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1
Sa, Yingshi 1965. "Reliability analysis of electric distribution lines". Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29546.
Testo completoAbstract (sommario):
Wood Poles are extensively used in North America as supports for electric distribution lines. On average, wood poles have a service life of 40 years with a replacement cost of approximately $2000. Since the distribution network is of relatively recent construction, maintenance and replacement costs have been relatively small compared to the total number of poles in service.The goal of this thesis is to use the FORM/SORM algorithm to evaluate the reliability of a single pole and the results obtained when applied to a sample of 887 wood poles inspected in the field. The procedure was also applied to a sample of poles designed according to the current codes in order to calibrate the evaluation procedure. The results indicate that the proposed procedure will improve the current maintenance and replacement strategy by guarantying a more uniform level of reliability throughout the network and by decreasing by up to 33% the number of wood pole replacements. (Abstract shortened by UMI.)
2
Kryukova, N. V., Evgen Viktorovych Goncharov e I. V. Polyakov. "Modern monitoring systems of electric power lines". Thesis, NTU "KhPI", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/38909.
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3
Bernardin, Sylvie. "Étude et analyse du délestage de glace atmospherique sur les cables /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1989. http://theses.uqac.ca.
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4
Fernandez-Ramirez, Eder-Ernesto. "Optimisation du taux de compensation série d'une longue ligne de distribution : cas de l'Hydro-Québec : Abitibi Téminscamingue [sic] /". Thèse, [Chicoutimi : Rouyn : Université du Québec à Chicoutimi] Université du Québec en Abitibi-Témiscamingue, 2006. http://theses.uqac.ca.
Testo completoAbstract (sommario):
Thèse (M.Eng.) -- Université du Québec à Chicoutimi, programme en partenariat avec l'Université du Québec en Abitibi-Témiscamingue, 2006.Bibliogr.: f. 136-139. Document électronique également accessible en format PDF. CaQCU
5
Kleinhans, Kevin. "Investigation into possible mechanisms of light pollution flashover of 275kv transmission lines as a cause of unknown outages". Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1071.
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6
Kobziev, V., e E. Krasowski. "Some lines of energysaving in electric power industry". Thesis, ДРУКАРНЯ МАДРИД, 2016. http://openarchive.nure.ua/handle/document/8409.
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7
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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8
Jerrell, Jeffrey W. "Critical span analysis of overhead lines". Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/16430.
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9
De, Villiers Wernich. "Prediction and measurement of power line carrier signal attenuation and fluctuation". Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52410.
Testo completoAbstract (sommario):
Thesis (MScEng)--University of Stellenbosch, 2001,ENGLISH ABSTRACT: A frequency domain Power Line Carrier (PLC) simulation program, with the ability to simulate signal attenuation including the coupling equipment, was developed. This simulation program was put to the test against the independent program of Professor L.M. Wedepohl and against practical field measurements. The predictions of the two programs were in precise agreement for a wide range of input parameters. Results from the field tests and predictions also showed close agreement. Further investigations, applying the simulation program, explained how ground conductors and soil resistivity influences PLC signal propagation. An experiment, which was developed to monitor PLC signal attenuation, was installed on the PLC system between Koeberg power station and Acacia substation, both near Cape Town. Data logged continuously over 28 days, indicated measurable and deterministic PLC signal attenuation variations with typical time constants of a few hours. Simulations of the PLC system indicated that the signal amplitude variations were influenced by changes in the height above the ground plane of the phase conductor. This significant finding creates the possibility to obtain real time knowledge of the sag of an Over Head Transmission Line (OHTL) by exploiting an operational PLC system. The knowledge about real time sag can be used in economical dynamic ampacity control systems. The practical and financial benefits to the electricity supply and distribution industry can be significant.
AFRIKAANSE OPSOMMING: 'n Frekwensie gebied "Power Line Carrier" (PLC) simulasie program wat die sein verswakking en die koppeling verliese kan naboots, is ontwikkel. Die program is getoets teen die onafhanklike program van Professor L.M. Wedepohl asook praktiese metings in die veld. Die vooruitskatings van beide programme is presies die selfde vir 'n wye reeks van parameters. Metings en nabootsings het ook noue ooreenstemming getoon. Verdere ondersoek, m. b. v. die program, is gedoen ten einde te verduidelik hoe grond-geleiers en grond weerstand die PLC sein se voortplanting beïnvloed. 'n Eksperiment om die PLC sein se verswakking mee te monitor is ontwerp. Die eksperiment was geïnstalleer in die PLC stelsel tussen Koeberg kernkragstasie en Acacia substasie, naby Kaapstad. Die eksperiment was vir 28 dae geaktiveer en die data wat die eksperiment opgelewer het toon meetbare PLC sein verswakking met tyd konstantes van 'n paar uur. Verdere nabootsings het gewys dat die veranderende verswakking in die PLC seinsterkte toegeskryf kan word aan die wisseling in hoogte van die fase geleiers bo die grondvlak. Hierdie bevinding is van besondere belang aangesien dit die moontlikheid oopmaak om die gemiddelde sak van kraglyne in reële tyd en onder bedryfs toestande te kan meet. Die informasie van die reële sak van kraglyne kan gebruik word in effektiewe stroomdrae-vermoë beheer stelsels. Die praktiese en finansiële voordele wat krag voorsieners en verspreiders hieruit kan put kan aansienlik wees.
10
Naredo, V. José Luis A. "Communication frequency response of high voltage power lines". Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26725.
Testo completoAbstract (sommario):
Several methods for calculating the electrical phase and modal parameters of overhead transmission lines are described in this thesis; then, a graphical method for evaluating communication frequency response of delta transmission lines -based on the guidelines given by W. H. Senn [12,13,14]- is developed. The graphical method, combined with the parameters calculation methods, obviates the need of large mainframe computers for the analysis of power line carrier (PLC) systems.
