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Wound Independently Controlled Stator Coil (WICSC) machines are a novel type of multiphase machine with the ability to change its pole-phase configuration during operation. This enables improved post-fault control and thus prolonged continuous operation. For a smooth transition to post-fault control, a quick and robust strategy for Fault detection and isolation (FDI) is essential. This master thesis concerns the design of a procedure to localise Open Phase Fault (OPF) and Open Switch Fault (OSF) in WICSC machines. The strategy is based on Harmonic Plane Decomposition (HPD), which generalises Vector Space Decomposition (VSD) to variable pole-phase machines. A previous iteration of the FDI strategy is analysed and developed further on MatLab. Experimental verification is performed on a WICSC motor with and without imitated OPF. A Printed Circuit Board (PCB) is designed to imitate OSF during operation. The outcome displays a fault detection within less than 30% of a fundamental current period. After no more than one period the full diagnosis is completed. Although only OPFs are tested, the results suggest the Fault detection and isolation (FDI)’s ability to identify OSFs as well. The parameter tuning is shown to be important for both correct fault localisation and avoiding false positives. Imbalances in the machine require special care when choosing the parameter values. Future work includes using the PCB for OSF tests and making the parameter tuning more robust. / WICSC-maskiner är en ny typ av multifasmaskin med förmågan att ändra sin polfas-konfiguration under drift. Detta möjliggör förbättrad reglering efter att fel uppstår och därmed förlängd drift. För att uppnå en mjuk övergång till reglering efter fel krävs en snabb och robust strategi för feldiagnosticering. Denna masteruppsats rör utvecklingen av en strategi för att detektera och lokalisera tomgångsfel i spolar och elektroniska brytare till WICSC-maskiner. Strategin baseras på HPD, som är en generalisering av VSD. En tidigare iteration av strategin analyseras och vidareutvecklas i MatLab. Experimentell verifiering utförs på en WICSC-motor med samt utan imiterade tomgångsfel i spolarna. En PCB designas för att imitera tomgångsfel i växelriktarens brytare. Resultaten ger en feldetektering på under 30% av en fundamental strömperiod. Efter maximalt en period är hela diagnosticeringen slutförd. Trots att endast spolfel testas pekar resultaten på att strategin även fungerar för brytarfel. Strategins parametervärden visar sig vara viktiga för både fellokaliseringen och för att undvika falska positiv. Obalans i maskinen ställer särsklit höga krav på justeringen av dessa värden. I framtida studier kommer PCB-enheten användas för att testa diagnosticering av brytarfel och göra justeringen av parametervärdena mer robust.

Bei oberflächennahen geothermischen Anwendungen kommt es zu Temperaturveränderungen im Untergrund, um Wärme zu gewinnen oder zu speichern. Die dadurch verursachten thermischen Auswirkungen können die thermischen, hydraulischen und chemischen Bedingungen des Untergrunds verändern und sich auf die Systemleistung auswirken. Die Situation wird noch komplizierter, wenn die Grundwasserleiter unterschiedlich gesättigt sind und eine Verunreinigung des Untergrunds vorliegt. In dieser Arbeit werden vollständig gekoppelte Wärme- und Stofftransportmodelle angewandt, um die Wechselwirkung zwischen oberflächennahen geothermischen Anwendungen und der unterirdischen Umgebung besser zu charakterisieren. Es werden drei verschiedene Szenarien untersucht. Zunächst werden die thermischen Auswirkungen und die Nachhaltigkeit einer intensiven oberflächennahen geothermischen Nutzung in einem Wohngebiet über einen Zeitraum von 24 Jahren bewertet. Überwachungsdaten des Standorts werden in das Modell integriert, und die Bedeutung standortspezifscher Kenntnisse für die Planung wird hervorgehoben. Zweitens wird der gekoppelte Feuchtigkeits- und Wärmetransport eines Erdwärmespeichersystems (BTES) untersucht. Es wird eine Sensitivitätsanalyse durchgeführt und die Wärmeentzugsefzienz zwischen verschiedenen Szenarien verglichen. Bei Austrocknung oder starker Gasphasenkonvektion werden signifkante Änderungen im Wärmetransportverhalten erwartet. Drittens wird ein nichtisothermes Drei-Komponenten-Zweiphasenströmungsmodell abgeleitet und mit der Finite-Elemente-Methode implementiert. Die Validierung des numerischen Modells bestätigt seine Fähigkeit, die gekoppelte Strömung sowie den Wärme- und Stofftransport in einem ungespannten Grundwasserleiter zu simulieren, der einem BTES-Betrieb ausgesetzt ist. Insbesondere wird das Potenzial für die thermisch verstärkte Verflüchtigung von Trichlorethylen (TCE) in wässriger Phase bewertet. Da durch die Wärmezufuhr eine Auftriebsströmung induziert wird, nimmt die Verringerung der Schadstoffmasse erheblich zu und erreicht nach fünf Jahren mehr als 70 %. Die in dieser Arbeit gewonnenen Erkenntnisse können durch die Verbesserung ihrer ökologischen und ökonomischen Leistungen zu einer breiteren Akzeptanz von Technologien der flachen Geothermie beitragen. / Shallow geothermal applications induce temperature changes in the subsurface for heat extraction or storage purposes. Their induced thermal impacts may alter the thermal, hydraulic, and chemical conditions of the subsurface and feedback on the system performance. The situation is further complicated in variably saturated aquifers and when subsurface contamination exists. In this work, fully coupled heat and mass transport models are applied to improve the characterization of interaction between shallow geothermal applications and the subsurface environment. Three different scenarios are investigated. First, the thermal impact and sustainability of intensive shallow geothermal exploitation in a residential area is evaluated over a 24-year period. Monitoring data from the site is integrated into the model and the importance of site-specifc knowledge for planning is highlighted. Second, the coupled moisture and heat transfer of a soil borehole thermal energy storage (BTES) system is explored. A sensitivity analysis is performed and the heat extraction efciency is compared among various scenarios. Signifcant changes in the heat transport behavior are expected when drying out or strong gas phase convection occurs. Third, a non-isothermal three-component two-phase flow model is derived and implemented with the fnite element method. Validation of the numerical model confrms its ability to simulate the coupled flow, heat and mass transport in an unconfned aquifer subject to BTES operation. In particular, the potential for thermally-enhanced volatilization of aqueousphase trichloroethylene (TCE) is assessed. As buoyant flow is induced due to heat injection, reduction of the contaminant mass grows considerably, reaching more than 70% after fve years. The fndings obtained from this thesis can contribute to a wider adoption of shallow geothermal technologies through the enhancement of their environmental and economical services.

