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Dissertations / Theses on the topic 'Lightning protection'
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1
Foya, Ufuk Candar. "Protection Of Structures Against Lightning." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605173/index.pdf.
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This thesis analyses the lightning protection concept. After a brief introduction to lightning, lightning discharge process and the consequences of a lightning stroke, the worldwide standards for the protection of structures against lightning are analysed and compared in the scope of requirement for the lightning protection.
The lightning protection systems since Franklin are traced and the protection methods are re-arranged in the basis of rolling sphere method. after discussing the changing philosophy in lightning protection, cage method is examined and applications of cage method are done according to different protection levels.
This thesis seek an answer to the question such that which the safest method for the protection of structures against lightning according to new requirements would be.
2
Cotton, Ian. "Lightning protection of wind turbines." Thesis, University of Manchester, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578062.
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Peesapati, Vidyadhar. "Lightning protection of wind turbines." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/lightning-protection-of-wind-turbines(e710c763-840e-4b76-b7a5-0d006c4e0983).html.
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Wind turbines are the largest contributor to renewable energy both in Britain and the rest of Europe. With a rise in the installed capacity and an increase in offshore wind energy due to governments green targets by 2020, there has been a large development in new wind turbines for optimized performance. The present thesis deals with the uncertainties in regards to the lightning phenomenon on wind turbines with emphasis on the rotor blades. Rotor blades are the most expensive part to replace in the event of lightning related damage. The research presents results based on lightning data analysis on wind turbines, backed up by finite element analysis testing of wind turbine systems. The final chapters include the testing and improving of lightning protection systems installed on modern day rotor blades. The first part of the thesis deals with the theoretical understanding of the lightning phenomenon and its effect on wind turbine systems. The core work of the research begins with the analysis of lightning data collected over Nysted wind farm and different wind turbines installed over the world. The data analysis helps in identifying the parts of the wind turbine that are at high risk to lightning attachment and related damage. The peak current levels of the lightning strikes seen on the wind turbine are compared with those in modern day lightning standards, and show that historic data in the standards are not an exact match to the real case scenarios. The lightning data analysis also sheds light into the importance of upward initiated lightning, which will become important for large wind turbines, especially in their new offshore environment. A full scale 3D FEA model of a wind turbine, with lightning protection systems installed in its rotor blades, is subjected to electrical stresses to find likely attachment points in regards to upward initiated lightning, and these results are later compared to those found in the data analysis. The second half of the thesis deals with the testing of new materials and prototype blades, to be introduced to reduce their radar cross section. The new materials include a large amount of carbon content which affects the efficiency of the lightning protection system. High voltage and high current tests backed up with finite element analysis have been performed to find how these new materials affect the performance of the lightning protection system. The results indicate that further work needs to be done before these new materials can be integrated into the blade, as they increase the risk of lightning related damage to the blade.
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Constable, Michael. "Design guidelines for lightning protection of PV systems." Thesis, Constable, Michael (2013) Design guidelines for lightning protection of PV systems. Other thesis, Murdoch University, 2013. https://researchrepository.murdoch.edu.au/id/eprint/21669/.
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Lightning is a powerful and potentially destructive force of nature; failure to include appropriate measures in the design and construction of buildings can have severe consequences. The electrical and physical forces released during a lightning strike can result in serious damage to structures, electrical infrastructure and the sensitive electronic components used in computers, media devices and electronic systems that have become crucial to the modern existence.
Developments in electronics technology have resulted in the increased proliferation of PV systems and devices that incorporate sensitive electronic components. The average modern home will include a PV system, microwave, inverter controlled air conditioner, multiple computers and permanently connected media devices; all contain electronic components that will fail when exposed to the electrical surges associated with lighting strikes.
PV arrays are generally installed on the roof or immediately adjacent to a structure and generally do not change the likelihood that lighting will strike a building. However the modules and their associated framework provide sharp conductive points that are close to the peaks or edges of a roof line. Therefore in the event that lightning strikes a building they are more likely to form part of the conductive path and provide a direct connection into the structures and electrical systems of the buildings they are mounted on.
This thesis documents the nature of lightning and the associated risk, a detailed gap analysis of International & Australian lightning protection standards and the development of lightning protection assessment tools. Additionally it documents the use of the developed tools to conduct a lighting protection assessment of the recently constructed Murdoch Engineering building, which includes 4 roof mounted PV systems that alter the building profile.
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Evans, Joanne Caroline. "Investigation into the effectiveness of non-conventional lightning protection." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366763.
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Song, Yang. "STUDY OF THE LIGHTNING PROTECTION ZONE OF THE FRANKLIN ROD." MSSTATE, 2004. http://sun.library.msstate.edu/ETD-db/theses/available/etd-05142004-102630/.
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The protection zone of the Franklin Rod is widely used in practice due to its effectiveness and the wide usage. The theories are based on the mathematical approaches, regardless of physical inherence of lightning strokes. The study of this thesis is based on computer analysis of the field distribution in pre-breakdown stage, laboratory experiments of various test configurations and mathematical modeling. The impact of the Franklin Rod¡¯s height and the polarity of impulse are considered. New equations are developed to calculate the striking distance to Franklin Rod both under negative and positive polarity lightning strokes. The lightning protection zone of the Franklin Rod can be predicted by a proposed elliptical model. The experimental data coincides to the calculated protection zone by proposed equations. Finally, the dual-rod lightning protection system is studied. The protection zone of the dual-rod protection system can be evaluated by a combination of Rolling Sphere Circular Model and elliptical model.
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Lewke, Bastian [Verfasser]. "Lightning Protection of Wind Turbine Blades and Hub / Bastian Lewke." Aachen : Shaker, 2010. http://d-nb.info/1122546319/34.
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Zhou, QiBin. "Lightning-induced impulse magnetic fields in high-rise buildings." online access from Digital Dissertation Consortium, 2007. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3290138.
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Mallick, Shreeharsh. "Laboratory study on lightning performance of dissipation devices." Master's thesis, Mississippi State : Mississippi State University, 2009. http://library.msstate.edu/etd/show.asp?etd=etd-07082009-111635.
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Sweers, G. James. "Methodology for the design assurance of aricraft lightning protection systems continued airworthiness." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6455.
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This thesis describes a new approach to lightning protection components design by
incorporating the use of multiple data sources, aircraft environmental threats models
and component characteristics to determine if the component design meets the
continued airworthiness requirements. This innovative aircraft lightning protection
component design methodology examines critical component characteristics and
evaluates these characteristics for long term survivability given known environmental
design data. Use of in-service data, test data, material sciences and detailed
component construction produces predictive results and provides inputs for the
design community.
A simple case of non-active lightning protection components was used to validate this
methodology, concluding that certain design degradation mitigations are necessary to
improve the continued airworthiness performance.
Following this validation, the methodology was exercised by several case studies using
actual design data from a large transport aircraft. The case studies provide for
understanding how the methodology can be applied and showed that value was
produced in creating design optimizations for the protection components. The case
studies also proved that the methodology could be applied to different lightning
protection designs spanning from structural design protection components to systems
infrastructure transport elements and wiring. For this work, analysis sheets were
designed to provide the necessary design assessments to apply the methodology.
Finally, the thesis concludes that application of this design methodology worked well
for evaluation and optimization of lightning protection components and may work
well for other aircraft system components. Future work associated with this study
suggests that the methodology could more effectively deployed by use of an
integrated computing system with the ability to share data efficiently between key
design groups including electrical wiring design, electrical earthing engineering,
electrical standards engineering, structural protection engineering and maintenance
engineering departments.
11
Wiid, P. Gideon. "Lightning protection and radio frequency interference mitigation for the Karoo Array Telescope." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4009.