A new technique for assessing coupling alternatives, based on Senn's method, is developed. The technique is applied to generate coupling recommendations; it is found that many of the current recommendations given elsewhere [21] are not reliable.
Finally, future work to be done in this field is proposed.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
11
Cecchi, Valentina Miu Karen Nan. "A modeling approach for electric power transmission lines in the presence of non-fundamental frequencies/". Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2583.
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12
Dirkse, van Schalkwyk W. J. "The placing of line surge arresters and fuses on 11 and 12 kV lines to protect equipment against lightning". Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52553.
Testo completoAbstract (sommario):
Thesis (MEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: Unshielded distribution lines has a poor performance during lightning activity. Lightning initiates flashovers between the phases and earth and causes line breakers to trip several times during a lightning storm. In addition equipment like fuses, surge arresters and transformers are damaged by lightning and cause in some cases long power interruptions to customers. The application of line surge arresters on distribution lines is a solution that is implemented worldwide to limit the lightning related problems. This thesis investigated using line surge arresters in conjunction with bushing-mount fuses to decrease nuisance fusing and transformer damage during lightning activity. Two new pieces of equipment (dropout surge arresters and transformer bushingmount fuses) were developed and strategically placed on 4 different distribution lines. Equipment failures decreased by 90 % while financially the project had an excellent return on investment.
AFRIKAANSE OPSOMMING: Distribusie lyne sonder skermdrade presteer swak gedurende weerlig aktiwiteit. Weerlig veroorsaak oorvonking tussen fases en aard geleiers wat lei tot breker klinke. Transformators, sekerings, stuwingsafleiers en ander toerusting word ook deur weerlig beskadig en veroorsaak in sommige gevalle lang toevoer onderbrekings. Installering van lyn stuwingsafleiers op distribusielyne is 'n metode wat wêreldwyd gebruik word om oorvonking en weerligskade te beperk. Hierdie tesis ondersoek die installering van lyn stuwingsafleiers en deurvoerder gemonteerde sekerings om transformator skade en onnodige blaas van sekerings te beperk tydens weerlig aktiwiteit. Nuwe toerusting (uitval stuwingsafleiers en transformator deurvoerder gemonteerde sekerings) was ontwikkel en strategies op 4 verskillende distribusie lyne geïnstalleer. 'n Negentig persent vermindering in toerusting beskadiging is behaal terwyl die projek finansiël 'n goeie opbrengs op belegging meegebring het.
13
Chen, Shelley L. "Programs for calculating high temperature ampacity and sag for overhead electrical conductors". Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/17933.
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14
Dale, Joel Kelly. "Electric field lines and voltage potentials associated with graphene nanoribbon". Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2471.
Testo completoAbstract (sommario):
Graphene can be used to create circuits that are almost superconducting, potentially speeding electronic components by as much as 1000 times [1]. Such blazing speed might also help produce ever-tinier computing devices with more power than your clunky laptop [2]. Graphite is a polymorph of the element carbon [3]. Graphite is made up of tiny sheets of graphene. Graphene sheets stack to form graphite with an interplanar spacing of 0.335 nm, which means that a stack of 3 million sheets would be only one millimeter thick. [1] This nano scale 2 dimensional sheet is graphene. Novoselov and Geim's discovery is now the stuff of scientific legend, with the two men being awarded the Nobel Prize in 2010 [4]. In 2004, two Russian-born scientists at the University of Manchester stuck Scotch tape to a chunk of graphite, then repeatedly peeled it back until they had the tiniest layer possible [2]. Graphene has exploded on the scene over the past couple of years. "Six years ago, it didn't exist at all, and next year we know that Samsung is planning to release their first mobile-phone screens made of graphene." - Dr Kostya Novoselov [4]. It is a lattice of hexagons, each vertex tipped with a carbon atom. At the molecular level, it looks like chicken wire [4]. There are two common lattice formations of graphene, armchair and zigzag. The most studied edges, zigzag and armchair, have drastically different electronic properties. Zigzag edges can sustain edge surface states and resonances that are not present in the armchair case Rycerz et al., 2007 [5]. This research focused on the armchair graphene nanoribbon formation (acGNR).
Graphene has several notable properties that make it worthy of research. The first of which is its remarkable strength. Graphene has a record breaking strength of 200 times greater than steel, with a tensile strength of 130GPa [1]. Graphene has a Young's modulus of 1000, compared to just that of 150 for silicon [1]. To put it into perspective, if you had a sheet of graphene as thick as a piece of cellophane, it would support the weight of a car. [2] If paper were as stiff as graphene, you could hold a 100-yard-long sheet of it at one end without its breaking or bending. [2]
Another one of graphene's attractive properties is its electronic band gap, or rather, its lack thereof. Graphene is a Zero Gap Semiconductor. So it has high electron mobility at room temperature. It's a Superconductor. Electron transfer is 100 times faster than Silicon [1]. With zero a band gap, in the massless Dirac Fermion structure, the graphene ribbon is virtually lossless, making it a perfect semiconductor. Even in the massive Dirac Fermion structure, the band gap is 64meV [6].
This research began, as discussed in Chapter 2, with an armchair graphene nanoribbon unit cell of N=8. There were 16 electron approximation locations (ψ) provided per unit cell that spanned varying Fermi energy levels. Due to the atomic scales of the nanoribbon, the carbon atoms are separated by 1.42Å. The unit vector is given as, ~a = dbx, where d = 3αcc and αcc = 1.42°A is the carbon bond length [5]. Because of the close proximity of the carbon atoms, the 16 electron approximations could be combined or summed with their opposing lattice neighbors. Using single line approximation allowed us to reduce the 16 points down to 8. These approximations were then converted into charge densities (ρ). Poisson's equation, discussed in Chapter 3, was expanded into the 3 dimensional space, allowing us to convert ρ into voltage potentials (φ). Even though graphene is 2 dimensional; it can be used nicely in 3 dimensional computations without the presence of a substrate, due to the electric field lines and voltage potential characteristics produced being 3 dimensional. Subsequently it was found that small graphene sheets do not need to rest on substrates but can be freely suspended from a scaffolding; furthermore, bilayer and multilayer sheets can be prepared and characterized.
