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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.
161

Optimization Of Electricity Markets In The Price Based And Security Constrained Unit Commitment Problems Frameworks

Sahin, Cem 01 July 2010 (has links) (PDF)
Operation of the electricity markets is subject to a number of strict and specific constraints such as continuous load-generation balance, security of supply, and generation technology related limitations. Contributions have been made to two important problems of the Electricity Markets, in the context of this study. In this study, Price Based Unit Commitment problem in the literature, which is a tool for the GENCO for operations planning, is extended considering the interdependencies between the Natural Gas (NG) and Electricity infrastructures and the uncertainty of Wind Power generation. The effect of the NG infrastructure physical limitations is considered via linearized NG transmission system equations, and the Wind energy sources and conventional generation resource uncertainties are simulated by Monte-Carlo simulations. The contribution of the forward energy Bilateral Contracts (BC), as a financial risk hedging tool is also included by modeling these in the proposed PBUC framework. In the case studies , it is observed that a GENCO could prevent its financial losses due to NG interruptions, by depositing only a portion of the midterm interrupted NG in the storage facilities. The Security Constrained Unit Commitment (SCUC) Problem is widely accepted tool in the industry which models the market clearing process. This study integrates two novelties to the SCUC problem / &bull / A discrete demand response model to consider active participation of the consumers, &bull / A hybrid deterministic/stochastic contingency model to represent the N-1 contingencies together with the uncertainties related with the wind power generation and system load. It is observed that the curtailment of available wind power capacity would enable the TSO to take corrective actions against occurrence of the contingencies and realization of the uncertainties in the most possible economical manner.
162

Optimal Location of Distributed Generation to Reduce Loss in Radial Distribution Networks

Sharma, Prashant Kumar January 2015 (has links) (PDF)
Power losses are always a cause of worry for any power grid. In India, the situation is even worse. Though recent reports by Ministry of Power shows that Aggregate Technical and Commercial losses (AT &C losses) have come down from 36.64% in 2002-03 to 27% in 2011-12, yet they are much higher than the losses seen in many of the developed nations. The reduction shown in power loss is because of the Electricity Act, 2003 and the amendments made to it in 2007 which controlled the commercial losses rather than the technical losses. According to Ministry of Power, technical losses (Transmission & Distribution losses or T&D losses) in India are reported to be 23.65% in 2011-12. However, according to the study done by EPRI, for systems deployed in developed countries, these losses are estimated to be in the range of 7-15.5%. T & D losses occur in four system components namely step-up transformers and high voltage transmission (0.5-1%), step down to in intermediate voltage, transmission and step down to sub transmission voltage level (1.5-3%), sub-transmission system and step down to low voltage for distribution (2-4.5%), and distribution lines (3-7%). 1% of power loss is approximately equivalent to annual loss of Rs 600 million for a single state. Hence, in a year, loss in distribution line alone causes approximate loss of Rs 1.8-4.2 billion per state. Understanding and reducing power losses in distribution lines which contribute nearly 50% of the total T&D losses assume significance and has formed the motivation for the work reported in the thesis. In recent years, the trend has been to encourage users to generate solar power predominantly at residential complexes and captive power plants at industrial complexes. It has been suggested in the literature that Distributed Generation (DG) can not only reduce the load demanded from the power grid but also the power loss. In this thesis, it has been shown that by the choice of proper size and location of DG, the power loss can be reduced substantially as compared to unplanned deployment of DGs. The objective of the thesis is to design strategy for location of distributed user generated power to maximize the reduction in power loss. The thesis begins with a study of distributed generation in primary distribution networks and proceeds to problem formulation, with the aim being to develop an algorithm that can find out the optimal locations for DG allocation in a network. A greedy approximation algorithm, named OPLODER (i.e. Optimal Locations for Distributed Energy Resources), is proposed for the same and its performance on a benchmark data set is observed, which is found to be satisfactory. The thesis then moves on to describe the actual data of 101,881 commercial, residential and industrial consumers of Bangalore metropolitan area. A loss model is discussed and is used to calculate the line losses in LV part of the grid and loss is estimated for the said actual data. The detailed analysis of the losses in the distribution network shows that in most cases the losses are correlated with the sanctioned load. However there are also some outliers indicating otherwise. The analysis concludes that the distributed generated sources need to be optimally located in order to benefit fully. Also presented thereafter is a study about the impact of electrical properties and the structure of the network on power loss. In the second part of the thesis, OPLODER was again used to process the BESCOM data of 101,881 consumers by modeling them to be connected in three topologies namely Bus (i.e. linear structure), Star (i.e. directly connected) and Hybrid (i.e. tree structure). In case of Bus topology, when DG capacity available is 5% of the demand in substation, OPLODER reduced the loss from 14.65% to 10.75%, from 11.63% to 7.71% and from 13.33% to 9.24% for IISc, Brindavan, and Gokula substations respectively. Similarly, for the same amount of DG in case of star topology, OPLODER reduced loss from 1.75% to 1.26%, from 3.39% to 2.59% and from 2.96% to 1.99% for IISc, Brindavan, and Gokula substations respectively. Thereafter, the available real world data is re-modeled as a tree-type structure which is closer to the real world distribution network and OPLODER is run on it. The results obtained are similar to those presented above and are highly encouraging. When applied to the three substations viz. IISc, Brindavan and Gokula, the power loss dips from 9.95% to 7.42%, from 6.01% to 4.44% and from 8.07% to 5.95%, in case of DG used is 5% of the demand in substation. For the optimal strategies worked out in the thesis, additional overheads will be present. These overheads are studied and it has been found that the present infrastructure and technologies will be sufficient to handle the smart distribution network and the optimal strategy for distributed sources.
163

