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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

A Diagnostic System for Remote Real-Time Monitoring of Marine Diesel-Electric Propulsion Systems

Andersen, Björn 22 January 2018 (has links)
An innovative diesel-electric power supply and propulsion system is a highly integrated electric system consisting of power generation, power distribution, and electrical drives. Every component of this system constantly produces operating data, which is read and evaluated by several programmable logic controllers, which in turn produce control signals. This thesis presents a diagnostic system that collects the operating data and control signals from all power supply, propulsion, and control components on board, saves them to a hard drive, and enables an engineer to view the data remotely over the internet, in real-time as well as in retrospect. An industrial computer, certified for on-board use, is embedded into the ship’s control unit, autonomously running the software that retrieves the data via an industrial Ethernet connection and makes it available to a remote user through a web interface or a database connection.
2

Optimal Control of Electrified Powertrains

Sivertsson, Martin January 2015 (has links)
Vehicle powertrain electrification, i.e. combining the internal combustion engine (ICE) with an electric motor (EM), is a potential way of meeting the increased demands for efficient and low emission transportation, at a price of increased powertrain complexity since more degrees of freedom (DoF) have been introduced. Optimal control is used in a series of studies of how to best exploit the additional DoFs. In a diesel-electric powertrain the absence of a secondary energy storage and mechanical connection between the ICE and the wheels means that all electricity used by the EMs needs to be produced simultaneously by the ICE, whose rotational speed is a DoF. This in combination with the relatively slow dynamics of the turbocharger in the ICE puts high requirements on good transient control. In optimal control studies, accurate models with good extrapolation properties are needed. For this aim two nonlinear physics based models are developed and made available that fulfill these requirements, these are also smooth in the region of interest, to enable gradient based optimization techniques. Using optimal control and one of the developed models, the turbocharger dynamics are shown to have a strong impact on how to control the powertrain and neglecting these can lead to erroneous estimates both in the response of the powertrain as well as how the powertrain should be controlled. Also the objective, whether time or fuel is to be minimized, influences the engine speed-torque path to be used, even though it is shown that the time optimal solution is almost fuel optimal. To increase the freedom of the powertrain control, a small energy storage can be added to assist in the transients. This is shown to be especially useful to decrease the response time of the powertrain, but the manner it is used, depends on the time horizon of the optimal control problem. The resulting optimal control solutions are for certain cases oscillatory when stationary controls would have been expected. This is shown to be neither an artifact of the discretization used nor a result of the modeling assumptions used. Instead it is for the formulated problems actually optimal to use periodic control in certain stationary operating points. Measurements show that the pumping torque is different depending on whether the controls are periodic or constant despite the same average value. Whether this is beneficial or not depends on the operating point and control frequency, but can be predicted using optimal periodic control theory. In hybrid electric vehicles (HEV) the size of the energy storage reduces the impact of poor transient control, since the battery can compensate for the slower dynamics of the ICE. For HEVs the problem instead is how and when to use the battery to ensure good fuel economy. An adaptive map-based equivalent consumption minimization strategy controller using battery state of charge for feedback control is designed and tested in a real vehicle with good results, even when the controller is started with poor initial values. In a plug-in HEV (PHEV) the battery is even larger, enabling all-electric drive, making it it desirable to use the energy in the battery during the driving mission. A controller is designed and implemented for a PHEV Benchmark and is shown to perform well even for unknown driving cycles, requiring a minimum of future knowledge. / Elektrifiering av drivlinan i fordon är ett sätt att möta kraven på transporter med hög effektivitet och låga utsläpp. Att byta ut förbränningsmotorn mot en elmotor kan ge vinningar avseende effektivitet, prestanda och utsläpp, men till en kostnad av lägre mobilitet på grund av eletriska energilagers relativt låga energitäthet i jämförelse med fossila bränslen. Att