15
Mullen, W. Grigg. "An evaluation of the utility of four in-situ test methods for transmission line foundation design /". This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07112007-092850/.
Testo completo
16
Du, Toit Nicolaas Serdyn. "Calibration of UV-sensitive camera for corona detection". Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/1016.
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17
Péter, Zsolt. "Modelling and simulation of the ice melting process on a current-carrying conductor = Modélisation et simulation de processus de délestage de glace par fonte sur un conducteur en présence de courant /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.
Testo completoAbstract (sommario):
Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2006.La p. de t. porte en outre: Thèse présentée à l'Université du Québec à Chicoutimi pour l'obtention du doctorat en ingénierie. CaQCU Bibliogr.: f. 260-264. Document électronique également accessible en format PDF. CaQCU
18
Tong, Sai-kit. "A computer-aided measurement system for monopolar high-voltage direct-current coronating lines /". [Hong Kong] : University of Hong Kong, 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12321771.
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19
Swapnil, Muhammad Mubassir. "Computing effects of electric and magnetic fields near overhead transmission lines". Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/63023.
Testo completoAbstract (sommario):
Analysis of Electric and Magnetic Fields produced by overhead transmission lines plays a critical role prior to their construction by electrical utilities. They affect the width of the transmission corridor and terrain clearances from overhead conductors. There is substantial interest in learning about the health effects of short and long-term exposure to these fields, as induced currents and voltages from parallel lines pose a hazard to line crews working on a de-energized line.
A MATHCAD program has been developed to compute the strengths of Electric and Magnetic Fields and to determine any induction currents and/or voltages due to the coupling effect of these fields. MATHCAD is an engineering software that allows programming and development of engineering calculations using natural mathematical syntax and variables. An overview of the theory of electric and magnetic fields is also provided in this paper. This research tests a few scenarios in the MATHCAD program, and the test results are verified against EPRI (Electric Power Research Institute) and IEEE (Institute of Electrical and Electronic Engineers) guidelines to ensure consistency. The results are also compared with the safety limits published by ICNIRP (International Commission on Non-Ionizing Radiation Protection) and IEEE. We also discuss the practical use of these results, along with potential future updates to the MATHCAD program.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
20
Tiancheng, Zhang, e Zhang Yunlin. "High voltage Direct Current lines in the Chinese electric power system". Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-12757.
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21
Davalbhakta, Aneesh. "Improved configurations of sensors for the measurement of tower footing resistance a thesis presented to the faculty of the Graduate School, Tennessee Technological University /". Click to access online, 2008. http://proquest.umi.com/pqdweb?index=0&did=1597632921&SrchMode=1&sid=4&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1279309880&clientId=28564.
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22
McWhorter, Bruce Burnett. "Transient temperature distributions in short-circuited electrical conductors". Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/15951.
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23
Yang, Lifeng. "Computer relaying for EHV/UHV transmission lines". Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/40085.
Testo completoAbstract (sommario):
As the power systems grow, system connections become more complex. Due to cost and environmental concern, more and more parallel lines and series compensated lines may be installed in the system. In order to efficiently use the transmission network, more nonlinear flexible devices such as the phase shifter and the advanced compensation system will be put into use. Once a fault occurs on such a system, a delay in clearing the fault is usually not permissive. This requires a new generation of relays which have high security and dependability and high operating speed. With the advent of high speed microprocessor and fiber optic communication technologies, it is possible to develop high performance relays. In this dissertation, a new generation of pilot relays and non-pilot relays were developed for a transmission line.
The pilot relays include the instantaneous percentage current differential (IPD), the phase comparison and the phasor based percentage current differential (PPD) principles. In the pilot protections the synchronized phasor measurement techniques are employed and digital CT saturation detectors are incorporated. All these schemes in primary protections feature charging current (or shunt current ) compensation. The phasor based principles are designed to work within one and a half cycles; while others based on sample by sample comparison are assumed to work in less than a cycle.
The non-pilot relays to be investigated in this dissertation include the fault location based and phase angle based directional distance relays. One cycle data window is used in the phasor calculation. Both the distance relays are assumed to make a trip decision in about one and a half cycles.
All algorithms were simulated against different fault conditions using EMTP outputs. The simulation results show all the pilot relay algorithms work well for EHV IUHV transmission lines including the series compensated lines. The fault location based distance relay works well in most cases, but it may give a wrong decision for the close-in fault with the fault resistance and may have a singularity problem. The phase angle based distance relay works very well for different fault conditions and is insensitive to fault resistance.
The modified phase angle based distance relay was also developed for the series compensated line. It would not lose the direction for faults with or without fault resistance, either for a compensated system in forward direction, or in an adjacent line in reverse direction. The overreach is within 20% of the protected zone. This relay algorithm is also based on the one-cycle data window DFT, and it can give a reliable trip decision in about two cycles.
All pilot relays with a fiber optic link and the phase angle based distance relay can constitute a new generation of protection systems for EHV IUHV transmission lines.Ph. D.
24
湯世傑 e Sai-kit Tong. "A computer-aided measurement system for monopolar high-voltage direct-current coronating lines". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B31207467.
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25
Navaratnam, Srivallipuranandan. "Series impedance and shunt admittance matrices of an underground cable system". Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26726.
Testo completoAbstract (sommario):
This thesis describes numerical methods for the evaluation of the series impedance matrix and shunt admittance matrix of underground cable systems. In the series impedance matrix, the terms most difficult to compute are the internal impedances of tubular conductors and the earth return impedance. The various formulae for the internal impedance of tubular conductors and for the earth return impedance are, therefore, investigated in detail. Also, a more accurate way of evaluating the elements of the admittance matrix with frequency dependence of the complex permittivity is proposed.
