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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

A Generalized Inverter Control Method for a Variable Speed Wind Power System Under Unbalanced Operting Conditions

Wu, Shuang 04 June 2010 (has links)
No description available.
522

Mixed-Integer Programming Methods for Transportation and Power Generation Problems

Damci Kurt, Pelin 29 September 2014 (has links)
No description available.
523

Design and Assessment of Vertical Axis Wind Turbine Farms

Shaheen, Mohammed Mahmoud Zaki Mohammed 12 October 2015 (has links)
No description available.
524

Landskap i Förändring : Vindkraftsetablering på landsbygd. En studie om hur vindkraftsverk påverkar rekreation och livskvalitet

Kammen, Joakim January 2021 (has links)
This study examines the consequences that the establishment of wind power hasrelated to recreation and quality of life for those who live in close proximity to windpower turbines in rural areas. This paper has focused on studying a small village in arural landscape close to mountain nature in Bergs municipality, Sweden. Wind turbines changes the landscape considerably and are difficult not to notice asthey are visible at both long and close distances. These are becoming an increasinglycommon phenomenon in rural areas and places where high winds are common. They are a good source of renewable energy in many aspects and are considered animportant part of the goal that Sweden's total electricity production shall consist of 100 percent renewable energy by the year 2040. It is important to know how people are affected by nearby wind turbines in aspects ofrecreation and quality of life to contribute to a deeper understanding of which maybe, can lead to better planning. This study is conducted using a qualitative study method where empirical data werecollected based on interviews. Additional data in the form of opinions have beencollected through statements sent to Bergs municipality regarding a plan proposal forwind power establishment in an area close to the village of Skålan. It is presented through the results and the discussion sections of this study that windpower establishment in close connection with inhabited environments in rural areascan have negative effects on recreational opportunities and quality of life.
525

Using Unsupervised Machine Learning for Outlier Detection in Data to Improve Wind Power Production Prediction / Användning av oövervakad maskininlärning för outlier-identifikation i data för att förbättra prediktioner av vindkraftsproduktion

Åkerberg, Ludvig January 2017 (has links)
The expansion of wind power for electrical energy production has increased in recent years and shows no signs of slowing down. This unpredictable source of energy has contributed to destabilization of the electrical grid causing the energy market prices to vary significantly on a daily basis. For energy producers and consumers to make good investments, methods have been developed to make predictions of wind power production. These methods are often based on machine learning were historical weather prognosis and wind power production data is used. However, the data often contain outliers, causing the machine learning methods to create inaccurate predictions. The goal of this Master’s Thesis was to identify and remove these outliers from the data so that the accuracy of machine learning predictions can improve. To do this an outlier detection method using unsupervised clustering has been developed and research has been made on the subject of using machine learning for outlier detection and wind power production prediction. / Vindkraftsproduktion som källa för hållbar elektrisk energi har på senare år ökat och visar inga tecken på att sakta in. Den här oförutsägbara källan till energi har bidragit till att destabilisera elnätet vilket orsakat dagliga kraftiga svängningar i priser på elmarknaden. För att elproducenter och konsumenter ska kunna göra bra investeringar har metoder för att prediktera vindkraftsproduktionen utvecklats. Dessa metoder är ofta baserade på maskininlärning där historiska data från väderleksprognoser och vindkraftsproduktion använts. Denna data kan innehålla så kallade outliers, vilket resulterar i försämrade prediktioner från maskininlärningsmetoderna. Målet med det här examensarbetet var att identifiera och ta bort outliers från data så att prediktionerna från dessa metoder kan förbättras. För att göra det har en metod för outlier-identifikation utveklats baserad på oövervakad maskininlärning och forskning har genomförts på områdena inom maskininlärning för att identifiera outliers samt prediktion för vindkraftsproduktion.
526

A Game-theoretic Framework to Investigate Conditions for Cooperation between Wind Power Producers and Energy Storage Operators

