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Negumbo, Rosalia. "Analysis for electrical energy and overall efficiency in distribution networks with harmonic distortion." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1103.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009Traditionally, harmonics are ignored in overall efficiency and energy usage studies. However, in the modern era, power systems contain levels of harmonics which can no longer be ignored by engineers, planners, energy conservationists and economists. The directions of power flows have to be considered when harmonics are present in the power network. A methodology and new formulae for individual and overall efficiency and energy usage is developed at each frequency (f1, h and H) and forms the main contribution to research in this field. Two case studies were conducted; a measurement based laboratory experiment set-up and a simulated case study. In the set-up, measurements of current, voltage and power at different points in the network for the 1st, 5th and 7th frequencies were taken. Current and voltage results were used for hand calculations to prove the measured power flows and directions. The measurements were taken with a Fluke 345 three-phase harmonic power quality analyzer. For the simulated case study, a network was investigated using the DIgSILENT and SuperHarm software packages. Their results were compared and it was found that DIgSILENT is the preferred package for power results. It was found that the total harmonic distortion limit for voltage in the simulated network exceeded an acceptable level. The harmonic mitigation solution chosen was to design a passive filter to decrease the distortion by shifting the resonance point of the network. The method to design the passive filter and its impact on efficiency and energy usage is included in the thesis. Unique power flow direction diagrams are developed as part of the methodology and form an essential step in the derivation of the new formulae. Efficiencies, power losses and energy usage at individual and combined frequencies were determined. Results showed the negative effects of harmonics on overall efficiency, energy usage and power losses of the system. The methodology and new formulae developed was found to be effective and their application is recommended for use by industry.
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陳偉樂 and Wai-lok Chan. "Multi-function monitoring system for harmonic and transient study of power networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31210727.
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Chan, Wai-lok. "Multi-function monitoring system for harmonic and transient study of power networks /." [Hong Kong : University of Hong Kong], 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13418051.
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Meru, Alan Henry Micheni. "Design and development of medium voltage open rack harmonic filters for distribution networks." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1087.
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Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2013Harmonic voltages and currents in distribution networks are on the increase in recent times due to the introduction of a proliferation of electronic controlled devices such as variable speed drives. These non-linear devices improve efficiency but distort the supply waveforms. To address the harmonic issues, harmonic filters are used to mitigate distortion levels and prevent damage. These harmonic filters are commonly found at medium voltage levels in power systems. The problem is that knowledge from the design to commissioning stages of these medium voltage harmonic filters are neither well developed nor adequately documented. The aim of this research is to investigate and expound upon the process whilst taking into account all the factors involved throughout the process from bringing such a filter into operation in the real world. Medium voltage harmonic filters are usually the open rack type found in outdoor installations. Capacitors and reactors are the main components used in the construction of such harmonic filters and in some instances resistors are also used. The physical size and spacing of such components determines the construction layout area and how this is done in practice warrants being researched and explained in this thesis. In order to make these factors explicit, a methodology is developed from design, to installation and commissioning and is applied to two networks which are used to prove that the developed methodology is applicable for the different types of harmonic filters designed. The network voltage levels are also different, thus implying that the components will have different design factors. The final arrangements of the harmonic filters are later drawn and shown in three-dimension (3D) as per dimensions. The 3D figures are a further contribution as the design is taken from theory and is ultimately implemented into an installation and construction layout for erection at site. Interviews and surveys are conducted with specialists in industry dealing with harmonic filter applications and the results are analysed as part of implementation of the developed methodology. The design, installation and construction phases are documented and shown to be effective in application and the work disclosed in this thesis will help newcomers to this specialised field and is recommended for use in industry.
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Chen, Yaow-Ming. "Active power line conditioner with neural network control /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841132.
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Maitra, Arindam. "A generic approach to network modeling for harmonic analysis." Diss., Mississippi State : Mississippi State University, 2002. http://library.msstate.edu/etd/show.asp?etd=etd-03272002-133910.
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Kaya, Ibrahim. "A Switch Mode Power Supply For Producing Half Wave Sine Output." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609781/index.pdf.
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In this thesisanalysis, design and implementation of a DC-DC converter with active clamp forward topology is presented. The main objective of this thesis is generating a rectified sinusoidal voltage at the output of the converter. This is accomplished by changing the reference signal of the converter. The converter output is applied to an inverter circuit in order to obtain sinusoidal waveform. The zero crossing points of the converter is detected and the inverter drive signals are generated in order to obtain sinusoidal waveform from the output of the converter. Next, the operation of the DC-DC converter and sinusoidal output inverter coupled performance is investigated with resistive and inductive loads to find out how the proposed topology performs. The design is implemented with an experimental set-up and steady state and dynamic performance of the designed power supply is tested. Finally an evaluation of how better performance can be obtained from this kind of arrangement to obtain a sinusoidal output inverted is thoroughly discussed
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Villalva, Marcelo Gradella 1978. "Estudo e aplicação de filtros ativos paralelos para sistemas trifasicos com quatro fios." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258788.
