Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, which impacts the distributions of pressure and shear stress on the blade surface. To design efficient propellers for operation at low Reynolds numbers, transitional effects must be included in the evaluations of propeller performance. In this work, transition modeling techniques in Reynolds Averaged Navier-Stokes computational fluid dynamics (RANS CFD) are utilized to evaluate and design propellers operating at low Reynolds numbers. The Galilean invariant γ transition model with an extension for crossflow transition is coupled to the SSG (Speziale, Sarkar, Gatski) /LRR (Launder, Reece, Rodi) -ω Reynolds stress transport turbulence model, with validation cases performed for flate plate boundary layers, 2-dimensional airfoils, a 3-dimensional wing, and 6:1 prolate spheroids. The performance of the coupled SSG/LRR-ω-γ Reynolds stress transition model for propellers with flow transition is then evaluated using experimental surface streamline and force data from four model-scale marine propellers. A method for the design of low Reynolds number marine propellers is presented using a transition-sensitive lifting line method coupled with the panel method code XFOIL. Initial geometries generated using the lifting-line method are then optimized in RANS CFD using the 2 equation γ-Reθ transition model and an adjoint method to warp the propeller shape to improve the efficiency. Two design studies are performed, including an open water propeller, and a propeller designed for a small autonomous underwater vehicle. / Doctor of Philosophy / Small-scale marine propellers exhibit transition from laminar to turbulent flow in the region near the surface of the blades. Regions of laminar and turbulent flow on the blade surface contribute differently to the overall thrust and torque on the propeller. Prediction of flow transition in the design process for small-scale marine propellers can improve the accuracy of the thrust and torque prediction compared to modeling the flow as purely laminar or turbulent. Propeller thrust and torque can be modeled using computational fluid dynamics (CFD) simulations, where transition modeling is accomplished by solving a transport equation for the intermittency γ, which represents the percentage of time the flow in a given location is turbulent. In this work, a transition model is coupled to a high-fidelity full Reynolds stress turbulence model, which solves 6 transport equations to solve for each component of the Reynolds stress tensor. The Reynolds stress tensor represents the turbulent velocity fluctuations in the governing equations solved in the CFD simulation. This coupled transition and turbulence model is then validated using experimental results of flows with a number of different transition mechanisms. The coupled model is then tested with a series of model-scale propellers, with results of the CFD simulations compared to the experimental results. A method for the design of propellers with flow transition is presented which incorporates transition effects. The designs generated by this method are then optimized in a CFD framework which morphs the blade geometry to improve the ratio of the thrust produced by the propeller to the torque, which corresponds to a higher efficiency. Two design cases are presented: a propeller designed for open water operation, and a propeller design for a small autonomous underwater vehicle.

I ett marint framdrivningssystem byggt av Rolls-Royce Marine i Kristinehamn, kallat POD Propulsion - MermaidTM, kyls systemets yttre delar med förbiströmmande vatten. Det kylande vattnet kompletteras av ett internt luftkylningssystem vilket, till följd av en lägre kylningskapacitet än för det externa vattnet, förorsakar en otillräcklig kylning i den sektor av elmotorns stator vars periferi kyls av kylluftsströmmen. En andel av statorn är således enbart luftkyld vilket medför att den axiella temperaturen i denna sektor uppnår ett lokalt maximum, kallad ”hotspot”, vilken är högre än för resten av elmotorns stator. Avsaknaden av en tangentiellt uniform temperatur i statorn medför begränsningar vid dimensionering av framdrivningssystemet. Begränsningar som kan få till följd att motorn i en POD överdimensioneras, gentemot fartygets effektbehov, sådan att elmotorn vid drift inte ska generera lika mycket värme och därmed undvika de höga statortemperaturerna. En effektiv kylning av hotspoten och därigenom en tangentiellt mer uniform temperatur skulle därmed medföra att elmotorn kan; dimensioneras mer effektivt och därigenom ge en lägre installationskostnad, uppnå en högre utnyttjandegrad samt leda till en förbättrad hydrodynamisk verkningsgrad. Rapporten ämnar genom både analytiska och numeriska simuleringar utvärdera ett flertal olika passiva kylningsmetoder som kan appliceras över POD-husets hotspot. De tilltänkta kylningsmetoderna baseras i grunden på två olika principer. En av principerna, kallad utvidgade ytor, avser kyla hotspoten genom att underlätta överföringen av värme från hotspoten till en förbipasserande fluid där den andra, genom tillämpning av ett ledande material, leder värme från hotspoten till en omgivande kallare yta. Resultaten visar att alla de tilltänkta modifikationerna, i varierande grad, möjliggör en temperatursänkning av det vertikala hotspotområdet, vilken är belägen intill luftkylningskanalen. De modifikationer som presterar bäst är modifikationerna som tillämpar en heatpipe som ledande material och modifikationen utvidgad solid gjort av koppar. Dessa modeller visar en 60 procentig temperatursänkning av den vertikala hotspoten relativt referensmodellen. Rapportens resultat kan även visa en temperatursänkning av luften då modifikationen ledande stag tillämpas, vilket är gynnsamt för fartygets luftkylningsprocess.