[pt] Nas últimas décadas, grandes investimentos foram feitos no desenvolvimento de modelos e métodos numéricos para prever e analisar os diferentes aspectos do processo de recuperação de óleo e gás. Neste contexto, os simuladores modernos devem ser capazes de incorporar uma grande variedade de opções para responder questões relacionadas ao gerenciamento de reservatórios de forma rápida e precisa. Neste trabalho, nós apresentamos um simulador de reservatórios baseado em uma arquitetura de plugins, onde diferentes formulações, solvers e modelos podem ser desenvolvidos, estendidos e aprimorados. A partir desta abordagem, utilizamos o modelo black-oil para implementar técnicas tradicionais e do estado da arte, como os métodos totalmente e adaptativamente implícito, os métodos de Newton-Raphson e Newton Inexato, controladores heurístico e PID para passo de tempo adaptativo e aproximações de fluxo de um ponto baseados no potencial de fase tradicional e C1-contínuo. Diversas configurações de plugins foram testadas e validadas com simuladores comerciais e seus desempenhos foram utilizados para determinar quais as mais adequadas para resolver problemas de escoamento multifásico. / [en] During the last decades, large investments were made towards the development of numerical models and methods to forecast and analyze the different aspects of oil and gas recovery. In this context, modern simulators must be able to incorporate a wide variety of options to answer questions related to reservoir management accurately and effectively. In this work, we present a reservoir simulator based on a plugin architecture, where different formulations, solvers, and models can be developed, extended, and enhanced. With this approach, we use the black-oil model to implement traditional and state-of-the-art techniques, including fully- and adaptiveimplicit methods, heuristic and PID time-step controllers, Newton-Raphson and Inexact Newton, and C1-continuous and conventional phase-potential single-point upstream weighting. Several plugin configurations were tested and validated with commercial simulators, and their performances were used to determine which are the most suitable to solve multiphase flow problems.

No / The advances of the polymer melt flow-induced crystallization behaviour and its influence on mechanical properties of high density polyethylene (HDPE) in micron injection (MI) were studied in the present paper. Analysis of mechanical performance, including yield stress and elongation at break, for samples adopted from different regions in a molded plaque showed that a higher injection speed, a higher mold temperature and a longer cooling time could effectively enhance the yield stress but negatively promoted the ductility. Then, the mechanisms of such variation of mechanical performance and the factors affecting it were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and polarized light microscopy (PLM). The super high shear rate during cavity feeding in MI molding not only induced a typical three-layered structure but also developed a highly oriented fibrously morphological structure in the skin layer. However, such fully oriented morphology was much negative in the interlayer and even could not be observed in the core layer. The results from SEM and PLM observations indicated that the orientation morphology varied significantly through the plaque's cross-section and thickness of the each layer changed with the process parameters and geometric position, and finally led to variation of the mechanical performance.