Various formulae have been developed for the earth return impedance of buried cables. Using the Pollaczek's formulae as the standard for comparison, the formula of Ametani and approximations proposed by other authors are studied. Mutual impedance between an underground cable and an overhead conductor is studied as well. The internal impedance of a laminated tubular conductor is different from that of a homogeneous tubular conductor. Equations have been derived to evaluate the internal impedances of such laminated tubular conductors.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
26
Marti, Luis. "Simulation of electromagnetic transients in underground cables with frequency-dependent modal transformation matrics". Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27442.
Testo completoAbstract (sommario):
This thesis presents a new model to simulate the behaviour of underground cable systems under transient conditions. The new cable model belongs to the class of time-domain, frequency-dependent models, and it is directly compatible with the solution algorithm of the EMTP (Electromagnetic Transients Program).
The most important feature of the new model is that it takes into account the frequency dependence of the modal transformation matrices and cable parameters, thus overcoming the main limitation of currently-used transmission line and cable models, which assume that the modal transformation matrices are constant
Conceptually, the new model is relatively simple. The system parameters which define the behaviour of an underground cable (namely the modal characteristic admittance matrix, the modal propagation matrix, and the modal transformation matrix), are expressed in closed form by approximating them with rational functions in the frequency domain. Therefore, in the time domain, all numerical convolutions can be expressed recursively. The host transients program (to which the model is interfaced) sees the new model as a constant, real admittance matrix, in parallel with a continuously-updated vector current source.
The accurate approximation by rational functions of the modal transformation matrix is possible when its elements are continuous and smooth functions of frequency. Standard eigenvalue/eigenvector algorithms are not well suited for this purpose. Therefore, a new procedure to generate eigenvalues and eigenvectors has been developed. This procedure is based on the Jacobi method, and it produces the desired smooth functions of frequency. This manuscript presents a number of simulations where the performance of the new cable model is compared with exact analytical solutions. These simulations show an excellent agreement between analytical and numerical answers. The effects of not taking into account the frequency dependence of the modal transformation matrices is illustrated with the simulation of a line-to-ground fault on a three-phase cable. The response of the new cable model is also compared with results measured in a field test
The new cable model is numerically stable. Its computational speed is comparable to that of frequency-dependent line models with constant transformation matrices.
The new cable model is general. Its extension to the simulation of multiple-circuit overhead transmission lines should also be of considerable practical importance.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
27
Olsen, Anders Tuhus. "Voltage Upgrading of Overhead Lines". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11218.
Testo completoAbstract (sommario):
Statnett wants to increase the transmission capacity in their 300 kV overhead lines by upgrading the operating voltage to 420 kV. To make this possible some modifications must be done. Insulator strings have to be elongated by two to four insulators and the air clearances must be checked. EN standards provide guidelines for how to calculate the air clearances adequately to provide required safety margins.It turns out that the formulas given by the standards provide greater safety margin than appropriate for upgraded transmission lines. By finding new proper safety margins, several towers which otherwise would have to be rebuilt to fulfill the requirements for clearances, can stay unmodified. When considering the number of towers in an average transmission line, there is obviously a great potential for saving money by putting some effort looking into proper minimum air clearances. By reduce the air clearance by approximately 10 cm, 6.5 mill. NOK were spared in a 65 km transmission line. It is therefore desirable to calculate the air clearances on the basis of smaller safety margins than described in the standard, but which is still within acceptable safety limits. In the formulas for minimum distances, the statistical withstand voltage U50%, gap-factors and altitude factors are examined for the cases of operating voltage, switching impulse and lightning impulse.Discrepancies between test results from a laboratory work conducted by STRI and calculations based on the EN standard of U50%, have been discovered. Tested U50 for switching impulses are 59 % higher than U50 from the standard. The same applies for lightning impulses where the tested value is 12 % higher than the standard. This gives reason to assume the standard to be somewhat conservative.Further, discrepancies are found between the standard EN 50341 that says that the gap factor when an insulator is present is the same as if no insulator is present, and Cigré report 72, which says that the gap factor should be corrected for the presence of insulators. Correction for insulators will lead to a lower gap factor i.e. lower break down strength along the insulator string than in the rest of the air gap. It turns out that the combination of rain and insulator string reduce the gap factor and thus, the withstand strength in the cases of switching impulses in the order of 6-13 % for V-string insulators and 20-34 % for I-string insulators and for continuous power frequency voltage in the order of 25 % for V-string insulators and 33-40 % for I-string insulators.Rain has no influence on the withstand strength of I-strings or V-strings exposed to lightning impulses.Several previous researches [1][2] shows the same tendencies of lack of correlation between U50 and gap factors when air gaps with insulator strings are exposed to lightning impulses. Thus, the gap factor is not sufficient to describe the discharge characteristics of air gaps with insulator strings exposed to lightning impulses.It is found that the air gap between phase and guy wire has approximately 7 % greater withstand strength than over the insulator string in a tower window. This additional safety margin is a desirable property in terms that the guy wires are the weakest point of a tower. This should however be verified by full-scale laboratory tests as this is mainly valid for the case of only the conductor-guy wire gap without the presence of the other air gaps that represent the tower window.
28
Guesdon, Cyril. "Etudes des répartitions des événements de verglas et de givre à travers le Québec /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2000. http://theses.uqac.ca.
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29
Leonard, Ronald William. "Application of the Monte Carlo method to the estimation of the risk of failure of transmission line insulation". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28496.
Testo completoAbstract (sommario):
A digital program has been developed which uses the Monte Carlo technique to estimate the risk of failure of transmission line insulation during system switching operations. The effect of overvoltage waveshape on insulation strength is included. A simple electrical system is used to demonstrate the method and to investigate some general aspects of error and parameter sensitivity.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
30
Crowder, Michael R. "Assessment of devices designed to lower the incidence of avian power line strikes /". PURL image only, 2000. http://www.arlis.org/docs/vol1/62243427.pdf.
