This work was composed of two main parts. In a first step, a electrochemical cell was developed, which could allow the in-situ, in-operando analysis of the functioning battery. The processes taking place inside a running lithium-sulphur cell were then observed and identified with the help of Raman spectroscopy. In a second step, the performance of the cell was studied while using novel cathode materials, as well as modified commercial separators.

Standardized parts like hydraulic accumulators are used in nearly every hydraulic system, in many cases even several. Therefore, even small changes in size and weight of accumulators can save considerable material costs. In mobile applications, hydraulic accumulators are used among others in hydro-pneumatic suspension systems. There is a strong focus on miniaturization and weight reduction, as the components always have to be transported with the vehicle. Energy density and energy content of conventional hydraulic accumulators cannot be maximized at the same time. This limitation can be overcome by adding a heat capacity with large surface into the gas volume of the accumulator. The heat capacity enlarges the isothermal frequency range and therefore enlarges the energy density of the accumulator at the given frequency and the given size. In this paper an experimental comparison of conventional hydraulic accumulators and accumulators with foam inserts shows, that at a specific frequency band, the stiffness of foam filled accumulators is significantly lower than of conventional accumulators. The energy density is about 11 % higher than in conventional accumulators. Consequently, a space reduction of about 18 % is possible.

Recently in more or all electric vehicles, higher voltage batteries are used which employ large number of cells in series. Series connection among cells may lead to single point of failures, safety and charge equalization issues that demand complex control and costly and/or lossy battery management methods. Most present day high voltage batteries use dissipative-charge balancing methods, which result in poor efficiency, additional thermal management burden and lower overall vehicle range. Furthermore, the output voltages of such batteries remain unregulated and may widely change with load and environmental conditions, complicating the overall power pass design of the electrical power system. As a step forward to address these issues, this thesis studies a fault-tolerant regulated active high voltage electric accumulator with integrated power electronics for safe charge and discharge of the high voltage energy storage system. / Thesis / Master of Applied Science (MASc)

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The energy consumption in the world continues to increase, which makes energy saving measures important. In Sweden, where buildings account for a large part of total energy use, heat exchangers in ventilation are important to reduce energy consumption. However, Sweden's winters are often cold over large parts of the country, causing frost in the heat exchanger and high and uneven heating power requirements for ventilation units. The heating system in the building is required to manage the biggest power demand that may arise. From the ventilation unit, the greatest heating power requirement is arise in the event of frost conditions, as the power requirement from the heating coil increases during defrosting. By installing an accumulator tank together with the ventilation unit, the power requirement can be evened out. Power requirement for three different scenarios where the storage tank is used has been calculated. By using thermodynamic equations and measurements from Swegon counter flow heat exchanger results were accomplished. Optimal defrosting cycle times were evaluated by theory and equations. Other defrosting methods have been calculated to be compared to the solution with the accumulator tank. In a case with 600 litres per seconds supply and exhaust air flow, outdoor temperature at -10 ° C, the power requirement to the unit could be reduced by 67 % using an accumulator tank. An accumulator tank with a volume of 73 litres was required. By using an accumulator tank with the ventilation unit, investment costs could decrease by approximately 18 000 SEK when district heating is used as energy source. However, the solution with the storage tank will not be able to reduce district heating costs more than reduced flow cost for the district heating. If a heat pump I used approximately 95 000 SEK in investment cost could be saved when using an accumulator tank. Electricity cost could also be reduced but not much. Compared to other defrosting methods, the solution with accumulator tank will require the lowest power requirement for the ventilation unit, heat recover  most energy in the heat exchanger and at the same time create an even heat power requirement at frost conditions. / Energianvändningen i världen fortsätter öka vilket gör energisparåtgärder viktiga. I Sverige där byggnader står för en stor del av den totala energianvändningen är värmeväxlare inom ventilation viktiga för att minska energiförbrukningen. Dock är Sveriges vintrar ofta kalla över stora delar av landet vilket orsakar frostproblem i värmeväxlaren och högt och ojämnt värmeeffektbehov till ventilationsaggregat. Byggnadens värmesystem måste dimensioneras efter det största effektbehov som kan uppstå. Från ventilationsaggregatet sker det största värmeeffektbehovet vid frostförhållanden eftersom effektbehovet från värmebatteriet ökar vid avfrostning. Genom att installera en ackumulatortank tillsammans med ventilationsaggregatet skulle effektbehovet kunna jämnas ut. Effektbehov för tre olika scenarion där ackumulatortank används har beräknats. Det skedde genom användande av termodynamiska ekvationer och mätningar från Swegons motströmsvärmeväxlare. Tiden för hur lång avfrostningscykel som är optimal har utvärderas genom teori och ekvationer. Andra avfrostnings metoder har beräknats för att kunna jämföras med lösningen med ackumulatortank. I ett fall med till-och frånluftflöde på 600 l/s och dimensionerande utomhustemperatur på -10 °C kunde effektbehovet fram till aggregatet minskas med 67% genom att använda en ackumulatortank. En ackumulatortank med volymen 73 liter krävdes. Genom att använda en ackumulatortank tillsammans med ventilationsaggregatet kunde investeringskostnaden kunna minskamed cirka 18000 kr när fjärrvärme används som energikälla. Lösningen med ackumulatortank kommer dock inte kunna minska fjärrvärmekostnaden mer än att minska eventuell flödeskostnad för fjärrvärmen. Vid användande av bergvärmepump skulle cirka 95000 kr i investeringskostnad kunna sparas vid användande av ackumulatortank. Eleffektkostnaden kunde även minskas men relativt lite. Jämfört med andra avfrostningsmetoder kommer en lösning med ackumulatortank kräva lägst effektbehov till ventilationsaggregatet, återvinna mest energi i värmeväxlaren och samtidigt skapa ett jämt värmeeffektbehov under frostförhållanden.