A significant level of research is currently being carried out in the development of driver support systems as they are expected to play a key role in minimizing road vehicle accidents and creating a safe driving environment under harsh weather conditions. However, the performance of some components used by existing driver support systems like LIDAR and visual cameras are affected by extreme weather conditions such as heavy rain fall and snow. Therefore, it is paramount to identify key locations in an automotive vehicle where such systems are least affect by external weather conditions, thereby, improving their overall performance. The field of research that deals with such questions from a simulation perspective is called contamination modeling. At the moment, one of the biggest knowledge gaps in this field is how to consider the effect of different materials on the movement of liquids such as water on different automotive surfaces like glass, plastic, rubber and painted metal. The work presented in this research study has been carried out to investigate and establish the most suitable simulation strategies to match numerical predictions with experimental data for flow of water over different automotive surfaces. Following a comprehensive parametric study of simulation parameters, it was found that the most suitable model that can be tweaked to achieve different flow properties with different surfaces is a dynamic contact angle model. The Blended Kistler model available in STAR-CCM+ required specific values for static, advancing and receding contact angles to optimize a surface for a given material. Therefore, droplet experiments of two droplet sizes were initially carried out for all tested materials at different inclinations and necessary flow parameters were recorded. All experiments were carried out using an approach known as light induced fluorescence imaging where the captured images provided a very convenient method for post processing in computational software. Results from droplet experiments showed that water moved quickest on plastic and slowest on glass. Static contact angle measurements were carried out first on horizontal surfaces. Afterwards, the surface was inclined at 15, 30, 45, 60, and 75 degrees to measure changes in contact angle and velocities. The surfaces for glass and painted metal were directly taken from the door of a Volvo S60 while a separate surface was used for plastic and rubber. These results were then used to create simulation setups for rivulets in STAR-CCM+ with the multiphase modeling approach known as volume of fluid. Rivulet simulations were carried out for all four materials at five different inclinations and the results were compared and validated with experimental data. The results show good correlation between numerical predictions for rivulet movement and experimental data emphasising on the possibility of fine-tuning the surfaces of a simulation setup to represent different material properties.

<p>  </p> <p>Cavitation is one of the most common causes of failures in axial piston machines. Due to the detrimental effects that cavitation has on unit performance, it is of important consideration both in the design of new units and in defining the operational limits of existing market products. The work in this thesis aimed to contribute to the current knowledge in both areas, with a focus on design considerations with respect to cavitation scalability, and on operating conditions by measuring cavitation severity under separate and combined inciting parameters. Though the application of unit scaling is common in industry for the design of pump families, there have been no comprehensive attempts to quantify whether cavitation in fluid power units may be adequately accounted for in published scaling laws. In this thesis, the scalability of cavitation phenomena was examined through a CFD scaling study performed using a modified version of the Full Cavitation Model.  Results indicate that linear scaling is consistent in maintaining volumetric efficiency performance within 1% across scaled units up to eight times larger or smaller than the baseline. However, the gas and vapor volume distributions vary significantly between scaled units, due largely to the linear non-scalability of fluid inertia and turbulent factors. Physical exchange between phases within a working fluid was shown to be time-dependent, such that the scaled-down unit exhibits bubble collapse rates up to 30% and 150% greater than the baseline and scaled-up units, respectfully. Considering these effects, the presented work demonstrates a potential for increased cavitation damage area when downscaling a unit and reduced risk in upscaling, despite the scaling law being a reliable indicator for volumetric efficiency. </p> <p>To define a more complete study of cavitation under a variety of operating conditions and inciting parameters, this a new experimental procedure and testing circuit was proposed with focus on repeatability by controlled pressure drops and preliminary quantification of inlet fluid quality. By measuring cavitation conditions under pressure starvation, incomplete filling, and combinations thereof, the direct effect of different inception methods on unit performance was shown to be readily identifiable. Through visualization of the inlet flow, reduction in inlet pressure levels was correlated to fluid cloudiness levels and bubble size, with transparency loss at 0.0 bar_g and transition from bubbly to plug flow at -0.4 bar_g. Incomplete filling-induced cavitation was also shown to be detectable by inlet flow conditions, with a distinct change in bubble coalescence rate when operating under shaft speeds greater than or equal to fill speed for a given inlet pressure. </p>

