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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.
21

Business valution - ČEZ Distribuce, a. s. / Ocenění podniku - ČEZ Distribuce, a. s.

Iser, Jan January 2011 (has links)
The goal of this thesis is to appraise the electricity distributor ČEZ Distribuce, a.s.. The Thesis includes information about the company, analysis of the regulatory environment, strategic and financial analysis. As the principal used method of valuation is the discounted cash flows to entity, key value drivers description and financial plan form a vital part of the work. Last section is consecrated to the core calculation of the value itself, using two phase discounted cash flows method. The results from DCF valuation are reinforced by comparable transactions analysis. The Thesis is ended with an estimation of the business value and its explanation.
22

Gerenciamento de refrigeradores para redução do pico de demanda em redes inteligentes / Smart management of refrigerators for peak load reduction

Niro, Glauco 18 August 2018 (has links)
Orientador: Luiz Carlos Pereira da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T12:45:34Z (GMT). No. of bitstreams: 1 Niro_Glauco_M.pdf: 13465948 bytes, checksum: 504eb63346ec29f71bef99cd507174e1 (MD5) Previous issue date: 2011 / Resumo: Os sistemas elétricos vêm sendo alvo de estudos que buscam torná-los mais inteligentes e seguros. Um novo paradigma surge com o conceito das redes inteligentes (smart grids), as quais incluem como uma das suas características principais a integração de equipamentos dos consumidores de forma ativa à operação do sistema elétrico. Um exemplo é o gerenciamento da demanda no horário de pico, aliviando a carga e aumentando a segurança do sistema, com o objetivo de obter benefícios para o sistema elétrico e também para os consumidores. Para que isso seja possível, são necessários alguns requisitos e avanços tecnológicos: existência de um portal de comunicação para interface entre o consumidor e seus aparelhos e a concessionária; equipamentos que permitam tal gerenciamento sem prejudicar e interferir na rotina dos consumidores; e mecanismos de compensação financeira para incentivar a participação dos consumidores. Nesta dissertação se propõe um estudo sobre um aparelho que apresenta potencial para esse tipo de gerenciamento, o refrigerador doméstico. Devido a sua inércia térmica e isolamento o refrigerador pode ser ligado e desligado durante algum tempo sem prejuízos para sua função principal. Os objetivos deste trabalho são: desenvolver um modelo adequado para a simulação computacional de um grupo de refrigeradores; implementar esquemas de gerenciamento que visem a redução de consumo no horário de pico; bem como analisar o efeito que estes procedimentos acarretariam em uma rede de distribuição de energia elétrica, levando em conta a redução do consumo no período de pico, a redução de perdas e a melhoria do perfil de tensão / Abstract: The electrical systems have been exposed to new researches and developments with the main objectives of a smarter and safer operation and planning. A new paradigm arises with the concept of smart grids, which include as one of its main characteristics the integration of consumer's appliances in the system operation in a more active way. An example is the demand-side management at peak time, relieving the load and increasing system security, in order to obtain benefits to the electrical system and also to consumers. In order to make this possible, some requirements and technological advances are necessary: the existence of a communication interface between the consumers and their appliances and the utility; smart appliances that allow such management without any damage or interference on the routine of the consumer; compensation mechanisms to encourage consumer participation. In this dissertation it is proposed a study about a device that has potential to this kind of management, the household refrigerator. Due to its thermal inertia and isolation, the refrigerator can be turned on and off for some time without degradation of its primary function. The objectives of this work are: development of an adequate model for the computational simulation of a group of refrigerators; implementation of management schemes to reduce the consumption at peak time; analysis of the impacts of such procedures to a distribution grid, taking into consideration the reduction of the consumption at the peak hours, reduction of losses and improvement on voltage profile / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica
23

Kritická analýza vstupu české energetické společnosti na trh na Slovensku / Critical Analysis of the Czech Energy Company on the Slovak Market