Zhodnocení efektivnosti konkrétního investičního záměru fotovoltaické elektrárny / Evaluation of Effectiveness Concrete Investmen Intention of Photofoltaic Power Station.

ŠVARCOVÁ, Petra January 2009 (has links)
This diploma work is dealing with problems related to production of electrical energy in compliance with environmental protection and assessment of its production from non-renewable sources in reference to sources being renewable. The work puts emphasis on the importance and utilization of solar electrical energy. The sun is a source that will not get dried or mined out and will not stop shining. The goal of diploma work was to appraise the investment effectiveness with regard to a photovoltaic power station and assess the power plant influence in relation to classic sources for energy production and environmental protection. Within the diploma work, there were appraised three variants of the investment project which assumed life time longer than 20 years comprising conventional financial flows, surface size of 30 000 m2 and roughly required output of 1.5 MW. Single options were assessed upon economical evaluation regarding different ways of financing, in terms of price, output and guarantees provided by suppliers including the assessment of grant influence on the project effectiveness. Based on these data, the most suitable version for the investment project of building up the photovoltaic power plant was chosen. At the conclusion, it is possible to state that the photovoltaic power plant is very considerate towards the living environment in contrast to classical sources for electrical energy production, for example coal-fired power plants which heavily contaminate the environment, and nuclear power plants with risks of radiation escapes.
164

Towards the design of flexibility management in smart grids : A techno-institutional perspective

Eid, Cherrelle January 2017 (has links)
The European policy focus on smart grids implies their development as an indispensable part of the future power system. However, the definition of a smart grid is broad and vague, and the actual implementation of a smart grid can differ significantly, depending on the stakeholders involved.This work aims to inform policy makers, the electricity industry and researchers about stakeholder interests and the technical complexities involved by presenting smart grids via a techno-institutional framework. This framework takes account of the technical nature of the electricity transport and supply service as well as the institutional nature of electricity markets, stakeholder perspectives and sector regulation. In addition, this work presents potential revenues resulting from flexibility management in smart grids and proposes a way forward for smart grids and flexibility management in Europe. / <p>QC 20170925</p>
165

Pozice Ukrajiny v euroasijském transportu ropy a zemního plynu / Ukraine’s Position in Eurasian Transport of Oil and Natural Gas