istället komplettera förbränningsmotorn med en elmotor erbjuder möjligheten att kombinera de två systemens fördelar och samtidigt undvika nackdelarna. Att använda mer än en motor i drivlinan ökar komplexiteten eftersom fler frihetsgrader har introducerats. Detta ställer ökade krav på utformningen av reglersystemet för att få ut det mesta av potentialen i drivlinan. I optimal styrning använder man matematiska modeller och optimeringsalgoritmer för att beräkna hur man bäst styr det modellerade systemet. Storleken på det elektriska energilagret påverkar dock valet av optimal styrnings-metod samt vilken detaljnivå på modellerna som behövs. I avhandlingen används optimal styrning i en serie studier av hur man bäst utnyttjar de extra frihetsgraderna som elektrifieringen har introducerat. I en diesel-elektrisk drivlina finns det ingen mekanisk koppling mellan motorn och hjulen, likt en växellåda i ett vanligt fordon, vilket gör att dieselmotorns varvtal är en frihetsgrad som måste styras. Avsaknaden av elektriskt energilager leder också till att all elektrisk energi till elmotorn måste produceras av förbränningsmotorn exakt då den behövs. Dessa två egenskaper, i kombination med den långsamma dynamiken hos turboaggregatet, ställer detta höga krav på god transientreglering. För att studera optimal styrning krävs bra modeller med goda extrapoleringsegenskaper. Med avseende på detta utvecklas två fysik-baserade modeller som uppfyller dessa krav och dessutom är tillräckligt glatta i det relevanta arbetsområdet för att möjliggöra gradient-baserade optimeringstekniker. Med optimal styrning och en av de utvecklade modellerna visas turbons dynamik ha stor påverkan på hur drivlinan bör styras. Att försumma turbodynamiken kan leda till felaktiga uppskattningar, både av drivlinans responstid, men även hur den bör styras. Kriteriet, det vill säga om bränsle eller tidsåtgången minimeras, påverkar också vilken motorvarvtal-motormoment-väg som är optimal, även om det visas att den tidsoptimala lösningen är nästan bränsleoptimal. För att ytterligare öka frihetsgraden i drivlinan kan ett elektriskt energilager användas för att assistera i transienterna. Detta visar sig vara särskilt användbart för att minska responstiden hos drivlinan, men hur det ska använda beror på tidshorisonten på optimeringsproblemet De resulterande optimala styrsignalerna är i vissa fall oscillerande där konstanta styrsignaler förväntas. Detta visas vara vare sig en effekt av den använda diskretiseringen eller modelleringsvalen som är gjorda. Istället är det för de lösta problemen faktiskt optimalt att använda periodiska styrsignaler för vissa stationära arbetspunkter. I experiment visas att pumparbetet skiljer sig beroende på om periodiska eller konstanta styrsignaler används, även om medelvärdet är detsamma. Huruvida detta ökar effektiviteten eller inte beror på arbetspunkt och periodtid. För hybridelektriska fordon (HEV) så minskar batteriets storlek effekten av dålig transientreglering då batteriet kan användas för att kompensera för den långsamma förbränningsmotordynamiken. Istället blir problemet i huvudsak hur mycket och när batteriet ska användas för att få god bränsleekonomi. En adaptiv mapp-baserad ekvivalentförbruknings-minimerande styrlag (ECMS) med återkopplad reglering baserad på batteriets laddningsnivå, utvecklas och testas i riktigt fordon med gott resultat, även vid dålig initialisering av regulatorn. För plug-in hybrider (PHEV) är batteriet större och kan dessutom laddas från elnätet, vilket medför möjlighet till rent elektrisk drift och att det är önskvärt att använda energin i batteriet under köruppdraget. För att minska energiåtgången är det däremot ofta lönsamt att blanda energin från bränsle och batteriet kontinuerligt under köruppdraget och se till att batteriet töms lagom till slutet av köruppdraget. För att åstadkomma detta måste då även urladdningstakten bestämmas. En regulator utvecklas för att minimera energiåtgången för en PHEV, det vill säga som försöker använda lagom av batteriet så det ska räcka hela vägen, men inte längre. Denna regulator implementeras för ett referensproblem, med gott resultat även för okända körcykler, trots ett minimum av framtidskunskap.
3

Frequency and voltage control of a high-penetration, no-storage wind-diesel system /

Tomilson, Andrew G., January 1998 (has links)
Thesis (M. Eng.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 169-176.
4

Time series modeling of hybrid wind photovoltaic diesel power systems

Quinlan, Patrick John Adrian. January 1996 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1996. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 143-162).
5

Performance-objective design of a wind-diesel hybrid energy system for Scott Base, Antarctica : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering in Mechanical Engineering at the University of Canterbury /

Frye, Jake A. January 2006 (has links)
Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 139-141). Also available via the World Wide Web.
6