Neste trabalho é pesquisada a aplicação de um controlador adaptativo auto-ajustável multivariável à instalação propulsora de um navio com motor Diesel e hélice de passo variável. Os sistemas convencionais de controle de propulsão marítima são projetados deterministicamente e, geralmente, baseados na condição nominal de operação da embarcação, definida pelo seu deslocamento de projeto, estado de mar e de casco. Entretanto, o navio raramente opera na sua condição nominal, já que o seu deslocamento não é sempre o mesmo e continuamente ocorrem variações no estado do casco e do mar. Adicionalmente deve-se mencionar o efeito de perturbações estocásticas como vento, ondas e corrente que atuam sobre o navio. Estas considerações sugerem que o controlador de uma instalação propulsora deva ser adaptativo, isto é , que os seus ganhos se ajustem às alterações que ocorrem no sistema ou no meio ambiente. A teoria do controlador adaptativo auto-ajustável empregada neste trabalho é desenvolvida para sistemas multivariáveis lineares estocásticos, descritos por uma equação vetorial de diferenças com coeficientes desconhecidos. A lei de controle é obtida a partir da minimização de um índice de desempenho onde são ponderados os vetores de saída, de referência e de controle. A aplicação do controlador auto-ajustável exige a estimação de parâmetros do modelo. Neste trabalho é utilizado o modo implícito, que estima diretamente os parâmetros do controlador, através do método dos mínimos quadrados recursivo. Para adequar a aplicação da teoria a um sistema não linear, que é o caso da instalação propulsora, é introduzido no algorítimo de estimação de parâmetros um fator de esquecimento variável para alterar a velocidade de convergência dos parâmetros.O desempenho do controlador auto-ajustável é verificado através de uma série de testes de simulação, envolvendo manobras de regulação e de traqueamento. Com estes testes é analisada também a influência da matriz do ruído, do tempo de processamento do controlador, da matriz de ponderação do vetor de controle, da condição inicial da matriz de parâmetros, do intervalo de amostragem e da condição de operação do sistema sobre o desempenho do controlador. Os resultados de cada manobra são comparados com os obtidos com um controlador convencional projetado especificamente para o navio considerado, constatando-se o bom desempenho do controlador auto-ajustável. / This work is concerned with the application of multivariable self-tuning controllers to diesel engine propulsion plant with variable pitch propeller. Conventional control systems for marine propulsion plants are designed employing deterministic criteria based on the ship\'s operating condition, which is defined by the design displacement, sea state and hull roughness. However, only seldom if ever will the ship find itself operating in such nominal condition since her displacement is not always the same and the sea state and hull roughness vary continuously with time. In addition one should take into consideration the effect on the ship of stochastic factors such as winds, waves and sea currents. The preceding considerations suggest that the controller for a marine propulsion plant should be capable of adjusting itself to varying operating conditions. In other words, it should be capable of tuning its gains according to alterations occurring within the system or imposed by the environment. The theory of self-tuning controller employed in this work has been developed for stochastic multivariable linear systems describe by a linear vector difference equation with unknown parameters. The control law is obtained by the minimization of one performance index in which are weighted the output, reference and control vectors. The application of the self-tuning controller requires the estimation of the model parameters. In this work the implicit way is used wich directly estimates the parameters of the controller by means of the recursive minimum least-square algorithm. In order to apply the theory to non-linear systems such as propulsion plants, a variable forgetting factor is introduced in the estimation algorithm to change the convergence speed of the parameters. The performance of the self-tuning controller is assessed by means of several simulations tests involving regulating and tracking maneuvers.The tests also assess the influence on the controller performance of such factors as the noise matrix, controller process time, initial condition of parameters matrix, sampling time and operating condition of the system. The results of each maneuver are compared with those obtained by a conventional controller specifically designed for the ship under consideration and it was verified that the self-tuning controller has a good performance.

