the direction of 3 phase induction motor rotation, and 3 phase induction motor operation in two places. Where the series is equipped with a protection system and can be operated manually and automatically.


Author(s):  
Hamideh Jafari ◽  
Javad Poshtan ◽  
Hamed Sadeghi

In this article, the most common induction motor faults including bearing outer race defect, broken rotor bar, and short-circuit of stator windings are diagnosed with high reliability. The decentralized fuzzy-integral data fusion method is used for information fusion in feature level. In the proposed scheme, the feature vectors are constructed using signatures created by time-domain characteristics obtained from stator three-phase current measurements. Partial matching of each feature is calculated by the fuzzy c-mean classifier algorithm, and features with high diagnosis ability are fused by Choquet fuzzy integral. The technique is validated experimentally on the 4 hp induction motor of an electropump, and the results are presented.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 609
Author(s):  
Jakub Kellner ◽  
Slavomír Kaščák ◽  
Michal Praženica ◽  
Patrik Resutík

This paper examines the properties of a multi-phase drive for EV (electric vehicles) and HEV (hybrid-electric vehicles) using a simulation model in the Matlab/Simulink environment and verifies the findings by experimental measurements on a real motor. The paper studies a five-phase induction motor, a suitable alternative for electric vehicles, due to its better properties such as better torque, smoother ripple, better fault tolerance, and the possibility of connecting stator windings to star, pentagon, and pentagram. The fundamentals of the article are to find out how this engine behaves in fault states, which can be called hazardous states. The paper presents a comprehensive evaluation of the decrease of mechanical power, torque, and power losses during motor operation without failure, in case of failure of one phase, and in case of failure of two adjacent phases and two non-adjacent phases, in different connections. In the simulations, the five-phase drive is powered from an ideal five-phase voltage source to verify the behavior of losses on the motor in fault conditions. Subsequently, the motor model is powered by a five-phase VSI, while the simulated waveforms are confirmed on a real motor, which is also powered by a five-phase VSI. The investigation results are the detection, which of the stator windings has better properties in the fault-free state and the case of fault states in operation. For which stator windings connection, it is most advantageous to design and dimension a five-phase induction motor.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4353
Author(s):  
Tomasz Drabek ◽  
Dawid Kara ◽  
Tomasz Kołacz ◽  
Tomasz Lerch ◽  
Jerzy Skwarczyński

The paper presents the results of laboratory tests and FEM 2D calculations of the DCEFSM (Direct Current Excited Flux Switching Machine) electric motor prototype, made based on the stator ferromagnetic sheets of the induction motor. Static measurements of torques, currents, power, efficiency, electromotive forces, and voltages of the motor under various operating conditions were performed, as well as the recordings of its currents and back-EMFs waveforms. FEM calculations of measured values were also performed. The obtained results allow us to conclude that the motor has the operating properties of an under-excited synchronous cylindrical motor and can be vector controlled like the PMSM motor. The results of measurements and calculations indicate the need to redesign the magnetic circuit of the stator.


2021 ◽  
Vol 4 (8(112)) ◽  
pp. 67-82
Author(s):  
Volodymyr Chenchevoi ◽  
Valeriy Kuznetsov ◽  
Vitaliy Kuznetsov ◽  
Olga Chencheva ◽  
Iurii Zachepa ◽  
...  

The paper presents studies of the system "induction generator-induction motor" with parametric asymmetry on a mathematical model to determine the quality of generated electricity in load operating modes. A mathematical model of the "induction generator-induction motor" system has been developed taking into account losses in steel and parametric asymmetry. The analysis of the transient characteristics of an induction generator when a motor load is connected in symmetrical and asymmetrical modes of operation is carried out. The results of changes in the main characteristics of an induction motor at various degrees of parametric asymmetry in the generator are presented. The quality of the generated electricity was analyzed based on the calculations of the unbalance coefficients for each of the operating modes. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an induction motor from an autonomous energy source based on an induction generator. On a thermal mathematical model, the study of the effect of the output voltage asymmetry on the heating of the connected induction motor was carried out. It is shown that the asymmetry of the output voltage of an induction generator reaches 3–10 % and causes overheating of the windings in excess of the permissible values. A regression model has been developed for studying the operating conditions of an induction motor when powered by an induction generator with an asymmetry of the stator windings. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of induction machines, in which they will not overheat above the maximum permissible temperature values of the corresponding insulation classes


2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.


Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.


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