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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.
71

Internetové ovládání laboratorních modelů / Internet based control of laboratory models

Dobrovolný, Petr January 2011 (has links)
This award solves design of two models that are designed to teach on PLC and in the future on the Control Web. Both models should be used in LabLink system, which allows you to remotely working on laboratory tasks. The first software model simulates the movement of trains on rail in relation on control from the PLC. The second model is a physical model of drill. In both models are solid managing and type of construction, which allows operation without physical intervention.
72

Analýza a inovace stejnosměrných elektrických motorků / DC Motors Analysis and Innovation

Šimko, František January 2011 (has links)
The thesis aims to explain the design a prototype of an innovated small engine. It is divided into three main parts. The first part is focused on the analysis of low power DC small engines available on the market. The second part consists of measuring, construction and loss analysis of a DC small engine with permanent magnets. The last part deals with the possible innovations of a small engine with permanent magnets and subsequent implementation of some of them. The innovations are supported by calculations and simulations.
73

Návrh pohonu elektrické tříkolky / Design of drive for electric powered tricycle

Filipec, Petr January 2011 (has links)
This work deals with designs of drive for two types electric powered tricycles (type for outdoor and indoor). Designs comprise general conception of drive. We selected optimal electric motors in terms of research electric engines and calculations. Next, we proposed batteries. The last part describes design power circuit and general financial expenses.
74

Návrh trenažéru přistání na padákovém kluzáku / Design of paraglider landing simulator

Wertheimer, Pavel January 2011 (has links)
Practice of landing with paraglider is very inefficient since every flight requires lengthy preparation. Therefore paragliding schools look for a more efficient alternative how to train new pilots. A paraglider flying simulator, which is the subject of this Master`s Thesis, could be that alternative. The design of the simulator includes three parts: a mechanical part - a frame to hang a pilot, that is the same as in real paraglider; an electronic part - scanning of pilot`s control actions and control of force in breaks of a paraglider; and a software part - a design of firmware for a microcontroller. Within the Master`s thesis a function prototype has been made.
75

Mikročerpadlo pro účely medikamentózní terapie / Micropump for Medicamentous Therapy

Ondrák, Tomáš January 2010 (has links)
This doctoral thesis originated as a requirement of micropump for artificial heart with using a suitable type of electric drive. It is an interdisciplinary cooperation of FSI Brno, Department of Fluid Engineering of Viktor Kaplan, FEKT Brno, Department of Power Electronics and finally the doctors from Cardiology Medical Center in St. Ann’s Hospital. FSI Brno made mechanical solutions of micropump, FEKT Brno solved electric drive and Cardiologic Medical Center gave the knowledge of human anatomy. Work deals with design, creation and testing of various types micropumps for medicamentous using. In this thesis was suggested various solutions of electric drive for micropump, its structure and function. Work is primarily experimental in nature and is heavily supported by a creative approach in creating a variety of proposed solutions. Several proposals of micropump have been made with different types of electric drives (DC motors, hybrid stepper motor, piezomotors). Finally, from the technical and economical point of view was chosen the most suitable type of electric drive and it was created a functional prototype of the double-action pump and its properties were tested.
76

Skibot 1.0, a Poling Cross-Country Skiing Robot

Kalliorinne, Otto January 2022 (has links)
This thesis project covers the development of a cross country skiing robot, with the purpose of being used as an instrument for measuring gliding properties of skis. The robot used in total 4 servomotors to control the motion of right and left arms with poles attached. A general movement pattern generator was developed to construct patterns that resemble the one of a human hand during poling. The final robot is able to generate a poling motion resulting in a forward propulsion, but further development to the design has to be made to use the robot for its intended purpose.
77

The Energy Efficiency Model of a DC Motor for the Control of HEVs / Energieffektivitetsmodellen för en likströmsmotor för styrning av HEV

