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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.
1

Exploring Opportunities for Novel Electricity Trading Strategies within a Virtual Power Plant in the European Power Market : New Possibilities in Power Trading Due to the Increased Share of Variable Renewable Energy

Ogden, Lillie January 2020 (has links)
This report explores the impacts of variable renewable energy (VRE) on power trading in the European wholesale electricity market. The intricate operation of a typical power exchange in Europe is accompanied by an equally complex balancing system. The increasing amount of VRE in the power system, such as wind and solar power, has far-reaching impacts for power traders in both this electricity market and the corresponding balancing system. As a result, the electricity market is evolving in unprecedented ways and new participants are entering the playing field to capitalize on the changing dynamics caused by VRE generators. One novel participant, the virtual power plant (VPP), possesses an advantage over other market participants by aggregating VRE generators with controllable renewable energy generators, like biogas and hydro plants, into one entity. This allows the VPP to both gain access to live VRE production data that larger plants don’t have, which it then utilizes to remotely dispatch various subpools of assets, and to provide balancing services to the grid. Subsequently, VPPs are able to trade VRE and other renewable electricity superiorly on the same spot markets and balancing systems as large central power plants and industrial consumers. The report asserts that VPP traders can earn profits through means of innovative trading strategies that exploit predictable market impacts caused by VRE power through a robust understanding of the electricity market and their unique access to data. / Denna rapport undersöker effekterna av variabel förnybar energi (VRE) på krafthandeln på den europeiska elhandelsmarknaden för stora aktörer. Den komplicerade driften av ett typiskt kraftutbyte i Europa åtföljs av ett lika komplicerat balanseringssystem. Den ökande mängden VRE i kraftsystemet, såsom vind- och solkraft, har långtgående effekter för krafthandlare på både denna elmarknad och motsvarande balanseringssystem. Som ett resultat utvecklas elmarknaden på enastående sätt och nya deltagare kommer in på spelplanen för att dra nytta av den förändrade dynamiken som orsakas av VRE-generatorer. En ny spelare, det virtuella kraftverket (VPP), har en fördel jämfört med andra marknadsaktörer genom att samla VRE-generatorer med styrbara förnybara energiproducenter, som biogas och vattenkraftverk, till en enhet. Detta gör att VPP både kan få tillgång till live VRE-produktionsdata som större anläggningar inte har, som den sedan använder för att distribuera olika underpooler av tillgångar och för att tillhandahålla balanstjänster till nätet. Därefter kan VPP: er handla med VRE och annan förnybar el på ett överlägset sätt på samma spotmarknader och balanseringssystem som stora centrala kraftverk och industrikonsumenter. Rapporten visar att VPP-handlare kan göra vinster genom innovativa handelsstrategier som utnyttjar förutsägbara marknadseffekter orsakade av VRE-kraft genom en detaljerad förståelse för elmarknaden och unik tillgång till data för produktionen av förnybar energi / <p>QC 20201118</p>
2

Polymer-based conductive fibers

Karlsson, Fredrik, Söderlöv, Erik January 2016 (has links)
Conductive polymers, since from their discovery, have become a prominent area of research and found many useful applications in all fields of our daily life. Examples are light emitting diodes, heat generation, chemical sensors and electro-active membranes. Polymer coated textile substrates give flexible and lightweight materials. One well utilized and thoroughly explored conductive polymer is poly(3,4-ethylenedioxythiophene) also known as PEDOT. Although there are different ways to produce PEDOT one of the most common is the VPP technique. The typical procedure when using VPP is to introduce the monomer vapor to an oxidant coated substrate so that it polymerizes on the surface of the substrate. Throughout this study, the VPP technique has been used to produce PEDOT on different textile fibers. Aim was first of all optimizing the process gaining low electric resistance, i. e. high conductivity, of produced coated fibers but also multilayer coatings of fibers. Outcome indicates some parameters not having a clear influence over the results while others had a more distinct impact. A noteworthy result was obtained by coating a substrate, namely lyocell fiber, multiple times with layers deposited directly on each other. This decreased the resistance from 5.1 (± 1.6) kΩ/10 cm to 1.0 (± 0.1) kΩ/10 cm, for one layer and multiple layers respectively. Adding 15 wt. % of the copolymer PEG-PPG-PEG to the oxidant solution decreased the resistance from 6.8 (± 1.2) kΩ/10 cm to 3.9 (± 0.8) kΩ/10 cm. Final conclusion is that among the ways, to improve conductivity for PEDOT coated fibers, applied in this study are best results obtained by multi-layer coating.
3