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Orientador: Ernesto Ruppert FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-04T17:39:56Z (GMT). No. of bitstreams: 1 Villalva_MarceloGradella_M.pdf: 5074196 bytes, checksum: 39f4e09d9f1f624c909a5ee7f2d3fa4d (MD5) Previous issue date: 2005
Resumo: o tema da qualidade de energia elétrica adquiriu grande importância em anos recentes. O número crescente de cargas baseadas em conversores eletrônicos criou a preocupação com a distorção harmônica em sistemas de energia elétrica. Qualidade de energia é um assunto importante tanto para as companhias distribuidoras e geradoras de energia elétrica como para os consumidores. A poluição harmônica pode causar sérios problemas às companhias e aos consumidores. Alguns dos possíveis problemas são a instabilidade na operação do sistema, distorções de tensão, perdas de energia, interferência eletromagnética e ressonâncias perigosas. A utilização de equipamentos para eliminação de harmônicos tornou-se necessária e são versas as soluções possíveis. Tradicionalmente se utilizam Itros passivos do tipo série ou paralelo. Esses Itros resentam como desvantagem suas grandes dimensões, seu custo elevado, elevadas perdas de energia, pouca e cácia, dependendência da interação com parâmetros do sistema e risco de introdução de novas freqüências de ressonância. O desenvolvimento recente da eletrônica de potência e do processamento digital de sinais tornou possível a utilização de Itros ativos de potência, que são condicionadores eletrônicos de energia. Filtros ativos de potência podem ser utilizados para realizar a Itragem de harmônicos em sistemas elétricos, sem os problemas apresentados pelos dispositivos passivos. Filtros ativos série são utilizados para eliminar distorções de tensão e Itros ativos paralelos são usados para eliminar correntes harmônicas originadas por carga não lineares. Esses últimos podem ainda ser usados para corrigir o fator de potência e para equilibrar as correntes de linha em sistemas desbalanceados com quatro os. Este trabalho estuda a aplicação de Itros ativos paralelos a sistemas trifásicos com quatro os. São estudados teorias de potências, métodos de compensação de harmônicos e sistemas de controle. A principal contribuição do trabalho está no emprego de um método seletivo de compensação de correntes baseado em redes neurais adaptativas, além do estudo do emprego de redes neurais no controle de correntes. Esses e outros assuntos foram experimentalmente comprovados com um protótipo de Itro ativo construí do em laboratório
Abstract: Electricity power quality has gained increased importance in the past few years. The growing number of power electronicsbased loads has created a preoccupation about harrnonic distortion in electric systems. Electricity power quality is an important issue both for energy utilities and consumers. Harrnonic poIlution may cause severe problems to electricity utilities and consumer networks such as system instability, voltage distortions, power losses, electromagnetic interference and harrnful resonances. The use ofharrnonic ltering equipment has become necessary and many solutions have been studied. Traditional passive devices such as tuned shunt lters and series reactors present disadvantages such as bulky sizes, high costs, increased losses, smaIl effectiveness, dependence on the parameters of the electric system and yet more risk of resonance with other elements of the network. Recent deve10pments in the major of power electronics and digital processing have made possible the pplication of electronic power conditioners such as series and shunt active lters. Active power lters may be used to overcome the drawbacks of passive devices. Series active power lters are used to reduce voltage distortions of electric systems. Shunt active power lters are used to mitigate harrnonic currents originated by nonlinear loads. The latter may be also used for increasing power factor and for balancing line currents in four-wire systems with unbalanced loads. This work is concerned with the application of shunt active power lters to three-phase four-wire electric systems. Power theories, compensation methods and control systems are discussed. The application of a se1ective compensation method based on adaptive neural networks and the employment of a neural network in the current controlIer are the main contributions of this work. These and other subjects were experimentalIy tested with a prototype of an active. power lter built in laboratory
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
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Takahashi, Seiichi, and Yukiharu Ohsawa. "Parallel electric fields in nonlinear magnetosonic waves." American Institite of Physics, 2007. http://hdl.handle.net/2237/12009.
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Elshaer, Ehab. "Millimetre-Wave Spectrum Sharing in Future Mobile Networks : Techno-Economic Analysis." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206078.
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Mobile operators passed through many phases in the market over the last several years, since the beginning of mobile broadband services. When the first smart phone was introduced in 2007, it caused a huge increase in the traffic and the users demand kept on increasing. This exponential growth has led to a severe shortage in the available capacity which caused that mobile users don’t have their promised quality of service and coverage. Operators began to put different scenarios for the next-generation mobile networks, putting in consideration the expected increase in the number of users along with their high demand.As a new proposed solution to the scarcity of empty spectrum slots, operating in higher frequency bands (noted as mmwave) emerged as a solution that will provide larger bandwidths with lower prices for the license. Mmwave will provide users with high data rates but on the other hand, has a low penetration rate that can be fixed by increasing the base stations. Another technique for the operators to follow is that they share their own spectrum with each other, by changing the classic way of exploiting the spectrum which proved a low efficiency and high cost, operators can increase their spectrum and coverage with lower cost.To get a clear understanding of how the operators will decide their future strategies, a technical analysis of the new strategies will not be enough, a technical one also will make it clearer and will help the operators in making the decision. The objective of this thesis is to perform a Techno-Economic analysis to get a full image of the system performance. Our system will consist of 2 operators working in mmwave band with antennas equipped with directional beamforming and the base station transmitters will consist of small cells serving outdoor users only. The main question we want to answer is what will be the effect of decreasing the beamwidth on the system performance and when the operators will need to share their spectrum with each other. The performance evaluation will be based on measuring the downlink achievable rate. As we will be performing an economical evaluation, the number of base stations required in each strategy will be an important parameter to evaluate its economic feasibility and cost savings. The different scenarios will include variations of the beamwidth and coordination between the operators with an objective of seeking the best performance along with cost savings. The results should give us a clear look on how the operators will decide for a certain strategy depending on downlink data rate as a KPI and the number of deployed base stations as a limiting factor.
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D'Achiardi, Pascualy David Humberto. "Transactive control of electric railway networks." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/121859.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 63-66).
This thesis proposes a transactive control mechanism that minimizes the operational costs of individual trains and integrates rail-side distributed energy resources (DERs) within an electric railway system. The operation of each individual train is posed as an energy cost minimization problem that is constrained by both the dynamics of the train and the specific schedule it must meet. The solution of this problem yields an optimal power profile for the train to follow. For each of the railway's segments, the proposed transactive controller determines the minimum average cost of electricity and the dispatch of the DERs based on the energy usage of the trains across space and time. By iterating between the transactive controller and the cost minimization scheme of the individual trains, the proposed methodology yields optimal power profiles of all the trains in the system and the dispatch of the generation assets. This methodology is tested through numerical simulation of the Amtrak Northeast Corridor service between University Park Station in the outskirts of Boston, Massachusetts and New Haven Station in Connecticut. Simulations of the southbound service over the course of a year demonstrate that the minimum cost operation reduces retail energy supply and delivery charges by 10% when compared to minimum work operation. We test the addition of solar generation across the system as an example of DER integration. The price signal of the transactive controller converges to within 1% after just 3 iterations for a single PV array and one train and within 4 iterations for two PV arrays and two trains.
Supported by award 1644877 from National Science Foundation, Cyber-Physical Systems program
by David Humberto D'Achiardi Pascualy.
S.M.
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Kamenskihs, Vsevolods. "Effect of an axial electric field on detonation waves." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104677.