Ce projet de thèse porte sur la recherche de nouveaux électrolytes et additifs dans le but d’améliorer la cyclabilité d’une électrode négative composite de formule Si0.32Ni0.14Sn0.17Al0.04C0.35 et d’obtenir une interface électrode|électrolyte stable. En effet, comme la plupart des matériaux à base de silicium, ce composite de grande capacité (plus de 600 mA.h.g-1) souffre actuellement d’une faible durée de vie provenant essentiellement des expansions volumiques qu’il subit lors de sa lithiation et de sa SEI défaillante. Deux types d'électrolytes ont été évalués : (i) un mélange de carbonates d’alkyles EC/PC/3DMC auquel a été ajouté un sel de lithium (LiPF6, LiTFSI, LiFSI ou LiDFOB) ainsi que des additifs aidant à la formation de la SEI tels que le carbonate de vinylène (VC) ou le carbonate de fluoroéthylène (FEC), (ii) des liquides ioniques (LI) contenant un cation ammonium quaternaire (N1114+), imidazolium (EMI+) ou pyrrolidinium (PYR+), associé à un anion à charge délocalisée comme le bis(trifluorométhanesulfonyl)amidure (TFSI-) ou le bis(fluorosulfonyl)amidure (FSI-). L’analyse du diagramme d’ionicité de Walden a permis de mettre en évidence la bonne dissociation de LiFSI et LiPF6 dans EC/PC/3DMC assurant ainsi des conductivités ioniques supérieures à 12 mS.cm-1. Bien que possédant des propriétés de transport a priori moins intéressantes dans ce mélange ternaire que les autres sels, LiDFOB forme en réduction une SEI permettant au composite de fournir les meilleures performances en cyclage sans additif avec 560 mA.h.g-1 pour un rendement coulombique de 98,4%. L’ajout d’additif est cependant nécessaire pour atteindre les objectifs fixés par le projet en termes de rendement coulombique (>99,5%). Dans ce cas, l’ajout de 2%VC+10%FEC au mélange ternaire est le plus intéressant avec LiPF6. Le matériau fourni ainsi des capacités de 550 mA.h.g-1 durant une centaine de cycles à un régime de C/5 avec un rendement coulombique de 99,8%. En milieu LI, les performances optimales sont atteintes avec le [EMI][FSI] et 1 mol.L-1 de LiFSI. Le composite atteint alors une capacité de 635 mA.h.g-1 durant 100 cycles à un régime de C/5 avec un rendement coulombique très proche de 100%, tout en s’affranchissant de l’ajout d’additifs. Malgré une viscosité bien plus élevée que celles des mélanges de carbonates d’alkyles, cette formulation permet de générer une SEI plus stable dont la nature, principalement minérale, est issue majoritairement des produits de réduction de FSI-. / This study focuses on new electrolytes and additives in order to improve the cyclability of a Si0.32Ni0.14Sn0.17Al0.04C0.35 negative composite electrode (Si-Sn) and to obtain a stable electrolyte|electrolyte interface. Indeed, like most silicon-based materials, this high-capacity Si-Sn composite (over 600 mA.hg-1) currently suffers from a short cycle life due to volume expansion during charge-discharge processes leading to the degradation of the SEI. To improve the quality of the interface, two kinds of electrolytes were evaluated: (i) mixtures of alkyl carbonates EC/PC/3DMC in which a lithium salt (LiPF6, LiTFSI, LiFSI or LiDFOB) and additives like SEI builder (vinylene carbonate (VC) or fluoroethylene carbonate (FEC)) were added, (ii) ionic liquids (IL) based on quaternary ammonium (N1114+), imidazolium (EMI+) or pyrrolidinium (PYR+) cation, associated with delocalized charge anions such as bis(trifluoromethanesulfonyl)imide (TFSI-) or bis(fluorosulfonyl)imide (FSI-). The Walden diagram confirms the efficient dissociation of LiFSI and LiPF6 in EC/PC/3DM ensuring ionic conductivities as high as 12 mS.cm-1. Although possessing limited transport properties in such a ternary mixture compared to other salts, LiDFOB forms, without additional additives, an high quality SEI allowing the composite to provide the best performances in half cells (560 mA.hg-1 and 98.4% coulombic efficiency). The use of additive is however necessary to reach the objectives fixed by the ANR research project in terms of coulombic efficiency (>99.5%). In this case, the addition of 2%VC+10%FEC to the ternary mixture is the most interesting composition with LiPF6 as lithium salt. So, the Si-Sn nanocomposite material reaches 550 mA.h.g-1 during 100 cycles at C/5 with 99.8% efficiency. In IL, the best performances are achieved in [EMI][FSI]/LiFSI (1 mol.L-1). The performances of the Si-Sn composite reaches 635 mA.h.g-1 for 100 cycles at C/5 with coulombic efficiency close to 100%, without additives. This electrolyte formulation generates a stable SEI which the mainly mineral composition, is predominantly derived from the reduction products of FSI-.

