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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.
41

Bezdrátové ovládání asynchronního motoru / Wireless control of induction machine.

Frelich, David January 2015 (has links)
This master's thesis is interested in concept of frequency converter for induction machine to power 2 kW. Control of this converter is wirelessly or via PC. The solution is based on execution with integrated circuits and microprocesors to control them.
42

Laboratorní ukázka řízení asynchronního motoru / Laboratory example of synchronous motor control

Vrtal, Václav January 2010 (has links)
This thesis deals with the speed control three-phase asynchronous motor revolutions by a frequency converter Sinamics G110 by way of the programmable automat SIMATIC S7-224XP. Control of programmable automat is realized the operator panel TP 177 micro. Communication between the PLC and frequency converter is realized by USS protocol on bus RS-485. The main goal was to design and implement software, which would allow operation to choose different variations of speed time histories (sinusoid, saw, jump course, etc.), but also the possibility to control the position. Another goal was to create graphical environment for the operator panel that allows manual control, editing and monitoring of engine speed. The last goal was to evaluate the results and summary of findings during commissioning.
43

Vázané modelování asynchronního motoru metodou konečných prvků / Coupled modeling of induction motor using finite element method

Gregor, Tomáš January 2015 (has links)
This thesis describes complex modeling of asynchronous motor by finite element method. Complex modeling concerns to making models based on different physical principles and their connection. Models are made in Ansys program components and their connection is made in program Ansys Workbench. This thesis includes creating electromagnetic model, thermal model, mechanical model and coupled model which connect partial models.
44

Trakční pohony s asynchronním motorem / Traction Drives with Asynchronous Motors

Běloušek, Josef January 2013 (has links)
The first part of this work is devoted to the design of a traction asynchronous motor. The second part focuses on the developed method of the equivalent circuit parameters identification of the asynchronous motor in the form of -network. It is explained here that the equivalent circuit in the shape of a -network, alternatively of an inverse 'I-network, is exactly equivalent and fully-fledged to a T-network, although one of two stray inductances is formally missing. Furthermore, the relationships for the conversions of the T-network parameters to the -network parameters and back, and of the T-network to the inverse 'I-network and back are found. The third part deals with the calculation of the torque and the current characteristics of the asynchronous motor. A sensitive analysis of the torque characteristic is carried out on the individual parameters of the equivalent circuit of the asynchronous motor in the form of a -network and a method of the measurement by means of a flywheel is used for the torque characteristic measurement of the asynchronous motor. The fourth part focuses on the verification of the identified -network parameters in the Matlab-model of the traction drive.
45

Proaktivní diagnostika a monitorování stavu trojfázových asynchronních motorů v průmyslovém podniku / Proactive diagnostics and monitoring of the state of three phase asynchronous motors in industrial company

Holub, Ondřej January 2016 (has links)
This master thesis deals with the proactive diagnostics and monitoring of state of the three phase asynchronnous motors in industrial company Bosch Diesel Jihlava. In master thesis is designed diagnostics system based on the selected suitable diagnostics methods and other appropriate process monitors the status of these technical equipments.
46

Auswahlsystematik für energieeffiziente quasistationäre elektrische Antriebssysteme: - am Beispiel von Pumpen- und Förderbandanlagen -

Schützhold, Jörg 29 June 2016 (has links)
Rund 70 % der Energieaufnahme von elektrischen Antriebssystemen wird von quasistationären Antrieben in Transportanlagen hervorgerufen. Eine gesteigerte Energieeffizienz führt neben reduzierten Energiekosten zu weiteren Nutzeffekten, wie z.B. einem verringerten Kühlaufwand, einem kleinerem Bauraum und einer höheren Lebensdauer der Komponenten. Zur Steigerung der Energieeffizienz dieser Transportanlagen werden in dieser Arbeit Methoden zur Auslegung der zugehörigen Antriebssysteme unter besonderer Berücksichtigung des Förderprozesses erarbeitet. Als repräsentative Transportanwendungen werden Pumpen- und Förderbandanlagen untersucht. Dabei wird das gesamte elektromechanische System analysiert, um das volle Energiesparpotenzial zu erfassen – beginnend mit dem Lastprofil des transportierten Förderguts bis hin zur elektrischen Energieversorgung. Hierzu werden alle Systemkomponenten modelliert, um die Verluste in verschiedenen Betriebspunkten im Volllast- und Teillastbereich abzuschätzen. Darauf aufbauend erfolgt die Erarbeitung praktikabler Projektierungshinweise und prozessspezifischer Auswahldiagramme, welche eine schnelle Vorauswahl der energieeffizientesten Antriebstopologie ermöglichen. Da die Verlustmodelle auf frei zugänglichen Datenblattangaben basieren, können die vorgestellten Methoden und Auswahlkriterien bereits in einem frühen Projektierungsstadium zur Auslegung einer energieeffizienten Transportanlage angewandt werden.
47