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The present thesis reports an investigation of the effects of an axial electric field (200V/cm – 8000V/cm) on the propagation of detonation waves in mixtures of 2CO+O₂ and C₂H₂+O₂+85%Ar. High speed streak camera together with photodiodes was used for detonation velocity and position measurements. Additionally, the voltage across the axial electrodes and the current in the field circuit were also monitored as the detonation traversed the electric field region. The experimental results show that the charged particles within the detonation reaction zone are attracted to the surface of the electrode creating a sheath at the boundary of the electrode that shields the bulk of the detonation plasma from further influence of the DC electric field of the electrode. The present results also show that the neither the detonation structure nor its velocity are influenced bythe presence of the sheath and the resulting current to the electrode. It is also found that the conducting gas behind the detonation wave carries the voltage across the test section to the second (ground) electrode. In an axial electrode configuration the detonation wave essentially reduces the gap between the two electrodes progressively as it propagates in the test section. The increase of the electric field ahead of the detonation may result in a breakdown of the unburned mixture ahead of the detonation and the development of a discharge. For a sufficiently high electric field an arc discharge occurs ahead of the detonation igniting the unburnt mixture upstream of the detonation. The lack of fresh mixture ahead of the detonation results in failure of the detonation, but subsequent reinitiation of the detonation may occur. The present study also indicates that contrary to the previous observations by Bone et el, no significant effect of the applied electric field on the detonation is observed except for cases where breakdown of the unburned mixture ahead of the detonation occurs.Cette étude décrit une analyse expérimentale dans le but de déterminer les effets que produit un champ électrique axiale ( 200 V/cm – 8000 V/cm) sur la propagation d'une vague de détonation gazeuse dans les mélanges stoechiométriques de 2CO + O₂ et C₂H₂ + O₂, dilué avec 85% d'argon. Des photographies de haute vitesse ainsi que des photodiodes ont été utilisées pour obtenir des mesures de la vitesse et de la position de la détonation. De plus, des mesures du voltage entre les électrodes positionnées axialement ainsi que du courant passant par le circuit du champs électrique ont été enregistrées durant la traversée de la détonation dans la zone du champs électrique. Les résultats expérimentaux montrent que les particules chargées dans la zone de réaction de la détonation sont attirées vers la surface de l'électrode. Ce phénomène crée une couche de protection à la frontière de l'électrode qui rends ainsi le coeur du plasma de détonation impérméable à l'influence du champs electrique DC provenant de celle-ci. Ces résultats permettent aussi de démontrer que ni la structure de la détonation ni sa vitesse ne sont influencées par la présence de cette couche de protection ainsi que par le courant généré par le mouvement des ions. Il se dégage de ces expériences que le gas conducteur derrière l'onde de chocde la détonation conduit le voltage le long de la section de test jusqu'à la seconde électrode ( terre). Dans ce type de configuration, l'onde de choc en se propageant dans la section de test réduit la distance inter-électrode progressivement. L'augmentation du champs électrique devant la détonationpeut être interprété par la rupture diélectrique du mélange non brûlés devant la détonation, ce qui entraine le développement d'une décharge électrique. Pour un champ électrique assez fort, un arc électrique peut allumer le mélange non brûlé en amont de la détonation. Le manque de mélange frais (non-brûlé) devant la détonation entraine l'échec de celle-ci, mais un réallumage peut se produire ultérieurement. L'étude démontre ainsi que contrairement à l'observation précédente faites par Bone & al, le champs electrique appliqué n'a que peu d'effet sur la détonation sauf lorsque les gazs frais rompent diélectriquement en amont de l'onde de détonation.
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Yuen, Kwok-hoo. "Probabilistic analysis of harmonics in railway traction system." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22143099.
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Hamrita, Takoi K. "On-line digital signal processing methods for the correction of errors in high voltage power waveform measurements." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/15921.
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Wang, Yen-Ju. "Modeling, prediction and mitigation of power distribution system voltage distortion caused by nonlinear loads /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974696.
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Raj, Kumar Bharathi Nieraj. "Electrical Networks of CorPower Wave Farms : Economic Assessment and Grid Integration Analysis of Voltage." Thesis, KTH, Elkraftteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-221833.
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On the path towards the commercialisation of wave energy, there are still certaindevelopmental challenges to be tackled by industry and academia. One of these challengesis the grid integration of wave farms along with the development of the offshore electricalnetworks for the farms. These networks are distinct from those of offshore wind farms oncertain features – connection layouts, electrical interface equipment (subsea connectors),power ratings and cable lengths amongst many others. These differences apart from somechallenges unique to wave farms make the corresponding research attractive.CorPower Ocean AB has been developing a 250 𝑘𝑊 point-absorber type Wave EnergyConverter (WEC) and the thesis investigates the afore-mentioned challenges with a stagewiseanalysis of wave farms comprising the CorPower WECs. Prior research on electricalnetworks for CorPower WECs is limited and in this regard the objective is to gain apreliminary insight into the electrical architecture of a pre-commercial wave farm.Furthermore, the entire study is based at the wave test site of the European Marine EnergyCentre (EMEC).Analysis of network architecture and operational constraints resulted in 4 networkvariants for the farm ratings of 2 𝑀𝑊 and 10 𝑀𝑊. Three of the variants are applied to a2 𝑀𝑊 farm and are subjected to a varied analysis after which the standout variant is chosenfor subsequent modelling and analysis in the form of a 10 𝑀𝑊 farm. The comparativeanalysis includes an investigation into the capital expenditure (CAPEX), the associatedcost uncertainty, technology readiness level (TRL) of the electrical components andnetwork efficiency.Dynamic modelling and simulation of the networks is then performed on DIgSILENTPowerFactory to provide the network efficiency and voltage quality parameters includingstep voltage change, operational voltage limits and voltage flicker. The voltage quality ofthe modelled networks at the connection point are largely found to be compliant to theUK Distribution Code, applicable at the EMEC site. But, the same could not be said for theresults at some of the internal points of the electrical networks of the wave farms as thevoltage levels at certain terminals were found to be on the higher side.From the results of the thesis, a greater understanding of the compatibility of variants fora 2 𝑀𝑊 farm and 10 𝑀𝑊 farm of 250 𝑘𝑊 point-absorber WECs, has been obtained.Overall, it