Ruban, Andriy January 2008 (has links)
The thesis focuses on theoretical and empirical analysis of oil and natural gas flows in Eurasia and maps Ukraine's transit position in the regional oil and gas supply chain. The aim of the thesis is to objectively evaluate possibilities of Eurasian energy integration by enlargement of the European energy market further to the East and to prospect Ukraine's involvement into a new geopolitical energy alliance, driven by EU. This dissertation builds up on economical, geographical, historical and political premises of markets integration as well as system approach of energy alliances development. It argues that (i) energy integration on contrary to traditional economic stream can be explained by system approach and geopolitical stream of energy expansionism; (ii) EU infrustructural oil and gas projects imply deeper integration of EU member-states with involed non-members and (iii) Ukraine's oil and gas transit status within Eurasian region facilitates its growing involvement into EU energy intiatives guided by the European rules. The thesis is organized into three chapters. The first one is predominately theoretical and seeks to summarize current theoretical approaches towards integration and trends of energy markets in Eurasia. The second chapter introduces the role of oil and gas transport capacities and Ukraine's transit status in resolving disparities of Eurasian energy supply chain. The third chapter describes condition of Ukrainian oil and gas infrastructure and tackles issues for reformation of national oil and gas transit pipelines. Securing access to energy supplies has been a driving factor of global development since the industrial revolution. Increasing demand for oil and gas has undermined energy and economic security of world centers. In Eurasia Europe and Asia has been competing for fossil fuels originating from Russia, Middle East and Central Asia. Since recently Eurasian energy security problem is being solved by development of new supply routes. These infrastructural projects are initiated by oil and gas consumers, suppliers and transitors competing over control in the infrastructure. Such competition destabilises Eurasian relations, leads to energy "wars", political conflicts and increases supplies disruption risks. To secure stability of energy supply chain producers, transitors and consumers of oil and gas resources should integrate, closely cooperate and jointly invest into improving the existing supply routes and efficiency of fuels consumtion, production and transportation. Oil and gas should be traded for technologies and capital securing control in the infrustucture of mutual interests. Development of further bilateral and multilateral tools of joint interest would also help in resolving energy related contradictions of the participating parties. The leading role in driving energy integration in Eurasia belongs to the EU being the most mature and advanced integration grouping in Eurasia. EU realises TEN-e projects and from recently a common foreign energy policy aimed to strengthen external cooperation with oil and gas suppliers and transitors, including Ukraine. Since 1970s Ukraine has been an important oil and gas transitor for Russian and Central Asian oil and gas to Europe. Ukrainian pipelines intermediate 10 % of oil and 50 % of gas imports of Europe. To counterbalance Russian energy diplomacy over Ukraine, EU is supporting Ukraine's efforts in such energy alliances as INOGATE or GUAM. Ukraine's recent accession to the South Eastern-European Energy Community should improve stability of gas and oil supplies to Europe and facilitate reformation of national transit capacities.
166

"Analýza podpory výroby elektrické energie z obnovitelných zdrojů v České republice a v některých vyspělých zemích, změny v letech 2010 - 2012" / "The current analytical procedures and policies of renewable energy production in the Czech Republic and some developed countries, the policy modifications that occurred between 2010 to 2012"

Juklíček, Jan January 2012 (has links)
This diploma thesis addresses the current analytical procedures and policies of renewable energy production in the Czech Republic and, mainly deals with the policy modifications that occurred between 2010 to 2012 which also influenced this policy. To give more explanation to the entire picture of the energetic situation in the Czech Republic we have to analyze the current potential situation of renewable and non renewable resources, the quality of electrical distribution network, the framework of available energy resources in the Czech Republic, the costs of producing energy and its impact on the environment. The current global trend in most developed countries is the development of renewable energy sources but, this is not the current case in the Czech Republic which has in its plans to reach its target set by the European Union for the year 2020 . But, instead the Czech Republic would like to set a different goal and decrease the use of renewable energy resources and increase the use of nuclear energy. The support of the analysis policy for renewable energy sources in the Czech Republic is measured in comparison with the European Union, the United States of America and the Peoples Republic of China. The main goal is to evaluate this policies support for renewable energy sources in the Czech Republic and for its possible improvement.
167

Vliv disperzních zdrojů na DS 22 kV při vřazení transformovny TR 110/22 KV / Effect of distributed generation on medium voltage 22 kV distribution system operation with a new 110/22 kV feeder

Konopová, Tamara January 2018 (has links)
This thesis deals with the issue of power flow analysis in a medium voltage (22kV) distribution network with a focus on the influence of distributed energy generation recources. At first the issue of operation of distributed energy resources and their reverse effects on the distribution system is presented in the thesis. Furtherly there are described their operational conditions from the legislation point of view. The part dealing with calculation compares two network configurations in terms of power quality and how the power quality is impacted by distributed energy resources. The attention is given to voltage conditions, short-circuit power, power conditions, losses and flicker. The first configuration corresponds to the real situation in the network, the other one is describing the changes after the new 110/22 kV substation implementation to the power supply area and the overal change of network configuration. The network model and run simulation is done using the E-Vlivy program.
168

A Novel Control Method for Grid Side Inverters Under Generalized Unbalanced Operating Conditions

Rutkovskiy, Yaroslav January 2020 (has links)
No description available.
169

All Infrastructure Projects Lead to Beijing: How the Belt and Road Initiative Has Influenced China’s Regional Policy

Grof, Katherine 29 August 2022 (has links)
No description available.
170

Optimisation of charging strategies and energy storage operation for a solar driven charging station

