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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tiesinio variklio apibendrinto modelio tyrimas / Investigation of generalized model of linear motor

Jankovskaja, Andželika 20 June 2005 (has links)
The analysis of linear motor magnetic properties and application of several linear motor models at work have been performed in consideration of its constructional speciality. The mathematical model of linear motor have been composed on programme QuickField. Varying parameters of linear motor (elements position, materials proportion of motors elements, thickness of secondary element, its position on air gap symmetry) have been maked magnetic properties, specific for several model of linear motor. The teoretical part represent generalized review of linear motors and description of its characteristics. The features of linear motors have been analysed here. The investigation part involving the creation of several linear motor models and analysis of magnetic properties on programme QuickField. This discribing geometric models creation, its parameters setting and making results for several models of linear motors. The programme displaying results in grafic, color map, vector and tables shapes. The results have been analysed and summarized. Finally the conclusions of investigation of linear motor have been formulated: efficiency, operating conditions, application of linear motors are conditioned by constructional speciality of several linear motor. The results of investigation can be used for rational and optimal realization of linear motors in various technological systems.
2

TRIFAZIŲ ASINCHRONINIŲ VARIKLIŲ DINAMINIAI MODELIAI / DYNAMIC MODELS OF THREE PHASE INDUCTION MOTORS

Petrovas, Andrius 29 June 2007 (has links)
Disertacijoje siekiamas tikslas: sudaryti trifazio asinchroninio variklio matematinius modelius fazinėje koordinačių sistemoje, esant įvairiems variklio apvijų jungimo būdams, sukurti modelį tiesiaeigio asinchroninio variklio dinamikos tyrimui, jo pagrindu sudaryti kompiuterinius modelius dažniu valdomiems asinchroniniams varikliams tirti. / The aim of dissertation is to develop mathematical and computer models of induction motor in phase coordinate system at various ways of stator windings connection, transform this model for investigation of dynamics of linear induction motor, and carry out computer models for investigation of frequency-controlled induction motors.
3

Variklio skaitmeninės apsaugos nuo netipinių darbo režimų tyrimas / Investigation of digital motor protection from non-regular operating conditions

Leonovas, Danielius 22 June 2005 (has links)
The digital protection relay for 550 kW - 1 MW asynchronous motors is investigated in this finishing work. In the theoretical chapter are examinated the structure of multifunctional protection relay, non-regular asynchronous motor operating conditions and their reasons. Two operating conditions are marked out, first - when supply current is changed, second - alternation in supply voltage. Next is made investigation of Siprotec 7SJ621 digital protection relay. There's made survey of 630 kW power asynchronous motor from non-regular operating konditions when there was overcurrent and overvoltage in the supply.
4

Trifazių asinchroninių variklių dinaminiai modeliai / Dynamic Models of Three Phase Induction Motors

Petrovas, Andrius 29 June 2007 (has links)
Disertacijoje keliamas tikslas - sudaryti trifazio asinchroninio variklio matematinį modelį, kuris ne tik adekvačiai aprašo nesimetriškų asinchroninių variklių dinamiką, bet ir kurio greitaveika būtų didesnė už universalaus elektrodinaminio modelio greitaveiką, ši modelį pritaikyti įvairiems variklio apvijų jungimo būdams, jo pagrindu sudaryti kompiuterinius modelius dažniu valdomiems asinchroniniams varikliams tirti. Pirmajame skyriuje aptariami šiuo metu dažniausiai naudojami asinchroninių variklių modeliai, aptariami jų privalumai ir trūkumai. Nesimetriško asinchroninio variklio matematinio modelio fazinėje koordinačių sistemoje lygtys išvestos antrajame skyriuje. Trečiasis skyrius skirtas kompiuteriniams asinchroninio variklio modeliams. Sudarytas universalus, t. y. visiems variklio apvijų jungimo atvejams tinkamas, programinis asinchroninio variklio modelis. Sudarytas Simulink paketui tinkamas objektinis asinchroninio variklio modelis. Ketvirtasis skyrius skirtas valdomų elektros pavarų modeliams. Sudaryti algoritmai inverterio-variklio ir lygintuvo-inverterio-variklio sistemų imitavimui. Pateikti šių sistemų imitavimo rezultatai. Sudarytas Simulink paketui tinkamas srovės kanalo metodu valdomos dažninės pavaros modelis. Darbo pabaigoje pateiktos išvados. / The aim of dissertation is to develop mathematical and computer models of induction motor in phase coordinate system at various ways of stator windings connection, transform this model for investigation of dynamics of linear induction motor, and carry out computer models for investigation of frequency-controlled induction motors. Chapter 1 discusses mathematical models of induction motors, their advantages and shortcomings. Mathematical model of induction motor in phase coordinate system applicable to consider non-symmetry of motors is derived in Chapter 2. Chapter 3 is devoted for computer models of induction motors. Universal algorithm of programmed motor model is elaborated and presented. Objective Simulink motor model is developed. Chapter 4 is devoted for models of controlled electric drives. Algorithm to simulate system inverter-motor is carried out and results of simulation are presented. Model of system rectifier-inverter-motor with changeable structure was proposed and simulations of transients are discussed. Model of drive, controlled by current channel is developed. General conclusions of the research are made.
5