If international agreements regarding the need to significantly reduce greenhouse gas emissions are to be met then there is a high probability that the shipping industry will have to reduce its greenhouse gas emissions. For emission reductions from ships greater than around 40% then alternatives to fossil fuels - such as nuclear energy - will very likely be required. Whilst nuclear powered ships have successfully operated at sea for a number of decades, these have been primarily naval systems (or derivatives of naval systems such as icebreakers) and a few demonstration projects using reactors with low power outputs. The operational requirement for large civilian vessels (for example high capacity factors and limited personnel) mean the naval and past demonstration reactor systems are ill-suited for use in the current fleet of commercial container ships. There have been relatively few studies performed addressing the likely requirements upon core design a marine reactor would have to meet. This study addresses those issues and also implements a Pressurised Water Reactor core design capable of achieving these requirements. Furthermore, in order to simplify reactor operation for a limited number of personnel on board, the chemical reactivity control system has been eliminated during power operation. This has resulted in a novel low power density core that does not require refuelling for 15 years. The neutronic and fuel performance behaviour of this system has been studied with conventional UO2 fuel and thorium-uranium oxide ((Th,U)O2) fuel. With respect to (Th,U)O2 fuel there has been limited analysis comparing the performance of key fuel characteristics, such as fission gas release and thermal conductivity, as a function of uranium content in (Th,U)O2 fuel and their impact on fuel behaviour. Furthermore, the performance of neutronic codes for modelling Th-232 and U-233 from a variety of experiments using modern nuclear data libraries (post 1990) is lacking. Both of these issues are addressed in this study. Whilst it is frequently stated that thorium-based oxide fuel is superior to UO2 fuel it was found that due to the sensitivity of thermal conductivity on temperature and uranium content this was not true for the core designed in this study. The (Th,U)O2 core showed no net economic benefits with respect to the UO2 core and it was found that the fuel performance of (Th,U)O2 fuel was worse than the UO2 fuel in the reactor designed here. The UO2 core design, however, was able to satisfactorily meet the majority of requirements placed upon the system.