Gong, Jindan January 2019 (has links)
The Swedish energy sector is undergoing transformational changes. Along with a rapid growth of renewables and a shift towards electromobility, the transformation is expected to bring challenges to the power system in terms of grid instability and capacity deficiency. Integrating distributed renewable electricity production into the electric vehicle (EV) charging infrastructure is a promising solution to overcome those challenges. The feasibility of implementing such a charging infrastructure system in northern Sweden is however uncertain, as the solar resources are scarce in the long winter period. This study aims to maximise the value of a solar powered EV charging station, placed in a workplace environment in Umeå. An integrated system model of the charging station is developed, comprising separate models of a solar PV system, a battery energy storage system (BESS), the workplace EV fleet and the building Växthuset, onto which the charging station will be installed. Three scenarios are developed to study the charging station’s system performance under different EV charging strategies and BESS dispatch strategies. Two additional scenarios are developed to study the potential grid services that the charging station can provide in the winter period. A techno-economic assessment is performed on each scenario’s simulation results, to measure their effect on the charging station’s value. It involves analysing the charging station’s profitability and how well the BESS is utilised by the end of a ten-year project period. The charging station’s grid impact is further assessed by its self-consumption of solar power, peak power demand and the grid energy exchange. The assessed charging station values indicate that the overall grid impact was reduced with dynamic EV charging strategies and that the BESS capacity utilisation was strongly influenced by its dispatch strategy. The charging station further implied a net capital loss under the explored scenarios, even while the dynamic charging strategies brought by a slightly increased economic value. Moreover, the studied winter scenarios showed a great potential for the charging station to provide ancillary services to the local distribution grid while maintaining an efficient BESS capacity utilisation. The winter period’s peak power demand was significantly reduced by optimising the BESS operation to shift peaks in the building’s load profile, and peaks caused by the additional EV charging demand and the EV heaters, to off-peak hours. On this basis, future research is recommended for improved simulations of the charging station operation and to study additional value-added features that the solar driven charging station can bring. / Sveriges energisystem genomgår en omfattande omställning. Förändringar i form av en ökad andel förnybar elproduktion och elektrifieringen av transportsektorn förväntas medföra stora utmaningar för elsystemets nätstabilitet och överföringskapacitet. Att integrera in distribuerad, förnybar elproduktion som en del av laddinfrastrukturen för elfordon ställer sig som en lovande lösning för att möta de väntande utmaningarna. Möjligheterna att tillämpa en sådan lösning i norra Sverige är däremot mindre självklara, då solresurserna är knappa under vintertid. Det här examensarbetet syftar till att maximera nyttan av en soldriven laddstation för elbilar, placerad på ett arbetsplatsområde i Umeå. En integrerad energisystemmodell av laddstationen har skapats, bestående av systemmodeller av solpaneler, ett batterienergilager, arbetsplatsens elbilsflotta samt byggnaden Växthuset, som laddstationen ska anslutas till. Tre scenarier har utformats för att undersöka hur laddstationens prestanda förändras beroende på olika laddstrategier för elbilarna och batterienergilagrets styrning. Ytterligare två scenarier har utvecklats för att utforska möjliga nättjänster som laddstationen kan bistå med under vintertid. Laddstationens värde har vidare bedömts utifrån systemets prestanda i de olika scenarierna. Bedömningen grundar sig på laddstationens lönsamhet och hur välutnyttjat batterienergilagret är efter en kalkylperiod på 10 år, samt på specifika påverkansfaktorer på elnätet. Faktorerna omfattar konsumtionen av egenproducerad el, toppeffektuttaget och nätöverföringarna orsakade av laddstationen. Från värderingen av laddstationen framgår det att de dynamiska laddstrategierna ledde till en, överlag, minskad påverkan på elnätet samt att styrningen av batterienergilagret hade stor inverkan på dess utnyttjandegrad. Laddstationens nettonuvärde förblev negativt i de tre scenarierna, även om de dynamiska laddstrategierna, ökade dess ekonomiska värde till en viss del. Vidare tyder simuleringen av vinterscenarierna på att det finns en stor potential för laddstationen att erbjuda tjänster för lokalnätet och samtidigt nyttiggöra sig av batterienergilagret. Växthusets toppeffektuttag reducerades märkbart genom att optimera batteristyrningen till att flytta effekttoppar orsakade av Växthusets ellastkurva eller elbilarnas laddning och uppvärmning, till de timmar där lasten var lägre. Med detta i bakgrund föreslås vidare studier som fokuserar på den integrerade energisystemmodellen för att förbättra simuleringarna, samt att undersöka möjligheterna till att erbjuda fler nättjänster, som ökar laddstationens mervärde.

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