Bhela, Siddharth 05 May 2015 (has links)
Game theory has its applications in various domains, but has only recently been applied to study open problems in smart microgrids. A simple microgrid system with a small wind farm, a storage facility and an aggregate load entity is studied here using a non-cooperative game-theoretic framework. The framework developed is used to study the behavior of rational market participants (players), namely wind power producer and energy storage. The framework is implemented to find the existence of any Nash equilibria and see if cooperation is a natural outcome of the game. If cooperation is not self-enforcing then usefulness of the framework to find the conditions for cooperation is presented. It must be noted that cooperation is not automatically guaranteed as the payoff of the energy storage operator is dependent on the strategy employed by the wind power producer. Similarly, the payoff for the wind power producer is highly intertwined with the strategy employed by the energy storage operator. Historical weather and market data is used to calculate expected payoffs for each possible combination of strategies. The results are presented in the form of payoff matrices and the best response algorithm and/or elimination of dominated strategies is used to find the Nash equilibrium. Sensitivity of the Nash equilibrium to various storage parameters like storage size, charging/discharging limits, charging/discharging efficiency, and other market parameters like energy imbalance penalties, efficiency of up/down regulation, and electricity market prices is studied and necessary conditions for cooperation are presented. / Master of Science
527

Wind Energy Perceptions and Environmentality : A Discourse Analysis of Local Views in Ockelbo

Abrahamsson, Filippa January 2024 (has links)
This paper aims to investigate some of the diverse perceptions of local populations in Sweden regarding wind energy, focusing on the Ockelbo area. Through a critical discourse analytical perspective, the analysis explores the community's attitudes toward their role in wind energy development and analyzes the presence of discursive elements. The study uses mostly interviews and shows that the local community generally supports wind energy. In contrast to many other areas, the Ockelbo area does not seem to have the individual gap of the Nimby attitude, whereby individuals have a positive attitude toward wind energy in general and a negative attitude toward wind energy in their nearby area. Instead, my informants are generally positive toward wind energy both in general and in Ockelbo. Furthermore, I have related my findings to the theory of environmentality, in which the responsibility for the environment is placed on the population rather than the state through knowledge production about the climate. I argue that elements of environmentality are present in the Ockelbo area through a climate IDF (discursive-ideological formation). This climate IDF frames fossil-free energy as a necessary measure against climate change, that the local population should feel responsible for accepting. This perceived responsibility can be attributed to government rationalities of the state. However, my material shows that the local community does not completely accept responsibility for allowing wind energy. Instead, most of my informants seem to discuss how different aspects of wind energy, such as economic compensation for it, conditions their acceptance for wind energy. Therefore, I do not think that the informants – and perhaps the Ockelbo community in general – are fully internalizing the state’s prioritization of wind energy in areas such as that of Ockelbo.
528

Komplexa utmaningar vid vindkraftsetableringar : En undersökning av Gävleborgs län

