At the beginning, the rst operation concern of electricity transmission networks is to ensure the security of power system. These interconnections are also used for the purpose of exchanging electricity from one country to another. They have a central role to achieve the integrated European electricity market by allowing electricity supplier to sell energy to a customer in another EU country. This enables market players to trade electricity depending on opportunities and prices in various bidding areas in Europe. The interconnections contribute therefore to the eectiveness of the European electricity market. The volume of trade is however limited by the physical limitations of the transmission lines, which are determined by the TSOs through cross border capacity calculations and assigned to the actors based on dierent market mechanisms (e.g. capacity allocation). The fast development of renewable energy sources has increased the imbalances between supply and demand. This further increases constraints on transmission lines, including the interconnections between neighboring countries. In order to manage this problematic situation, the modication of the bidding areas conguration is often considered as a solution. Dierent studies developed methods based on nodes aggregation or minimization of re-dispatching costs to dene the price areas. However, the impact of this kind of measure on the overall system is not well studied. This master thesis work presents a general methodology to study the impact of a new bidding zone conguration in the French electrical network from a market point of view. In order to dene a relevant bidding zone conguration in the system, physical ows on the lines are determined and the two ends of binding links are located in two dierent bidding zones. Then, electricity price, social welfare evolution and modication of the ows due to the new generation pattern are presented in order to evaluate and analyze the impact of the new bidding zone conguration on the market. The modelling limits are analyzed in order to evaluate the proposed approach.

Since the modern world is totally dependent on electricity, it is necessary to ensure that electrical power is generated and transmitted to end users with minimum interruptions. Given the importance of electricity for the operation of our society, it is really important to fill continuously good safety conditions. This policy must handle two major areas: reducing the risk of occurrence of a crisis and its management if a very constraining disturbance happens. This master’s thesis is mainly focused on this last point. With the continuous increasing of consumption and the high investment costs, it becomes more complicated to ensure good safety margins, since the network is exploited closer to its limits. A recent study demonstrates that the South-West region of France was prone to voltage collapses after very severe faults and as a result the need of an under-voltage load shedding in this region was evokated. In parallel, to ensure the voltage stability, RTE (Réseau de Transport d’Electricité - Electricity Transmission Network) has invested also in equipments such as capacitors and static reactive power compensators. With newly installation of compensation means on the network, the necessity to develop a new device called SMACC (Système avancé pour le contrôle de lacompensation - Advanced system for the control of the compensation) capable of handling more efficiently the control of these batteries of capacitors has been highlighted. Ultimately the thesis focuses also on the new HVDC (High-voltage direct current) line between France and Spain. This line is a key for long-term voltage stability study, since itincreases the exchange capacity between France and Spain, and has the ability to provide or absorb reactive power to the network.

Power system harmonics are a topic of significant concern when considering power quality issues in systems containing Variable Speed Drives. The extent to which grid-connected power electronics based motor drives affect power quality is tightly enforced through standards, and must be adhered to. To ensure compliance, harmonic models of Variable Speed Drives and relevant components of the connected power system are evaluated. When necessary, analysis results can be used to aid the design of additional harmonic mitigation measures. Harmonic assessments are most commonly carried out using time-domain models. This thesis details the fundamentals of harmonic assessment and mitigation measure design. Matlab implementations of those fundamentals are discussed, with comments regarding the accuracy and limitations of each. State of the art analytical harmonic models for Voltage Source Variable Speed Drives are analyzed and compared, from which a new model for 3-level inverter Variable Speed Drives is proposed. The new model can be implemented in any numerical computing environment and is thought to generate a harmonic current spectrum for an approximate judgement of harmonic compliance based on the current injection method. / Övertoner i kraftsystem innehållande frekvensomriktare är ett viktigt ämne när el-kvalité behandlas. Den grad nätanslutna elektroniska motorsystem påverkar el-kvalitén är noggrant upprätthållen av standarder och måste följas därefter. För att säkerställa att standarder upprätthålls utvärderas modeller för frekvensomriktare och relevanta komponenter. När det anses nödvändigt kan resultaten vara vägledande för design av ytterligare övertonsminskande åtgärder. Utvärdering av övertoner görs i allmänhet med hjälp av modeller i tidsdomän. Denna uppsats går igenom grunderna för bedömning av övertoner och design av övertonsminskande åtgärder. Matlab-modeller av dessa diskuteras i termer av precision och begränsningar. De främsta analytiska modeller for frekvensomriktare undersöks och jämförs, varefter en ny modell av en växelriktare med 3 nivåer föreslås. Denna modell kan med enkelhet implementeras i numeriska datormiljöer och framställer ett frekvensspektrum av strömmen för en approximativ bedömning av el-kvalité baserad på ströminmatningsmetoden.