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Thesis (PhD (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: South Africa and Australia are now the two remaining countries bidding for the Square Kilometre Array (SKA), the biggest and most sensitive project ever undertaken in radio astronomy. The South African SKA is demonstrating its technology capabilities through the Karoo Array Telescope (KAT or MeerKAT). The development of KAT is taking place in stages to optimise design and minimise risks at each stage. An array of seven 12 m antennas will be complete by the end of 2009, called KAT-7. The following phase will see the construction of MeerKAT, which will lead to eighty arrayed dishes. Lightning and RFI studies for KAT-7 are the focus of this dissertation. Due to the extent and complexity of the South African demonstrator project, these studies have largely been conducted on a single structure. Parameters for the dish antenna and pedestal design changed throughout their development. To be effective, the doctoral research had to track these changes appropriately. A Method of Moments frequency domain computational electromagnetic code, FEKO, is used throughout the study. The consequences of direct and indirect lightning strikes are examined for the KAT-7 structure. Important FEKO model verification is achieved through measurement of physical scale models in an anechoic chamber. The microwave simulation code, CST, gives direct comparison of FEKO results by using a finite volume time domain method of calculation. Using frequency domain analysis on these models, the lightning down conductor design over the dish antenna bearings is optimised with cost-effectiveness as one driving parameter. RFI coupling levels for different designs are compared to each other to identify areas requiring RFI mitigation. Analysis of resonances enables evaluation of the mitigation at frequencies sensitive to radio astronomy. A Sommerfeld integral ground plane is used together with the computational model to investigate the use of the concrete foundation steel reinforcing as part of the lightning earthing electrode system. Different interconnections of the steel reinforcing elements are critically evaluated. The KAT-7 design incorporated clear lightning protection and RFI mitigation policies derived from recommendations contained within this dissertation.
AFRIKAANSE OPSOMMING: Suid-Afrika en Australie is nou die oorblywende twee lande wat bie vir die Vierkante Kilometer Reeks (SKA), die grootste en mees sensitiewe projek nog ooit in radio astronomie onderneem. Die Suid Afrikaanse SKA demonstreer sy tegnologiese bekwaamheid met die Karoo Reeks Teleskoop (KAT of MeerKAT). Die ontwikkeling van KAT vind plaas in fases om die ontwerp te optimaliseer en risikos te minimaliseer met elke fase. ’n Reeks van sewe 12 m antennas, genaamd KAT-7, sal teen die einde van 2009 klaar wees. Die volgende fase behels die konstruksie van MeerKAT, wat sal lei tot ’n tagtig-skottel reeks. Die fokus van hierdie proefskrif hanteer weerlig en radiofrekwensie steurings (RFS) vir KAT-7. As gevolg van die omvang en kompleksiteit van die Suid-Afrikaanse demonstreerder projek, is die studies hoofsaaklik op een struktuur gedoen. Parameters vir die antenna-skottel en -voetstuk ontwerp het met hul ontwikkeling deurgaans verander. Om effektief te wees, moes die doktorale navorsing hierdie veranderinge toepaslik volg. ’n Metode-van-Momente frekwensiedomein rekenaar elektromagnetiese kode, FEKO, is deurgaans met die studie gebruik. Die gevolge van direkte en indirekte weerligslae vir die KAT-7 struktuur is ondersoek. Belangrike FEKO model bevestiging is bereik met metings van skaalmodelle in ’n anego¨ıse kamer. Die mikrogolf-simulasie kode, CST, gee ’n direkte vergelyking met die FEKO resultate deur ’n eindige-volume-tyd-domein metode van berekening te gebruik. Met behulp van frekwensiedomein analise van hierdie modelle, is die weerligafleierontwerp oor die antenna-skottel laers ge-optimaliseer, met koste-effektiwiteit as een van die drywingsparameters. RFS koppelingsvlakke vir onderskeie ontwerpe is teen mekaar opgeweeg om areas te identifiseer wat RFS tempering benodig. Analise van resonansies stel die evaluering van die tempering in staat teen frekwensies wat sensitief is vir radio astronomie. ’n Sommerfeld integrale grondvlak word saam met die rekenaarmodel gebruik om die insluiting van die beton se staalversterking as deel van die aardingselektrodestelsel te ondersoek. Verskillende bindmetodes van die onderlinge staalversterkingselemente word krities ge¨evalueer. Die KAT-7 ontwerp inkorporeer duidelike weerligbeveiligings- en RFS temperingstrategie ¨e, komende van aanbevelings in hierdie proefskrif omskryf
12
Ölund, Martin. "Electrical Surge Protection at Hydropower Plants." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-310318.
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Hydropower plants contains a lot of vital electrical power technology such as generators and transformers. To prevent damage to this equipment due to overvoltage, they are often protected by surge arrester and in some cases also by surge capacitors. The design and dimension of these components vary between different sites and regions and are often done using a template without considering the actual conditions of the site. In this thesis Simulink and Simscape Power System are used to study the case when a hydropower station is exposed to overvoltage. One of Fortum’s hydropower stations is simulated when being exposed to lightning and switching overvoltage to see how the existing overvoltage protection handles this stress. The results show that the surge arresters mounted in front of the generator managed to keep it safe for all overvoltage scenarios it is exposed to. They also shows that the surge capacitors mounted in front of the generator reduces the gradient of the overvoltage surge. However, as the surge arresters already keeps the overvoltage at safe levels, there is no need of reducing the overvoltage gradient and the surge capacitors becomes excessive in this particular hydropower plant.Vattenkraftverk innehåller många vitala komponenter så som generatorer och transformatorer. För att skydda dessa oftast väldigt dyra komponenter mot överspänningar, används ventilavledare och ibland också överspänningskondensatorer. Utformning och dimensionering av skydden varierar mellan olika anläggningar och regioner. Dimensioneringen av skydden görs ofta schablonmässigt, utan någon väsentlig anpassning till de faktiska förhållandena. I detta examensarbete används simuleringsverktyget Simulink tillsammans med tillägget Simscape Power Systems för att simulera vad som händer när ett vattenkraftverk utsätts för olika överspänningar. Ett av Fortums vattenkraftverk studeras när det utsätts för blixt- och kopplingsöverspänningar för att se vad ventilavledarna samt överspänningskondensatorerna i denna anläggning fyller för funktion. Resultaten visar att ventilavledarna monterade framför generatorn klarar av att hantera alla överspänningar de utsätt för under simuleringarna. Resultaten visade också att överspänningskondensatorerna monterade framför generatorn sänker spänningsgradienten, men eftersom ventilavledarna redan håller spänningen på en säker nivå blir överspänningskondensatorerna överflödiga i denna station.
13
Manna, Tapan K. "Impulse impedance of grounding systems and its effect on tower crossarm voltage : a dissertation presented to the faculty of the Graduate School, Tennessee Technological University /." Click to access online version, 2006. http://proquest.umi.com/pqdweb?index=97&did=1208141981&SrchMode=1&sid=1&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1256323226&clientId=28564.
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Becerra, Marley. "On the Attachment of Lightning Flashes to Grounded Structures." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8871.
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Sant'Anna, Cezar José. "Estudo do desempenho de sistemas de aterramento frente às descargas atmosféricas em instalações de baixa e média tensão /." Bauru : [s.n.], 2005. http://hdl.handle.net/11449/90798.
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Orientador: André Nunes de SouzaBanca: Geraldo Francisco Burani
Banca: Pedro da Costa Júnior
Resumo: O presente trabalho possui como linha mestra a apresentação de proposições técnicas para as instalações de baixa e média tensão na incidência de descargas atmosféricas, visando diminuir danos nos equipamentos elétricos dos consumidores. Para a realização dessas proposições foram estudados e analisados diversos casos relacionados ao sistema de aterramento recomendados pelas normas e publicações técnicas. A diretriz metodológica adotada nesta pesquisa incorporou estudos correlatos já consolidados, experimentos e também simulações computacionais. Os resultados obtidos foram analisados levando-se em conta a influência dos sistemas de aterramento e seus componentes, tais como: tipos de eletrodos, solo, tipo de condutor de descida e dispositivos de proteção contra surtos.
Abstract: The master line of this present study consists of the presentation of technical propositions related to low and medium tension installations in the incidence lightning, aiming to decrease damages on consumer's electrical equipment. For the accomplishment of those propositions, several cases related to the earthing systems recommended standards and publications have been studied and analyzed. The methodological directive adopted in the present research has been incorporated already consolidated correlate studies consolidated, experiments, as well as digital simulations. The results obtained have been analyzed taking into account the influence of the earthing systems and their components, such as: electrodes, soil, descending conductors and protection devices.
Mestre
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Mercer, Douglas. "Thor's hammer deflected : a history of the protection of power systems from lightning, with special reference to Queensland, 1950 to 1995 /." [St. Lucia, Qld.], 2001. http://adt.library.uq.edu.au/public/adt-QU20020712.164134/index.html.
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Грудина, А. В. "Реконструкція електричної частини підстанції 110/6 кВ." Master's thesis, Сумський державний університет, 2019. http://essuir.sumdu.edu.ua/handle/123456789/76188.
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Проаналізовано режим роботи підстанції і доведена необхідність модернізації основного обладнання. Розраховано та вибрано устаткування електричної частини підстанції. Проведено перевірку грозозахисту і заземлення, а також, розраховано релейних захист підстанції.