Tiesinio asinchroninio variklio valdymo būdų modeliavimas / Modeling of Control Modes of Linear Induction Motor

Geglis, Andžej 20 June 2005 (has links)
The analysis of the feature and application of linear induction motors at work have been performed; mathematical models of linear motors have been studied; mathematical description of induction machine have been presented; coordinate transform have been studied; dynamic equations in moving and move-less systems of axes of linear induction motor have been presented; the analysis of the classification of induction drives control modes have been performed. Four models of the frequency-regulated electric drives with linear induction motors have been studied: when the motor is supplied from variable frequency mains supply, when the motor is supplied from frequency converter, when frequency is changed by program, when frequency is changed in close-loop by vector control system. The characteristics of those models have been compared and performed. The received results are summarized in the conclusions.
6

Elektros pavaros su tiesiaeigiu asinchroniniu varikliu tyrimas / Research of Electric Drive with Linear Induction Motor

Šveistys, Valdas 30 September 2008 (has links)
Baigiamajame magistro darbe nagrinėjama elektros pavaros su tiesiaeigiu asinchroniniu varikliu konstrukciniai ypatumai, savybės, mechaninės charakteristikos bei kokybės rodikliai. Programiniu paketu MathCAD 2001 Professional yra sudarytas matematinis tiesiaeigio asinchroninio variklio modelis. Tyrimas atliekamas eksperimentiniu būdu, keičiant TAV parametrus (Reynoldso skaičių, neferomagnetinį sluoksnį, oro tarpą, induktoriaus plotį, variklio apvijų skaičių ir pan.), gaunamos tam tikram modeliui būdingos mechaninės charakteristikos. Magistro darbe pateikiama bendra elektros pavarų su tiesiaeigiais asinchroniniais varikliais apžvalga ir jų savybių analizė. Tiriamoji dalis apima apibendrinto tiesiaeigio asinchroninio variklio matematinio modelio sudarymą ir mechaninių charakteristikų tyrimą programiniu paketu MathCAD 2001 Professional. Programa skaičiavimo rezultatus pateikia grafiniu pavidalu. Gauti rezultatai yra analizuojami ir apibendrinami. Išnagrinėjus teorinius ir praktinius tiesiaeigio asinchroninio variklio darbo režimų aspektus, pateikiamos išvados ir pasiūlymai. Tyrimo rezultatai gali būti panaudoti elektros pavarų su tiesiaeigiais asinchroniniais varikliais racionaliam ir optimaliam realizavimui greitaeigių elektros pavarų technologinėse sistemose. Darbą sudaro 7 dalys, įvadas, literatūros elektros pavaros su tiesiaeigiu asinchroniniu varikliu klausimais apžvalga, tyrimo tikslas ir uždaviniai, skaičiuojamoji dalis, tyrimo rezultatų apibendrinimas, išvados ir... [toliau žr. visą tekstą] / In master thesis researching high-speed electric drive with Linear Induction Motor (LIM) design peculiarities, internals and indexes of quality. Using program MathCAD 2001 Professional was created mathematical model of Linear Induction Motor. By changing Linear Induction Motor parameters (Reynolds's number, SE thickness, air gap, inductor width, number of coils and etc) getting for the defined model appropriate mechanicals characteristics. In master thesis the view of electric drive with Linear Induction Motor has been reviewed and their features analyzed. In the investigation part involves the creation of Linear Induction Motor mathematical model and investigation of mechanicals characteristics on program pack MathCAD 2001 Professional. The program displays results in graphical form. The results are analyzed and generalized. After analyzing theoretical and practical LIM motor aspects of operations, conclusions and suggestions are formed. The results of research can be used for rational and optimal realization of LIM in various technological systems. Structure: introduction, literature electrical drive with LIM questions review, research purpose and tasks, calculation part, summary of research results, conclusions and suggestions, references.
7

Asinchroninių variklių su sinusinėmis trifazėmis apvijomis tyrimas / Research of Asynchronous Electric Motors With Sinusoidal Windings