The objective of this thesis is to develop a model that will integrate multiple buoys to a power take-off hub. The model will be derived using a time domain analysis and will consider the hydraulic coupling of the buoys and the power take-off. The derived model is reproduced in MATLAB in order to run simulations. This will give possibility to conduct a parameter study and evaluate the performance of the system. The buoy simulation model is provided by Wave4Power (W4P). It consists of a floater that is rigidly connected to a fully submerged vertical (acceleration) tube open at both ends. The tube contains a piston whose motion relative to the floater-tube system drives a power take-off mechanism. The power take-off model is provided by Ocean Harvesting Technologies AB (OHT). It comprises a mechanical gearbox and a gravity accumulator. The system is utilized to transform the irregular wave energy into a smooth electrical power output. OHT's simulation model needs to be extended with a hydraulic motor at the input shaft. There are control features in both systems, that need to be connected and synchronized with each other. Another major goal within the thesis is to test different online control techniques. A simple control strategy to optimize power capture is called sea-state tuning and it can be achieved by using a mechanical gearbox with several discrete gear ratios or with a variable displacement pump. The gear ratio of the gear box can be regulated according to a 2D look up table based on the average wave amplitude and frequency over a defined time frame. The OHT power take-off utilizes a control strategy, called spill function, to limit the excess power capture and keep the weight accumulator within a span by disengaging the input shaft from the power take-off. This is to be modified to implement power limitation with regulation of the gear ratio of the gearbox. / +46736290781