is believed that the thesis has contributed to the growing reservoir ofinformation on offshore electrical networks of wave farms and the corresponding gridintegration issues.På vägen mot kommersialisering av vågenergi finns det fortfarande vissautvecklingsutmaningar som måste hanteras av industrin och akademin. En av dessautmaningar är grid integrationen av våg farmar tillsammans med utvecklingen av deoffshore elnäten för gårdarna . Dessa nätverk skiljer sig från de vindkraftverk som finns påvissa områden - anslutningslayouter, elektrisk gränssnittsutrustning (subsea-kontakter),effektvärden och kabellängder bland många andra. Dessa skillnader förutom vissautmaningar som är unika för våg farmar gör att motsvarande forskning attraktiv.CorPower Ocean AB har utvecklat en punktabsorberande Wave Energy Converter (WEC)på 250 𝑘𝑊 och avhandlingen studerar på de ovan nämnda utmaningarna med en stegvisanalys av våg anläggningar som omfattar CorPower WEC. Tidigare forskning på elnät förCorPower WEC är begränsad och målet är att få en preliminär inblick i den elektriskaarkitekturen hos en kommande kommersiell våggård. Dessutom är hela studien baseradpå vågtestplatsen för European Marine Energy Center (EMEC).Analys av nätverksarkitektur och operativa begränsningar resulterade i 4nätverksvarianter för gårdarna på 2 MW och 10 𝑀𝑊. Tre av varianterna appliceras på en2 𝑀𝑊 gård och utsätts för en varierad analys varefter den utmärkbara varianten väljs förefterföljande modellering och analys i form av en 10 𝑀𝑊 gård. Den jämförande analyseninnefattar en undersökning av kapitalkostnaderna (CAPEX), associeradkostnadsosäkerheten, teknologis mognadsgrad (TRL) för de elektriska komponenternaoch nätverkseffektiviteten.Dynamisk modellering och simulering av nätverket utförs sedan på DIgSILENTPowerFactory för att tillhandahålla nätverkseffektivitet och spänningskvalitetsparametrarinklusive stegspänningsbyte, driftsspänningsgränser och spänningsflimmer.Spänningskvaliteten hos nätverket vid anslutningspunkten är i stor utsträckning befunnitatt överensstämma med den brittiska distributionskoden, som är tillämplig på EMECplatsen.Detsamma kunde inte sägas om resultaten på några av de inre punkterna ielnätens våg farmar, eftersom spänningsnivåerna vid vissa terminaler befanns vara på dethögre sidan.Av avhandlingens resultat har en större förståelse erhållit för varianternas kompatibilitetför en 2 𝑀𝑊 gård och 10 𝑀𝑊 gård med 250 𝑘𝑊 punktabsorberande WEC. Generellt ärdet troligt att avhandlingen har bidragit till den växande information om offshore elnät avvåg farmar och motsvarande grid integrationsfrågor.
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Holmgren, Åke J. "Quantitative vulnerability analysis of electric power networks." Doctoral thesis, KTH, Transporter och samhällsekonomi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3969.
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Disturbances in the supply of electric power can have serious implications for everyday life as well as for national (homeland) security. A power outage can be initiated by natural disasters, adverse weather, technical failures, human errors, sabotage, terrorism, and acts of war. The vulnerability of a system is described as a sensitivity to threats and hazards, and is measured by P (Q(t) > q), i.e. the probability of at least one disturbance with negative societal consequences Q larger than some critical value q, during a given period of time (0,t]. The aim of the thesis is to present methods for quantitative vulnerability analysis of electric power delivery networks to enable effective strategies for prevention, mitigation, response, and recovery to be developed. Paper I provides a framework for vulnerability assessment of infrastructure systems. The paper discusses concepts and perspectives for developing a methodology for vulnerability analysis, and gives examples related to power systems. Paper II analyzes the vulnerability of power delivery systems by means of statistical analysis of Swedish disturbance data. It is demonstrated that the size of large disturbances follows a power law, and that the occurrence of disturbances can be modeled as a Poisson process. Paper III models electric power delivery systems as graphs. Statistical measures for characterizing the structure of two empirical transmission systems are calculated, and a structural vulnerability analysis is performed, i.e. a study of the connectivity of the graph when vertices and edges are disabled. Paper IV discusses the origin of power laws in complex systems in terms of their structure and the dynamics of disturbance propagation. A branching process is used to model the structure of a power distribution system, and it is shown that the disturbance size in this analytical network model follows a power law. Paper V shows how the interaction between an antagonist and the defender of a power system can be modeled as a game. A numerical example is presented, and it is studied if there exists a dominant defense strategy, and if there is an optimal allocation of resources between protection of components, and recovery.QC 20100831
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Holmgren, Åke. "Vulnerability analysis of electric power delivery networks." Licentiate thesis, KTH, Land and Water Resources Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1738.
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Disturbances in the services provided by the infrastructuresystemse.g. electric power supplies and communicationscan have serious implications for everyday life,economic prosperity and national security. The disturbances canbe initiated by natural disasters, adverse weather, technicalfailures, human errors, sabotage, terrorism or acts of war. Theaim of this thesis is to study methods for proactivevulnerability analysis of electric power delivery networks(i.e. to analyze their sensitivity to threats and hazards), andto formalize vulnerability as a theoretical concept.
The thesis consists of three papers. In the first paper, wediscuss concepts and perspectives for developing a methodologyfor vulnerability studies with the help of the followingthemes: The properties of the infrastructure systems, threatsand hazards, vulnerability and consequence analysis, andmeasures for creating robust and resilient systems.
In the second paper we discuss how to assess vulnerabilityof power delivery systems with the help of standard powersystem performance indices. In two case studies, Swedish powerdelivery disturbance data is analyzed with statistical methods.We demonstrate that the disturbance size of large disturbancesfollows a power law distribution, and that the time betweendisturbances is exponentially distributed.
In third paper, we model electrical power networks asgraphs, and conduct empirical studies of two power transmissiongrids. We calculate values of topological characteristics ofthe networks and compare their error and attack tolerance, i.e.their performance when vertices are disabled, with twofrequently used model networks. Further, we perform a graphinfluenced vulnerability analysis of a fictitious powernetwork, and evaluate di.erent strategies to decrease thevulnerability of the system.
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Holmgren, Åke J. "Quantitative vulnerability analysis of electric power networks /." Stockholm : Division of Safety Research, Royal Institute of Technology, 2006. http://www.diva-portal.org/kth/theses/abstract.xsql?dbid=3969.
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Papadopoulos, Panagiotis. "Integration of electric vehicles into distribution networks." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/19539/.