CAI, JIACHENG January 2020 (has links)
This thesis studies a DC motor for a racing hybrid electric vehicle (HEV) prototype.The development of optimization-based energy management strategies (EMS) necessitates an accurate quasi-static model of the driving motor, which includes a 2D efficiency map with the torque outputand rotating speed as the inputs. However, a DC motor's efficiency varies a lot at differentoperating points and the efficiency map from the technical manual does not match the various applications in reality.In view of this, this thesis investigates a field testing based quasi-static modeling method to construct the DC motor efficiency map with only portable and brief testing resources. Firstly, a testbench is designed, manufactured, integrated, and configured with necessary accessories. The testbench consists of the motor under test, a braking motor to provide load torque, a servo-amplifier for torque control and sensing, a host computer for data acquisition, and power supplies. Then, a self-contained testing plan is designed by which as many as possible different testing points can be covered based on the braking motor's power limit. After that, the experiments are successively performed on the test bench, and the input electric power along with the output mechanical power at steady state are recorded. Multiple data process methods are explored to analyze the collected testing data. Root mean square (RMS) is used to reduce the measuring variance. Invalid outliers are identified and filtered out based on the residuals. The qualified samples are employed to build up the 2D efficiency map by fourth-degree polynomial regression. Then, three methods, linear, quadratic, and cubic fittings are attempted separately to estimate the relationships between the input power and output torque at different speeds. The results show that the quadratic model is the best option which results in smaller root mean square error (RMSE) and fair computation complexity. To conclude, the quasi-static dynamic model of a DC motor, which includes a 2D efficiency map and the speed-based polynomial expression of input power, can be properly established by a new method relying on less and simpler devices in contrast to those traditional methods. This method bypasses a bulk of tedious modulations on precise motor speed control which is heavily dependent on a high-precision sensor. The formulated 2D efficiency map will effectively support the future development of model-based EMS. The polynomial expression provides a more efficient approach to estimate instantaneous energy efficiency for an embedded system application. / Denna avhandling studerar en likströmsmotor för en prototyp av ett elektriskt hybridfordon (HEV) för racing. Utvecklingen av optimeringsbaserade energihanteringsstrategier (EMS) kräver en precis kvasistatisk dynamisk modell av den drivande motorn, som inkluderar en en 2D-karta (effektivetetskarta) som beskriver hur verkningsgraden beror på moment och rotationshastighet. Verkningsgraden hos likströmsmotorn varierar dock mycket beroende på arbetspunkt och verkningsgradskartan från databladen stämmer inte alltid med de olika applikationerna i verkligheten. Givet detta undersöker denna avhandling en fältprovsbaserad kvasistatisk modelleringsmetod för att uppskatta likströmsmotorns effektivitetskarta med endast flyttbara och begränsade testresurser. Till att börja med är en testbänk designad, tillverkad, integrerad och konfigurerad med alla nödvändiga komponenter. Testbänken består av den motor som testas, en bromsmotor för att ge belastningsmoment, en servoförstärkare för vridmomentstyrning och mätning, samt en dator för datainsamling och strömförsörjning. Sedan utformas en fristående testplan som gör att så många olika testpunkter som möjligt kan täckas, baserat på bromsmotorn effektgräns. Därefter utförs experimenten successivt på testbänken där ingående elektrisk effekt och utgående mekanisk effekt mäts i jämviktsläget. Flera olika metoder undersöks för att analysera den insamlade testdatan. Kvadratiskt medelvärde används för att minska variansen i testdatan. Ogiltiga outliers identifieras och filtreras ut baserat på hur mycket de avviker från medelvärdet. De godkända testpunkterna används för att bygga upp 2D-effektivitetskartan genom en fjärde gradens polynom regression. Därefter används tre olika metoder, linjära, kvadratiska och kubiska för att skapa kurvanpassningar genom polynomregression för att beskriva sambandet mellan ingångseffekt och utgångseffekt vid olika hastigheter. Resultaten visar att den kvadratiska metoden är det bästa alternativet eftersom det ger en mindre medelkvadratavvikelse och en hanterbar beräkningskomplexitet. Avslutningsvis kan den kvasistatiska dynamiska modellen för en likströmsmotor, som inkluderar en 2D-effektivitetskarta med det hastighetsbaserade polynomuttrycket för ingångseffekt, skapas av en ny metod som förliter sig på mindre och enklare materiel än traditionella metoder. Denna metod kringår en stor del av den omständiga modulering som precis varvtalsstyrning kräver vilken även är väldigt beroende på högprecisionssensorer. Den formulerade 2D-effektivitetskartan kommer ge betydande stöd till framtida utveckling av modelbaserade energihanteringsstrategier 2 (EMS). Polynomuttrycket ger ett mer effektivt tillvägagångssätt för att uppskatta omedelbar energieffektivitet för en inbäddad systemapplikation.
78