Neste trabalho é pesquisada a aplicação de um controlador adaptativo auto-ajustável multivariável à instalação propulsora de um navio com motor Diesel e hélice de passo variável. Os sistemas convencionais de controle de propulsão marítima são projetados deterministicamente e, geralmente, baseados na condição nominal de operação da embarcação, definida pelo seu deslocamento de projeto, estado de mar e de casco. Entretanto, o navio raramente opera na sua condição nominal, já que o seu deslocamento não é sempre o mesmo e continuamente ocorrem variações no estado do casco e do mar. Adicionalmente deve-se mencionar o efeito de perturbações estocásticas como vento, ondas e corrente que atuam sobre o navio. Estas considerações sugerem que o controlador de uma instalação propulsora deva ser adaptativo, isto é , que os seus ganhos se ajustem às alterações que ocorrem no sistema ou no meio ambiente. A teoria do controlador adaptativo auto-ajustável empregada neste trabalho é desenvolvida para sistemas multivariáveis lineares estocásticos, descritos por uma equação vetorial de diferenças com coeficientes desconhecidos. A lei de controle é obtida a partir da minimização de um índice de desempenho onde são ponderados os vetores de saída, de referência e de controle. A aplicação do controlador auto-ajustável exige a estimação de parâmetros do modelo. Neste trabalho é utilizado o modo implícito, que estima diretamente os parâmetros do controlador, através do método dos mínimos quadrados recursivo. Para adequar a aplicação da teoria a um sistema não linear, que é o caso da instalação propulsora, é introduzido no algorítimo de estimação de parâmetros um fator de esquecimento variável para alterar a velocidade de convergência dos parâmetros.O desempenho do controlador auto-ajustável é verificado através de uma série de testes de simulação, envolvendo manobras de regulação e de traqueamento. Com estes testes é analisada também a influência da matriz do ruído, do tempo de processamento do controlador, da matriz de ponderação do vetor de controle, da condição inicial da matriz de parâmetros, do intervalo de amostragem e da condição de operação do sistema sobre o desempenho do controlador. Os resultados de cada manobra são comparados com os obtidos com um controlador convencional projetado especificamente para o navio considerado, constatando-se o bom desempenho do controlador auto-ajustável. / This work is concerned with the application of multivariable self-tuning controllers to diesel engine propulsion plant with variable pitch propeller. Conventional control systems for marine propulsion plants are designed employing deterministic criteria based on the ship\'s operating condition, which is defined by the design displacement, sea state and hull roughness. However, only seldom if ever will the ship find itself operating in such nominal condition since her displacement is not always the same and the sea state and hull roughness vary continuously with time. In addition one should take into consideration the effect on the ship of stochastic factors such as winds, waves and sea currents. The preceding considerations suggest that the controller for a marine propulsion plant should be capable of adjusting itself to varying operating conditions. In other words, it should be capable of tuning its gains according to alterations occurring within the system or imposed by the environment. The theory of self-tuning controller employed in this work has been developed for stochastic multivariable linear systems describe by a linear vector difference equation with unknown parameters. The control law is obtained by the minimization of one performance index in which are weighted the output, reference and control vectors. The application of the self-tuning controller requires the estimation of the model parameters. In this work the implicit way is used wich directly estimates the parameters of the controller by means of the recursive minimum least-square algorithm. In order to apply the theory to non-linear systems such as propulsion plants, a variable forgetting factor is introduced in the estimation algorithm to change the convergence speed of the parameters. The performance of the self-tuning controller is assessed by means of several simulations tests involving regulating and tracking maneuvers.The tests also assess the influence on the controller performance of such factors as the noise matrix, controller process time, initial condition of parameters matrix, sampling time and operating condition of the system. The results of each maneuver are compared with those obtained by a conventional controller specifically designed for the ship under consideration and it was verified that the self-tuning controller has a good performance.

Energy efficiency and propulsive characteristics of a 10 cm undulatory rainbow trout (oncorhynchus mykiss) swimming in a stationary position are considered. Two CFD simulations are performed utilizing dynamic grid meshing (FLUENT 6.3). The first simulation uses a laminar flow model with an added hydrofoil shape in order to test if thrust and drag can be brought to unity. The second simulation uses a Large-Eddy Simulation (LES) turbulence model to determine if transition to turbulence along the fish's surface leads to boundary layer separation. The expected results caused by adding these two features to earlier simulations do not occur. Thrust and drag are not found to be equal with usage of the thicker fish shape; instead both thrust and drag increase by 40-80% while diverging in value. Evidence of boundary layer separation is not present with usage of the LES turbulence model. Swimming energy efficiency is calculated to be 70% in both simulations. A brief analyses of boundary layer and downstream wake are included, showing general agreement with earlier studies. Limitations of the simulation are discussed. Future work regarding the author's preparation for an additional simulation of a rainbow trout utilizing a swimming method known as the Karman Gait is also considered. This preparation includes the creation of a 2-D grid domain and programs to define the kinematics of the fish and produce a specified vortex inlet condition.