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The objectives of this research were to investigate the impact of electric vehicle battery charging on grid demand at a national level and on the steady state parameters of distribution networks. An agent-based control system that coordinates the battery charging of electric vehicles according to electric vehicle owner preferences, distribution network technical limits and electricity prices was designed and developed and its operation was tested experimentally. The impact on grid demand peak increases at the national systems of Great Britain and Spain was evaluated using low and high electric vehicle uptake levels of 7% and 48.5% of the car fleet for the year 2030 with a deterministic method. It was found that a low uptake will not raise significantly the grid demand peaks in both countries under investigation. However, a high uptake will raise significantly the grid demand peaks. The impact from residential electric vehicle battery charging on steady state voltages, power line losses, transformers’ and cables’ loadings of distribution networks was evaluated using a deterministic and a probabilistic method. It was found that low and medium uptake levels of electric vehicles equivalent to 12.5% and 33% per residential area of 384 customers in 2030, can be safely accommodated by reinforcing the distribution network. A combination of reinforcements, installation of microgenerators and control of electric vehicle battery charging will be required to accommodate safely a high uptake of 71% with regards to the constraints studied. An agent-based control system that coordinates the battery charging of electric vehicles was designed and developed. Search techniques and neural networks were used for the decision making processes. The ability of the agent-based control system to operate successfully in both normal and abnormal conditions for the electrical network was proved with experimental validation in the laboratory of Tecnalia research institute in Spain.
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Eyisi, Chiebuka. "Load Estimation for Electric Power Distribution Networks." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5935.
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In electric power distribution systems, the major determinant in electricity supply strategy is the quantity of demand. Customers need to be accurately represented using updated nodal load information as a requirement for efficient control and operation of the distribution network. In Distribution Load Estimation (DLE), two major categories of data are utilized: historical data and direct real-time measured data. In this thesis, a comprehensive survey on the state-of-the-art methods for estimating loads in distribution networks is presented. Then, a novel method for representing historical data in the form of Representative Load Curves (RLCs) for use in real-time DLE is also described. Adaptive Neuro-Fuzzy Inference Systems (ANFIS) is used in this regard to determine RLCs. An RLC is a curve that represents the behavior of the load during a specified time span; typically daily, weekly or monthly based on historical data. Although RLCs provide insight about the variation of load, it is not accurate enough for estimating real-time load. This therefore, should be used along with real-time measurements to estimate the load more accurately. It is notable that more accurate RLCs lead to better real-time load estimation in distribution networks.
This thesis addresses the need to obtain accurate RLCs to assist in the decision-making process pertaining to Radial Distribution Networks (RDNs).This thesis proposes a method based on Adaptive Neuro-Fuzzy Inference Systems (ANFIS) architecture to estimate the RLCs for Distribution Networks. The performance of the method is demonstrated and simulated, on a test 11kV Radial Distribution Network using the MATLAB software. The Mean Absolute Percent Error (MAPE) criterion is used to justify the accuracy of the RLCs.M.S.E.E.
Masters
Electrical Engineering and Computing
Engineering and Computer Science
Electrical Engineering
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Kostiner, Barry J. (Barry Joseph). "Spatial market equilibrium for resistive electric networks." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/37544.
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Al-Tubuly, Abdulnasir. "Roaming Interoperability for Electric Vehicle Charging Networks." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35157.
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The purpose of this thesis is to analyze the maturity and the performance of the currently available roaming solutions that provide interoperability and roaming services to Electrical Vehicle Charging Networks.
At least three different entities are involved in an Electrical Vehicle (EV) charging roaming scenario, namely the EV, the home charging network and the visited charging network. All of these entities have to interface and interact with each other on the physical and the communication protocols level.
The Open Clearing House Protocol (OCHP) roaming protocol is implemented and its performance is evaluated against the e-Clearing.net test platform. The protocol functionality for billing and its suitability for different scenarios is also evaluated. Furthermore, an extension to the protocol is proposed to support prepaid subscription, and its performance is also estimated.
The findings of this study have verified the performance and the maturity of the OCHP protocol, and strongly recommends the implementation of roaming protocols and clearing houses. The estimated performance of the proposed extension confirmed that both prepaid and postpaid billing can be realized using the tested roaming protocol and clearing house implementations.
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Campillo, Javier. "From Passive to Active Electric Distribution Networks." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-31592.
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Large penetration of distributed generation from variable renewable energy sources, increased consumption flexibility on the demand side and the electrification of transportation pose great challenges to existing and future electric distribution networks. This thesis studies the roles of several actors involved in electric distribution systems through electricity consumption data analysis and simulation models. Results show that real-time electricity pricing adoption in the residential sector offers economic benefits for end consumers. This occurs even without the adoption of demand-side management strategies, while real-time pricing also brings new opportunities for increasing consumption flexibility. This flexibility will play a critical role in the electrification of transportation, where scheduled charging will be required to allow large penetration of EVs without compromising the network's reliability and to minimize upgrades on the existing grid. All these issues add significant complexity to the existing infrastructure and conventional passive components are no longer sufficient to guarantee safe and reliable network operation. Active distribution networks are therefore required, and consequently robust and flexible modelling and simulation computational tools are needed for their optimal design and control. The modelling approach presented in this thesis offers a viable solution by using an equation-based object-oriented language that allows developing open source network component models that can be shared and used unambiguously across different simulation environments.
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Christoforidis, George P. "Harmonic analysis of power systems connected to converter substations." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/14994.
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陳卓雄。 and Chuk-hung Chan. "Design and evaluation of active power factor correction circuit operation in discontinuous inductor current mode." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31220344.
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Chan, Chuk-hung. "Design and evaluation of active power factor correction circuit operation in discontinuous inductor current mode /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2062315X.
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Ferreira, Luis Antonio Fialho. "A network-based approach to power system security assessment and control." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/15721.
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Maurini, Corrado. "ELECTROMECHANICAL COUPLING OF DISTRIBUTED PIEZOELECTRIC TRANSDUCERS FOR PASSIVE DAMPING OF STRUCTURAL VIBRATIONS: COMPARISON OF NETWORK CONFIGURATIONS." Phd thesis, Virginia Tech, 2002. http://tel.archives-ouvertes.fr/tel-00994396.