Development of Push Control Strategy for Diesel-Electric Powertrains

Bodin, Johannes January 2018 (has links)
In diesel-electric powertrains, the wheels are mechanically decoupled from the internal combustion engine (ICE). The conventional control approach for such a powertrain is to let the driver control the traction motor while the ICE realizes speed control, causing power to be pulled through the powertrain. An alternative approach is to push power forward by letting the driver control the ICE instead. In this thesis, a conceptual simulation model of a diesel-electric powertrain is compiled and the charcteristics of this novel approach investigated. It is concluded that the new approach makes full ICE power utilization possible even with engine performance reductions present, and also that it handles load prioritization in a natural way. However, takeoff from standstill and low-speed driving become difficult due to the effective gear ratio growing towards infinity for decreasing vehicle speed, causing high traction torques at low speed.
7

Beitrag zur Integration eines elektrischen Einzelradantriebes in eine Landmaschine

Geißler, Mike 21 February 2017 (has links) (PDF)
Am Beispiel einer Landmaschine wurde die Integration eines dieselelektrischen Einzelradantriebes unter der Berücksichtigung der spezifischen Anforderungen nachgewiesen. Die Integration des elektrischen Antriebes in die Fahrzeugfelge führt zu einem abgeschlossenen System mit definierten Schnittstellen. Zur Umsetzung des Antriebssystems werden unterschiedliche Lösungen diskutiert und die Vorzugsvariante realisiert. Für das Antriebssystem und das Fahrzeug werden die Funktionsnachweise mittels Simulationsergebnissen, Prüfstands- und Fahrversuchen erbracht. Ebenso wird der Nutzen eines elektrischen Einzelradantriebssystems diskutiert.
8

Um estudo sobre instalações propulsoras para empurradores fluviais. / A study about propulsion plant for fluvial towboats.

Pereira, Newton Narciso 28 March 2007 (has links)
Este trabalho está voltado para a avaliação de alternativas de instalação propulsora para o empurrador de comboios fluviais. Estes comboios devem atender o objetivo da Petrobras / Transpetro de transportar álcool e derivados de petróleo pela hidrovia Tietê-Paraná. São apresentados como elementos de subsídio para o trabalho um estudo da demanda de álcool combustível em âmbito mundial e os argumentos para seu uso, bem como da oferta brasileira do produto. Além disso, apresentam-se, de forma sucinta, as principais restrições da hidrovia Tietê-Paraná, que devem servir de base para o projeto do comboio, e as características dos comboios em operação na hidrovia, que transportam outras cargas. São apresentados os critérios estabelecidos para construção de comboios fluviais adaptados ao transporte de álcool e derivados de petróleo, segundo as exigências da Norman e das sociedades classificadoras. O trabalho apresenta também uma investigação sobre novas concepções de instalação propulsora para emprego no empurrador. Assim, para seleção da instalação propulsora do empurrador são consideradas três alternativas: a instalação Diesel, que é concepção empregada em todos os comboios da hidrovia, e duas instalações dieselelétrica, uma convencional e outra com sistema Azipod. São empregados como critérios de avaliação o custo operacional do comboio, o impacto ambiental produzido pela emissão de gases e a segurança de navegação do comboio. Como método de avaliação multi-criterial foi utilizado o método de análise hierárquica. Os resultados da avaliação indicaram uma preferência pela instalação propulsora Diesel. / This work focuses on the evaluation of alternatives of main propulsion plants for towboats of fluvial convoys. These convoys must attend the objectives of Petrobras/Transpetro of transporting ethanol and oil derivatives through Tiete-Parana waterway. A study of the demand for ethanol worldwide and the arguments for its use are presented as supporting elements for the work, as well as the Brazilian supply of the product. Moreover, the main restrictions of the Tiete-Parana waterway, which must be the basis for the project of the convoy, and the characteristics of the convoys in operation in the waterway, which transport other loads, are succinctly presented. Complying with Norman 02 requirements and classifying societies, the criteria established for the construction of fluvial convoys adapted to the transport of ethanol and oil derivatives are also presented here. The work also presents an investigation about new concepts of propulsive installation for the use in the towboat. Therefore, for the selection of the propulsion system of the towboat, three alternatives are considered: the Diesel plant, which is the concept used in all convoys of the waterway, and two Diesel-electric propulsion systems, a conventional one and another with an Azipod system. The operational cost of the convoy, the environmental impact produced by the emission of gases and the safety of navigation of the convoy are used as criteria for evaluation. The method of hierarchical analysis was used as method of evaluation. The results of the evaluation indicated a preference for the Diesel propulsion plant.
9