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31
Cokkinides, George J. "Frequency dependent transmission line modeling with grounding representation". Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/15494.
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32
Savoullis, Yiannakis C. "Experimental verification and modification of a real-time ampacity program for overhead conductors". Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/17840.
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33
Li, Quan. "AC loss characteristics of monolayer and multilayer superconducting power transmission cables". Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609500.
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34
Filipovic-Gledja, Visnja. "A probability based unified model for predicting electrical, mechanical and thermal characteristics of stranded overhead-line conductors". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ30086.pdf.
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35
Crnojacki, Zorica. "Extra high voltage transmission corridor siting : technical, public, institutional and regulatory considerations /". Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-10032007-171749/.
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36
Li, Xiaojuan. "Estimations of power system frequency, phasors and their applications for fault location on power transmission lines". University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0125.
Testo completoAbstract (sommario):
The thesis is devoted to the development of new algorithms for estimation of system frequency, power system phasors and transmission line fault location in the context of power system protection and control. A z-transform signal model combined with a nonlinear post-filtering scheme to estimate the operating frequency in a power system is first developed in the thesis. The signal model parameters are identified by an optimisation method in which the error between the model output and the actual signal that represents a voltage or current in the power system is minimised. The form and the structure of the signal model do not require iterations in the optimisation process for parameter identification. The system operating frequency is directly evaluated from the model parameters. Effects of noise and any frequency components other than the operating or supply-frequency on the accuracy are countered very effectively by applying a median post-filtering on the time series representing the frequency estimates derived from the model. Extensive simulation studies and comparisons with previously-published frequency estimation techniques confirm the high performance of the method developed in the thesis in terms of accuracy and time delay. With respect to power system phasor estimation, a method is developed based on waveform interpolation in the discrete time-domain to counter the spectral leakage errors arising in forming, by discrete Fourier transform (DFT), the supply frequency phasors representing power system voltages and currents when there are system frequency deviations from the nominal value. The interpolation scheme allows DFT evaluation to be performed with a time window length which is exactly equal to the fundamental period of the voltage or current waveform. Comparative studies presented in the thesis confirm the improvements achieved by the method proposed over other previouslypublished techniques in terms of accuracy and computing time. With the availability of accurate operating frequency and phasor estimates, an optimal fault location method based on multi-conductor distributedparameter line model is developed. The method is a general one which is applicable to any transmission line configurations, including multi-terminal lines. The fault location method is based on the minimisation of an objective function in which the fault distance is a variable. The objective function is formed from combining the phase-variable distributed-parameter equations of individual line sections from the fault point to the line terminals. The multivariable minimisation leads to high accuracy and robustness of the fault location algorithm in which any voltage/current measurement errors, including sampling time synchronisation errors, are represented in the estimation procedure as variables in addition to the fault distance. Extensive simulation studies are performed to verify that the method developed is highly accurate and robust. The thesis is supported by two international publications of which the candidate is a joint author.
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Gueye, Babacar Salif. "Suitability of Casuarina equisetifolia as utility poles in Senegal". Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-01102009-063410/.
Testo completo
38
Wells, M. Glenn. "Transient temperature distributions in overhead fiber-optic ground wires". Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/16885.
Testo completo
39
Li, Xiaoyong. "Added CFO voltages from fiberglass poles and its electrical degradation". Master's thesis, Mississippi State : Mississippi State University, 2001. http://library.msstate.edu/etd/show.asp?etd=etd-11092001-113706.
Testo completo
40
Bao, Yufei. "Integrated optical tapped-delay-lines : design, analysis and implementation". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/15446.
Testo completo
41
Adamov, Minja Gemisic. "Measurements of local electric fields by doppler-free laser spectroscopy of hydrogen resonance lines". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2007. http://dx.doi.org/10.18452/15576.
Testo completoAbstract (sommario):
In dieser Arbeit wurde eine einfache laserspektroskopische Messmethode für lokale elektrische Feldstärken im Hinblick auf ihre Messmöglichkeiten und -grenzen untersucht. Als empfindliche optische Feldsensoren dienen dabei Wasserstoffatome, für die die Stark-Aufspaltung der Spektrallinien im elektrischen Feld wohl bekannt und exakt berechenbar ist. Die experimentellen Untersuchungen wurden an einer Niederdruck-Gaszelle durchgeführt, in der ein elektrisch geheizter Wolframdraht für thermische Dissoziation von Wasserstoffmolekülen sorgte. Die Wasserstoffatome wurden durch zwei gegenläufige Laserstrahlen Doppler-frei angeregt. Die Durchstimmung der schmalbandigen Laserstrahlung über den Wellenlängenbereich der Zwei-Photonen-Resonanz lieferte direkt das vom elektrischen Feld hervorgerufene Stark-Spektrum des angeregten Zustands. Weil die Methode im Gegensatz zu ähnlichen, erheblich aufwendigeren Verfahren nur die niedrigsten Wasserstoff-Energieniveaus benutzt, die mit Zwei-Photonen-Anregung direkt aus dem Grundzustand erreichbar sind, kommt sie mit einem einzigen Laser aus. Für das erste angeregte Niveau mit n = 2 wird Strahlung bei 243 nm benötigt, das nächsthöhere Niveau mit n = 3 erfordert 205 nm. Für n = 2 wurden Untersuchungen an Wasserstoff und Deuterium durchgeführt und Stark-Spektren mittels optogalvanischer Detektion gemessen. Schwerpunkt der Arbeit waren aber die Messungen an Wasserstoff für n = 3, bei denen zusätzlich Balmer-alpha-Fluoreszenz im Sichtbaren zur Detektion eingesetzt werden konnte. Bei elektrischen Feldern bis 200 V/cm wurden Stark-Spektren für drei verschiedene Polarisationszustände der Laserstrahlung aufgenommen. Als Ergebnis konnte jeweils ein Paar isolierter Stark-Komponenten in den Spektren identifiziert werden, dessen gut messbarer Frequenzabstand durch Vergleich mit theoretischen Werten die Bestimmung der elektrischen Feldstärke ermöglicht.A method for electric field measurements that observes the Stark spectra of the low excited levels n = 2 and n = 3 of atomic hydrogen has been explored in this work. As advantage these levels can be excited Doppler-free from the ground state by a single laser and the highly resolved Stark spectra are easy to understand and to be calculated. Good sensitivity of electric field measurements is achieved with specially designed solid state laser systems, which provide tuneable pulsed UV radiation with a high pulse peak-power and a narrow bandwidth needed for Doppler-free two-photon excitation. Using hydrogen and deuterium the Stark spectra of the n = 2 level are detected as optogalvanic signal. For three different cases of laser polarization the n = 3 spectra of hydrogen are measured simultaneously with optogalvanic and laser induced Balmer alpha fluorescence detection. Electric fields down to 200 V/cm can be determined from the Stark spectra of n = 2 level, while the spectra of n = 3 level enable measurements of electric fields as small as 50 V/cm in each of the three cases of laser polarization.