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In this work passive piezoelectric devices for vibration damping are studied. It is developed the basic idea of synthesizing electrical wave guides to obtain an optimal electro-mechanical energy exchange and therefore to dissipate the mechanical vibrational energy in the electric form. Modular PiezoElectroMechanical (PEM) structures are constituted by continuous elastic beams (or bars) coupled, by means of an array of PZT transducers, to lumped dissipative electric networks. Both refined and homogenized models of those periodic systems are derived by an energetic approach based on the principle of virtual powers. Weak and strong formulation of the dynamical problem are presented having in mind future studies involving the determination of numerical solutions. In this framework the effectiveness of the proposed devices for the suppression of mechanical vibrations is investigated by a wave approach, considering both the extensional and flexural oscillations. The optimal values of the electric parameters for a fixed network topology are derived analytically by a pole placement technique. Their sensitivities on the dimensions of the basic cell of the periodic system and on the design frequency are studied. Moreover the dependence of damping performances on the frequency is analyzed. Comparing the performances of different network topological configurations, the advantages of controlling a mechanical structure with an electric analog are shown. As a consequence of those results, new interconnections of PZT transducers are proposed. An experimental setup for the validation of the analytical and numerical results is proposed and tested. A classical experience on resonant shunted PZT is reproduced. Future experimental work is programmed.
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阮國豪 and Kwok-hoo Yuen. "Probabilistic analysis of harmonics in railway traction system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31225561.
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Solomyak, Margarita. "Essential spanning forests and electric networks in groups /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/5767.
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Shaaban, Mohamed Mohamed Abdel Moneim. "Calculation of available transfer capability of transmission networks including static and dynamic security." Thesis, Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576817.
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Mbango, Fessor. "Investigation into alternative protection solutions for distribution networks." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1107.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009Recently, due to concerns about the liberalization of electricity supply, deregulation and global impact on the environment, securing a reliable power supply has become an important social need worldwide To ensure this need is fulfilled, detailed investigations and developments are In progress on power distribution systems protection and the monitoring of apparatus which Is part of the thesis. The main objective of a protection schemes is mainly to keep the power system stable by isolating only the affected components or the section of the electricity network in which the fault has developed while allowing the rest of the network to continue operating. It is important to note that the protection equipment does not prevent faults from occurring, but it limits the damaging effect of the fault and protects other healthy equipment. This is only achieved if the protection system of the electrical network involved complies with the requirements and purpose of the electrical protection standards. These requirements include the Operational speed, Reliability, Security and Sensitivity. In conventional substations that are still existing Within the utilities networks, a number of long cables are then used to complete the links between substation equipment in order for them to communicate (hardwired). This method is uneconomical and is being phased out completely in the near future. Over the last few years a new standard for substation automation communication has been developed Within the International Electrotechnical Commission (IEC), the IEC 61850. This standard defines the integration requirements of multi-vendor compliant relays and other lED's for multiple protection schemes as well as control and automation techniques. In this particular thesis, Distribution protection is the area of interest, particularly the application of Time and Overcurrent protection schemes. A look into different protection alternatives and the application of new technologies for Electrical Power Distribution Systems that unify protection and control units so that they can be incorporated into Intelligent Substation as opposed to the most existing (conventional substation) is analyzed. The proposed algorithm has been verified through simulations of the CPUT and Eureka three phase power distribution systems. A testing Lab is also part of this thesis and Is meant for experiments as well as simulation performance in order to gain knowledge and skills for designing and engineer substations with lEG 61850 standards equiprnents. The results indicate that the reduction of copper wiring cable has increased and the communication speed has improved and simplified.
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Kirawanich, Phumin. "Fuzzy logic control for an active power line conditioner /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060114.
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Hänninen, Seppo. "Single phase earth faults in high impedance grounded networks : characteristics, indication and location /." Espoo [Finland] : Technical Research Centre of Finland, 2001. http://www.vtt.fi/inf/pdf/publications/2001/P453.pdf.
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Van, Greunen Corneluis Erasmus. "Neutral-point-clamped shunt active filter." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1265.
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Gursoy, Ekrem Niebur Dagmar. "Independent component analysis for harmonic source identification in electric power systems /." Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/1781.
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Eren, Levent. "Bearing damage detection via wavelet packet decomposition of stator current /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074397.
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Amushembe, Hilde. "Flow charts and indices for evaluating true efficiency and effectiveness of harmonic filters in power systems." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/1182.
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Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of TechnologyTraditionally, efficiency is defined for sinusoidal networks and not for non-sinusoidal networks. For this reason, the efficiency formula and indices for efficiency calculations are reviewed. The concepts for determining powers, efficiency and power direction of flow in a non-sinusoidal network are explained. A new index „True Efficiency‟ is introduced to represent efficiency in non-sinusoidal circuits. Harmonic filters are installed in networks with harmonic distortion levels above the set standards for harmonic mitigation. However, there are no specific indices for evaluating the effectiveness of filter(s), hence the introduction of the index „Filter Effectiveness‟. Two software tools are utilised to develop flow charts and indices for evaluating true efficiency and effectiveness of harmonic filters in a power system under distorted waveform conditions. In this way, the effect that distortions have on efficiency can be determined and the effectiveness of the mitigation measure in place can be evaluated. The methodologies are developed using a step-by-step approach for two software packages. Three case studies were conducted on a large network. This network has multiple harmonic sources and capacitor banks. The first case study considered a network with two harmonic sources and three capacitor banks of which two are at the point of common coupling (PCC) and one is at a load bus; the second case study considered Case 1 with two capacitor banks at the PCC used as components for the 2nd - order filter and the third case considered Case 2 with a Notch filter added at one of the load buses. The network was simulated using DIgSILENT and SuperHarm software packages. DIgSILENT can calculate powers while SuperHarm gives current and voltages and power is hand calculated. The two packages were used together to test their compatibility and verify the network modelling. For the different investigations conducted, the software-based methodologies developed to calculate true efficiency in a network with multiple harmonic sources and capacitor banks have been shown to be effective. The indices developed for evaluating the effectiveness of harmonic filters proved to be effective too. The two software packages used proved to be compatible as the results obtained are similar. The methodologies can easily be adapted for investigations of other large networks as demonstrated in this study. The true efficiency methodologies are thus recommended for application in this field as it will help determine efficiency for networks with non-linear loads and help mitigate the distortions.
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Bi, Tianshu. "Distributed intelligent system for on-line fault section estimation of large-scale power networks." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576714.
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Grau, Iñaki. "Management of electric vehicle battery charging in distribution networks." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/48664/.