Pekárek, Ondřej January 2017 (has links)
Práce se za pomocí podrobné analýzy odvětví charakterizuje doporučení malým společnostem působících v segmentu distribuce elektrické energie zajímající strategii vstupu společnosti na trh v zahraničí. Nejdůležitější část práce se soustředí na podrobnou analýzu vnějšího prostředí slovenského trhu a vnitřního prostřední zvolené firmy, čili PEST a SWOT analýzu. Za pomocí těchto metod jsou charakterizovány příležitosti a hrozby zvoleného trhu a současně silné a slabé stránky zvolené společnosti. Závěr diplomové práce zaujímá konkrétní návrh strategie a doporučení společnosti vstupu na slovenský trh.
24

Electricity Distribution Network Planning Considering Distributed Generation

Huang, Yalin January 2014 (has links)
One of EU’s actions against climate change is to meet 20% of our energy needs from renewable resources. Given that the renewable resources are becoming more economical to extract electricity from, this will result in that more and more distributed generation (DG) will be connected to power distribution. The increasing share of DG in the electricity networks implies both increased costs and benefits for distribution system operators (DSOs), customers and DG producers. How the costs and benefits will be allocated among the actors will depend on the established regulation. Distribution networks are traditionally not designed to accommodate generation. Hence, increasing DG penetration is causing profound changes for DSOs in planning, operation and maintenance of distribution networks. Due to the unbundling between DSOs and electricity production, DSOs can not determine either the location or the size of DG. This new power distribution environment brings new challenges for the DSOs and the electric power system regulator. The DSOs are obliged to enable connection of DG meanwhile fulfilling requirements on power quality and adequate reliability. Moreover, regulatory implications can make potential DG less attractive. Therefore regulation should be able to send out incentives for the DSOs to efficiently plan the network to accommodate the increasing levels of DG. To analyze the effects of regulatory polices on network investments, risk analysis methods for integrating the DG considering uncertainties are therefore needed. In this work, regulation impact on network planning methods and network tariff designs in unbundled electricity network is firstly analyzed in order to formulate a realistic long-term network planning model considering DG. Photovoltaic (PV) power and wind power plants are used to demonstrate DG. Secondly, this work develops a deterministic model for low-voltage (LV) networks mainly considering PV connections which is based on the worst-case scenario. Dimension the network using worst-case scenario is the convention in the long-term electricity distribution network planning for the reliability and security reason. This model is then further developed into a probabilistic model in order to consider the uncertainties from DG production and load. Therefore more realistic operation conditions are considered and probabilistic constrains on voltage variation can be applied. Thirdly, this work develops a distribution medium-voltage (MV) network planning model considering wind power plant connections. The model obtains the optimal network expansion and reinforcement plan of the target network considering the uncertainties from DG production and load. The model is flexible to modify the constraints. The technical constraints are respected in any scenario and violated in few scenarios are implemented into the model separately. In LV networks only PV connections are demonstrated and in MV networks only wind power connections are demonstrated. The planning model for LV networks is proposed as a practical guideline for PV connections. It has been shown that it is simple to be implemented and flexible to adjust the planning constraints. The proposed planning model for MV networks takes reinforcement on existing lines, new connection lines to DG, alternatives for conductor sizes and substation upgrade into account, and considers non-linear power flow constraints as an iterative linear optimization process. The planning model applies conservative limits and probabilistic limits for increasing utilization of the network, and the different results are compared in case studies. The model’s efficiency, flexibility and accuracy in long-term distribution network planning problems are shown in the case studies. / <p>QC 20140217</p> / Elforsk Risknanlys II
25

GEOGRAPHY AND THE COSTS OF URBAN ENERGY INFRASTRUCTURE: THE CASE OF ELECTRICITY AND NATURAL GAS CAPITAL INVESTMENTS

Senyel, Muzeyyen Anil January 2013 (has links)
No description available.
26

The Development of the River Resources of the United States is a Public Function

Smith, Roger 08 1900 (has links)
This investigation is an analysis of the social or economic effects of TVA electricity. It is the purpose of this endeavor to present a well-documented case supporting the thesis that the development of our water resources is a public function.
27

Desenvolvimento de sistema para estudo de tensões induzidas em linhas de média tensão por descargas atmosféricas. / A system for study of lightning induced voltages on medium voltage lines.