The widely-used passenger and car ferries, sailing regularly and carrying heavy loads, form a unique type of marine vessel, providing vital transportation links to the coastal regions. Modern ferry ships usually are equipped with multiple diesel engines as prime movers. These diesel engines consume a large amount of marine diesel fuel with high fuel costs, and high emissions of greenhouse gas (GHG) and other harmful air pollutants, including CO2, HC, NOx, SO2, CO, and PM. To reduce fuel costs and the harmful emissions, the marine industry and ferry service providers have been seeking clean ship propulsion solutions. In this work, the model-based design (MBD) and optimization methodology for developing advanced electrified vehicles (EV) are applied to the modelling, design and control optimizations of clean marine vessels with a hybrid electric propulsion system. The research focuses on the design and optimization of the hybrid electric ship propulsion system and uses an open deck passenger and car ferry, the MV Tachek, operated by the British Columbia Ferry Services Inc. Canada, as a test case. At present, the ferry runs on the Quadra Island – Cortes Island route in British Columbia, Canada, with dynamically changing ocean conditions in different seasons over a year. The research first introduces the ship operation profile, using statistical ferry operation data collected from the ferry’s voyage data recorder and a data acquisition system that is specially designed and installed in this research. The ship operation profile model with ship power demand, travelling velocity and sailing route then serves as the design and control requirements of the hybrid electric marine propulsion system. The development of optimal power control and energy management strategies and the optimization of the powertrain architecture and key powertrain component sizes of the ship propulsion system are then carried out. Both of the series and parallel hybrid electric propulsion architectures have been studied. The sizes of crucial powertrain components, including the diesel engine and battery energy storage system (ESS), are optimized to achieve the best system energy efficiency. The optimal power control and energy management strategies are optimized using dynamic programming (DP) over a complete ferry sailing trip. The predicted energy efficiency and emission reduction improvements of the proposed new ship with the optimized hybrid propulsion system are compared with those of two benchmark vessels to demonstrate the benefits of the new design methodology and the optimized hybrid electric ship propulsion system design. These two benchmarks include a conventional ferry with the old diesel-mechanical propulsion system, and the Power Take In (PTI) hybrid electric propulsion systems installed on the MV Tachek at present. The simulation results using the integrated ship propulsion system model showed that the newly proposed hybrid electric ship could have 17.41% fuel saving over the conventional diesel-mechanical ship, and 22.98% fuel saving over the present MV Tachek. The proposed optimized hybrid electric propulsion system, combining the advantages of diesel-electric, pure electric, and mechanical propulsions, presented considerably improved energy efficiency and emissions reduction. The research forms the foundation for future hybrid electric ferry design and development. / Graduate

This dissertation focuses on the introduction and development of an integrated model-based design and optimization platform to solve the optimal design and optimal control, or hardware and software co-design, problem for hybrid electric propulsion systems. Specifically, the hybrid and plug-in hybrid electric powertrain systems with diesel and natural gas (NG) fueled compression ignition (CI) engines and large Li-ion battery energy storage system (ESS) for propelling a hybrid electric marine vessel are investigated. The combined design and control optimization of the hybrid propulsion system is formulated as a bi-level, nested optimization problem. The lower-level optimization applies dynamic programming (DP) to ensure optimal energy management for each feasible powertrain system design, and the upper-level global optimization aims at identifying the optimal sizes of key powertrain components for the powertrain system with optimized control. Recently, Li-ion batteries became a promising ESS technology for electrified transportation applications. However, these costly Li-ion battery ESSs contribute to a large portion of the powertrain electrification and hybridization costs and suffer a much shorter lifetime