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This thesis investigated the management of electric vehicle battery charging in distribution networks. Different electric vehicle fleet sizes and network locations were considered. The energy storage capacity and backup generator’s energy requirements were calculated to achieve daily energy balance in a low voltage distribution network with micro-generation. The effect of the electric vehicle battery demand as controllable loads on the backup generator energy requirements was assessed. It was found that the use of electric vehicles as controllable loads reduced the energy requirements from the backup generator or made it unnecessary to achieve energy balance. Two control algorithms for the battery charging management of electric vehicles clustered in battery charging facilities were designed and developed. One algorithm calculates electric vehicle battery charging profiles for vehicles located in a parking space. Different charging policies were investigated, showing the ability of the control algorithm to define the electricity profile of the parking space according to network constraints and the policies’ objectives. The second algorithm calculates the number of batteries and chargers that are required to satisfy the battery demand of electric vehicle battery swapping stations. The impact of the number of chargers and batteries on the swapping station’s electricity load profile were evaluated. An agent-based control system was designed and developed for the battery charging management of electric vehicles dispersed in distribution networks. The electric vehicle battery charging schedules are calculated according to electricity prices and distribution network technical constraints. The real-time operation of the agent-based control system was demonstrated in the laboratory of TECNALIA’s research centre in Bilbao, Spain. A series of experiments showed the ability of the control system to operate and manage the electric vehicle battery charging when the distribution network is operated within its loading capacity and when the network technical limits are violated.
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El-balluq, Tariq Nuri. "Adaptive speed control of electric drives using neural networks." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399007.
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ZEBULUM, RICARDO SALEM. "NEURAL NETWORKS IN LOAD FORECASTING IN ELECTRIC ENERGY SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1995. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9514@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREsta dissertação investiga a utilização de Redes Neurais Artificiais (RNAs) na área de previsão de carga elétrica. Nesta investigação foram utilizados dados reais de energia relativos ao sistema elétrico brasileiro. O trabalho consiste de quatro partes principais: um estudo sobre o problema de previsão de carga no contexto de sistemas elétricos de potência; o estudo e a modelagem das RNAs para previsão de carga; o desenvolvimento do ambiente de simulação; e o estudo de casos. O estudo sobre o problema de previsão de carga envolveu uma investigação sobre a importância da previsão de demanda de energia na área de sistemas elétricos de potência. Enfatizou-se a classificação dos diversos tipos de previsão de acordo com o seu horizonte, curto e longo prazo, bem como a análise das variáveis mais relevantes para a modelagem da carga elétrica. O estudo também consistiu da análise de vários projetos na área de previsão de carga, apresentando as metodologias mais utilizadas. O estudo e a modelagem de RNAs na previsão de carga envolveu um extenso estudo bibliográfico de diversas metodologias. Foram estudadas as arquiteturas e os algoritmos de aprendizado mais empregados. Constatou-se uma predominância da utilização do algoritmo de retropropagação (Backpropagation) nas aplicações de previsão de carga elétrica horária para curto prazo. A partir desse estudo, e utilizando o algoritmo de retropropagação, foram propostas diversas arquiteturas de RNAs de acordo com o tipo de previsão desejada. O desenvolvimento do ambiente de simulação foi implementado em linguagem C em estações de trabalho SUN. O pacote computacional engloba basicamente 3 módulos: um módulo de pré-processamento da série de carga para preparar os dados de entrada; um módulo de treinamento da Rede Neural para o aprendizado do comportamento da série; e um módulo de execução da Rede Neural para a previsão dos valores futuros da série. A construção de uma interface amigável para a execução do sistema de previsão, bem como a obtenção de um sistema portátil foram as metas principais para o desenvolvimento do simulador. O estudo de casos consistiu de um conjunto de implementações com o objetivo de testar o desempenho de um sistema de previsão baseado em Redes Neurais para dois horizontes distintos: previsão horária e previsão mensal. No primeiro caso, foram utilizados dados de energia da CEMIG (Estado de Minas Gerais) e LIGHT (Estado do Rio de Janeiro). No segundo caso, foram utilizados dados de energia de 32 companhias do setor elétrico brasileiro. Destaca-se que a previsão mensal faz parte de um projeto de interesse da ELETROBRÁS, contratado pelo CEPEL. Para ambos os casos, investigou-se a influência do horizonte de previsão e da época do ano no desempenho do sistema de previsão. Além disso, foram estudadas as variações do desempenho das Redes Neurais de acordo com a empresa de energia elétrica utilizada. A avaliação do desempenho foi feita através da análise das seguintes estatísticas de erro: MAPE (Mean Absolute Percentage Error), RMSE (Root Mean Square Error) e U de Theil. O desempenho das RNAs foi comparado com o de outras técnicas de previsão, como os métodos de Holt-Winters e Box & Jenkins, obtendo-se resultados, em muitos casos, superiores.
This dissertation investigates the application of Artificial Neural Networks (ANNs) in load forecasting. In this work we have used real load data from the Brazilian electrical system. The dissertation is divided in four main topics: a study of the importance of load forecasting to electric power systems; the investigation of the ANN modeling to this particular problem; the development of a neuro-simulador; and the case studies. It has been made an investigation of the objectives of load forecasting to power systems. The different kinds of load forecasting have been classified according to the leading time of the prediction (short and long term). The more important variables to model electric load were also investigated. This study analyses many projects in the area of load forecasting and presents the techniques that have been traditionally used to treat the problem. The ANNs modeling to load forecasting involved a deep investigation of works that have been published. The ANNs architectures and learning algorithms more commonly used were studied. It has been verified that the Backpropagation algorithm was the more commoly applied in the problem (particularly, in the problem of short term hourly load forecasting). Based on this investigation and using the backpropagation algorithm, many Neural Networks architetures were proposed according to the desired type of forecasting. The development of the neuro-simulator has been made in C language, using SUN workstations. The software is divided in 3 modules: a load series pre-processing module, to prepare the input data; a training module to the load series behavior learning; and an execution module, in which the Neural Network will perform the predictions. The development of a friendly interface to the forecasting system execution and the portability of the system were main goals during the simulator development. The case studies involved testing the system performance for 2 cases: hourly and monthly predictions. In the first case, load data from CEMING (State of Minas Gerais) and LIGHT (State of Rio de Janeiro) has been used. In the second case load data from 32 companies of the Brazilian electrical system has been used. Monthly load forecasting is involved in a project of interest of two companies of the electric sector in Brazil: CEPEL and ELETROBRÁS. In both cases, influences of the forecasting horizon and of the period of the year in the system´s performance has been investigated. Besides, the changes in the forecasting performance according to the particular electric company were also studied. The performance evaluation has been done through the analysis of the following error figures: MAPE (Mean Absolute Percentage Error), RMSE (Root Mean Square Error) and Theil´s U. The ANN performance was also compared with the performance of other techniques, like Holt-Winteres and Box-Jenkins, giving better results in many cases.
