Målet med den här undersökningen har varit att se om fastigheten Orkestern 1 går att koppla off-grid och om det är ekonomiskt försvarbart eller om en on-grid lösning är bättre. Förutsättningarna är goda med ett stort tak med plats för solpaneler i öst-västlig riktning och en årsmedelvind på 4 m/s. Då huset är nybyggt och välisolerat är även energiförbrukning låg. För att kunna beräkna hur mycket energi som ska produceras i form av värme och el med hjälp av solceller, vindkraftverk, pelletskamin och dieselverk upprättas en energibalans och energifördelning med hjälp av transmission och ventilationsberäkningar. Lagring av energi görs i form av pellets, batteri och biodiesel. Simuleringsprogrammet för solceller Polysun används för att beräkna produktion av solel över varje månad på året. Diagram upprättas över året indelat i månader där det framgår hur stort energibehovet är och visar hur stor del varje energiproducent har varje månad. En pay-off kalkyl görs för att se om det är ekonomiskt lönsamt och för att kunna jämföra mellan två olika off-grid system. Pay-off kalkylen används också för att jämföra mellan off-grid och on-grid system. Resultatet landar i att on-grid systemet är ekonomiskt hållbart medan off-grid systemet inte är det men är ändå fullt genomförbart. / The main target of this examination has been to see if the real estate Orkestern 1 has the possibility to go off-grid and if it is economical defendable or if on-grid solution is a better way to go. The prerequisites are good with a large roof to place solar panels to the east and west, a yearly average windspeed at 4 m/s and a low energy consumption because the house is new built and well insulated. To calculate how much energy that must be produced in form of heat and electricity with solar cells, windmills, pellet stove and diesel generator an energy balance and an energy distribution will be prepared with help of calculations of transmission and ventilation loses. Storage of energy will be done in form of pellets, battery and biodiesel. The simulation program for solar panels Polysun is used to calculate the produced solar energy for each month on the year. Diagram is prepared for each month to see the need of energy and how much every energy producer is delivering. A straight pay-off calculation is done to see if there are any economic benefits and to compare between off-grid and on-grid systems. The result will be that on-grid system is better economical but still the off-grid system is doable.

During the recent prolonged drought in La Guajira, Colombia, the child mortality rate surged to 23.4 per 1000. With the focal point in rural Alta Guajira, a lack of rainfall and wind resulted in an acute potable water scarcity. This paper presents data gathered from interviews conducted with members of the Wayúu indigenous group residing in Alta Guajira and the results surveying in field the solutions already present to the water scarcity. Four potential technological solutions were then devised and evaluated in this context: wind-driven wells, solar-driven wells, solar stills, and reverse osmosis desalination systems. This study shows that reverse osmosis desalination systems are economically unfeasible due to their high initial investment. Solar stills are concluded to be potentially viable for drought emergencies but prohibitively expensive due to their low productivity and area requirements. Solar-driven wells frequently break in the region, likely due to inadequate insulation in underground electrical components, but they represent a crucial yet non-existent complement for water production. Wind-driven wells are the most prominent water source, although relying solely on these creates significant risks. Hence a suggestion for mainly wind-driven production, complemented with solar-driven production, and backed by emergency systems of manual wells and solar stills is suggested.

Among the renewable energies, wind energy presents the highest growth in installed capacity and penetration in modern power systems. This is why reliability of wind turbines becomes an important topic in research and industry. To this end, condition monitoring (or health monitoring) systems are needed for wind turbines. The core of any condition monitoring system (CMS) are fault diagnosis algorithms whose task is to provide early warnings upon the occurrence of incipient (small magnitude) faults. Thanks to the use of CMS we can avoid premature breakdowns and reduce significatively maintenance costs.<p><p>The present thesis deals with fault diagnosis in sensors of a doubly-fed induction generator (DFIG) for wind turbine (WT) applications. In particular we are interested in performing fault detection and isolation (FDI) of incipient faults affecting the measurements of the three-phase signals (currents and voltages) in a controlled DFIG. Although different authors have dealt with FDI for sensors in induction machines and in DFIGs, most of them rely on the machine model with<p>constant parameters. However, the parameter uncertainties due to changes in the operating conditions will produce degradation in the performance of such FDI systems.<p><p>In this work we propose a systematic methodology for the design of sensor FDI systems with the following characteristics: i) capable of detecting and isolating incipient additive (bias, drifts) and multiplicative (changes in the sensor<p>gain) faults, ii) robust against changes in the references/disturbances affecting the controlled DFIG as well as modelling/parametric uncertainties, iii) residual generation system based on a multi-observer strategy to enhance the isolation process, iv) decision system based on statistical-change detection algorithms to treat the entire residual and perform fault detection and isolation at once.<p><p>Three novel sensor FDI approaches are proposed. The first is a signal-based approach, that uses the model of the balanced three-phase signals (currents or voltages) for residual generation purposes. The second is a model-based approach<p>that accounts for variation in the parameters. Finally, a third approach that combines the benefits of both the signal- and the model-based approaches is proposed. The designed sensor FDI systems have been validated using measured voltages, as well as simulated data from a controlled DFIG and a speed-controlled induction<p>motor. <p><p>In addition, in this work we propose a discrete-time multiple input multiple output (MIMO) regulator for each power converter, namely for the rotor side converter (RSC) and for the grid side converter (GSC). In particular, for RSC<p>control, we propose a modified feedback linearization technique to obtain a linear time invariant (LTI) model dynamics for the compensated DFIG. The novelty of this approach is that the compensation does not depend on highly uncertain parameters such as the rotor resistance. For GSC control, a LTI model dynamics<p>is derived using the ideas behind feedback linearization. The obtained LTI model dynamics are used to design Linear Quadratic Gaussian (LQG) regulators. A single design is needed for all the possible operating conditions. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