compared to other key powertrain components. Different battery performance modelling methods are reviewed to identify the appropriate degradation prediction approach. Using this approach and a large set of experimental data, the performance degradation and life prediction model of LiFePO4 type battery has been developed and validated. This model serves as the foundation for determining the optimal size of battery ESS and for optimal energy management in powertrain system control to achieve balanced reduction of fuel consumption and the extension of battery lifetime. In modelling and design of different hybrid electric marine propulsion systems, the life cycle cost (LCC) model of the cleaner, hybrid propulsion systems is introduced, considering the investment, replacement and operational costs of their major contributors. The costs of liquefied NG (LNG), diesel and electricity in the LCC model are collected from various sources, with a focus on present industrial price in British Columbia, Canada. The greenhouse gas (GHG) and criteria air pollutant (CAP) emissions from traditional diesel and cleaner NG-fueled engines with conventional and optimized hybrid electric powertrains are also evaluated. To solve the computational expensive nested optimization problem, a surrogate model-based (or metamodel-based) global optimization method is used. This advanced global optimization search algorithm uses the optimized Latin hypercube sampling (OLHS) to form the Kriging model and uses expected improvement (EI) online sampling criterion to refine the model to guide the search of global optimum through a much-reduced number of sample data points from the computationally intensive objective function. Solutions from the combined hybrid propulsion system design and control optimization are presented and discussed. This research has further improved the methodology of model-based design and optimization of hybrid electric marine propulsion systems to solve complicated co-design problems through more efficient approaches, and demonstrated the feasibility and benefits of the new methods through their applications to tugboat propulsion system design and control developments. The resulting hybrid propulsion system with NG engine and Li-ion battery ESS presents a more economical and environmentally friendly propulsion system design of the tugboat. This research has further improved the methodology of model-based design and optimization of hybrid electric marine propulsion systems to solve complicated co-design problems through more efficient approaches, and demonstrated the feasibility and benefits of the new methods through their applications to tugboat propulsion system design and control developments. Other main contributions include incorporating the battery performance degradation model to the powertrain size optimization and optimal energy management; performing a systematic design and optimization considering LCC of diesel and NG engines in the hybrid electric powertrains; and developing an effective method for the computational intensive powertrain co-design problem. / Graduate

This master thesis addresses the control of electric propulsion motors in a marine context. The focus lies mainly on the implementation of field oriented control (FOC) in a field programmable gate array (FPGA). The hypothesis is that FPGAs provide performance advantages over microcontroller-based control solutions by enabling parallel processing. Zparq AB, a startup specializing in electric marine propulsion, serves as the industry partner for this project. They develop sustainable alternatives to traditional fossil fuel powered propulsion, and the aim is to develop every included part of their electric propulsion systems inhouse. That makes the development of an FPGA-based motor control solution relevant to their goal. The research question focuses on how multiple marine propulsion motors can be controlled from a single FPGA. To answer this, the study investigates relevant engineering aspects such as reference frame transformations, motor control strategies, pulse width modulation (PWM) methods and technological aspects of modern FPGA architectures. For developing the motor controller, a Digilent Arty Z7-20 FPGA board is used. In the design process, all included functions are written as code in a hardware description language (HDL). This approach aims at maintaining complete insight in all details of the solution. Two variants of conventional FOC are developed; one with position feedback from an encoder and one sensorless. The developed motor controller is tested by controlling a brushless direct