Women Empowerment in Bangladesh : A Study of the Village Pay Phone Program

Hultberg, Linda January 2008 (has links)
<p>The purpose with this study is to find out how the mobile phone and the Village Pay Phone from Grameen Telecom have been implemented into women’s life in rural Bangladesh. It also aims to study how the women have become empowered by this program. The sample constitutes sixteen female owners. A purposeful cluster sampling was used to depict six villages from various parts of Bangladesh. When arriving in the villages a snowball sampling method was used to find female VPP owners. The sampling method was chosen to include a sample of various characteristics. The study has a hermeneutic phenomenological approach, which aims to find out how the women experience the VPP and what meaning the women put in it. To collect empirical data interviews with open questions were used that opened up for conversation and the possibility to understand a range of experiences and nuances of meanings. The findings indicate that the majority of the women handed over the VPP to their husband or a male relative. The reason why is the families’ pressure on them to adjust to Purdah and seclusion, too much domestic work, lack of education, or because of the attitude among men and women both that business is a male domain. The study shows that women mostly gained some prestige. Also, they got a greater self-esteem to meet strangers since the VPP made them meet more people. But it has also brought quarrels and broken some friendships. All women are now more able to call family and relatives when they needed or wanted to and said that they have full access to use the mobile phone for this purpose. Still many are put in a dependency relation to others as they need help to use it. The women, however, are no longer owners of a status symbol because the mobile phone is more available for others today, but they are still known by name. Their homes do no longer attract visitors as it once did during the initiation of the program. There has also been a significant decrease in demand for the VPP that has lessened the income much and some have become even poorer from the VPP and women seldom benefitted personally from the profit. A few of the women mentioned that the family atmosphere had improved but most of them did not say that they had gained influence in the family as a result of the VPP.</p>
4

Women Empowerment in Bangladesh : A Study of the Village Pay Phone Program

Hultberg, Linda January 2008 (has links)
The purpose with this study is to find out how the mobile phone and the Village Pay Phone from Grameen Telecom have been implemented into women’s life in rural Bangladesh. It also aims to study how the women have become empowered by this program. The sample constitutes sixteen female owners. A purposeful cluster sampling was used to depict six villages from various parts of Bangladesh. When arriving in the villages a snowball sampling method was used to find female VPP owners. The sampling method was chosen to include a sample of various characteristics. The study has a hermeneutic phenomenological approach, which aims to find out how the women experience the VPP and what meaning the women put in it. To collect empirical data interviews with open questions were used that opened up for conversation and the possibility to understand a range of experiences and nuances of meanings. The findings indicate that the majority of the women handed over the VPP to their husband or a male relative. The reason why is the families’ pressure on them to adjust to Purdah and seclusion, too much domestic work, lack of education, or because of the attitude among men and women both that business is a male domain. The study shows that women mostly gained some prestige. Also, they got a greater self-esteem to meet strangers since the VPP made them meet more people. But it has also brought quarrels and broken some friendships. All women are now more able to call family and relatives when they needed or wanted to and said that they have full access to use the mobile phone for this purpose. Still many are put in a dependency relation to others as they need help to use it. The women, however, are no longer owners of a status symbol because the mobile phone is more available for others today, but they are still known by name. Their homes do no longer attract visitors as it once did during the initiation of the program. There has also been a significant decrease in demand for the VPP that has lessened the income much and some have become even poorer from the VPP and women seldom benefitted personally from the profit. A few of the women mentioned that the family atmosphere had improved but most of them did not say that they had gained influence in the family as a result of the VPP.
5