Carvalho, Thaís Ohara de 27 May 2004 (has links)
A busca de uma melhor qualidade da energia passa necessariamente por um melhor entendimento dos fenômenos relacionados às descargas atmosféricas. No caso de redes de distribuição com tensões nominais inferiores a 69 kV, uma parcela significativa das interrupções se deve às sobretensões induzidas por descargas próximas às linhas. Este trabalho teve por objetivo desenvolver e implantar um sistema para estudo de tensões induzidas em linhas de distribuição devido a descargas atmosféricas indiretas através da obtenção simultânea das formas de onda de tensões induzidas em duas linhas com diferentes configurações. Além das linhas, equipadas com divisores de tensão especialmente projetados para medições de tensões impulsivas, também fazem parte do sistema uma torre metálica para captação de descargas, construída nas proximidades das linhas, o sistema de medição instalado em sua base para registro de correntes de descargas que eventualmente incidam em sua estrutura e o programa computacional que gerencia os processos de aquisição e armazenamento de dados. A metodologia adotada no estudo é pioneira no que se refere a descargas naturais, pois somente em pesquisa desenvolvida pelo Grupo de Alta Tensão e Descargas Atmosféricas (GATDA/USP) através de modelo em escala reduzida foram obtidos registros simultâneos de tensões induzidas pelas mesmas descargas em linhas de distribuição com e sem proteção. O presente estudo representa uma extensão da pesquisa realizada com modelo reduzido, sendo a metodologia anteriormente desenvolvida transportada para um sistema em escala real. O sistema entrou em operação no final de fevereiro de 2002, tendo sido registradas várias formas de onda de tensões induzidas, comprovando o seu desempenho satisfatório. Este trabalho descreve os principais componentes do sistema e apresenta alguns dos resultados preliminares obtidos. / For improving the energy quality it is essential to understand the phenomena related to the lightning discharges. In the case of distribution networks with rated voltages lesser than 69 kV, there is a significant number of interruptions caused by overvoltages induced by lightning discharges near to the lines. The aim of this work was to develop and to implement a system to study lightning induced voltages on distribution lines through simultaneous acquisition of induced voltages waveforms on two lines with different configurations. Besides the lines, equipped with voltage dividers specially designed to measure impulsive voltages, also belong to the system a metallic tower built in the vicinity of the lines, the measuring system installed at its base to register lightning currents that eventually hit it and the computer programme that manages the acquisition and data storage process. The methodology adopted in the study is pioneer concerning natural lightning, since records of voltages induced simultaneously on unprotected and protected distribution lines by the same lightning event were obtained only in a previous research developed by the High Voltage / Lightning Research Group (GATDA/USP), by means of a scale model. The present study represents an extension of that research, so that the same methodology previously developed has been transferred to a real scale system. The system started to operate in the end of February 2002 and several induced voltages waveforms have been registered, confirming its satisfactory performance. This Dissertation describes the system and its main components and shows some of the preliminary results obtained so far.
28

Desenvolvimento de sistema para estudo de tensões induzidas em linhas de média tensão por descargas atmosféricas. / A system for study of lightning induced voltages on medium voltage lines.

