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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.
21

Malý asynchronní motor zvláštního typu / Special small induction motor

Trubák, Vojtěch January 2018 (has links)
This term paper is focused on theory and calculation of an induction motor with solid rotor. It is divided into six chapters, the first one being an introduction and the last being a conclusion. Second chapter is dedicated to magnetism. There is briefly description of a skin depth of a conductor and calculation method for impedance of a conductive solid. Third chapter is focused on theory of an induction machines, their construction, equivalent circuit and some of their properties. Fourth chapter is dedicated to calculation of an induction motor with solid rotor and its parameters. Fifth chapter is comparing results of calculation done in fourth chapter for an already existing motor with measured values.
22

Feasibility of an Electric Jetpack

Youard, Timothy John January 2010 (has links)
The Martin Aircraft Company Limited has been developing the Martin Jetpack for over 25 years. The recent worldwide launch of the Jetpack has enabled the company to step up its research and development programme. The goal of this project was to determine the feasibility of an electrically powered version of the Martin Jetpack. The feasibility of the Electric Jetpack was determined by researching energy storage technologies, researching power cable technologies, simulations of flight times, surveys of electric motors, and the development of a simulation program which was used to optimise some preliminary custom motor designs. The overall conclusion of this project was that the Electric Jetpack was feasible only when it was powered through a tethered power cable, and on-board energy storage was not used. An investigation into current energy storage technologies showed that the Electric Jetpack is not considered feasible when using on-board energy storage, however it is possible to obtain flight for a very short time. The energy storage technologies studied were batteries, fuel cells, and ultra-capacitors. It was found that the best performing technology was the lithium iron nano-phosphate battery. A simulation of flight time showed that this battery type would be able to provide flight for approximately 3.6 minutes. Future trends indicated that the Electric Jetpack with on-board energy storage may eventually be feasible when using a lithium-ion based battery due to improvements being made in energy density and power density. By using a tethered power cable, the weight of the on-board energy storage could be eliminated. This was shown to be a feasible method for powering the Electric Jetpack for applications where the Jetpack needs to only be operated in a small area. The best cable type to use was a multi-stranded flexible cable operating at a high DC bus voltage. The weight of a 5 meter power cable using a 1000 V bus voltage was shown to be 4.9 kg. Potential applications for this kind of Jetpack could include thrill rides and rescue operations from multi-storied buildings. A cable made from carbon nanotubes was shown to be a future technology that could offer a lighter cable. A survey of currently available electric motors showed that none met both the power density and speed required by the Electric Jetpack, even when using a tethered power cable to eliminate the energy storage weight. Because of this, a custom motor design was needed. Research into motor technologies showed that the permanent magnet brushless DC (PMBLDC) motor was the most suited type for the Electric Jetpack. The permanent magnet brushless AC (PMBLAC) motor was also suitable. A PMBLDC motor simulation program was developed using MATLAB which could be used to optimise preliminary custom designs. A characterisation of allowable motor time constants for the PMBLDC motor type was made in order to speed up the simulation time. The optimisation results showed that a power density of 5.41 kW/kg was achievable for the motor when it was located inside the ducted fan tubes, and a power density of 6.56 kW/kg was achievable when the motor was located outside the ducted fans and operated at a higher speed. The motor designs were shown to be within the expected torque per unit rotor volume (TRV) range for aerospace machines. The best power density figures would leave between 37 kg and 42 kg of weight for the motor driver/controller, cable weight, and miscellaneous motor parts. This was considered to be feasible. An FEM simulation was made on one of the optimised motor designs. The FEM results agreed with the parametric results within reasonable accuracy. The parametric back-EMF waveform over-estimated the effects of slotting.
23

Investigation of electromagnetic compatibility (EMC) of low-voltage (<60V) DC electric motors in construction machinery application

Luong, David, Salloum, Ibrahim January 2019 (has links)
The brushed DC motor is a source of electromagnetic emission that may cause interference. The main issues with brushed DC motor are arcing, which occurs between the brushes and commutator, and inrush current. It is possible to decrease the electromagnetic emissions by addressing the source (brushed dc motor) and the installation. The source may be addressed by using filters in the form of X2Y-capacitors on the terminals or ferrites on the cables. The installation does not produce any emission, but it is possible to lower its contribution. This is done by altering the installation like changing the placement of cables and provide good coupling. An effective way of decreasing inrush currents is by using negative-thermal-coefficient (NTC) thermistors. Another measure to improve the EMC properties of the brushed DC motor is to design the motor so that it can trap EM emissions. Some of these parameters are motor house material, end-cap material, vent holes or slots on motor housing, placement of power terminals, crimping tabs and motor enclosure.
24