42
Coggins, David Paul. "Single-ended traveling wave fault location on radial distribution lines". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/27951/.
Testo completoAbstract (sommario):
In this thesis a single-ended traveling wave fault location algorithm is developed for autonomously locating short circuit faults on a radial distribution line using the high frequency traveling wave transients. The traveling wave pattern observed at the sub-station is correlated with the traveling wave pattern predicted using time tree analysis for different fault locations and fault resistance. Genetic search techniques are used to evolve an initial population of possible fault locations to determine the most likely fault location. It is shown through extensive EMTP simulations that the scheme is capable of finding the location of three phase faults, inter-phase faults and single-phase faults for fault resistances ranging from 0 - 1000 ohm on a radial distribution line with five sub-feeders. A new high speed FPGA based data acquisition system is developed suitable for capturing traveling wave fault data from a radial distribution line with the necessary fidelity for the proposed fault location algorithm. The data acquisition system is deployed on a Medium Voltage distribution line in the Santa Caterina region of Brazil. A branched communication network is constructed out of RG-58 coaxial cable and a Time Domain Reflectometry device is used to capture the reflection pattern under different fault conditions. The fault location algorithm is adapted to work with TDR a opposed to fault generated traveling waves. The location algorithm is capable of locating faults with resistance between 0 and 75 ohm up to three zones away from the injection point.
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Sellers, Sally M. "Caculation of ampacity for underground electrical cables". Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/18973.
Testo completo
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Liao, Jen-Chyi. "Computer simulation of multiple coupled transmission lines in electronic packaging application". Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184659.
Testo completoAbstract (sommario):
A method for simulating the transient responses of networks containing lossless transmission lines and lumped parameter elements of circuits, both linear and nonlinear, has been developed and investigated. The method combines the technique of network analysis and that of modal decomposition of transmission lines. A prototype computer simulation program, called UANTL, based on the developed algorithm has been implemented. Several example networks have been simulated using this program. The results have been compared with those generated by the well known circuit simulator program called SPICE. UANTL has shown several advantages over SPICE in simulating the transient responses of networks containing transmission lines. A description of the prototype version of UANTL and a summary of the results of numerical experiments are included.
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Chen, Shuoqi. "Characterization of semiconductor-based guided wave structures using field theoretical analysis techniques". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21927.pdf.
Testo completo
46
Visser, Abraham Johannes. "Transformerless series dip/sag compensation with a multilevel cascaded inverter". Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52592.
Testo completoAbstract (sommario):
Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: This thesis covers the development of a multilevel cascaded inverter for the purpose of costeffective transformerless series dip compensation. Of all known power quality problems, voltage dips are the greatest reason for concern. Dips/sags occur more frequently than outages and therefore tend to be more costly for industry as modem technical equipment becomes all the more sensitive to the quality and reliability of supply. A number of devices already exist to compensate for this problem, but the cost of most of these systems does not always justify the financial losses they compensate for. All of these systems are using transformers and/or large filter components that contribute to the size, price and losses to quite a large extent. Series injection dip compensators offer the advantage of only having to compensate for the decrease in supply voltage during a dip. This results in a significant reduction in the converter ratings and energy storage requirements compared to conventional uninterruptible power supplies or shunt injection power quality devices. Existing inverter topologies, including multilevel inverters, were therefore studied and compared as possible solutions for cost-effective transformerless series dip compensation. On the basis of these considerations the multilevel cascaded inverter seems to be the most cost-effective option. The relatively low harmonic content of its unfiltered output also eliminates the need for a large output filter. A single-phase dip compensator, with this topology, was designed and built according to specifications stated by Eskom, the main utility in South Africa. Batteries as energy storage and automotive MOSFETs as switching components, proved to be most cost-effective options for the specified power ratings. Control algorithms for dip compensation with the multilevel inverter were also developed. Some of these algorithms are based on existing techniques, but two new algorithms were also developed to implement force commutation of the thyristors and to share the power dissipation in the dip compensator. Simulations indicated that these algorithms could be suitable and sufficient for their application. This dip compensator with its control algorithms was tested with a dip generator, developed at the University of Stellenbosch, for different types of loads. The experimental results confirmed the simulations and showed a very good performance for the specified conditions. An optimised design of this dip compensator will make it a cost-effective solution for dip compensation.