L’une des principales exigences d’utilisation d’un adhésif est son aptitude à conserver sa capacité à supporter des efforts, appliqués de manière répétée, tout au long de sa vie en service. Toutefois, on dénombre peu d’études sur le comportement en fatigue des assemblages collés. De plus, ces études concernent majoritairement la propagation de fissures et non l'amorçage. Le comportement en fatigue d’assemblages collés est généralement caractérisé grâce à des essais simple-recouvrement auxquels sont associés des états de contrainte complexes présentant de fortes concentrations de contrainte. Le but de ce travail est de développer un outil prédictif du comportement cyclique d’un adhésif dans un assemblage soumis à un chargement de fatigue, en utilisant des essais basés sur l’utilisation d’un montage Arcan modifié. Ce type de montage utilise des éprouvettes générant un état de contrainte avec peu d’effets de bord et un maximum au centre du joint de colle. Une base expérimentale constituée d'essais monotones, cycliques et de fluage pour différents modes de chargement sont présentés. Les résultats expérimentaux concernant un adhésif bi-composant polyuréthane SikaForce®-7817 L60MR permettent de caractériser un comportement reproductible. Ces résultats soulignent une évolution non-linéaire des déformations et fortement dépendante du type de chargement. Ce comportement peut être décrit par l’utilisation d’un modèle visco-élastique-visco-plastique. Implanté dans un code de calcul par éléments finis, ce modèle a permis d’analyser l’influence des phénomènes visqueux. Afin de limiter les temps d'essais, une identification inverse des paramètres a été menée à partir d'une campagne d'essais Arcan en fluage/recouvrement. Les simulations par éléments finis ont permis de décrire le comportement cyclique de structures collées et en utilisant un critère de rupture pertinent, d'effectuer un calcul de durée de vie à l'amorçage d'une fissure. Ce travail a été appliqué à l’étude du comportement en fatigue d'assemblages collés pour applications éoliennes offshores. Aussi, à partir de la stratégie développée, des estimations de la durée de vie de structures composites collés ainsi que d’un cas d’application représentatif ont été réalisées. / Estimating capacities of adhesives to endure repetitive loadings is an essential point to perform fatigue assessments. Nevertheless, few studies have been performed on the cyclic behaviour of adhesively bonded structures. Moreover, fatigue crack initiation is less studied for adhesives than the fatigue crack propagation. Fatigue behaviour is mainly analysed using lap-shear type specimens, which are associated with complex stress states and stress concentrations. The aim of this work is to develop a predictive tool describing the cyclic behaviour of an adhesive in an assembly under fatigue loading using an experimental approach based on modified Arcan tests. Such a device is associated with low edge effects and a maximum stress state in the centre of the adhesive. Accurate experimental results under monotonic, creep and cyclic loading are presented for several load amplitudes, mean loads and loading rates. For a two-component polyurethane SikaForce®-7817 L60 MR adhesive, experimental results led to reproducible behaviour. These results underline that the evolutions of the non linear strains strongly depend on the loading type. This behaviour is well described using a visco-elastic-visco-plastic model with non-linear viscous parameters. This model, implemented in 3D finite element simulations, allows analysing the influence of viscosity. In order to limit the experimental test time the inverse identification of the model parameters is performed from modified Arcan creep-relaxation tests. The finite element simulations of bonded structures allowing an efficient description of the cyclic behaviour and using an adequate failure criterion based on the viscous strains evolutions, a validation on fatigue life predictions is performed. This work is dedicated to the study of fatigue of bonded structures in offshore windmills applications. From this strategy a fatigue life estimation of composite structures tests and on an application test is proposed.