Thaís Ohara de Carvalho 27 May 2004 (has links)
A busca de uma melhor qualidade da energia passa necessariamente por um melhor entendimento dos fenômenos relacionados às descargas atmosféricas. No caso de redes de distribuição com tensões nominais inferiores a 69 kV, uma parcela significativa das interrupções se deve às sobretensões induzidas por descargas próximas às linhas. Este trabalho teve por objetivo desenvolver e implantar um sistema para estudo de tensões induzidas em linhas de distribuição devido a descargas atmosféricas indiretas através da obtenção simultânea das formas de onda de tensões induzidas em duas linhas com diferentes configurações. Além das linhas, equipadas com divisores de tensão especialmente projetados para medições de tensões impulsivas, também fazem parte do sistema uma torre metálica para captação de descargas, construída nas proximidades das linhas, o sistema de medição instalado em sua base para registro de correntes de descargas que eventualmente incidam em sua estrutura e o programa computacional que gerencia os processos de aquisição e armazenamento de dados. A metodologia adotada no estudo é pioneira no que se refere a descargas naturais, pois somente em pesquisa desenvolvida pelo Grupo de Alta Tensão e Descargas Atmosféricas (GATDA/USP) através de modelo em escala reduzida foram obtidos registros simultâneos de tensões induzidas pelas mesmas descargas em linhas de distribuição com e sem proteção. O presente estudo representa uma extensão da pesquisa realizada com modelo reduzido, sendo a metodologia anteriormente desenvolvida transportada para um sistema em escala real. O sistema entrou em operação no final de fevereiro de 2002, tendo sido registradas várias formas de onda de tensões induzidas, comprovando o seu desempenho satisfatório. Este trabalho descreve os principais componentes do sistema e apresenta alguns dos resultados preliminares obtidos. / For improving the energy quality it is essential to understand the phenomena related to the lightning discharges. In the case of distribution networks with rated voltages lesser than 69 kV, there is a significant number of interruptions caused by overvoltages induced by lightning discharges near to the lines. The aim of this work was to develop and to implement a system to study lightning induced voltages on distribution lines through simultaneous acquisition of induced voltages waveforms on two lines with different configurations. Besides the lines, equipped with voltage dividers specially designed to measure impulsive voltages, also belong to the system a metallic tower built in the vicinity of the lines, the measuring system installed at its base to register lightning currents that eventually hit it and the computer programme that manages the acquisition and data storage process. The methodology adopted in the study is pioneer concerning natural lightning, since records of voltages induced simultaneously on unprotected and protected distribution lines by the same lightning event were obtained only in a previous research developed by the High Voltage / Lightning Research Group (GATDA/USP), by means of a scale model. The present study represents an extension of that research, so that the same methodology previously developed has been transferred to a real scale system. The system started to operate in the end of February 2002 and several induced voltages waveforms have been registered, confirming its satisfactory performance. This Dissertation describes the system and its main components and shows some of the preliminary results obtained so far.
29

Perspectives on the vulnerability of the Swedish electricity distribution system : Extreme weather conditions and climate change

Plejert, Tina January 2005 (has links)
<p>This study deals with the perspective of vulnerability of the Swedish electricity distribution system to climate and weather related risks. How and to what extent the electricity sector is adapting to the risk and what possibilities are formed in this respect are investigated. This is a quantitative and qualitative analysis where statistical data has been used to apprehend the extent of disturbances of the electricity distribution system and their causes. Interviews have been used in order to investigate different views among actors working within the electricity distribution system sector.</p><p>The result shows that the dominating cause of disturbances in the electrical network in Sweden is the weather, giving most hours of breaks. The countryside has more often disturbances than urban areas. It also emerges that it is the lines overhead that are most affected by disturbances. The system is flexible. If one line is disturbed the electricity can be distributed using another line (redundancy). It seems like there is a diversion between the respondents on how and if a future climate change really is a risk for the electricity distribution system. It is clear that the vulnerability has increased in the society during the past 10-20 years, and so has the societal costs of the disturbances because of the increasing dependence on electricity. Reducing the consequences of a weather related impact on the electrical system will make society more resilient and less vulnerable. The respondents in this study are somewhat adapting to the weather related risks that they have identified with technical solutions. It is important to learn more about how the electrical system properties influence the sensitivity in society. There is a need to investigate the dependency of electricity in society. It is also important that all the actors have the same interpretation of the difference between a recurrent event and a nature disaster. More work should be done to clarify where the responsibility for adapting the electrical sector to the possible climate change lies. This complex responsibility issue with all affected actors influences the sensitivity of society and the electrical system.</p>
30

Effectiveness of the Asset Register as a Management Instrument for the Electricity Distribution Infrastructure within the Stellenbosch Municipality.

Gabone, Derick. January 2008 (has links)
<p>The study seeks to establish the state of infrastructure management system, pertaining to electricity distribution, as an example of policy implementation.</p>

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