AFRIKAANSE OPSOMMING: Hierdie tesis dek die ontwikkeling van 'n multivlakwisselrigter, in kaskade, met koste-effektiewe transformatorlose duik kompensasie as mikpunt. Van al die bekende toevoerkwaliteit probleme wek duike in die spanning die meeste kommer. Duike kom meer gereeld voor as kragonderbrekings en neig daarom om 'n groter onkoste te wees vir die industrie soos wat moderne tegnologiese toerusting al hoe meer sensitief raak vir die kwaliteit en betroubaarheid van die toevoer. 'n Aantal toestelle wat vir hierdie probleem kompenseer bestaan reeds, maar die koste van hierdie stelsels regverdig nie altyd die finansiële verliese wat hulle moet elimineer nie. Al hierdie stelsels gebruik transformators en/of groot filter komponente wat grootliks bydra tot die grootte, prys en verliese van hierdie stelsels. Serie-injeksie kompenseerders het die voordeel dat hulle net kompenseer vir die verlies in die toevoerspanning tydens die duik. Dit het 'n beduidende vermindering in die omsetterkenwaardes en energiestoorvereistes tot gevolg in vergelyking met ononderbroke kragbronne (UPS) of newe-injeksie toevoerkwaliteit toestelle. Daarom IS bestaande wisselrigtertopologië, insluitende multivlakwisselrigters, bestudeer en vergelyk as moontlike oplossings vir koste-effektiewe serie duik-kompensasie. Van al hierdie moontlikhede lyk die multivlakwisselrigter, in kaskade, na die mees koste-effektiewe opsie. Die relatiewe lae harmoniese inhoud van sy ongefilterde uittree elimineer die behoefte aan 'n groot uittreefilter. 'n Enkelfase duik kompenseerder, met hierdie topologie, is ontwerp en gebou volgens die spesifikasies wat vasgestel is deur Eskom, die hoof elektriese kragvoorsiener in Suid-Afrika. Dit het geblyk dat batterye, en MOSFETte uit die motorbedryf, die mees koste-effektiewe opsies bied vir onderskeidelik die energiestoor en skakelkomponente. Beheeralgoritmes VIr duik kompensasie met die multivlakwisselrigter is ook ontwikkel. Sommige van hierdie algoritmes is gebaseer op bestaande tegnieke, maar twee nuwe algoritmes is ook ontwikkel vir die kommutering van die tiristors en die deling van die drywingsverkwisting in die duik kompenseerder. Simulasies dui aan dat hierdie algoritmes geskik en voldoende kan wees vir hulle toepassing. Hierdie duik kompenseerder met sy beheeralgoritmes is getoets vir verskillende tipes laste met 'n duikgenerator wat ontwikkel is by die Universiteit van Stellenbosch. Die eksperimentele resultate bevestig dit wat verkry is uit die simulasies en wys 'n goeie werkverrigting vir die gespesifiseerde kondisies. 'n Geoptimeerde ontwerp van hierdie duik kompenseerder sal dit 'n koste-effektiewe oplossing maak vir duik kompensasie.
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Matandirotya, Electdom. "Measurement and modelling of geomagnetically induced currents (GIC) in power lines". Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2459.
Testo completoAbstract (sommario):
Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016.Geomagnetically induced currents (GIC) are currents induced in ground-based conductor networks in the Earth's surface. The GIC are driven by an electric eld induced by geomagnetic variations which are a result of time-varying magnetospheric-ionospheric currents during adverse space weather events. Several studies have shown that there is a likelihood of technological damage (the power grid) in the mid- and low-latitude regions that could be linked to GIC during some geomagnetic storms over the past solar cycles. The effects of GIC in the power system can range from temporary damage (e.g. protective relay tripping) to permanent damage (thermal transformer damage). Measurements of GIC in most substations are done on the neutral-to-ground connections of transformers using Hall-effect transducers. However, there is a need to understand the characteristics of GIC in the power lines connected to these transformers. Direct measurements of GIC in the power lines are not feasible due to the low frequencies of these currents which make current measurements using current transformers (CT) impractical. This thesis discusses two techniques that can be employed to enhance understanding GIC characteristics in mid-latitude regions. The techniques involve the measurement of GIC in a power line using differential magnetometer measurements and modelling GIC using the finite element method. Low frequency magnetometers are used to measure magnetic felds in the vicinity of the power lines and the GIC is inferred using the Biot-Savart law. A finite element model, using COMSOL-Multiphysics, is used to calculate GIC with the measured magnetic field and a realistic Earth conductivity profile as inputs. The finite element model is used for the computation of electric field associated with GIC modelling.
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Schilder, Melanie. "Wideband modelling of capacitive voltage sensors for open-air transmission line applications". Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53222.