current (BLDC) motor, and the results prove the functionality of the encoder-based variant. They also show a latency of less than 15 microseconds and indicate the feasibility of the chosen approach. The modularity of the FPGA is demonstrated by successfully controlling two motors, using two copies of the developed solution in a single FPGA. A discussion on combining FPGA-based controllers with wide bandgap (WBG) semiconductors is also included, where the main discussed advantage is high switching frequency. In conclusion, the results and insights from the project contribute to future development of FPGA-based motor control solutions, both within Zparq and the research field. The insights regarding the specific chosen approach for the FPGA development can also be useful for similar projects. / Detta masterarbete behandlar styrning av elektriska motorer i ett marint kontext. Fokus ligger huvudsakligen på implementeringen av fältorienterad styrning (FOC) i en ifält-programmerbar grindmatris (FPGA). Hypotesen är att FPGAer erbjuder prestandafördelar jämfört med mikrokontroller-baserade styrlösningar, genom att möjliggöra parallella beräkningsprocesser. Zparq AB, ett startup som specialiserar sig på elektriska marina drivsystem, är industripartner för detta projekt. De utvecklar hållbara alternativ till traditionell fossildriven framdrift och målet är att på egen hand utveckla alla ingående delar i deras elektriska drivsystem. Det gör att utvecklingen av en FPGA-baserad lösning för motorstyrning är relevant inom ramen för deras mål. Forskningsfrågan fokuserar på hur ett flertal motorer för marin framdrift kan styras från en enda FPGA. För att svara på detta undersöks relevanta tekniska aspekter såsom koordinattransformationer, motorstyrningsstrategier, metoder för pulsbreddsmodulering (PWM) samt teknologiska aspekter av moderna FPGA-arkitekturer. För utvecklingen av motorstyrningen används ett Digilent Arty Z7-20 FPGA-kort. I designprocessen formuleras alla inkluderade funktioner som kod i ett hårdvarubeskrivande språk (HDL). Detta tillvägagångssätt syftar till att ha god insyn i hela lösningen, ner på detaljnivå. Två varianter av konventionell FOC utvecklas; en med positionsfeedback från vinkelgivare och en sensorlös. Den utvecklade motorstyrningen testas genom att driva en borstlös likströmsmotor (BLDC) och resultaten visar på den vinkelgivarbaserade variantens funktionalitet. De visar även att fördröjningen är under 15 mikrosekunder, samt på genomförbarheten av det valda tillvägagångssättet. Modulariteten i FPGAn demonstreras genom att framgångsrikt styra två motorer med hjälp av två kopior av den utvecklade lösningen i en och samma FPGA. En diskussion kring att kombinera FPGA-baserad styrning och halvledare med brett bandgap (WBG) är också inkluderad, där den huvudsakliga fördelen som diskuteras är hög switchfrekvens.svis bidrar resultaten och insikterna från projektet till framtida utveckling av FPGA-baserade lösningar för motorstyrning, både inom Zparq och övriga forskningsfältet. Insikterna från det specifika valda tillvägagångssättet för FPGA-utvecklingen kan även de vara användbara i liknande projekt.

The purpose of this study is to compare the life-cycle cost and environmental impact of the existing fuel-based propulsion system, on public commuter ferries in Stockholm, with a battery based propulsion system. The study is divided into multiple layers. First, the operating characteristics of the route Line 80 within Stockholm’s waterborne public transportation (WPT) are collected, such as fuel consumption, propulsion power output, speed, voyage time and propulsion system configuration. Second, based on the energy demand of the route, important parameters related to the existing fuel-based propulsion system and the battery-based propulsion system are accounted for and modeled. Third, Life Cycle Assessment (LCA) and the cost assessment methods are applied to examine the effectiveness of the electrification of commuter ferries on a financial and environmental scale. With the help of the software GaBi 2020, GREET 2020, and other literature studies, the environmental impacts at the construction, use and end-of-life (EOL) phase are evaluated. There are in total 8 scenarios considered, 4 for the fuel-based and 4 for the battery-based propulsion system. The environmental performance of these 8 scenarios are discussed in terms of Globalwarmingpotential(GWP), Acidificationpotential(AP), Eutrophicationpotential(EP) and Photo-chemical ozone creation potential (POCP). Themostpollutingphaseistheusephase for all scenarios. Propulsion system powered by diesel (scenario 1) is