Mechanism Design for Virtual Power Plant with Independent Distributed Generators

Kulmukhanova, Alfiya 07 1900 (has links)
We discuss a model of a virtual power plant (VPP) that provides market access to privately-owned distributed generations (DGs). The VPP serves passive loads, processes bids from generators, and trades in the wholesale market. The generators can be renewable or thermal, and they act strategically to maximize their own profit. The VPP establishes the rules of the internal market to minimize the cost of energy and the cost of balancing while ensuring generator participation and load balancing. We derive a heuristic mechanism for internal market and propose a dynamic programming approach for minimizing the VPP cost. We present illustrative simulations for both single and multistage market bidding and then compare the resulting performance to the centralized VPP model, where the DGs are assumed to be owned by the VPP. We show that the proposed design incentivizes the DG agents to behave the same as in the centralized case, but the optimal cost paid by VPP is higher due to the payments to the DG owners.
6

Optimization of community based virtual power plant with embedded storage and renewable generation

Okpako, O., Adamu, P.I., Rajamani, Haile S., Pillai, Prashant January 2016 (has links)
No / The current global challenge of climate change has made renewable energy usage very important. There is an ongoing drive for the deployment of renewable energy resource at the domestic level through feed-in tariff, etc. However the intermittent nature of renewable energy has made storage a key priority. In this work, a community having a solar farm with energy storage embedded in the house of the energy consumers is considered. Consumers within the community are aggregated in to a local virtual power plant. Genetic algorithm was used to develop an optimized energy transaction for the virtual power plant. The results shows that it is feasible to have a virtual power plant setup in a local community that involve the use of renewable generation and embedded storage. The result also show that when maximization of battery state of charge is considered as part of an optimization problem in a day ahead market, certain trade-off would have to be made on the profit of the virtual power plant, the incentive of the prosumer, as well as the provision of peak service to the grid.
7

Evaluation of community virtual power plant under various pricing schemes

Okpako, O., Rajamani, Haile S., Pillai, Prashant, Anuebunwa, U.R., Swarup, K.S. 13 October 2016 (has links)
Yes / Technological advancement on the electricity grid has focused on maximizing its use. This has led to the introduction of energy storage. Energy storage could be used to provide both peak and off-peak services to the grid. Recent work on the use of small units of energy storage like battery has proposed the vehicle to grid system. It is propose in this work to have energy storage device embedded inside the house of the energy consumer. In such a system, consumers with battery energy storage can be aggregated in to a community virtual power plant. In this paper, an optimized energy resource allocation algorithm is presented for a virtual power plant using genetic algorithm. The results show that it is critical to have a pricing scheme that help achieve goals for grid, virtual power plant, and consumers. / Mr. Oghenovo Okpako is grateful to the Niger Delta Development Commission of Nigeria for funding the work. The work has been also supported by the British Council and the UK Department of Business innovations and Skills under the GII funding of the SITARA project.
8

Investigation of an optimized energy resource allocation algorithm for a community based virtual power plant

Okpako, O., Rajamani, Haile S., Pillai, Prashant, Anuebunwa, U.R., Swarup, K.S. 01 September 2016 (has links)
Yes / Recently, significant advances in renewable energy generation have made it possible to consider consumers as prosumers. However, with increase in embedded generation, storage of electrical energy in batteries, flywheels and supercapacitors has become important so as to better utilize the existing grid by helping smooth the peaks and troughs of renewable electricity generation, and also of demand. This has led to the possibility of controlling the times when stored energy from these storage units is fed back to the grid. In this paper we look at how energy resource sharing is achieved if these storage units are part of a virtual power plant. In a virtual power plant, these storage units become energy resources that need to be optimally scheduled over time so as to benefit both prosumer and the grid supplier. In this paper, a smart energy resources allocation algorithm is presented for a virtual power plants using genetic algorithms. It is also proposed that the cause of battery depreciation be accounted for in the allocation of discharge rates. The algorithm was tested under various pricing scenarios, depreciation cost, as well as constraint. The results are presented and discussed. Conclusions were drawn, and suggestion for further work was made. / Mr. Oghenovo Okpako is grateful for the support of the Niger Delta Development Commission of Nigeria for supporting the work. The work has been also supported by the British Council and the UK Department of Business innovations and Skills under the GII funding of the SITARA project.
9