Multiphase Electrical Machines (MPEMs) with variable phase-pole configurations have recently gained interest as it offers advantages such as a larger operating range and improved fault tolerance compared to more traditional MPEMs. The current state-of-the-art modeling and control method, Vector Space Decomposition (VSD), has the drawback of introducing discontinuities in the model when transitioning from one phase-pole configuration to another. The newly developed Harmonic Plane Decomposition (HPD) theory, which is an extension of the VSD, solves this issue by unifying all possible phase-pole configurations into one transformation. To enable further research on HPD theory and MPEMs with variable phase-pole configuration, a test bench is desired to obtain experimental results. The Sustainable Power Lab at KTH already possesses a MPEM with varying phase-pole configurations, the Wound Independently- Controlled Stator Coils machine (WICSC machine), but is missing a complete drive that can capitalize on the additional degrees of freedom that the machine offers. The aim of the thesis is to commission the test bench by implementing HPD control on a Digital Signal Processor (DSP) and design the missing hardware required to close the signal chain. The HPD control was implemented on a Xilinx System on a Chip (SoC) programmed using C and hardware description languages. Part of the control was tested but due to issues with the data acquisition, the complete control was not managed to be fully tested and verified. For the missing hardware, three Printed Circuit Boards (PCBs) were designed for the test bench. Two of them were built and tested, and one PCB was designed but not fabricated during the project. / Multifasmaskiner med variabel fas pol konfiguration har på senaste tiden fått mer uppmärksamhet på grund av fördelar som mer operationspunkter och förbättrad feltolerans jämfört mot mer traditionella multifasmaskiner. Den modernaste metoden, Vector Space Decomposition (VSD), för att styra traditionella multifasmaskiner har nackdelen att modellen blir diskontinuerlig när man går från en fas pol konfiguration till en annan. Den nyutvecklade Harmonic Plane Decomposition (HPD) teorin, vilket är en påbyggnad på VSD, löser det problemet genom att samla alla möjliga fas pol konfigurationer till en transform. För att fortsätta forskningen kring HPD och multifasmaskiner med variabel fas pol konfiguration behövs en testbänk för att kunna skaffa experimentella resultat. Elkraftlabbet på KTH har redan investerat i en multifasmaskin med variabel fas pol konfiguration, men saknar en komplett växelriktare som kan utnyttja maskinens alla frihetsgrader. Målet med projektet var att färdigställa testbänken genom att implementera HPD styrningen på en processor och konstruera hårdvara som testbänken saknade. HPD styrningen implementerades på en systemkrets från Xilinx och programmerades med C och hårdvarubeskrivande språk. Delar av styrningen kunde testas men på grund av problem med inläsningen av data så gick det inte att verifiera hela den implementerade styrningen. Till testbänken konstruerades också tre kretskort varav två byggdes, testades och fick sin funktionalitet verifierad. Det andra kretskortet konstruerades men blev inte tillverkat under projektet.

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In the recent decades, an increased interest into multiphase machines has developed due to certain beneficial properties they have over the standard three- phase machines. Proper modelling of a multiphase machine allows access to higher degrees of freedom given by the ability to control higher order harmonic frames. This feature is of particular interest in the area of parameter estimation as it may provide an opportunity to implement methods that are not feasible in three- phase machines. Modelling of a real six- phase machine meant for marine application with a functioning control structure is carried out on MATLAB/Simulink; considering nonlinear relations, cross coupling and saturation effects, the model includes the machine’s behavior in the fundamental frame as well as the next two higher order harmonic frames. Stator resistances and permanent magnet flux linkage are estimated online and simultaneously during various operating points. It is shown that stator resistance may be accurately estimated by means of DC test signal injections into the highest order harmonic frame; thus, minimizing torque ripple and additional loss generation. Permanent magnet flux linkage is accurately estimated via reactive power calculations on the fundamental frame which remains undisturbed by the aforementioned test signals. / Under de senaste decennierna har intresset för flerfasmaskiner ökat, på grund av i vissa avseenden, fördelaktiga egenskaper i jämförelse med traditionella trefasmaskiner. En väl genomförd modellering av flerfasmaskiner möjliggör högre grader av frihet givet förmågan att kontrollera frekvensplan av högre ordning. Denna funktion är av särskilt intresse inom parameteruppskattning, då det kan ge möjligheter att implementera metoder som är omöjliga i trefas maskiner. En modell av en verklig sexfasmaskin, byggd för en marin tillämpning och med ett givet styrsystem, har skapats i MATLAB/Simulink. Modellen tar hänsyn till ickelinjära förhållanden, korskopplingar och mättning. Den inkluderar även maskinens egenskaper i det fundamentala frekvensplanet och de två nästkommande frekvensplanen av högre ordning. Statorresistansen och permanentmagneternas sammanlänkade flöden uppskattas i realtid för olika driftsförhållanden. Det visar sig att statorresistansen kan uppskattas noggrant genom inmatning av en DC testsignal i högsta ordningens frekvensplan vilket minimerar momentrippel och extra förluster. Permanentmagneternas flöden kan uppskattas noggrant genom beräkning av den reaktiva effekten i det fundamentala frekvensplanet som är opåverkat av de ovan nämnda testsignalerna.