considered as a reference for comparative analysis of 7 other scenarios. The best performing system is the one powered by batteries with the assumption of an electricity mix based on hydro, wind and nuclear power, which is scenario 7 and 8 with a net reduction of GWP by more than 98%, AP by 90%, EP by 96%, and the POCP by 96%. If we consider the current Swedish electricity mix (scenario 5 and 6), the decrease in GWP, AP, EP and POCP are 90%, 80%, 82% and 91% respectively. Alternative fuels also present promising results for GWP in comparison to diesel (with the origin of the feed-stock creating mostly negative impacts) but the contribution to other impact categories is significantly higher. With inputs from the industry and the environmental evaluation, the cost assessment compares the costs related to fuel-based and battery-based propulsion systems with different energy sources. For the battery-based system, 3 scenarios are modeled for two different types of Li-ion batteries. The vessels in the developed scenarios are charged more frequently than the existing electric vessel and the number of charging stations is varied. The costs that are included in the assessment are the initial capital cost, the cost for fuel/electricity, maintenance cost, end-of-life cost and emissions cost. When concerning all the cost categories, the battery-based system is more cost-efficient than a fuel-based system, if run on the Swedish electricity mix, due to the lower cost for electricity and emissions. The reduction of cost is more than 68% when comparing traditional diesel with battery-based systems, but the source of the electricity is very important. / Syftet med denna studie är att jämföra livscykelkostnaden och miljöpåverkan av de befintliga framdrivningssystemen på pendelbåtarna inom Stockholms kollektivtrafik, med batteridrivna system på motsvarande båtar. De befintliga framdrivningssystemen drivs av olika typer av diesel. Studien är uppdelad i flera steg. Först samlas driftsegenskaperna in, såsom bränsleförbrukning, framdrivningseffekt, hastighet, färdtidochframdrivningssystemetsuppbyggnad, etc, på linje 80, som är en del av Stockholms vattenburna kollektivtrafik. För det andra undersöks det befintliga framdrivningssystemet som drivs av diesel eller alternativa bränslen som RME eller HVO och fullt batteridrivna system utifrån energibehovet. För det tredje tillämpas metoderna för kostnadsanalys och livscykelanalys (LCA) för att undersöka hur elektrifieringen av pendelbåtar påverkar ekonomin och miljön. Med hjälp av programmet GaBi 2020, GREET 2020 och andra litteraturstudier utvärderas miljöpåverkan av faserna tillverkning, användning och avfallshantering. Det är totalt 8 scenarier som övervägs, 4 för bränslebaserade och 4 för batteri baserade framdrivningssystem. Hur bra dessa 8 scenarier presterar miljömässigt diskuteras i termer av växthuseffekt (GWP), försurning (AP), övergödning (EP) och marknära ozon (POCP). Den fasen med mest utsläpp, för alla scenarier, är användningsfasen. Framdrivningssystemet som drivs av diesel (scenario 1) används som referens att jämföra de övriga 7 scenarierna mot. Det system som presterar bästa är det som drivs av batterier, med antagandet att elmixen är baserad på vatten-, vind-och kärnkraft, detta motsvarar scenario 7 och 8 med en reduktion av GWP på mer än 98%, AP med 90%, EP med 96% och POCP med 96%. Om vi tittar på den aktuella svenska elmixen (scenario 5 och 6) så är minskningen av GWP, AP, EP och POCP 90%, 80%, 82% respektive 91%. Alternativa bränslen ger också lovande resultat för GWP jämfört med diesel (där råvarans ursprung skapar mest negativa effekter) men bidraget till andra påverkanskategorier är betydligt högre. Med input från företag och miljöutvärderingen kan kostnadsanalysen jämföra kostnaderna för bränslebaserade och batteri baserade framdrivningssystem med olika energikällor. Det batteri baserade systemet modelleras även på 3 utvecklade scenarier för 2 olika typer av batterier. Fartygen i de utvecklade scenarierna laddas oftare än det befintliga batteridrivna fartyget och antalet laddstationer varierar mellan scenarierna. De kostnader som inkluderas i analysen är de initiala kapitalkostnaderna, kostnaden för bränsle/el, underhållskostnader, avfallshanteringskostnader ochutsläppskostnader. Medallakostnaderinkluderadeiberäkningarna är batteri baserade system mer kostnadseffektiva än bränslebaserade system om de körs på svensk elmix, tack vare de lägre kostnaderna för el och utsläpp. Minskningen av den totala kostnaden är mer än 68% när man jämför traditionell diesel med batterisystem, men elens ursprung är mycket viktig.