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Major, Maximillian R. "High-fidelity simulations of transverse electric waves propagating through Alcator C-Mod." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112469.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (page 28).
This project represents an attempt to model the propagation of microwaves into Alcator C-Mod's plasma in high fidelity and with a reduced number of degrees of freedom. The success of this endeavor would accelerate progress within the field of fusion energy, as simulations of C-Mod's plasmas, or other plasmas in general, can be run more quickly while still maintaining their accuracy. The main procedure involves producing simulations within COMSOL that use mode numbers based on a power spectrum of waves at 4.6 GHz. These simulations are then overlaid to model how the waves will propagate as a function of position, plasma density, and local flux. Future work could focus on verifying the accuracy of the simulations when compared to data acquired from C-Mod as well as ensuring the run-time of the simulations is indeed faster than other methods.
by Maximillian R. Major.
S.B.
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Shivacharan, Rajat S. "SELF-PROPAGATING, NON-SYNAPTIC HIPPOCAMPAL WAVES RECRUIT NEURONS BY ELECTRIC FIELD COUPLING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1554920779970426.
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Cho, Namhun. "Allocation of individual harmonic emission limits in accordance with the principles of IEC/TR 61000-3-6." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49075.
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A model of the accurate harmonic allocation methods is developed to improve the current emission limits of IEEE Std.519. IEC 61000-3-6 and IEEE Std. 519 have by now been accepted as two well known standards for interconnecting the MV and HV-EHV customers to utility systems and widely adopted as standards to many power utilities. It is worth noting that the harmonic current emission limits of both standards have not been compared and justified with analytical proofs because there is still no explanation that discusses the origin of the emission limits in IEEE Std. 519, or the complex feature of IEC 61000-3-6. Two new novel methods of allocating the harmonic current emission limits for MV customers and HV-EHV customers have been proposed. Both methods have been developed in accordance with the principles of IEC 61000-3-6. Task II has compared and investgated the emission limits of both IEC 61000-3-6 and IEEE Std. 519. The difference, inconsistency and inaccuracy have been proven with the perspective of practical evaluations based on their own principles. The investigations focus on the specific numerical proofs of the resulting voltage distortions and the current emission limits in the MV and HV-EHV systems rather than on the philosophies. The proposed methods strongly support IEC 61000-3-6 and IEEE Std. 519, and add to their value; these methods could also help utilities allocate fairly and accurately harmonic emission limits to their MV and HV-EHV customers.
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Šimek, Petr. "Analýza dosahu signálu bezdrátových sítí." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363825.
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This master's thesis describes process of design and development of the system for calculating the coverage of wireless networks, it is implemented as a web portal and written in the Java programming language. The text of the thesis describes the work with the used platforms, a description of the ITU-R calculation method P.1812, which is used for calculation electric field strength and basic information about electromagnetic waves. The main function of the system is to calculate and display coverage of wireless networks and customer management information.
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Yang, Jiarui. "Reinforcement Learning-based Handover in Millimeter-wave Networks." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295495.
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Millimeter Wave (mmWave) is a key technology to meet the challenge of data rates and the lack of bandwidth in sub-6GHz networks. Due to a high operation frequency, the mmWave network has unique channel characteristics and a relatively high pathloss. Therefore, a dense deployment of Base Station (BS) is necessary, leading to a more frequent handover, which may cause a degradation of User Equipment (UE) experience. Furthermore, a massive number of devices cause an interference issue and a high dropping probability. In this project, we propose a handover method based on Reinforcement Learning (RL). This handover method provides a seamless connection and considers the load balancing. To verify the proposed method, Q-learning is selected to solve this RL problem and a simulation environment of mmWave is set up, including the pathloss model, system model, and beamforming. The average data rate, number of handovers, and number of available resources are evaluated during the movement of UEs. The results are compared with rate-max method and random backup method in different interference scenarios. Our proposed method shows a notable performance in terms of data rate, for example, while doubling the interference, the data rate decreases 8.6% with our method while it decreases 20% with the random-backup method. Moreover, our method has the minimum number of handovers in the trajectory. The performance in multiple trajectories is also illustrated and it performs as expected.Millimeter Wave (mmWave) är en nyckelteknologi för att möta utmaningen med datahastigheter och bristen på bandbredd i sub-6GHz-nätverk. På grund av den höga driftsfrekvensen har mmWave-nätverket unika kanalegenskaper och en relativt hög banförlust. Därför är en tät användning av basstationen (BS) nödvändig vilket leder till en mer frekvent överlämning, vilket kan orsaka en försämring av User Equipment (UE) upplevelse. Dessutom orsakar ett stort antal enheter störningsproblem och en hög dropping probability. I det här projektet föreslår vi en överlämningsmetod baserad på Reinforcement Learning (RL). Denna överlämningsmetod ger en sömlös anslutning och tar hänsyn till lastbalanseringen. För att verifiera den föreslagna metoden har en simuleringsmiljö på mmWave ställts in, inklusive banförlust-modellen, systemmodellen och strålformning. Genomsnitt datahastighet, antal överlämningar och antal tillgängliga resurser utvärderas under förflyttning av UE: er. Resultaten jämförs med rate-max metod och slumpmässig säkerhetskopieringsmetod i olika störningsscenarier. Vår föreslagna metod visar en anmärkningsvärd prestanda när det gäller datahastighet, till exempel, när interferensen fördubblas minskar datahastigheten 8,6% med vår metod medan den minskar 20% med slumpmässig säkerhetskopieringsmetod. Dessutom har vår metod det minsta antalet överlämningar i banan. Prestandan i flera banor illustreras också och den fungerar som förväntat.
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Zhang, Yuan. "STM Investigation of Electric Polar Molecular Self-Assembly and Artificial Electric Polar Molecular Rotors." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1416927903.
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Radibratovic, Branislav. "Reactive optimization of transmission and distribution networks." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/28264.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Begovic, Miroslav; Committee Member: Divan, Deepakraj; Committee Member: Dorsey, John; Committee Member: Ferri, Bonnie; Committee Member: Lambert, Frank.