Проаналізовано та досліджено переваги та недоліки в роботі обмежувачів перенапруг. Проведено техніко-економічне обґрунтування заміни обладнання.
Особливу увагу при виконанні магістерської роботи було приділено питанням охорони здоров'я та безпеки праці персоналу підстанції під час виконання робіт.
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Liu, Yaqing. "Transient Response of Grounding Systems Caused by Lightning: Modelling and Experiments." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4556.
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Gerini, Francesco. "Locating lightning strikes and flashovers along overhead power transmission lines using electromagnetic time reversal based similarity characteristics." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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Questo lavoro di tesi si pone l’obiettivo di analizzare, verificare e implementare un nuovo metodo per la localizzazione di guasti in rete e fulminazioni basato sulla teoria ”Electromagnetic Time Reversal”. L’applicabilità della teoria è inizialmente discussa, successivamente utilizzando le classiche equazioni delle linee e le basi della teoria EMTR viene proposta una soluzione analitica per la localizzazione del guasto e/o della fulminazione. La accuratezza del metodo utilizzato viene discussa in relazione al numero di misure necessarie alla localizzazione mettendo in evidenza pro e contro rispetto alle tecniche attuali. Viene in seguito presentato un secondo metodo di localizzazione anch’esso basato sulla teoria EMTR ma non ancora verificato su un grande numero di casi, chiamato Similarity Property Method. Utilizzando il software EMTP per l’analisi di transitori e con l’ausilio di MatLab entrambi i metodi vengono testati su diverse tipologie di reti e con diverse condizioni al contorno. Infine una analisi conclusiva viene proposta, indicando come e se i metodi presentati possono essere da considerare migliorativi delle attuali tecniche di localizzazione di guasti e/o fulminazioni.
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Sueta, Hélio Eiji. "Uso de componentes naturais de edificações como parte integrante do sistema de proteção contra descargas atmosféricas - uma visão relativa aos danos físicos." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-15022006-172839/.
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Este trabalho apresenta alguns aspectos específicos sobre o tema proteção de estruturas contra descargas atmosféricas, principalmente no que se refere ao uso de partes estruturais das edificações como integrantes do sistema de proteção. São discutidos neste trabalho diversos pontos polêmicos referentes ao tema, tais como: captores especiais, o sistema dissipativo e o uso das ferragens das colunas de concreto armado como parte dos subsistemas de descida e de aterramento. São abordados, também, os principais danos que podem ocorrer nas edificações devido às descargas atmosféricas, principalmente quando a proteção utilizar partes naturais da estrutura, tais como: os telhados metálicos e as emendas das ferragens das colunas de concreto armado. Após uma verificação do estado da arte no assunto, onde são estudados diversos trabalhos, normas e livros sobre as características das descargas, sobre os danos oriundos das descargas, blindagens, medições de campos eletromagnéticos, distribuição de correntes e sobre a normalização e ensaios referentes à proteção de estruturas contra descargas atmosféricas, o assunto foi estudado em três partes que compõem os subsistemas do SPDA. No subsistema de captação, os danos em telhas metálicas e de concreto protendido foram estudados através de ensaios e verificações teóricas e, principalmente, experimentais. No subsistema de descida, o estudo experimental deu enfoque às emendas das ferragens e ao uso destas como descidas naturais. Finalmente, no subsistema de aterramento, as fundações das edificações foram estudadas através de verificações experimentais como parte do aterramento. Este trabalho acrescenta ao conhecimento atual sobre o assunto, diversas particularidades não contempladas nas normas e nas publicações mais recentes no que tange à proteção de estruturas contra as descargas atmosféricas utilizando partes naturais das edificações.This work presents some specific aspects on the subject lightning protection of structures, mainly when the use of structural parts of the buildings as part of the protection systems is concerned. Several polemical issues are discussed, such as: special air-termination, the dissipation array system and the use of steel-reinforcing rods of the reinforced concrete columns as part of the down-conductor system and of the earth-termination system. Also treated is the main damage that can occur to the buildings due to lightning, mainly when the protection system uses the natural components of the structures, such as: the metallic rooftops and the joints of the steel-reinforcing rods of the reinforced concrete columns. After examining the state-of-the-art in the subject, which analyses several papers, standards and books about lightning characteristics, damage resulting from lightning, shieldings, measurements of electromagnetic fields, distribution of currents and about standardisation and tests related to the protection of structures against lightning, the subject was studied in the three parts that compose the lightning protection systems. In the air-termination system, the damage to metallic rooftops and to pre-stressed concrete rooftop tiles was studied by means of tests and theoretical and mainly experimental analyses. In the down-conductor system, the experimental study focused on the joints of the steel-reinforcing rods and on the use of these as natural down-conductors. Finally, in the earth-termination system, the foundations of the buildings were studied (as part of the grounding) through experimental analyses. This work adds to the current knowledge about the subject several particularities which are not observed in the standards or in the most recent publications concerning the lightning protection systems in buildings that use their natural components for this purpose.
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Shigihara, Miltom. "Modeling of the behavior of medium voltage insulators against lightning overvoltages." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/106/106131/tde-27102015-091635/.
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Lightning causes important transient disturbances on transmission and distribution systems, with consequent damages to equipment, outages, and general decrease of the power quality. The assessment of the lightning dielectric strength of power equipment is generally based on tests performed using the standard lightning impulse voltage (1.2 / 50 µs waveshape), although the characteristics of the lightning overvoltages depend on many parameters and may vary widely. The behavior of insulators when subject to non-standard impulses depends both on the voltage amplitude and waveshape, and therefore a reliable model is required to produce the corresponding volt-time curves. Although there is no method universally accepted for this purpose, one of the most used is the Disruptive Effect (DE) model, which is based on the integration method concept. The application of this model involves the estimation of some parameters for which different procedures have been proposed in the literature, as for instance the procedures by Darveniza and Vlastos, by Hileman, by Chowdhuri et al., and by Ancajima et al. Tests of representative lightning overvoltages were performed to obtain the critical flashover overvoltages (CFO) and the volt-time curves of typical porcelain pin-type insulators considering three standard medium-voltage distribution classes (15 kV, 24 kV, and 36 kV) and five impulse voltage waveshapes, of both polarities. These tests provided data for the analyses of the insulators\' behavior and the results obtained using the different procedures for estimating the DE parameters. It is shown that in some cases insulator flashover is not predicted. A new method is then developed and proposed for evaluating the dielectric behavior of MV insulators. The method is validated using the typical insulators of the three voltage classes and the five lightning impulse voltages considered, of positive and negative polarities. The calculated volt-time curves showed in general a good agreement with the measured results for all the cases studied. The mean difference between the measured and calculated times to breakdown, for all the cases considered, was about 1.3 s; while the maximum difference was 4.0 s. The application of the proposed method to evaluate the occurrence of insulator flashovers in the shield wire line (SWL) system implemented in the State of Rondônia due to nearby lightning strikes supports previous conclusions that indicate that lightning has a significant impact on the SWL system performance in regions with high ground flash density.Descargas atmosféricas produzem distúrbios transitórios significativos em sistemas de transmissão e distribuição, com consequentes danos em equipamentos, interrupções e redução geral na qualidade de energia elétrica. A avaliação da suportabilidade dielétrica frente às descargas atmosféricas do equipamento de potência é geralmente baseada em ensaios realizados usando o impulso atmosférico de tensão normalizada (forma de onda 1.2 / 50 µs), contudo as características das sobretensões atmosféricas dependem de muitos parâmetros e podem variar amplamente. O comportamento dos isoladores quando sujeitos a impulsos não normalizados depende tanto da magnitude como da forma de onda da tensão, e então um modelo confiável é necessário para se obter as curvas tensão-tempo correspondentes. Embora não haja um método universalmente aceito para essa finalidade, um dos mais utilizados é o modelo de Efeito Disruptivo (DE), que é baseado no conceito do método de integração. A aplicação desse modelo envolve a estimativa de alguns parâmetros para os quais diferentes procedimentos têm sido propostos na literatura, como por exemplo, os procedimentos de Darveniza e Vlastos, de Hileman, de Chowdhuri et al. e de Ancajima et al. Ensaios de sobretensões atmosféricas representativas foram feitos para obter as tensões de descarga disruptiva (CFO) e as curvas de tensão-tempo de isoladores de porcelana típicos, tipo pino, considerando três classes de tensão de distribuição de média tensão (15 kV, 24 kV e 36 kV) e cinco formas de onda de impulso de tensão, de ambas as polaridades. Estes ensaios proporcionaram dados para as análises do comportamento dos isoladores e os resultados obtidos usando os diferentes procedimentos para estimar os parâmetros necessários para a aplicação do modelo do Efeito Disruptivo. É mostrado que em alguns casos a disrupção no isolador não é prevista por tais procedimentos. Um novo método é, então, desenvolvido e proposto para avaliar o comportamento dielétrico dos isoladores de média tensão. O método é validado usando os isoladores típicos das três classes de tensão e as cinco formas de tensões de impulso atmosféricos consideradas, de polaridades positiva e negativa. As curvas tensão-tempo calculadas mostraram, em geral, boa concordância com os resultados medidos para todos os casos estudados. A diferença média entre os tempos de disrupção medidos e calculados, para todos os casos considerados, foi da ordem de 1,3 s; enquanto a máxima diferença foi de 4,0 s. A aplicação do método proposto para avaliar a ocorrência de disrupções em isoladores do Sistema de Cabo Para-raios Energizados (PRE), implementado no estado de Rondônia, devido a descargas atmosféricas indiretas, apoia as conclusões previamente obtidas que indicam que as descargas atmosféricas têm impacto significativo sobre o desempenho do sistema PRE em regiões com alta densidade de descargas para solo.
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Sant'Anna, Cezar José [UNESP]. "Estudo do desempenho de sistemas de aterramento frente às descargas atmosféricas em instalações de baixa e média tensão." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/90798.
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santanna_cj_me_bauru.pdf: 665147 bytes, checksum: 6306cdfa87c4bda06d03c808dedff5fd (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O presente trabalho possui como linha mestra a apresentação de proposições técnicas para as instalações de baixa e média tensão na incidência de descargas atmosféricas, visando diminuir danos nos equipamentos elétricos dos consumidores. Para a realização dessas proposições foram estudados e analisados diversos casos relacionados ao sistema de aterramento recomendados pelas normas e publicações técnicas. A diretriz metodológica adotada nesta pesquisa incorporou estudos correlatos já consolidados, experimentos e também simulações computacionais. Os resultados obtidos foram analisados levando-se em conta a influência dos sistemas de aterramento e seus componentes, tais como: tipos de eletrodos, solo, tipo de condutor de descida e dispositivos de proteção contra surtos.
The master line of this present study consists of the presentation of technical propositions related to low and medium tension installations in the incidence lightning, aiming to decrease damages on consumer's electrical equipment. For the accomplishment of those propositions, several cases related to the earthing systems recommended standards and publications have been studied and analyzed. The methodological directive adopted in the present research has been incorporated already consolidated correlate studies consolidated, experiments, as well as digital simulations. The results obtained have been analyzed taking into account the influence of the earthing systems and their components, such as: electrodes, soil, descending conductors and protection devices.
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MARUMO, JULIO T. "Avaliação da contaminação provocada por para-raios radioativos de amerício-241 descartados em lixões." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11475.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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MESTRINER, DANIELE. "Lightning-induced voltages on power lines: advances in modelling, computational effort optimization and innovative tools for the protection of overhead distribution lines." Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1008296.
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The continuous growth of MV overhead distribution systems requires a constant improvement in terms of security and power quality. One of the most critical event that can cause the fault of a distribution line is represented by the atmospheric discharges and, among them, the most dangerous one is no-doubt the lightning stroke.
In the transmission and distribution systems, lightning transients can be caused by either direct or indirect strikes. Indirect strikes are much more frequent than direct strikes and can cause flashovers, especially when the line insulation level is low.
The computation of the lightning induced-voltages (i.e. the one related to the indirect strikes, which represent the most critical issue in distribution systems) is a very complicated task for two main reasons: 1) the number of uncertain parameters is high: it involves a correct representation of the current that flows in the lightning channel as well as a correct representation of the soil conductivity where the power line is located. 2) The computational complexity of the calculations that allow evaluating the final overvoltage is high because in this case we are dealing with the computation of electromagnetic fields and with the effect of such fields on the power line.
Concerning the protecting measures the most widely employed are the use of shield wires, surge arrester and the increase of the line insulation level.
This thesis aims at improving the problem of the lightning-induced voltages in overhead distribution lines in terms of three main concepts: 1) innovation of the existing models, 2) optimization of the computational effort and 3) introduction of innovative tools for the protecting scheme. In this framework, the thesis proposes a new channel-bae current model (1) , an analytical technique for the electromagnetic fields computation (2) , a new scheme for the lightning-induced voltages computation (2), a new approach for reducing the computational effort of the lightning performance computation (2 and 3) and an innovative approach for the evaluation of the mitigation effect of shield wires on the lightning-induced voltages (3).
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Spozito, Junior José Saverio [UNESP]. "Sistema de aterramento com cabo contrapeso representado por linhas de transmissão implementado em Matlab com circuitos em cascatas de PÍ." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/87156.
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spozitojunior_js_me_ilha.pdf: 739577 bytes, checksum: 774270e35ff8542bb48191719879dc4a (MD5)Este estudo é um levantamento de artigos e publicações sobre os diversos sistemas de aterramento existentes. Os sistemas de aterramento estão diretamente ligados à proteção das instalações de subestações e equipamentos empregados na geração, transmissão e distribuição de energia elétrica que por ocasião das descargas atmosféricas diretas ou por tensões induzidas por campos eletromagnéticos decorrentes, possam ser prejudicados. O Método propõe o estudo de um sistema de aterramento, com cabo contrapeso, utilizando abordagem por linhas de transmissão representada por uma cascata de circuitos π, analisado e simulado pelo “Software Matlab”. Utilizou-se a simulação com o emprego de programa no Matlab para linhas de transmissão de energia elétrica, a primeira com comprimento de dez mil metros e outra com oitenta metros, utilizada como referencial na comparação das respostas aos sinais de entrada aplicados nos circuitos π simulando o cabo contrapeso com seus componentes representado pelos parâmetros elétricos. Através de variação no parâmetro resistividade do solo comparou-se os resultados mostrados nos gráficos da tensão elétrica na terminação do cabo contrapeso, simulado como uma linha de transmissão com terminação em aberto. Como analise adicional em termos de segurança foi implementado no programa a analise das tensões elétricas ao longo do cabo contrapeso, excitado por aplicação de sinais de tensão elétrica e de corrente elétrica estabelecendo a comparação entre os potenciais elétricos sobre o solo em valores máximos que podem afetar seres vivos
This study is a survey of articles and publications on the various existing grounding systems. The grounding systems are directly linked to the protection of substation facilities and equipment used in the generation, transmission and distribution of electric power, due to induced voltages by lightning’s generating electromagnetic fields . The method proposed in this study, about a grounding system made with a buried cable using the approach by transmission lines method, represented by a cascade of π circuits analyzed and simulated by Matlab Software. The simulation with the Matlab program on transmission lines of electricity, one ten thousand meters in length and another eighty meters respectively, to serve as a reference in comparison between responses to input signals applied to the cable simulated by π circuit employing the parameters involved. Through variation in the soil resistivity parameter, the results are shown in the graphs of voltage in the termination of the grounding cable, simulated as an open line at end. As further analysis in terms of safety, was implemented the analysis of the voltages along the cable, by applying voltage signals and current to check the electrical potentials on the ground, the maximum values that affect persons
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Клочко, О. О. "Аналіз робочого режиму електричної підстанції 110/6 кВ та модернізація обладнання." Master's thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/71332.
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Проведений аналіз існуючого режиму роботи підстанції і доведена необхідність її модернізації. Проведений вибір і перевірка основного устаткування підстанції. Проведено перевірку грозозахисту і заземлення. Вибраний релейних захист підстанції. Досліджена доцільність переходу від розрядників до обмежувачі перенапруг. Проведено техніко-економічне обґрунтування заміни обладнання. Особливу увагу при виконанні магістерської роботи було приділено питанням охорони здоров'я та безпеки праці. Для службового персоналу на даній підстанції представлені заходи по техніці безпеки.
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Spozito, Junior José Saverio. "Sistema de aterramento com cabo contrapeso representado por linhas de transmissão implementado em Matlab com circuitos em cascatas de PÍ /." Ilha Solteira : [s.n.], 2012. http://hdl.handle.net/11449/87156.
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Orientador: Luiz Fernando BovolatoBanca: Sérgio Kurokawa
Banca: Rodrigo Capobianco Guido
Resumo: Este estudo é um levantamento de artigos e publicações sobre os diversos sistemas de aterramento existentes. Os sistemas de aterramento estão diretamente ligados à proteção das instalações de subestações e equipamentos empregados na geração, transmissão e distribuição de energia elétrica que por ocasião das descargas atmosféricas diretas ou por tensões induzidas por campos eletromagnéticos decorrentes, possam ser prejudicados. O Método propõe o estudo de um sistema de aterramento, com cabo contrapeso, utilizando abordagem por linhas de transmissão representada por uma cascata de circuitos π, analisado e simulado pelo "Software Matlab". Utilizou-se a simulação com o emprego de programa no Matlab para linhas de transmissão de energia elétrica, a primeira com comprimento de dez mil metros e outra com oitenta metros, utilizada como referencial na comparação das respostas aos sinais de entrada aplicados nos circuitos π simulando o cabo contrapeso com seus componentes representado pelos parâmetros elétricos. Através de variação no parâmetro resistividade do solo comparou-se os resultados mostrados nos gráficos da tensão elétrica na terminação do cabo contrapeso, simulado como uma linha de transmissão com terminação em aberto. Como analise adicional em termos de segurança foi implementado no programa a analise das tensões elétricas ao longo do cabo contrapeso, excitado por aplicação de sinais de tensão elétrica e de corrente elétrica estabelecendo a comparação entre os potenciais elétricos sobre o solo em valores máximos que podem afetar seres vivos
Abstract: This study is a survey of articles and publications on the various existing grounding systems. The grounding systems are directly linked to the protection of substation facilities and equipment used in the generation, transmission and distribution of electric power, due to induced voltages by lightning's generating electromagnetic fields . The method proposed in this study, about a grounding system made with a buried cable using the approach by transmission lines method, represented by a cascade of π circuits analyzed and simulated by Matlab Software. The simulation with the Matlab program on transmission lines of electricity, one ten thousand meters in length and another eighty meters respectively, to serve as a reference in comparison between responses to input signals applied to the cable simulated by π circuit employing the parameters involved. Through variation in the soil resistivity parameter, the results are shown in the graphs of voltage in the termination of the grounding cable, simulated as an open line at end. As further analysis in terms of safety, was implemented the analysis of the voltages along the cable, by applying voltage signals and current to check the electrical potentials on the ground, the maximum values that affect persons
Mestre
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Чистяков, О. М. "Проектування системи електропостачання та визначення втрат електричної енергії заводу металовиробів." Master's thesis, Сумський державний університет, 2020. https://essuir.sumdu.edu.ua/handle/123456789/82361.
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Приведена загальна характеристика підстанції, виконані розрахунки: середні та розрахункові навантаження цехів та заводу методами коефі-цієнта використання та попиту, а також були вирішені задачі по визначенню опти-мальної потужності трансформаторів КТП; оптимального перерізу зовнішньої жив-лячої лінії 10 кВ та кабельних ліній внутрішньозаводської мережі 0,38 кВ; оптима-льної потужності компенсуючих пристроїв 0,38 кВ по мінімуму приведених затрат в СЕП. Вибрані кабелі і комутаційні апарати стійкі до дії струмів КЗ. Для трансфор-маторів КТП передбачений захист від ненормальних режимів роботи. При розраху-нку цехових мереж була вибрана оптимальна система електропостачання, яка забез-печує допустимі втрати напруги в лініях. В економічній частині дипломної роботи були розраховані основні техніко-економічної показники системи електропоста-чання підприємства, які дозволяють зробити висновок про економічну доцільність системи.
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Перепелиця, І. С. "Розрахунок режимів роботи та модернізація обладнання ПС 110/6 кВ у зв’язку з переходом на клас напруги 20 кВ." Master's thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/71302.
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Наведено характеристики понижувальної підстанції 110/6 кВ та проведений аналіз існуючої схеми підстанції і доведена необхідність її модернізації. Проведено обробку графіків навантаження. Проведена заміна силових трансформаторів напругою 110/6 кВ на 110/20 кВ що дало змогу зменшити втрати електричної енергії на підстанції. Розраховані струми короткого замикання. Обрано нове обладнання, таке як: високовольтні та низьковольтні вимикачі, роз’єднувачі та інші комутаційні апарати. Також проведено заміну шин, ТС, ТН, ТВП. Розрахований грозозахист відповідно ДСТУ Б В.2.5-38:2008. Проведено моделювання зовнішнього освітлення ПС, ЗРП в програмному комплексі DIALux. Проведено техніко-економічне обґрунтування доцільності модернізації освітлення ПС, ЗРП та розраховано термін окупності капітальних вкладень переходу на клас напруги 20 кВ. У розділі охорона праці проаналізовані виробничі фактори, що діють на персонал підстанції, заходи з організації електробезпеки на підстанції, розглянуто електробезпеку при монтажі обладнання на підстанції та пожежна безпека при експлуатації силових трансформаторів.
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Bedel, Vincent. "Mise en oeuvre et optimisation d'un revêtement conducteur poly(époxy) : fils submicroniques d'argent pour la protection foudre de structures aéronautiques." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30144/document.
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Ce travail s'inscrit dans une problématique de mise en œuvre et d'étude d'un revêtement conducteur polymère extrinsèque pour la protection foudre des structures aéronautiques de type composite polymère renforcé fibres de carbone (CFRP). Le revêtement est composé d'une matrice poly(époxy) haute performance bi-composant fluide à température ambiante et de fils submicroniques d'argent à haut facteur de forme (AgNWs) obtenus par un procédé polyol. Une attention particulière a été portée à l'étude de l'influence des AgNWs sur la modification de la cinétique de réticulation du système, sa structure physique et sa mobilité moléculaire. La mesure des niveaux de conductivité volumique et surfacique du revêtement met en avant un seuil de percolation électrique pour un taux volumique en AgNWs inférieur à 1%. Une approche originale permettant la détermination des mécanismes de conduction a été effectuée au moyen des mesures de densités de courant imposées dans le revêtement en fonction du taux de charge en AgNWs et de la température. L'analyse du comportement électrique des échantillons aux valeurs critiques de densités de courant a permis d'appréhender les phénomènes responsables des mécanismes de dégradation. Enfin des essais foudres ont été effectués sur des substrats représentatifs d'une structure aéronautique avec différents types de protection foudre. L'analyse des échantillons par ultrasons après essais foudres a mis en avant l'efficacité du revêtement composite polymère conducteur poly(époxy)/AgNWs développé pour lutter contre le délaminage structurel du CFRPThis work deals with the processing and the study of an extrinsic conductive polymer coating for the lightning strike protection of the aircraft carbon fibre reinforced polymer (CFRP) structural parts. The coating consist in a low viscosity bi component high performance poly(epoxy) matrix and silver submicronic wires with a high aspect ratio (AgNWs) obtained by a polyol process. The kinetic parameters, the physical structure and the molecular mobility of the matrix had been investigated as a function of the filler content. The surface and bulk conductivities had been measured as a function of filler content. It exhibits a percolation threshold below 1% in volume. The conduction mechanisms had been studied following an uncommon method of current density measurement as a function of the AgNWs content and the temperature. The critical electrical behaviour of each sample had been investigated through the current density method. It has permitted to understand the phenomenon responsible for the composite's degradation. Finally, lightning strike tests on representative configurations had been carried out. The ultrasonic inspections have highlighted the efficiency of the poly(epoxy)/AgNWs coating to avoid the structural delamination of the CFRP
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Theethayi, Nelson. "Electromagnetic Interference in Distributed Outdoor Electrical Systems, with an Emphasis on Lightning Interaction with Electrified Railway Network." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5889.
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Метенько, Микола Володимирович, and Mykola Metenko. "Система електропостачання підприємства з виробництва шкіряних виробів." Bachelor's thesis, Тернопільський національний технічний університет імені Івана Пулюя, кафедра електричної інженерії,Тернопіль, Україна, 2021. http://elartu.tntu.edu.ua/handle/lib/35335.
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Головна мета, яка стоїть перед легкою промисловістю і одним із її напрямів - виробництвом шкіряних виробів на сучасному етапі розвитку ринкової економіки є збільшення випуску якісних конкурентоздатних товарів, які користуються підвищеним попитом у населення.
Швидке прогресування процесів виробництва одягу та його шкіряних елементів вимагає від інженерно–технічних працівників швейної галузі промисловості широкого та поглибленого знайомства з багатьма процесами, вміння аналізувати та взаємопов’язувати їх між собою в залежності від конкретних виробничих умов для підвищення якості продукції та ефективності виробництва.
Головним завданням швейно–шкіряних виробництв є задоволення зростаючої потреби населення в одязі високої якості і різноманітного асортименту. Вирішення цієї проблеми здійснюється на основі прискорення науково-технічного прогресу, зростання продуктивності праці, удосконалення методів і операцій виготовлення продукції та виробництва в цілому.
Сучасна швейна галузь, що випускає одяг масового виробництва, характеризується досить високим рівнем техніки, технологій організації виробництва, наявністю великих спеціальних підприємств і виробничих об’єднань.
Підвищення ефективності цієї галузі пов’язане не тільки з осучасненням техніки і технології швейно–шкіряного виробництва, але й створенням машин і систем програмного забезпечення та управління, нових транспортних пристроїв, механізмів автооператорів, приладів регулювання, автоматизованого контролю та управління.У кваліфікаційній роботі бакалавра розроблена система електропостачання підприємства з виробництва шкіряних виробів для підвищення ефективності виробництва та надійності електропостачання споживачів. Розраховані електричні навантаження силової та освітлювальної електромережі; розраховані і вибрані типи та номінали комутаційних апаратів електромережі виробництва, типорозміри кабельно–провідникової продукції, максимальні струми к. з., схема та надійність блискавкозахисту підприємства,а також схема під'єднання до однотрансформаторної підстанції.
In the qualification work of the bachelor the power supply system оf the enterprise on production of leather products for increase of efficiency production and reliability of power supply consumers is developed. Electrical loads of the power and lighting mains are calculated; types and denominations of switching devices of the power grid of production, standard sizes of cable-conductor products, maximum short-circuit currents, the scheme and reliability of lightning protection of the enterprise are calculated and selected, and the scheme of connection to a single-transformer substation is developed.
ЗМІСТ Реферат 3 Вступ 6 1 Аналітичний розділ 9 1.1 Стан і перспективи виробництва натуральної шкіри в Україні 10 1.2 Основні етапи технології обробки шкіри 11 1.3 Основні операції технології виробництва виробів зі шкіри 14 1.4 Елементи систем електропостачання та їх класифікація 15 1.5 Вибір основних параметрів і елементів системи електропостачання промислових підприємств 16 1.6 Типові принципові схеми електропостачання підприємств 18 1.7 Особливості під’єднання малих підприємств до електричних мереж 20 1.8 Загальна характеристика електроспоживання підприємства 21 1.9 Аналіз вихідних даних на проектування та загальна характеристика електроприймачів 22 2 Розрахунковий розділ 23 2.1 Визначення розрахункових навантажень електроприймачів і розробка схеми електропостачання 23 2.2 Складання схеми електропостачання підприємства 24 2.3 Розрахунок потужності розподільчих пристроїв 24 2.4 Розрахунок освітлювального навантаження 32 2.5 Розрахунок навантаження щитів освітлення 40 2.6 Визначення повної потужності підприємства 42 3 Проектно–конструкторський розділ 43 3.1 Вибір площі перерізу проводів і жил кабелів 433.2 Вибір захисної апаратури електромережі 48 3.3 Вибір конструкції блискавкозахисту об’єкту з розрахунком його надійності 55 4 Безпека життєдіяльності та основи охорони праці 60 4.1 Безпека життєдіяльності на швейному виробництві 60 4.2 Заходи з охорони праці на швейному виробництві 63 Загальні висновки 66 Перелік посилань 68
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Lombetti, D. M. "Tufting of complex composite structures." Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/11076.
Full textAbstract:
This study focuses on the effect of tufting on the mechanical and electrical properties of carbon composites using a variety of tuft materials, such as aramid, steel and copper. Several configurations were investigated based on a case study, involving the reinforcement of stiffener-to-skin interfaces of a tail cone. The effect of tuft and base composite material, tufting depth and inclination on the delamination resistance in mode I was evaluated, the associated bridging laws were determined and the failure mechanisms were identified. A simplified superposition model of the delamination response of tufted composites was developed. The electrical performance of tufted composites was determined in simulated lightning strike tests and set against the through-the-thickness electrical conductivity of the materials. The results of mechanical testing showed that the delamination performance depends strongly on the material response of the tufts, with both the bridging behaviour and final toughness levels influenced directly by the strength, ductility and ultimate strain of the tufts. Interactions between the tufts and the surrounding composite, such as interfacial shear and bridging induced by tuft pull-out, play a significant role in the overall behaviour generating a deviation from a simple superposition of the base material and tuft response. The balance between interfacial shear and tuft elongation results in a decreasing trend of delamination toughness with increasing tufting depth for low ductility materials, whilst the trend is reversed for the high ductility copper tufts. This balance is also affected by the properties of the base material, with tougher matrices leading to dominance of shear effects and a weaker enhancement introduced by tufting. Inclination of tufts leads to an increase in crack energy release rate due to the activation of a ploughing mechanism. Metallic and carbon tufts have a positive effect on lightning strike response, with copper tufting offering strike protection at an improved level compared to standard copper mesh solutions.
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Гаврилюк, В. С. "Розробка системи електропостачання та освітлення заводу металовиробів." Master's thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/71338.
Full textAbstract:
Приведена загальна характеристика підстанції, виконані розрахунки: середні та розрахункові навантаження цехів та заводу методами коефіцієнта використання та попиту, а також були вирішені задачі по визначенню оптимальної потужності трансформаторів КТП; оптимального перерізу зовнішньої живлячої лінії 10 кВ та кабельних ліній внутрішньозаводської мережі 0,38 кВ; оптимальної потужності компенсуючих пристроїв 0,38 кВ по мінімуму приведених затрат в СЕП. Вибрані кабелі і комутаційні апарати стійкі до дії струмів КЗ. Для трансформаторів КТП передбачений захист від ненормальних режимів роботи. При розрахунку цехових мереж була вибрана оптимальна система електропостачання, яка забезпечує допустимі втрати напруги в лініях. В економічній частині дипломного проекту були розраховані основні техніко-економічної показники системи електропостачання
підприємства, які дозволяють зробити висновок про економічну доцільність
системи.
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Manduch, Viliam. "Návrh ochrany proti úderu blesku a jištění datových rozvodů u FVE." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219405.
Full textAbstract:
This thesis deals with the problems associated with the lightning. It deals with the stablishment, descriptions and analyzes of risk the living organisms and objects are facing. The work focuses on the description and implementation of protection against these adverse effects. Its objective is to devise a system for lightning protection for chosen PV power plant to meet the requirements of standard of EN 62305. The work is also the analysis of shadow effects in the collecting system for PV power systems.
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Polášek, Roman. "Návrh přepěťové ochrany pro objekt s nebezpečím výbuchu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220681.
Full textAbstract:
This master´s thesis deals with the designing process of surge protection for the object potentially explosive atmospheres and according to a set of standards ČEN EN 62305 and ČSN EN 60079. This work consists of four main parts. The first part deals with the theory of lightning and surges. Subsequently, in the second part is devoted to the theory of protection against these phenomena and proposals for external and internal lightning protection and surge. This chapter also deals with more demands on electrical installations in hazardous areas. The third part deals with the analysis of the risks to the subject paint and according to ČSN EN 62305-2 ed.2 and at the conclusion of the study is a proposal for external lightning protection and internal surge protection.
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Cheng, Mei-Chung, and 鄭美俊. "Study on Lightning Protection and Lightning Induced-Voltages Estimation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/55369686275186889907.
Full textAbstract:
碩士國立臺灣大學
電機工程學研究所
92
For a country situated at the subtropical zone, such as Taiwan, lightning occurs very often, especially in summer, when there are thunderstorms. When the lightning hit the overhead-lines, it would inject the huge energy into overhead-lines. Outage by surge through overhead-lines would decrease power quality. Lightning can be divided into many types. The one most threatening to people and structure is the cloud to ground discharged. There are two kinds of cloud to ground discharged. One is upward, and the other is downward. The downward lightening happens more frequently. At present, Lightning rods and Lightning Eliminators are the more popular devices of lightning protection. My research focus on compared Structure, theory, protection effect of those devices, and collected standards, experiments from foreign as well as domestic. Another research topic is evaluated lightning induced voltages on nearby overhead-lines. Lightning is a transient, high-current discharge whose path length is measured in kilometers. During flash, neighbor electromagnetic field change violently, that would induce voltages on close-by metal. To find induce-voltages on overhead-lines must be transformed lightning phenomenon into numeric equation first. Apply Maxwell-equations to equal space electromagnetic, using Agrawal Model to describe coupling between overhead-lines and electromagnetic. Transmission equation can find the solution of induce-voltages by lightning. Finally, this thesis applied above solutions will offer a program by MATLAB. It can find solutions quickly and correctly in different conditions.
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Ting, Chi-Yuan, and 丁繼沅. "A Research on Lightning Protection." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/11863777006489063574.
Full textAbstract:
碩士南榮技術學院
工程科技研究所碩士在職專班
97
A lightning strike to a structure is one of the important natural disaster for the buildings. The electric shocks will cause the serious damage to the wiring and the building itself.Therefore, the installation of lightning conductors is important for the safety of buildings. Most of the modern buildings have lightning protection installation.However, because lightning strikes happened frequently, for better protection of human lifes and buildings, the traditional lightning protection tactics still have rooms for improvement. For the design for lightning rods,there are the Protective Angle Method、the Rolling Sphere Method and the Mesh Size Method.For the Protective Angle Method, the protection angle is changed with the height of the construction.To keep the low failure rate,the protection angle has to be reduced when the height of the structure is increased. The Rolling Sphere Method is to use a sphere with radius S, rolling along the part that need to be protected from lightning strike. Where S is the striking distance for the lightning. The part below the sphere to the ground will get protection from the lightening. The Mesh Size Method is using a network of lightning protectors set up on top of the structure in order to conduct the lightning . In this paper, we apply these three different protect methods to the building structures for an ample protection for the staff and the equipment inside the structures . There will also be the discussion for the design of lightning install methods and their the protetion efficiency.
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Chachaia, Fernando Hausse. "Lightning protection of thatched roofed structures." Thesis, 2009. http://hdl.handle.net/10539/5932.
Full textAbstract:
Abstract
This work describes the design of external lightning protection system for thatched
roofed structures. Lightning is a natural phenomenon that has an unpredictable strike
location. Therefore in creating an external LPS, it is possible to create a path for the
discharge that minimizes its harmful effects to a structure. There are many international
documents and standards that describe methods of providing lightning protection. It has
traditionally been accepted practice to install lightning protection masts near a thatched
structure. However in solving one problem a number of others may have been created.
This work explores alternative lightning protection designs for thatched roofed structures.
Tests were performed in a laboratory environment to determine the level at which that
will ignite from a direct strike to thatch material. These tests were performed using a
combination impulse generator. It was found that thatch started to smoke at 10 kA. And
ignition of the thatch occurred at 20 kA with a charge of 45 C.
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Su, Wen, and 蘇文. "Applying Lightning Arrester for Distribution System Protection." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/36356746318019028151.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
94
Abstract Lightning surge could causes short-circuit faults for power systems, which in turn may bring power distribution systems to sudden interruption. Lightning would even damage some power equipments and influence the quality of power supply. Choosing the lightning arresters which meet necessary requirements and installing them in proper locations could make the most out of the protection.The main purpose of this thesis is to discuss applying lightning arresters to lightning surge overvoltage protection for distribution power systems. This thesis takes advantage of Electromagnetic Transients Program (EMTP) to simulate the surge voltage on power distribution lines resulting from lightning and the effects after the surge voltage. From the knowledge of the level of surge voltage and knowing the insulated withstand of power equipments, one can choose the correct types of lightning arresters and install them on the rods of overhead power distribution lines. Then the lightning arresters can be fully utilized and the surge voltage can be limited under the Basic Insulation Level (BIL), preserving some extra margin to gain the Protection Margin (PM) essential for power equipments.
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Lu, Tzong-Yi, and 盧宗益. "Study of Lightning Protection For LNG Facilities." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/46570002242456068588.
Full textAbstract:
碩士國立成功大學
電機工程學系專班
92
Lightning activity can create a lot of problems for gas-handling facilities. In this paper, the causes of overvoltages and their related threats suffer from the lightning strike, the objectives of grounding system, the prevention of the Dissipation Array System（DAS） from being struck by lightning, and the functions of surge protection devices are described firstly. Then, taking an example of first Liquified Natural Gas（LNG） plant in Taiwan to select the most cost-effective protection system.
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Swanson, Andrew Graham. "High frequency current distribution in a structure with application to lightning protection systems." Thesis, 2008. http://hdl.handle.net/10539/5868.
Full textAbstract:
In concrete reinforced buildings, the steel framework is required to be bonded and is often
used as a cost effective method of lightning protection. In defining lightning protection
zones, it is essential to understand where the lightning current due to a direct strike will
flow. A number of models exist to evaluate the current distribution, but are often applied
to relatively simple structures.
Using Maxwell’s equations, an approximate skin effect model is proposed and used to eval-
uate the lightning current distribution in a complex structure. A reduced scale model of
a structure, consisting of conductors arranged in rings, is developed to verify the model.
Particular attention is given to the return path of the current, ensuring an even distrib-
ution of the current in the structure.
The equivalent circuit showed an even distribution of current across each conductor at
dc and low frequencies and a distribution that concentrated in the outer conductors for
higher frequencies. The measurements from the structure confirmed that the current con-
centrates in the outer conductors at high frequencies. Applying a reduced scale lightning
impulse, it is shown that the majority of the current flows on the outermost conductors.
Any current on the inner conductors is not only greatly decreased in magnitude, but
significantly slower in time than the applied impulse.
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Μπελεκούκιας, Ιωάννης. "Μελέτη των παραμέτρων του κεραυνού σε πληγέν κτίριο." Thesis, 2011. http://hdl.handle.net/10889/5385.
Full textAbstract:
Το θέμα της παρούσας πτυχιακής εργασίας είναι η Μελέτη των παραμέτρων του κεραυνού σε πληγέν κτίριο. Πριν αναλυθούν οι επιπτώσεις του κεραυνού στο κτίριο είτε αυτό έχει αντικεραυνική προστασία είτε όχι, με την βοήθεια μαθηματικών μοντέλων, πρέπει να γίνει εκτενής αναφορά σε έννοιες αναγκαίες ως προς την κατανόηση των ατμοσφαιρικών ηλεκτρικών φαινομένων και ειδικότερα του κεραυνού.
Έτσι στο πρώτο μέρος της εργασίας γίνεται εκτενής αναφορά και περιγραφή των ηλεκτρικών ατμοσφαιρικών φαινομένων και τον τρόπο που δημιουργείται ηλεκτρικό φορτίο στην ατμόσφαιρα. Στην συνέχεια γίνεται αναφορά και περιγραφή στο τρόπο με το οποίο φορτίζεται το σύννεφο και γενικότερα στην ηλεκτρική συμπεριφορά του για να φθάσουμε στην ανάλυση του κεραυνού.
Στην προσπάθεια ανάλυσης των κεραυνών επιχειρείται η περιγραφή της φυσικής των κεραυνών, του ρεύματος του οποίου έχει και των σχετικών παραμέτρων που τον διέπουν, καθώς και της συχνότητας με την οποία συμβαίνουν οι κεραυνοί, χαρακτηριστικό το οποίο είναι πολύ σημαντικό για την μελέτη της αντικεραυνικής προστασίας ενός κτιρίου. Επίσης στην συνέχεια της εργασίας αναφέρονται οι τρόποι προσδιορισμού της ζώνης προστασίας ενός κτιρίου.
Στο τελευταίο μέρος χρησιμοποιώντας το πρόγραμμα MATLAB (και συγκεκριμένα το γραφικό περιβάλλον Simulink) θα γίνει προσομοίωση του πλέγματος προστασίας για το υπό μελέτη κτίριο στον υπολογιστή. Για την μοντελοποίηση θα πρέπει να καθοριστούν η μορφή του ρεύματος που εισέρχεται στην κατασκευή λόγω του κεραυνού, το μοντέλο κάθε ράβδου και της συνολικής κατασκευής, καθώς και οι τιμές των ηλεκτρικών παραμέτρων.This thesis attends to analyze the parameters of lightning in a directly stricken building. Before analyzing the effects of lightning in the building either has lightning protection or not, with the help of mathematical models, should be made extensive reference to concepts necessary to understand the atmospheric electrical phenomena and especially the lightning. So the first part of this thesis is a detailed report and description of electrical atmospheric phenomena and the way that electric charge generated in the atmosphere. The following sections discuss and describe the way in which the cloud is charged and the general electrical behavior of it, to get to the analysis of lightning. In the effort to analyze the lightning, is attempted describing the physics of lightning, the power which has and the relevant parameters that it has and the frequency with which lightings occur, a feature which is very important for the study of a building lightning protection. Also this thesis tries to describe methods of public buildings protection, the way they are placed and how we determine the buffer zone of a building. In the final part using the program MATLAB (namely the graphical Simulink) we will simulate the grid protection for the building under study in the computer. For modeling should specify the form of electricity entering the building due to lightning, the model of each bar and the overall design and the values of electrical parameters.