Girdvainis, Voldemaras 18 June 2010 (has links)
Darbe įvertintos aštuonių tipų trifazių asinchroninių variklių statoriaus apvijų elektromagnetinės savybės, atlikus jų kuriamų sukamųjų magnetovarų harmonines analizes ir pagal jų rezultatus apskaičiavus elektromagnetinio efektyvumo koeficientus. Gauta, kad geriausius elektromagnetinius parametrus turi didžiausio vidutinio ir sutrumpinto žingsnio sinusinės trifazės apvijos su optimizuota sukamąja magnetovara. Eksperimentiškai išnagrinėtas gamyklinis trifazis asinchroninis 1,5 kW galios variklis su viensluoksne formine ir tas pats pervyniotas variklis su sinusine statoriaus apvija. Gamyklinio asinchroninio variklio su viensluoksne formine apvija ir pervynioto variklio su sinusine trifaze apvija visi energetiniai rodikliai apskaičiuoti atlikus jų tuščiosios veikos ir apkrovos bandymus bei panaudojus atskirų galios nuostolių metodą. Gauta, kad pervynioto asinchroninio variklio su sinusine trifaze apvija prie nurodytosios apkrovos statoriaus apvijos fazinė srovė sumažėjo 8,2 %, imama iš tinklo galia sumažėjo 5,3 %, galios nuostoliai sumažėjo 10,4 %, naudingumo koeficientas padidėjo 1,9 % ir galios koeficientas padidėjo 3,4 %, lyginant su gamyklinio asinchroninio variklio, esant tai pačiai apkrovai, atitinkamais energetiniais rodikliais. Nustatyta, kad asinchroninis variklis, turintis trifazę apviją su didesniu elektromagnetinio efektyvumo koeficientu, turi ir geresnius energetinius rodiklius. / The paper assesses the electromagnetic properties of stator winding of eight types of three-phase asynchronous motors, by performing harmonic analyses of the rotary magnetomotive forces they generate and using these results to calculate the electromagnetic efficiency coefficients. It was established that the best electromagnetic parameters are those of the sinus tri-phase winding with the largest medium and shortened step with optimised rotary magnetomotive force. Experimental analysis of a factory-made three-phase asynchronous 1,5 kW motor with a single layer form winding and the same rewound motor with sinus stator winding was performed. All energetic indicators of the factory-made asynchronous motor with a single layer form winding and the rewound motor with sinus three-phase winding were calculated after performing their no-load and load testing, and using the method of separate power loss. It was established that the phase current of the stator winding of the rewound asynchronous motor with a sinus three-phase winding, deceased by 8,2 percent at the indicated load, the power from the mains decreased by 5,3 percent, the power loss decreased by 10,4 percent, the efficiency coefficient increased by 1,9 percent and the power coefficient increased by 3,4 percent as compared to the respective indicators of the factory-made asynchronous motor at the same load. It was established that the asynchronous motor which has the three-phase winding with the larger electromagnetic... [to full text]
8

Tiesiaeigės iešmo pavaros valdymo sistemos tyrimas / Research of Control System for Point Drive with Linear Motor

Korvel, Pavel 16 June 2014 (has links)
Baigiamajame magistro darbe nagrinėjama iešmo elektros pavara su tiesiaeigiu asinchroniniu cilindriniu varikliu. Programiniu paketu ,,Matlab“ yra sudaryti pavaros matematiniai modeliai α, β koordinačių sistemoje. Uždaviniai – tiesiaeigės iešmo elektros pavaros kompiuterinio modelio sudarymas, tyrimas ir dinaminių charakteristikų imitavimas. Literatūros analizės dalyje išnagrinėtos tiesiaeigės elektros pavaros, jų taikymo sritys bei valdymo būdai. Magistro darbo teorinėje dalyje pateikiamos tiesiaeigių elektros pavarų skaičiavimo ir valdymo metodikų analizės. Tiriamoji dalis apima iešmo elektros pavaros su tiesiaeigiu cilindriniu asinchroniniu varikliu matematinių modelių sudarymą ir dinaminių charakteristikų tyrimą programiniu paketu ,,Matlab“. Matematiniai modeliai yra sudaromi pavarai veikiant skirtingais darbo režimais (pavara perjungiama neapkrauta, pavara perjungiama apkrovus nominalia apkrova ir iešmą perjungiant pabaigoje ir pradžioje trukdant papildomai pasipriešinimo jėgai) ir tyrimo rezultatai pateikiami grafiškai. Gauti rezultatai yra palyginami ir apibendrinami. Išnagrinėjus teorinius tiesiaeigės iešmo elektros pavaros su asinchroniniu cilindriniu varikliu darbo režimų aspektus, pateikiamos išvados ir pasiūlymai. Tyrimo rezultatai gali būti panaudoti iešmo elektros pavaros su tiesiaeigiu asinchroniniu varikliu racionaliam ir optimaliam realizavimui geležinkelio transporto automatinio valdymo sistemose. Darbą sudaro 9 dalys: santrumpos ir simboliai, įvadas... [toliau žr. visą tekstą] / The final Bachelor thesis analyses point electric drive with cylinder-type linear asynchronous motor. Software package ,,Matlab“ was used to prepare mathematical models of the drive in α, β coordinate system. Objectives: preparing and analyzing a computer model of linear point electric drive, simulation of dynamic characteristics. The analysis of literary sources deals with linear electric drives, their application areas and methods of control. Theoretical part of the Master thesis presents analyses of calculation and control methods of linear electric drives. The analytical part of the thesis includes mathematical models of point electric drive with cylinder-type linear asynchronous motor and the analysis of dynamic characteristics using software package ,,Matlab“. Mathematical models were prepared when the drive operated in different modes (the drive switched without load, the drive switched with nominal load, the switch connected at the end or beginning, thereby blocking additional resistance force). Research results were presented in a graphical form. Obtained results were compared and summarized. Following the analysis of the theoretical aspects of operating modes of linear point electric drive with cylinder-type asynchronous motor, conclusions and recommendations were presented. Research results can be used for rational and optimal realization of point electric drive with linear asynchronous motor in automatic railway control systems. The thesis consists of nine parts:... [to full text]
9