Utvärdering av roterande borstlösfrekvensomformare tillspårledningar / Evaluation of rotating brushlessfrequency converters for trackcircuit

Aldahan, Leith, Kudoori, Ivan January 2019 (has links)
Spårledningar används inom tunnelbanan för att visa tågets position samt bestämma tågets hastighet genom att bryta spänningsamplituden i signalen vid olika frekvenser. Frekvensen till spårledningen fås från en roterande frekvensomformare. I dagens anläggning används roterande frekvensomformare med borstar. Dessa avger i relärum mycket värme och ger miljöproblem i form av koldamm från borstarna. Det befintliga systemet är gammal och har funnits i drift över 30 år, därför håller reservdelar på att ta slut samt service till systemet svårtillgängligt. Detta examensarbete har undersökt möjligheten att uppgradera till nyare system som bygger på en lösning med roterande borstlös frekvensomformare där reservdelarna och service är tillgängliga i minst 25 år. Undersökningen jämför olika roterande borstlösa frekvensomformare från olika leverantörer för att hitta en frekvensomformare där kraven från Trafikförvaltningen uppfylls. Studien har haft fokus på problemområdet med borstade frekvensomformaren som producerar skadliga ämnen såsom koldamm och värmen i relärum. Diskussioner med tillverkningsföretag av roterande borstlös frekvensomformaren har skett under denna studies gång där möjliga alternativ för vidare utveckling av systemet i relärum analyseras. I projektet har även diskuterat möjligheten att använda det nya systemet av frekvensomformare med borstlösa motor och generator istället för den nuvarande borstade frekvensomformaren som finns i anläggningen. Resultatet har även visat att den roterande borstlösa frekvensomformaren kan omvandla frekvensen till 75 Hz. Det nya systemet uppfyller kraven från Trafikförvaltningen samt att systemet håller i minst 25 år till. Att systemet håller minst i 25 år till var ett stort krav av Trafikförvaltningen som uppfylldes under denna studie. / Track lines are used in subway stations to show the train locations and determine the speed of the train by chopping the frequency. The frequency of the track lines is obtained from a rotary frequency converter. In today's stations, rotary frequency converters with brushes are commonly used. These emit a great deal of heat in some relays and produce environmental problems in the form of carbon dust from the brushes. The existing systems have been used for over 30 years and obtaining spare parts and conducting maintenance on the systems can be difficult. This degree project examines the possibility of newer systems being built on a rotating brushless frequency converter, where the spare parts and servicing would be available for at least the next 25 years. The project surveys and compares different rotating brushless frequency converters from different suppliers to find an identical frequency converter to meet the requirements of the Traffic Administration. The result of this study has had a lot of focus on the problem area with the brushed frequency converter that produces harmful substances such as carbon dust and the heat in the relay room. Discussions with manufacturing companies of rotating brushless frequency converters have been made during this study where possible options were discussed for further development of the system in relay rooms. The result has also discussed the possibilities of using the new system of frequency converters with brushless motor and generator instead of the current brushed frequency converter available in the facility. The result has also shown that the rotating brushless frequency converter can convert the frequency to 75 Hz. The new system meets RAMS requirements of the Trafikförvaltning, and the system lasts for at least 25 years. This was a major requirement of the Trafikförvaltning, which was fulfilled during this study.
48

Contributions à l’étude de machines multi-enroulements pour l’aéronautique : machine synchrone à aimants permanents pour la tolérance aux défauts : machine asynchrone pour la traction / Contributions to the study of multi-winding machines for aeronautic : Permanent Magnet synchronous Motor for fault tolerant applications : Asynchronous motor for Taxiing