This thesis addresses the issues of (inter)harmonics propagation on electrical grids. More specifically it concerns two different kinds of studies. The first one is the harmonic impact of the integration of new technologies such as Electric Vehicle charging parks which generate harmonic voltages. The second one is the propagation on these grids of communication signals such as the pricing signal. These two kinds of voltages behave a priori the same way since they are superimposed to the fundamental feeding voltage, with a higher frequency. However, their main structural difference is that, while harmonic voltages generated by electric cars are unwanted on electrical grid, the pricing signal is intended at certain points of the grid. For the first kind of studies, concerning harmonics generated by Electric Vehicles, the aim of this project was to determine the problems that may appear on electrical grids when electric car parks are connected thereto. To do so, laboratory measurements on several Electric Vehicle models, separately or simultaneously, were performed. From their results, different models of EVs have been drawn up enabling to perform simulations on an existing car park. Some measurements were then carried out on this car park in order to conclude on its impact on the Power Quality of the grid. The second study is about the pricing signal propagation. It focuses on different ways of modeling grid components, especially loads, in simulation tools at the specific frequency of this signal. For Medium Voltage grids, several load models can be found in the literature and are compared in this report. For Low Voltage grids, a model based on the results of recent measurements is suggested in the report.

In this work techniques for heating the fusion reactor ITER to thermonuclear temperatures, over 100 million kelvin, is investigated. The temperature is numerically computed for different heating configurations. The heat leakage is modeled to occur only via diffusion. The diffusion is assumed to be a combination of Bohm and gyro-Bohm diffusion. Basic conditions for a fusion reactor has been studied. The power needed for the different heat sources for the plasma to ignite is computed. Plots of the temperature profiles are included in the results together with plots showing the Q-value dependency on the power and the major radius.

SCRAP is a student experiment that aims to validate theories on electron density fluctuations induced by the presence of dust particles connected to the phenomenon of polar mesospheric summer echoes (PMSE). Radar echoes are to be measured from a dust cloud of metallic microparticles released into the mesosphere above northern Sweden using a sounding rocket in spring 2015. This report presents a subproject of selecting the best size, amount and material of the dust particles to be used. A collisionless model describing the charging of and wave backscattering from the dust cloud has been compiled and applied for typical mesospheric conditions. The results indicate that the charging is dominated by photoelectric emission, leading to a positive steady-state charge number between about 10 and 1000 in less than 24 s. The particle characteristics are shown to be measurable by computing the scattering cross-section originating in the propagation of dust acoustic waves. The choice of optimal particle parameters depends on two competitive effects. For large particles of high density and low photoelectric yield, the measured signals will be stronger but also broader in the frequency spectrum. Of the alternatives considered, silver particles of 0.1 <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cmu" />m radius are found to be the best choice.

The aim for this bachelor thesis is to determine the altitude of the auroral acceleration region occuring on the dayside. Substantial work has already been done on this topic, but for occurrence at the nightside. In this paper only negative quasi-static potential structures were considered, as they are the main contributor for producing aurora. The data for this study was obtained by the Cluster satellite constellation, and was processed by scripting in MATLAB in order to find the events for this paper. Namely, 17 passages of the auroral oval, especially occurring within two magnetic local time sectors, symmetrically around noon (12 MLT). The results show that the acceleration region occurs from below 2 RE up to an altitude of 4.5 RE with an average of 3.40 ± 0.84 RE, considerably higher than for the nightside. More specifically, fore and afternoon sectors have altitude averages of 2.44 ± 0.49 RE and 4.00 ± 0.26 RE, respectively. A significant difference between the two sectors. By regarding the pseudo altitude and classifying identified events as either -part of a larger scale coherent structure or - a small scaleauroral arc, a general occurrence pattern and height-dependence of the AAR was discovered. The large-scale arcs occur on average at a higher altitude (3.89 ± 0.22 RE) than the small-scale arcs (2.82 ± 0.80 RE).

In this report the development of a spectrograph for confirming the size of the particles in a particle cloud is described. With the wavelength dependency of Mie-scattering, it can be determined if the particles are of the desired size. There is a significant trade-off effect between size and resolution of an optical system. The spherical aberrations that arise due to the focal length being short compared to the lens diameter are reduced by using lens combinations called achromatic doublets, both as collimating and focusing lenses. The manufactured spectrograph has a resolution of about 10 nm that is approximately as expected from the optical design. But the spectrograph suffers from stray light. This remains to be reduced with aperture stops, non-reflective interior and fore-optics.

This Bachelor Thesis is done within the project SCRAP (SCattering of Radar Waves on Aerosols in Plasmas), which aims to investigate the role of microparticles in the mesosphere. A sounding rocket is to be launched in spring of 2015 containing the experiment. The rocket will eject two free falling units (FFUs) which each subsequently releases a cloud of conductive microparticles into the mesosphere. The particle cloud will interact with the surrounding plasma and can thereafter be observed indirectly by using radar backscattering. In this project two different aspects of the microparticles have been studied. The first one is the way electromagnetic radiation is scattered on them, where known solutions to simplified versions of the problem are adapted in a simple computer program. The second part deals with the particle release mechanism for the FFU. Three different release techniques have been evaluated mainly on the amount of particle agglomeration caused by the releasing. The results show that the method called gunpowder approach has advantages over the others in a number of ways, including the particle dust capacity and the particle separation.

A step towards improving living standards for elderly and patients is to incorporate healthcare systems in the home. Aiming to increase the safety and independence of these groups this paper highlights a few possible approaches. Specifically the focus has been on; fall detection using the Electroencephalography (EEG) sensor Emotiv EPOC, a monitoring and drug administration system, a control system for home appliances based on EEG and sleep improvement with EEG in the smart home. A fall detection study has been performed, determining whether a fall can be differentiated from similar events. The study concludes that EEG sensors might have potential as part of a fall detection system. The remainder of the project is theoretical. It holds potential, however experiments need to be performed for further conclusions.