Numerical Optimal Control of Hybrid Electric Trucks : Exhaust Temperature, NOx Emission and Fuel Consumption

Andersson, Fredrik, Andersson, Hampus January 2018 (has links)
The controls for a parallel hybrid electric truck are optimized using numerical optimal control. Trade-offs between catalyst light-off times, NOx emission and fuel consumption have been investigated for cold starts at two operating points, as well as temperature differences between conventional and hybrid powertrains during WHTC (World Harmonized Transient Cycle). A model describing the temperature dynamics of the aftertreatment system is implemented as well as temperature-based deNOx performance for both Cu-Zeolite and Fe-Zeolite catalysts. Control is performed in a piecewise linear fashion, resulting in a total of 23 states including control signals. It is shown that high temperatures can be a larger threat to catalyst performance when running the WHTC than low temperatures, for both conventional and hybrid powertrains. Furthermore, decreasing the light-off time of the catalyst does not always lead to decreased NOx emission, instead there is a trade-off between light-off time and NOx emission. It is found that there are controls that will realize decreased NOx emission for a hybrid truck during cold starts at the expense of increased fuel consumption.
10

Um estudo sobre instalações propulsoras para empurradores fluviais. / A study about propulsion plant for fluvial towboats.

Newton Narciso Pereira 28 March 2007 (has links)
Este trabalho está voltado para a avaliação de alternativas de instalação propulsora para o empurrador de comboios fluviais. Estes comboios devem atender o objetivo da Petrobras / Transpetro de transportar álcool e derivados de petróleo pela hidrovia Tietê-Paraná. São apresentados como elementos de subsídio para o trabalho um estudo da demanda de álcool combustível em âmbito mundial e os argumentos para seu uso, bem como da oferta brasileira do produto. Além disso, apresentam-se, de forma sucinta, as principais restrições da hidrovia Tietê-Paraná, que devem servir de base para o projeto do comboio, e as características dos comboios em operação na hidrovia, que transportam outras cargas. São apresentados os critérios estabelecidos para construção de comboios fluviais adaptados ao transporte de álcool e derivados de petróleo, segundo as exigências da Norman e das sociedades classificadoras. O trabalho apresenta também uma investigação sobre novas concepções de instalação propulsora para emprego no empurrador. Assim, para seleção da instalação propulsora do empurrador são consideradas três alternativas: a instalação Diesel, que é concepção empregada em todos os comboios da hidrovia, e duas instalações dieselelétrica, uma convencional e outra com sistema Azipod. São empregados como critérios de avaliação o custo operacional do comboio, o impacto ambiental produzido pela emissão de gases e a segurança de navegação do comboio. Como método de avaliação multi-criterial foi utilizado o método de análise hierárquica. Os resultados da avaliação indicaram uma preferência pela instalação propulsora Diesel. / This work focuses on the evaluation of alternatives of main propulsion plants for towboats of fluvial convoys. These convoys must attend the objectives of Petrobras/Transpetro of transporting ethanol and oil derivatives through Tiete-Parana waterway. A study of the demand for ethanol worldwide and the arguments for its use are presented as supporting elements for the work, as well as the Brazilian supply of the product. Moreover, the main restrictions of the Tiete-Parana waterway, which must be the basis for the project of the convoy, and the characteristics of the convoys in operation in the waterway, which transport other loads, are succinctly presented. Complying with Norman 02 requirements and classifying societies, the criteria established for the construction of fluvial convoys adapted to the transport of ethanol and oil derivatives are also presented here. The work also presents an investigation about new concepts of propulsive installation for the use in the towboat. Therefore, for the selection of the propulsion system of the towboat, three alternatives are considered: the Diesel plant, which is the concept used in all convoys of the waterway, and two Diesel-electric propulsion systems, a conventional one and another with an Azipod system. The operational cost of the convoy, the environmental impact produced by the emission of gases and the safety of navigation of the convoy are used as criteria for evaluation. The method of hierarchical analysis was used as method of evaluation. The results of the evaluation indicated a preference for the Diesel propulsion plant.

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