Asplin, Joel, Norinder, Terese January 2024 (has links)
Den pågående trenden att investera i fossilfri el kan betraktas ur olika perspektiv.Debatten gällande vindkraft är väl känd. Högskolan i Gävle engagerar sig i projektet "Förankrad i med och motvind (FIMM)" tillsammans med organisationen Hela Sverige ska leva. FIMM syftar till att öka kunskapen om lokala vindkraftsetableringar och fungera som stöd för bygder med fokus på lokal delaktighet. Denna rapport syftar till att undersöka hur komplexa utmaningar i form av lokala vindkraftsetableringar bör angripas ur ett lokalt perspektiv i Gävleborgs län. Arbetet angriper frågorna genom systematiska litteraturöversikter, geografisk kartläggning, statistikfördelning, beräkningar samt intervjuer med lokala aktörer.Resultaten påvisar en komplexitet i etableringen med anledning av olika lokala behov. Vidare påvisas att Gävleborg har stor potential att bidra till både regional och nationell energiförsörjning. En av de främsta tekniska utmaningarna har påvisats varaatt utpekade vindkraftsområden inte reflekterar de senaste tekniska framstegen. Inställningen till vindkraft i länet varierar mellan de undersökta aktörerna och kunskapsnivå har inte kunnat påvisas påverka inställningen. Politikerna och företagarna tenderar att vara mer positiva och allmänhetens inställning är mer blandad. Inblandning av allmänheten och förmedling av kunskap ska enligt resultatet ske av opartisk förmedlare, där tidig inblandning i processen påvisats vara avgörande för inställningen till etablering. Även kompensation har setts som positiv för etableringen, förslagsvis ekonomisk men inte nödvändigtvis. Vindkraften anses ha en viktig roll i Gävleborgs framtid och kan ge betydande bidrag av fossilfri energi. Brist på fortsatt utveckling kan ha negativa konsekvenser för lokalt näringsliv och välstånd. Slutsatserna är att ett ökat systemperspektiv och en ökad kunskapsbredd anses vara fördelaktig för samtliga inblandade aktörer i processen om den kommer från pålitlig förmedlare. Vidare föreslås att allmänheten engageras tidigt i processen, gärna redan under planeringsprocessen av mark för kommunen eller dokument för riktlinjer gällande vindkraft. Ytterligare förslag är att vindkraftsområden och riksintressen revideras med avseende av de tekniska framstegen med tätare intervall för att bättre återspegla de aktuella förutsättningarna. Eventuell ekonomisk kompensation föreslås regleras nationellt eller regionalt men bör anpassas efter lokala behov. Vidare föreslås att den kommunala tillstyrkan görs om till en avstyrkan. Slutligen rekommenderas att både scenarier med och utan vindkraftsetablering ska presenteras av opartisk förmedlare ur ett lokalt perspektiv gärna med aktuella empiriska data och goda exempel. / The ongoing trend to invest in fossil-free electricity can be viewed from different perspectives. The debate regarding wind power is well known. The University of Gävle is involved in the project “Förankrad i med och motvind (FIMM)” together with the organization “Hela Sverige ska leva”. FIMM aims to increase knowledge about local wind power establishments and act as support for the community with a focus on local participation. This report aims to investigate how complex challenges in the form of local wind power establishments should be addressed from a local perspective in Gävleborg County. The work addresses the issues through systematic literature reviews, geographical mapping, statistical distribution, calculations and interviews with local actors. The results show a complexity in the establishment due to different local needs. Furthermore, it is shown that Gävleborg has great potential to contribute to both regional and national energy supply. One of the main technical challenges has been shown to be that designated wind power areas do not reflect the latest technological advances. The attitude towards wind power in the county varies between the investigated actors and the level of knowledge has not been shown to affect the attitude. Politicians and business owners tend to be more positive and public attitudes are more mixed. Involvement of the public and dissemination of knowledge should, according to the results, be done by impartial intermediaries, where early involvement in the process has been shown to be decisive for the attitude towards establishment. Compensation has also been seen as positive for establishment, preferably financial but not necessarily. Wind power is considered to have an important role in the future of Gävleborg and can make a significant contribution to fossil-free energy. Lack of further development can have negative consequences for local business and prosperity. The conclusions are that an increased systemic perspective and breadth of knowledge will be beneficial for all actors involved in the process if it comes from a reliable intermediary. Furthermore, it is suggested that the public be involved early in the process, preferably already during the planning process of land for the municipality or documents for guidelines regarding wind power. A further suggestion is that wind energy areas and national interests are revised with regard to technical progress at more frequent intervals to better reflect the current conditions. Any financial compensation is proposed to be regulated nationally or regionally but should be adapted to local needs. Furthermore, it is proposed that the municipal endorsement be changed to a rejection. Finally, it is recommended that both scenarios with and without wind power establishment should be presented by impartial intermediaries from a local perspective, preferably with current empirical data and good examples.
529

Grön kolonialism i vindkraftverksfrågan i Sápmi : - en policyanalys av nationella strategin för en hållbar vindkraftsutbyggnad / Green colonialism in the wind power issue in Sápmi : – A policy analysis of the national strategy forsustainable wind power development

Larsson, Frida January 2024 (has links)
The green transition does not only bring positive effects, but it can also have a negative impact on groups that are in vital need of a reverse of the climate crisis to the extent that they actively oppose a sustainable initiative. This is the case in the land-use conflict between the Sámi and the wind power industry. The purpose of this study is to critically analyze the representation of indigenous perspectives in the policy document "National Strategy for Sustainable Wind Power Expansion" to investigate how the climate crisis reinforces colonial effects on the Sámi people. To achieve this, Carol Bacchi's critical discourse analysis "What’s the Problem Represented to Be?" (WPR) has been adapted in combination with the concept of green colonialism to implement a critical review of indigenous representation in the government-produced "National Strategy for Sustainable Wind Power Expansion." Conflicting land-use interests constitute an identified problem, which is intended to be resolved through coexistence—a complex issue to address for many reasons. Sámi influence is presented as both a priority and a problem in the"National Strategy for Sustainable Wind Power Expansion." This representation can be explained by colonial structures that underpin the formulation of this representation, thereby contributing to the further reproduction of colonial power structures.
530