Aplicación de fragmentador de roca, Plasma FRAG BE, en sectores productivos de la Compañía Minera Cerro de Pasco cercanas a zonas urbanas para reducir impactos generados durante la fragmentación del macizo rocoso

Cueva Rojas, Alexander, Huaynate Ríos, Andree William 20 December 2020 (has links)
La presente investigación se desarrolló en Compañía Minera Cerro de Pasco (CMCP) donde se busca aplicar el uso del Plasma como agente de fragmentación de macizo rocoso en sectores productivos de la mina cercanas a zonas de expansión urbanas. La finalidad del estudio consiste en comparar los valores de Velocidad Pico Partícula (VPP) entre el uso de Plasma Frag Be vs el ANFO a una distancia promedio igual en ambos casos. En tal sentido, se construye el modelo matemático Imperialist Competitive Algorithm (ICA) – linear, el cual permite estimar valores de VPP y a su vez modificar las variables de entrada como el burden, el espaciamiento, la longitud de taco, el factor de carga, la cantidad máxima de Plasma por disparo y la distancia entre el punto de fragmentación y la ubicación del sismógrafo. El modelo ICA-linear queda validado mediante la aplicación de 4 indicadores de rendimiento estadísticos los cuales son: el coeficiente de determinación, el error cuadrático medio, el error absoluto medio y el error porcentual absoluto medio cuyos resultados son 0.817, 5.001, 1.979 y 14% respectivamente. Los resultados de comparar los valores de VPP a una distancia promedio de 172 metros como se determinó según el estudio, en el caso del Plasma Frag Be los valores estimados son nulos, es decir no se registrarán valores a dicha distancia, mientras que en el caso del ANFO los registros muestran un valor promedio de 8.802 mm/s para la misma distancia mencionada, lo cual demuestra que los valores de VPP en el caso del uso del Plasma como fragmentador de macizo rocoso son considerablemente menores que cuando se utiliza ANFO. / The present research was developed at Compañía Minera Cerro de Pasco (CMCP) where the aim is to apply the use of Plasma as a rock fragmentation agent in productive sectors of the mine close to urban expansion areas. The purpose of the study is to compare the values of Peak Particle Velocity (PPV) between the use of Plasma Frag Be vs ANFO at an equal average distance in both cases. In this sense, the Imperialist Competitive Algorithm (ICA) - linear mathematical model is built, which allows estimating PPV values and in turn modifying the input variables such as the burden, spacing, stemming, power factor, maximum charge of Plasma per delay and the distance from the blast-point to the seismograph. The ICA-linear model is validated by applying 4 statistical performance indicators which are: the determination coefficient, the mean square error, the mean absolute error and the mean absolute percentage error whose results are 0.817, 5.001, 1.979 and 14% respectively. The results of comparing the PPV values at an average distance of 172 meters as determined by the study, in the case of Frag Be Plasma the estimated values are zero, that is, no values will be recorded at that distance, while in the case of ANFO the records show an average value of 8,802 mm/s for the same distance mentioned, which shows that the PPV values in the case of the use of Plasma as a rock mass fragmentation device are considerably lower than when ANFO is used. / Tesis
10

Förbättringsförslag av VPP : ett verktyg för planering och kommunikation mellan platsledning och yrkesarbetare / A proposal of improvement of VPP : a tool for planing and communication in construction sites