The Master´s thesis describes continuous automatic train protection system and its functional properties, principally the transmission of special encoded signal between stationary part and rail vehicle. There is also summarized some important information about the gear rotational speed sensors and its communication with other onboard peripherals. Depends by analysed parameters of electrical signals, the general suggestion of portable electronic device is outlined. Portable electronic device or TESTER will be used to in phase of testing mobile part of automatic train protection system mounted onboard of rail vehicle. Tester will generate equivalent electrical signals to signals in system automatic train protection and the real system response will be possible to evaluate. The generator block allows to model real electrical signals in automatic train protection technology type LS or type EVM and signals rail vehicle odometry.

This diploma thesis entitled Design and realization of a mobile photovoltaic power plant is dividet into two parts. In the first, theoretical part one can learn about the state of representation of renewable energy sources in the field of electrical power engineering and about the structure of photovoltaic power station systems. The secont part of this thesis is focused on the own design and realization of the mobile photovoltaic power plant, on the selection of individual suitable components and ther dimensioning. In addition, a model of a mobile power plant has been created, on the basis of which the power plant was constructed. Finally, one can find a source code analysis of a power plant monitoring using a microcontroler

Rozptýlená výroba elektrické energie využívající obnovitelné zdroje, jako je sluneční energie, přispívá ke snížení emisí skleníkových plynů. Z hlediska provozu distribuční soustavy je také výhodné, aby energie byla primárně spotřebována v místě výroby. To je částečně možné přizpůsobením spotřeby, ale především využitím akumulačních systémů. V této práci je představen hybridní systém složený z fotovoltaické elektrárny, akumulátoru elektrické energie a akumulátoru tepelné energie. Výběr a parametry všech částí hybridního systému jsou popsány v práci. Akumulátor elektrické energie je navržen a sestaven z LiNiMnCoO2 článků a řídícího systému zajišťujícího bezpečný provoz. Řídicí systém akumulátoru (BMS) zajistí odpojení baterie, pokud je překročen některý z provozních parametrů baterie. Návrh baterie i sestavy je popsán v práci. Akumulátor tepelné energie sestává z výkonového spínače a nádrže na teplou vodu s topnou patronou pro odporový ohřev vody. Na základě rešerše komerčně používaných zařízení pro regulaci příkonu byly definovány jejich nedostatky a na základě nich bylo navrženo optimální řešení. Řešení spočívá v použití komerčního polovodičového spínacího prvku. Pro tento výkonový spínací prvek byla vytvořena zpětnovazební řídící smyčka s regulátorem výkonu, který byl implementován v prostředí softwaru LabVIEW. V práci je také uveden postup návrhu chladiče spínacího prvku a LCL filtru, který je klíčový pro splnění požadavků elektromagnetické kompatibility. V druhé části práce je popsán návrh nadřazeného řídícího algoritmu, jehož úkolem je řídit výkonové toky v hybridním systému tak, aby byly splněny požadavky definované jak uživatelem, tak i okamžitým stavem akumulátorů. Algoritmus byl implementován v prostředí LabVIEW. Funkčnost celého systému byla ověřena měřením v laboratorních podmínkách. Z výsledků plyne, že nadřazený řídící algoritmus funguje správně. Řídící smyčka tepelného akumulátoru je stabilní a reguluje zátěž na požadovanou hodnotu. Přidanou hodnotou je kratší reakční doba na změnu toku výkonu oproti hybridnímu měniči a díky tomu dochází k minimalizaci přetoků elektrické energie do distribuční sítě. Na práci je možné navázat rozšířením stávajícího algoritmu o možnost řízení/ovládání více typů akumulačních jednotek a generátorů nebo implementováním odlišných strategií řízení.