Novel Multilevel Converter for Variable-Speed Medium Voltage Switched Reluctance Motor Drives

Shehada, Ahmed 31 March 2017 (has links)
A novel multilevel converter that is especially suited for high speed multi-megawatt switched reluctance motor drives operating at the medium voltage level is presented. The drive is capable of variable speed, four-quadrant operation. Each phase leg of the converter contains an arbitrary number of cascaded cells connected in series with the phase winding. Each cell contains a half-bridge chopper connected to a capacitor. The converter is named the cascaded chopper cell converter. The modular nature of the converter with the ability to add redundant cells makes it very reliable, which is a key requirement for medium voltage drive applications. A comprehensive control algorithm that overcomes the challenges of balancing and controlling cell capacitor voltages is also proposed. A suitable startup algorithm to limit startup current and switching losses, as well as ensure that cell capacitor voltages remain controlled at startup, is suggested. Details of the drive design such as component sizing and control parameter selection are also discussed. A detailed simulation model is developed and explained, and simulation results are provided for primary validation. Operation with standard current and speed control is first simulated. Then a scheme that gives way to a controller that operates the drive in single-pulse mode is developed and presented. This single-pulse control scheme controls the turn-on and turn-off angles, as well as the energization voltage level, in order to obtain high efficiency. Practical considerations related to the drive such as reliability, efficiency, and cost considerations are also discussed. Finally, a detailed comparison of the proposed converter to another competing converter is performed. Besides its scalability to high voltages and powers, the reliability and efficiency of the proposed converter makes it also a candidate for sub-megawatt applications requiring minimum downtime, or any application where high efficiency or improved performance is required. A small part of this work is also dedicated to brushless dc machines. Control methods for a new converter for brushless dc machines are proposed and verified via simulation. The main advantage of this converter with the proposed control is that it allows exact control of torque or speed up to twice the rated speed, without resorting to current phase advancing or other flux-weakening techniques. / Ph. D.
79

AVERAGE-VALUE MODELING OF HYSTERESIS CURRENT CONTROL IN POWER ELECTRONICS

Chen, Hanling 01 January 2015 (has links)
Hysteresis current control has been widely used in power electronics with the advantages of fast dynamic response under parameter, line and load variation and ensured stability. However, a main disadvantage of hysteresis current control is the uncertain and varying switching frequency which makes it difficult to form an average-value model. The changing switching frequency and unspecified switching duty cycle make conventional average-value models based on PWM control difficult to apply directly to converters that are controlled by hysteresis current control. In this work, a new method for average-value modeling of hysteresis current control in boost converters, three-phase inverters, and brushless dc motor drives is proposed. It incorporates a slew-rate limitation on the inductor current that occurs naturally in the circuit during large system transients. This new method is compared with existing methods in terms of simulation run time and rms error. The performance is evaluated based on a variety of scenarios, and the simulation results are compared with the results of detailed models. The simulation results show that the proposed model represents the detailed model well and is faster and more accurate than existing methods. The slew-rate limitation model of hysteresis current control accurately captures the salient detail of converter performance while maintaining the computational efficiency of average-value models. Validations in hardware are also presented.
80

Construção, acionamento e ensaios do motor bifásico de imã permanente no rotor (MBIPR) / not available

Borelli, Rafael 10 June 2005 (has links)
Visando uma opção de substituição, onde for possível e aplicável, do motor de indução monofásico, este trabalho relata o estudo teórico, a construção, o acionamento e os ensaios de um motor bifásico com ímã permanente no rotor, de baixa potência, utilizando imãs de ferrita na confecção do rotor. / This work shows the theoretical studies, building, driving systems and tests of a small-power double-phase motor with ferrite permanent-magnet in the rotor, based on the original structure of a single-phase induction motor. The objective is to create an option to replace the single-phase induction motor where it is possible and applicable.

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