Information Extraction and Design of An Assisted QA system in Motor Design

Luo, Hongyi January 2022 (has links)
The Linz Center of Mechatronics’ SymSpace platform is designed to provide intelligent design and training for the traditional engineer training and industrial design approach in the field of motor design, which relies on the engineer’s own experience and manual work. This paper first analyzes and explores the usage patterns and possible improvement perspectives of motor design components using SymSpace user data. Then an attempt is made to summarize the motor design manual provided by LCM using a text summary model and use it for training engineers. Next, a question-and-answer system model was used to try to provide an aid system for engineers in design. The evaluation of text summaries and question and answer systems is difficult in the motor design domain because the amount of redundant textual information in this domain is small and key information is often presented in detail rather than in the main stem of the sentence. In this case, instead of evaluating the model using traditional machine scores, this paper refers to the feedback from LCM experts as future users. The final results show that, despite the problems of difficulty in explaining the reasons; the possibility of being misleading; and the loss of information details, both attempts are generally positive and the exploration in this direction is worthwhile. / Symspace från Linz Center of Mechatronics är utformad för att tillhandahålla intelligent design och utbildning för den traditionella ingenjörsutbildningen och den industriella designmetoden inom motorkonstruktion, som bygger på ingenjörens egen erfarenhet och manuellt arbete. I den här artikeln analyseras och utforskas först användningsmönster och möjliga förbättringsperspektiv för komponenter för motorkonstruktion med hjälp av användaruppgifter från Symspace. Därefter görs ett försök att sammanfatta den motorkonstruktionshandbok som tillhandahålls av LCM med hjälp av en modell för textsammanfattningar och använda den för att utbilda ingenjörer. Därefter användes en modell för ett system med frågor och svar för att försöka tillhandahålla ett hjälpsystem för ingenjörer vid konstruktion. Utvärderingen av textsammanfattningar och fråga-och-svar-system är svår inom motorkonstruktionsområdet eftersom mängden överflödig textinformation inom detta område är liten och nyckelinformation ofta presenteras i detalj snarare än i huvudstammen av meningen. I det här fallet hänvisar den här artikeln i stället för att utvärdera modellen med hjälp av traditionella maskinpoäng till feedback från LCM-experter som framtida användare. De slutliga resultaten visar att trots problemen med svårigheten att förklara orsakerna, möjligheten att vara vilseledande och förlusten av informationsdetaljer är båda försöken generellt sett positiva och att utforskningen i denna riktning är värd att fortsätta.
25

Development of a novel sensor for soot deposition measurement in a diesel particulate filter using electrical capacitance tomography

Huq, Ragibul January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This paper presents a novel approach of particulate material (soot) measurement in a Diesel particulate filter using Electrical Capacitance Tomography. Modern Diesel Engines are equipped with Diesel Particulate Filters (DPF), as well as on-board technologies to evaluate the status of DPF because complete knowledge of DPF soot loading is very critical for robust efficient operation of the engine exhaust after treatment system. Emission regulations imposed upon all internal combustion engines including Diesel engines on gaseous as well as particulates (soot) emissions by Environment Regulatory Agencies. In course of time, soot will be deposited inside the DPFs which tend to clog the filter and hence generate a back pressure in the exhaust system, negatively impacting the fuel efficiency. To remove the soot build-up, regeneration of the DPF must be done as an engine exhaust after treatment process at pre-determined time intervals. Passive regeneration use exhaust heat and catalyst to burn the deposited soot but active regeneration use external energy in such as injection of diesel into an upstream DOC to burn the soot. Since the regeneration process consume fuel, a robust and efficient operation based on accurate knowledge of the particulate matter deposit (or soot load)becomes essential in order to keep the fuel consumption at a minimum. In this paper, we propose a sensing method for a DPF that can accurately measure in-situ soot load using Electrical Capacitance Tomography (ECT). Simulation results show that the proposed method offers an effective way to accurately estimate the soot load in DPF. The proposed method is expected to have a profound impact in improving overall PM filtering efficiency (and thereby fuel efficiency), and durability of a Diesel Particulate Filter (DPF) through appropriate closed loop regeneration operation.
26

Design of a Switched Reluctance Motor for a Light Sport Aircraft Application

Abdollahi, Mohammad Ehsan January 2022 (has links)
With the rapid growth of air travel, concerns about the emissions of greenhouse gas emissions resulting from the air transportation sector are growing. Although the current battery technologies might not be adequate for all-electric regional aircraft, the energy density of the current battery technologies could be adequate to electrify light-sport aircraft used for training and recreation. Due to the nature of the propeller load and noise isolation of the cabin, switched reluctance motors can be an excellent candidate for the propulsion system of electrified light-sport aircraft. The proposed SRM is designed to replace a 70 kW permanent magnet synchronous motor used in the aerospace industry with similar volume constraints and operational requirements. In order to meet the high-power density requirements of this application, a design framework is proposed which includes several layers of the design process. The design objectifies are the average torque, torque ripple, and radial forces by integrating the control and geometry design into the proposed framework. A comprehensive design process is carried out with the proposed framework, and a detailed coil design process is performed. The rotor cut-outs are designed to reduce the weight of the motor. The thermal performance of the motor has been analyzed for the calculated motor losses and the cooling system constraints. / Thesis / Master of Applied Science (MASc)

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