Roboto valdymo sistema / Robot control system

Mitka, Darius 21 June 2004 (has links)
The final work of master studies reviews various industrial robots constructions and parameters, from which they are characterized. Robotics systems and control of flexible production have been discussed in here. Various robots’ drives and their control advantages and disadvantages are analyzed. In the practical part original robot global movement platform is suggested and algorithm of two flexible production bays handling is created. Static characteristics of linear drive used in platform are calculated. Using software package “Matlab Simulink” model of symmetrical linear induction motor (LIM) is created and dynamic characteristics are gained. Concluding part presents inferences and suggestions.
10

Fazinių įtampų asimetriškumo įtakos asinchroninių variklių darbui tyrimas / Investigation of Influence of Asymmetric Voltage on Characteristics of Asynchronous Motors

Baltrimas, Linas 18 June 2010 (has links)
Asimetrinė fazinių įtampų sistema stipriai pablogina asinchroninių variklių darbą. Tyrimo tikslas – ištirti trifazio asinchroninio variklio darbą, esant įvairioms maitinimo įtampos fazorių modulių asimetrijoms. Asinchroninio variklio visi energetiniai rodikliai apskaičiuoti atlikus jų tuščiosios veikos ir apkrovos bandymus bei panaudojus atskirų galios nuostolių metodą. Įtampos asimetriškumo lygis gaunamas panaudojus simetrinių dedamųjų metodą. Atsiradus asimetrijai, asinchroninio variklio oro tarpe kuriamas elipsinis sukamasis magnetinis laukas, kuris sukelia variklyje ir sukimo, ir stabdymo momentus. Tik esant simetrinei fazinių įtampų sistemai (ka = 0 %), prie variklio nurodytosios apkrovos visi kiti dydžiai gaunami nurodytieji. Teoriškai ir eksperimentiškai ištyrus 1,1 kW galios asincroninį elektros variklį gauta, kad esant asimetrinei fazinių įtampų sistemai (ka = 11 %), prie nurodytosios apkrovos asinchroninio variklio iš tinklo vartojama galia P1 padidėjo 22,4 %, apsisukimai n sumažėjo, o slydimas s padidėjo 94,7 %, galios nuostoliai ΣP padidėjo 101 %, elektromagnetinis momentas Mem padidėjo 4,9 %, naudingumo koeficientas η sumažėjo 21,4 % ir galios koeficientas cos φ sumažėjo 0,9 %. / Asymmetrical phase system of voltages significantly degrades induction motors work. The study objective - to explore the three-phase asynchronous motor at different power supply modules vector asymmetry. All energetic indicators of the asynchronous motor winding were calculated after performing their no-load and load testing, and using the method of separate power loss. Asymmetry voltage level obtained by using the method of symmetrical components. The emergence of asymmetry in the induction motor air gap created elliptical rotary magnetic field, which caused an engine torque and braking points. Only a symmetrical phase voltage system (ka = 0%), the given load on the engine all the other values given are obtained. Theoretical and experimental study of 1,1 kW electric asynchronous motor revealed that in asymmetric phase voltage system (ka = 11%), at the given induction motor load from the mains power is used in P1 increased by 22,4%, n speed decreased and the slip increased by 94,7%, power ΣP loss has increased 101%, the electromagnetic torque Mem increased by 4,9%, the efficiency η decreased 21,4% and power factor cos φ decreased by 0,9%.

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