Sjöström, Ebba, Winström, Anton January 2018 (has links)
Syfte: Visuella verktyg kan hjälpa till att minska de mänskliga fel som sker på arbetsplatsen samt skapa en kortare informationstid. Informationen erhålls betydligt snabbare och mer korrekt genom att visualisera informationskanalen där foton, scheman, posters, grafiska bilder och färgkodning är fungerande visuella verktyg. Byggföretagen har, för att effektivisera sina arbetsplatser, tagit fram visuella verktyg, bland annat Visuell Planering Produktion (VPP). Målet med detta examensarbete är att undersöka hur planering och kommunikation mellan platsledning och yrkesarbetare ute i produktionen kan förbättras med stöttning av VPP. För att få svar på det har tre frågeställningar tagits fram:1. Vad är det huvudsakliga syftet med användning av VPP?2. Hur fungerar den dagliga planeringen och kommunikationen idag?3. Hur kan VPP förbättras för att bli ett mer användbart verktyg att tillämpa för platsledningen i produktionen?Metod: Tre metoder är valda för att kunna svara på de tre frågeställningarna. Kvalitativa intervjuer med platschef, arbetsledare och lagbas, dokumentanalys och observationer i samband med intervjuer.Resultat: Planeringen och kommunikation mellan platsledning och yrkesarbetare kan förbättras med hjälp av VPP, dock endast om platsledningen får den utbildning de behöver för att använda verktyget på rätt sätt. Det är även viktigt att platsledningen får anpassa verktyget efter sina behov.Konsekvenser: Verktyget med sina tavlor och möten har i dagsläget förbättringspotential, tre brister med verktyget är: Det saknas information och utbildning till platsledningen på arbetsplatserna Det nya arbetssättet ses inte som mer positivt än det nuvarande Nuvarande utformning på bodarna innefattar platsbristFör att verktyget ska bli bättre finns det vissa punkter som är extra tydliga i resultatet där empirin och analysen ligger till grund för förbättringsförslaget. Förbättringen bör innehålla: Mer ingående utbildningar till platsledningen och mer lättillgänglig information En grundlig förklaring till verktygets användning och dess fördelar Varje projekt ska kunna anpassa VPP för det aktuella projektetBegränsningar: Det teoretiska ramverket kunde inkluderat begrepp som Lean, där VPP har sin grundtanke. Intervjurespondenterna saknade i viss mån erfarenhet och kunskap kring VPP och detta kan spegla en mer generell verklighet kring ämnet. / Purpose: Visual tools can help reduce the human errors that occur in the workplace and create a shorter information time. The information is obtained significantly faster and more accurately by visualizing the information channel where photos, schedules, posters, graphics and color coding are visual tools that are used. To make their workplaces more effective, a construction company has developed a visual tool named Visual Planning Production (VPP). VPP aims to visualize the project and its workflows with various kinds of boards for easier communication between the management and workers. The aim of this study is to investigate how planning and communication between management and craftsmen in production can be improved with the support of VPP. Three questions has been created:1. What is the main purpose of using VPP?2. How does the daily planning and communication work today?3. How can VPP be improved to become a more useful tool to apply for the site management in production?Method: Three methods were selected to answer the three questions. Qualitative interviews with site management and craftsmen leader, document analysis and observations on projects.Findings: Planning and communication between site management and craftsmen can be improved with the help of VPP. This only applies if the site management is given the education they need to use the tool properly. It is also important that the site management can adapt the tool to its project needs. VPP will then provide the transparency and foresight that the project needs to work.Implications: The tool with its boards and meetings currently has potential of improvement. Three examples of difficulties with the tool is: There is no information and education for the site management The new way of working is not seen as more positive than the current one There isn’t space enough in the rooms to hang the boardsThe findings from the analysis tells us what about the tool that can be improved. Some of these points are: A more thorough education for the site management and accessible information A thorough explanation of the use of the tool and its benefits To be able to customize equipment and meetings as needed in the projectsLimitations: The theoretical framework could include concepts like Lean, where VPP has its roots. A general verging of reality is not applicable to this report as the report only concerns two projects in the same geographical area. Interviewers lacked some experience and knowledge about VPP, and this may reflect on a more general reality about the subject.

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