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Tai, Jenq-Yih, and 戴正義. "Lightning Protection Performance of Overhead Wires of Substations." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/8hp43w.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
97
The lightning stroke is the phonomena of nature, to prevent direct lightning stroke to equipments, the overhead ground wires are installed at most substations. The lightning surge is then drawn into the ground grid, so the lightning protection performance of overhead ground wires is very important to the safe and reliable operation of the power system. The lightning protection performance of substations is affected by the transient characteristics of grounding grids if the direct lightning happens. And the transient characteristics of grounding grids depend upon the shape and size of the grid, the feedpoint, the shape, and amplitude of the impulse current and soil parameters. The influence of these factors on the characteristics of grounding grids shound be taken account by designers. The major lightning protection methods of substations are the installation of lightning rods and overhead ground wires. The research takes the rolling method to analyze the protection performance of Long-Chi E/S of Taipowe. The ATP software was used to simulate the transient voltage of overhead ground wires if the direct lightning stroke happened. The simulation includes various lightning location, the grounding resistance of towers, the lightning current, feedpoint and grid spans to the voltage of tower’s foot, ground wires current, overhead ground current and Ground Potential Rise
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Jhang, You-Ming, and 張佑銘. "Analysis of Lightning Protection Grounding System for Buildings." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/87490270023948284642.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
94
When a lightning strikes a building, a large lightning current will flow to facilities inside the building and the ground. This lightning current may damage facilities and even hurt humans due to the ground potential rise. In order to mitigate the damage, a lightning protection grounding system for buildings is introduced. Grounding plays an important role for a lightning protection grounding system. This paper will analyze and compare the equipotential common grounding system and independent grounding system used as a lightning protection system for buildings. Particularly, we will analyze the difference of grounding systems in time- and frequency-domain. Moreover, the maximum permissible step and touch voltages for humans will be used to evaluate the safety of grounding systems.
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Zhang, Wei-Yu, and 張瑋育. "Simulation and Analysis of Lightning Strike Protection and Protection Margin for Secondary Substation." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/665z84.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
102
This study is developing lightning strike protection for S/S (Secondary Substation) and protection margin simulation analysis. To protect arresters on transmission lines or substation outdoor, Taipower applies ZnO Arresters widely used for its characteristics as non-linear, fast-response, great absorptive capacity, and non-continuity. In this ATP-EMTP to simulate whether S/S outside meets protection margin criteria of ANSI/IEEE under various lightning current and analyze the relationship between arresters location and protection margin. Based on the results, this study builds up lightning strike protection model for S/S and sets up transmission equipment parameters. Through this model, power designers will figure the characteristics of substation and plan the quantities and location of Arresters with fair cost while substation rebuilding.
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Hon, Chung Wei, and 仲偉弘. "A Research on Lightning Protection of Buildings in Taiwan." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/33246729065556945295.
Full textAbstract:
碩士國立臺灣科技大學
工程技術研究所
83
The land resourse in Taiwan area has been devaloped continuously and massively for several years. The risk of lightning striking damages to ward building is getting higher and higher by the followingtwo things:first,the fact of raising height and dense location of the buildings;second,the frequent occurence of thunder storms in Taiwan area during summer and autumn season.Although most damages of direct lightning strikes are not serious and thereis no significant record about the damage. This paper discusses both the idea and themethod of how to prevent the lightning striking damages from the following three layers- design,construct,use and maintenance,and also provide the suggestion on revising current laws. We hope a construction thought can be stated in this research fieid, so that a reasonable, applicable and prospective process can be provided to actually protect the buildings from lightning striking damages.
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LIU, MING-KAI, and 劉明凱. "Analysis and Simulation of Lightning Protection for Transmission Line." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/52259491705281713796.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
104
Overhead transmission line is essential to power transmission. Built on open areas, overhead transmission lines are struck by lightning quite often. This thesis uses simulation analysis software to verify and discuss lightning protection measures of transmission lines in Taiwan.The measures are increasing ground wire protective angles, strengthening line insulation, adding coupling ground wires, lowering the resistance of grounding system and installing line surge arresters. Use simulation analysis software to create some same modules as actual transmission line parameters. Then by increasing ground wire protective angles, strengthening line insulation, adding coupling ground wires, lowering the resistance of grounding system or installing line surge arresters, lightning protection features are investigated. With applying the above lightning protection measures on the 69kV transmission line A and 161kV transmission line B, the simulation result shows that only lowering the resistance of grounding system is most ineffective to lightning protection and flashover improvement. Strengthing insulation of insulators or widening arcing horn gap can increase lightning impulse negative polarity critical flashover voltage and prevent back flashover. Increasing ground wire protective angles, adding coupling ground wires, or installing line surge arresters can hide lightning path, control voltage difference of insulator string and reduce flashover and back flashover of insulators respectively. Those measurements helps improve lightning protection systems. To improve reliability and qulity of power supply, the result of this research will be a reference at the lightning protection of overhead transmission lines.
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Chen, Shi-Chien, and 陳世傑. "Analysis of Lightning Protection Methods for Overhead Transmission Lines." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45285600816091229157.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
98
Abstract “Lightning” is a kind of energy which is very hard to be controlled. A lightning stroke produces high voltage and large current that will cause the damage of everything which is attacked by the lightning stroke directly. Besides, lightning stroke can damage the people, animals, and objects around indirectly. Then the overhead transmission lines erected in open fields are much easier to be attacked by thunderbolt. The damage of transmission lines and related equipments caused by lightning stroke will result in enormous economic losses, especially for those factories in Science Park. Thus the science industry has set up very high standard on the quality and reliability of electric power supply. Therefore, the utility makes every endeavor to improve lightning protections. This thesis studies the design of lightning protection by analyzing the lightning stroke and explaining every kind of lightning protective measure. Moreover, the thesis also investigates the sheltering capability of all lightning protective measures and the terminal voltage of the insulators under lightning by using the T-Flash software, and the probability of being attacked by the lightning is also examined. It is found that adopting two overhead ground lines with a minus five-degree sheltering angle will be a better protective structure, with even better performance by adding the line arrestor. Keywords: Lightning Protection Method, Power Quality, Power Reliability, Lightning Sheltering, Impulus Flashover Voltage
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Jiang, Jheng-lun, and 姜政綸. "Transient Analysis and Protection of Wind Farms under Lightning Strokes." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/20219056209134308252.
Full textAbstract:
博士國立臺灣科技大學
電機工程系
101
Lacking natural resources and dependent on imports for over 99 % of its energy supply, renewable energy development is a priority for Taiwan. According to Taiwan Power Company (Taipower), renewable energy composed only 2.6 % of total power generation device capacity in 2011, revealing Taiwan’s continued dependence on fossil fuels. In the development plan for Taiwan’s new energy policy published in November 2011, the Thousand Wind Turbines program became a crucial element in renewable-energy planning, and it is estimated that this plan will generate 4,200 MW by 2030. Wind turbines are also a critical element in plans in the global renewable-energy sector. Therefore, responding to the massive development of wind turbine (farms), the effects of connecting these turbines to the power system, and planning lightning protection measures considering Taiwan’s geographic location in an area of frequent lightning strikes are all critical topics that must be examined. Considering local wind turbine structures, information on lightning, and power distribution system types, this study uses ATP-EMTP to analyze the transient characteristics of lightning generation and provides Taiwan-specific suggestions for lightning protection. In this paper, case simulation and analysis is divided and examined in three topics. First, IEC TR 61400-24 statistics demonstrate that lightening most commonly damages the control systems of wind turbines. Consequently, this paper analyzes the impact of lightning strikes on the control system of wind turbine, considering peak values 24 kA and 40 kA of lightning currents and rise/duration periods of 5/20 μs, grounding resistance 2 Ω, 5 Ω or 10 Ω, and tower and control equipment grounding methods. A single wind turbine connected to a 69 kV/161 kV bus system is then simulated to analyze the extent of the impact on the system terminal and on the user terminal when lightning strikes a wind turbine examining the wind turbine transformer and arrester conditions, the distance of the turbine-bus connection, and radial, loop or double bus types. Finally, an entire wind farm connected to a 161 kV bus system is simulated to analyze the extent of the impact on the system terminal and user terminal considering one to five wind turbines connected together, the interconnection conditions regarding the ground of various wind turbines, and different bus types. Overall, wind turbines, bus terminals, and user terminals presented in this study could provide reference for lightning protection.