Velly, Nicolas 06 April 2011 (has links)
Le projet d'avion électrique vise à remplacer les vecteurs énergétiques que sont les fluides hydrauliques et l'air comprimé par le courant électrique et d'obtenir en conséquence une diminution significative de la consommation en carburant Dans cette thèse, nous proposons deux solutions : la première dans un souci d'accroitre la disponibilités des actionneurs électriques et la seconde pour la traction au sol (taxiage d'avion). Dans la première étude, nous nous plaçons dans le cadre d'un actionneur pour lequel il est demandé une redondance électrique. Ceci peut être le cas d'un actionneur de mode « normal », redondé par un actionneur de type secours, mais où les fiabilités cumulées ne sont pas suffisantes, et où la partie électrique et la commande du système dit normal est redondé. Nous proposons une topologie de moteur synchrone à aimants permanents à bobinage à plots à deux étoiles découplées magnétiquement et à courant de court-circuit limité. Pour les machines à plots, nous avons établi un modèle semi analytique dans le but de prédire l'amplitude de la résultante des forces radiales agissant sur le rotor de cette machine en cas de fonctionnement en modes sain et dégradé. Nous avons établi le modèle de cette machine en vue de la commande et nous avons validé expérimentalement ce principe de conception sur un prototype dimensionné au laboratoire et réalisé par une société du groupe SAFRAN. Dans la seconde étude, nous avons investigué sur l'utilisation de moteurs multi-enroulements permettant de répondre au mieux à un cahier des charges exigeant pour une application de traction d'aéronefs: le « green taxiing ». Le principe est de permettre de faire varier le coefficient de couple d'un moteur de manière à optimiser la masse du moteur mais aussi les contraintes sur le convertisseur qui l'alimente permettant d'atteindre de larges plages de vitesse. Le modèle en vue de l'alimentation a été développé et validé par une comparaison à une résolution par éléments finis en magnétodynamique / The more electrical aircraft project aims at replacing most of current power generation sources by electrical ones. Consequently this replacement might generate a significant decrease of the fuel consumption. Through this thesis we determine two electrical solutions allowing on the one hand the increase of disponibility level of the actuators and on the other handthe aircraft taxiing by electrical means. We firstly focused on electrical actuators that require electrical redundancy. A first mean to achieve this redundancy is to use two actuators. Nevertheless this solution is not relevant under the reliability constraint because the global failure rate is increased. A double star permanent magnet synchronous motor with concentrated winding is proposed in which a special care was taken to the short circuit current limitation and the magnetic decoupling between the two star winding. We established a semi-analytic model for this kind of motors to predict the amplitude of the resultant of the radial forces acting on the rotor of the machine when operating under normal and faulty operation. We established the model of the machine in order to determine the command strategy. We experimentally validated all of the design principles mentioned above through a prototype designed in the laboratory and built by one of the SAFRAN group company. We secondly investigated on the way to apply the multi winding principles to a brand new project linked to the aircraft taxiing called “green taxiing”. The goal is to obtain a motor topology that allows operating on a wide speed range thanks to the command strategy and the change of its torque coefficient. We established the model of the machine and we compared the results given by this ingenious model to the results given by a finite element resolution using a transient magnetic application
49

Využití termovizní kamery pro měření teploty elektrických strojů / Utilization of infrared camera for temperature measurement of electrical machines

Líbal, Jan January 2009 (has links)
The master‘s thesis deals with utilization of infrared camera for temperature measurement of electrical machines. The first part describes non-contact temperature measuring, the second part describes principle of sensors that evaluate quantity of incident infrared radiation. In the next part there is termovision camera SAT-HY 6800 presented and the instructional manual for SAT Report computer programme created. This computer programme is used for analyzing of termovision pictures from the SAT-HY 6800 termovison camera. The chapter 7 describes temperature measuring of one-phase asynchronous motor type J22TO484. The chapter 8 describes temperature measuring of semiconductor components of EC motor G6 series. Both of these motors are produced by ATAS elektromotory Náchod a.s. The last part of the thesis describes creation of animation of one-phase asynchronous motor type J22TO455. The animation was created in 3ds Max computer programme.
50

Optimalizace chladicího systému asynchronního stroje / Optimization of the cooling of induction machines

Halfar, Ivo January 2012 (has links)
This master‘s thesis deals with problems of optimization of cooling in electrical machines. This work includes introduction to the theory of mathematical optimization and brief introduction to optimization problems. This thesis deals with using of program Ansys Workbench for the thermal analysis in electrical machines and optimization of their cooling. Thesis contains thermal analyse of specific asynchronous motor with the squirrel cage and optimization of its cooling.

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