The regulation of Section 17 (2a) of the German Energy Economy Act against the background of current developments of the German and European offshore wind industry

Fischer, Felix Friedrich 12 1900 (has links)
Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: With the introduction of Section 17 of the EnWG (German Energy Economy Act), the legislator created a new situation for the complex relationships in the German offshore wind industry. The transmission system operators are now obliged not only to provide the connection for offshore wind farms, but also to reimburse the developers of such plants for the costs they incurred in the course of planning the cable connection between the wind farm and the onshore grid. Forecasts had predicted that by 2007 numerous offshore wind farms would be operational. But no development company in the entire sector had moved beyond the planning phase. However, the rapid development of the offshore wind industry is important in order to achieve the German goal to generate 20% of all energy from renewable energy sources by 2020 and thus contribute to the prevention of grave climate changes. It is also important for the domestic labour market and the initiation of further exports of energy technologies. Early domestic growth will eventually payoff as offshore wind energy is implemented by more countries, which will then rely on the experience of German companies. Under these circumstances, Section 17 (2a) S.3 of the EnWG induces a positive impulse for offshore development. Under the financial constraints that dampened the expectations of developers of offshore wind farms, the suggested reimbursement will offer welcome relief. However a broad interpretation of Section 17 (2a) S.3 of the EnWG must be applied in order to reach the goal of actually enhancing offshore development, as is the legislator's intent. Such a broad interpretation of the reimbursement claim will lead to rapid implementation of the new law, as this will be in the interest of the developers and transmission system operators. The developers will have a large interest in beginning with the actual construction of the wind farm, and the transmission system operators will need to proceed with the planning of the cable connection. Even though improvements remain necessary the introduction of Section 17 (2a) S.3 EnWG can be considered a success. / AFRIKAANSE OPSOMMING: Met die inwerkingstelling van afdeling 17 van die EnGW (Duitse Energie Ekonomie Wet), het die regering 'n nuwe situasie geskep vir die komplekse verhouding in die Duitse see-gebonde wind-energie industrie. Die transmissie stelsel operateurs word nou verplig om nie net die verbinding met die wind-plaas te verskaf nie, maar moet ook die ontwikkelaar van die aanleg vergoed vir enige kostes wat hulle aangegaan het met die beplanning van die verbinding tussen die windplaas en die elektrisiteits-netwerk. Vooruitskattings het voorspel dat verskeie see-gebonde windplase operasioneel sou wees teen 2007. Geen ontwikkelingsmaatskappy het egter al tot dusver verder as die beplanningstadium gevorder nie. Desnieteenstaande, die spoedige ontwikkeling van die see-gebonde wind industrie is onontbeerlik in die Duitse mikpunt om 20% van energiebehoeftes op te wek vanuit hernubare bronne teen 2020 en om dus klimaatsverandering teen te werk. Dit is ook belangrik vir werkskepping in Duitsland en vir die uitvoer van energie tegnologie. Spoedige groei in die industrie sal uiteindelik dividende lewer soos seegebonde wind-energie deur ander lande ontwikkel word en gevolglik op Duitse ervaring moet staatmaak. Onder hierdie omstandighede het afdeling 17 (2a) 5.3 van die EnGW 'n positiewe effek op seegebonde ontwikkeling. As gevolg van die dempende effek wat finansiele beperkinge het op die verwagtinge van ontwikkelaars sal die terugbetalings welkome verligting bied. Dit is egter nodig om 'n bree interpretasie van afdeling 17 (2a) 5.3 van die EnGW te gebruik om die mikpunt van werklike bevordering van seegebonde ontwikkeling te bewerkstellig soos die wetgewer beoog. So 'n bree interpretasie sal lei tot spoedige implimentasie van die nuwe wet omdat dit in die belang van ontwikkelaars en transmissie-netwerk eienaars sal wees. Die ontwikkelaars sal baat daarby om spoedig met ontwikkeling te begin, terwyl die netwerk operateurs vordering sal moet maak met die beplanning van die kabel-verbinding. Ten spyte daarvan dat verdere verbeteringe nodig is kan die inwerkingstelling van afdeling 17 (2a) 5.3 van die EnGW as 'n sukses gereken word.

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