Testo completoAbstract (sommario):
Thesis (PhD)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: This dissertation considers the wideband modelling of capacitive voltage sensors for open-air transmission line applications. Two novel topologies were introduced, namely a differential parallel plate sensor with a floating faraday cage for the interface instrumentation and a coaxial sensor mounted around the earth conductor with a faraday cage connected to the earth conductor. The modelling and analysis procedures included the derivation of equivalent circuit models in order to simulate the calibration factor, the loading effect of the interface instrumentation and the effect of leakage to ground, both in the time- and frequency domain. In order to obtain a flat frequency response from very low frequencies (less than 5 Hz) to very high frequencies (several MHz) it is important that the interface instrumentation have a high input impedance and galvanic isolation be maintained. This was achieved by developing interface instrumentation with a fibre-optic link operated from battery power. The instrumentation represents a fairly unique approach in that the data is digitised before transmission across the serial fibre-optical link, where-as conventional interfaces use analogue optical technology. Despite the added complexity and high power requirements introduced by the digitising process, the improved versatility is expected to yield a superior interface solution. The instrumentation has a bandwidth of approximately 6 MHz, with an optional anti-aliasing filter at 1 MHz. Special consideration should be given to the support structure as any unbalanced leakage to ground will introduce variations in the frequency response towards the low-frequency end. Leakage of a 100 MQ was found to influence the frequency response of the circuit up to frequencies of 1 kHz. Extensive simulation studies were conducted to obtain qualitative and quantitative insight into the differential sensor topology and the associated electric fields. The improvement of a differential plate sensor over the traditional single element plate sensor was demonstrated using twodimensional simulations. Further simulations with a three-dimensional package showed that the two-dimensional simulations are insufficient, because the boundary conditions and end effects have a great influence on the calibration factor of the sensor. Extensive laboratory tests were also undertaken to evaluate the sensor topology as well as the effects of the interface instrumentation and leakage to ground. Excellent correlation were found between the measured and simulated waveforms, both in the time- and frequency domains regarding the calibration factor as well as the added poles or zeros at low frequencies. It can therefore be deduced that a valid circuit model was suggested for these sensor topologies in the frequency range from 10 Hz to 1 MHz. Keywords: Capacitive sensors, Open-air voltage sensors
AFRIKAANSE OPSOMMING: Hierdie verhandeling beskou die wyeband modellering van kapasitiewe spanningsensors vir opelug transmissie lyn toepassings. Twee oorspronklike topologieë is voorgestel, naamlik 'n differensiële parallel plaat sensor met 'n aparte faraday hok vir die koppelvlak instrumentasie en 'n koaksiale sensor wat rondom die aardgeleier monteer word met die faraday hok ook aan die aardgeleier gekoppel. Die modellerings en analise prosedures het ingesluit die afleiding van ekwivalente stroombaanmodelle vir simulasie van die kalibrasiefaktor asook die belasingseffek van die koppelvlak instrumentasie en lekweerstand na grond in beide die tyd- en frekwensie gebiede. Om 'n plat frekwensieweergawe te verkry vanaf baie lae frekwensies (laer as 5 Hz) tot by baie hoë frekwensies Cn paar MHz), is dit belangrik dat die koppelvlak instrumentasie 'n hoë intreeimpedansie het en galvaniese isolasie verseker word. Dit was bereik deur koppelvlak instrumentasie te ontwikkel met 'n optiese vesel koppeling wat met battery krag aangedryf word. Die instrumentasie verskaf 'n redelik unieke aanslag in die opsig dat die data gemonster word voordat dit oor die seriële optiese vesel skakel gestuur word, terwyl konvensionele koppelvlakke analoog optiese tegnologie gebruik. Ten spyte van die toegevoegde kompleksiteit en hoë drywingsvereistes van die versyferingsproses, het die instrumentasie se veelsydigheid toegeneem tot die mate dat dit as 'n beter koppelvlak oplossing beskou word. Die instrumentasie het 'n bandwydte van ongeveer 6 MHz, met 'n opsionele teen-vou filter by 1 MHz. Die ondersteuningstruktuur is van besondere belang aangesien enige ongebalanseerde lekweerstand na grond afwykings in die frekwensieweergawe sal veroorsaak aan die lae frekwensie kant. Lekweerstand van 100 MQ sal die frekwensieweergawe beïvloed tot by ongeveer 1 kHz. Uitgebreide simulasies is gedoen om kwalitatiewe en kwantitatiewe insig in die differensiële sensor topologie en die geassosieerde elektriese velde te verkry. Die verbetering van 'n differensiële parallel plaat sensor in vergelyking met die tradisionele enkel element plaat sensor is demonstreer met twee-dimensionele simulasies. Verdere simulasies met 'n drie-dimensionele pakket het gewys dat die twee- dimensionele simulasies onvoldoende is aangesien grensvoorwaardes en randeffekte 'n groot invloed het op die kalibrasiefaktor van die sensor. Uitgebreide laboratorium toetse is ook gedoen om die sensor topologie sowel as die effekte van die koppelvlak instrumentasie en lekweerstand na grond te evalueer. Uitstekende korrelasie is gevind tussen gemete en voorspelde golfvorms, in beide die tyd- en frekwensie gebied met betrekking tot die kalibrasie faktor sowel as die toegevoegde pole en zeros by lae frekwensies. Die gevolgtrekking is dus dat 'n geldige stroombaanmodel voorgestel is vir die sensor topologieë vir die frekwensie bereik van 10Hz to 1 MHz. Sleutelwoorde: Kapasitiewe sensors, Ope-lug spanningsensors
49
Markovic, Dejan. "Induced currents in gas pipelines due to nearby power lines". Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060807.155002/index.html.
Testo completo
50
Chan, Morgan Hing Lap. "Channel characterization and forward error correction coding for data communications on intrabuilding electric power lines". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29071.
Testo completoAbstract (sommario):
The use of intrabuilding electric power lines for data communications and local area networking is of growing interest. In this thesis, an original work to study the very important signal propagation and noise characteristics of the complex and hostile power line networks has been completed. Various impairments such as high and varying signal attenuation levels, periodic signal fading and impulse noise were identified. Estimates of the amplitude, pulse width and interarrival distributions of impulse noise were obtained. Communication signal attenuation of power line networks was explored. The effects of electrical loading on these communication channel factors were examined. Implications of the results for intrabuilding communications are addressed.
To combat power line impulse noise, channel fading, attenuation and other impairments, forward error correction (FEC) coding and bit interleaving is proposed and shown to be very effective, and is an essential component for reliable communication over power lines. The performance of interleaved hard and soft decision decoding of repetition codes with or without erasure has been analysed, using a simple first order power line noise model. Various random and burst error correcting block codes have been evaluated, using actual recorded bit error patterns encountered on power line data channels.
Based on studies of the channel and error correction coding, an actual low cost FEC coded communication system for use on intrabuilding power lines was successfully designed, implemented and tested. Real time performance results of coded and uncoded data transmissions on typical power lines were experimentally determined. Convolutional codes as well as repetition coding and bit interleaving are used to overcome burst errors and other impairments encountered on power line channels. The emphasis is on high speed transmission at bit transmission rates up to 57.6 kbits/s. Typical practical coding gains from 10 to 20 dB were achieved at bit error rate of 10⁻⁴ on various noisy links. It is successfully demonstrated that with appropriate and inexpensive FEC coding, reliable high speed data transmission over power lines is feasible, even at very small interleaving delay.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate