In this diploma thesis it was introduced the issue of power line communication and network architecture design with goal to create own concept of smart house system. Consequently, the necessary communication protocols are designed and described based on the concept. Further is described the implementation of the designs and testing of the realized system under laboratory conditions using the real communication devices. Summary of the achieved results is supported by demonstration of real functionality.

Thesis (PhD)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The Square Kilometre Array (SKA) and its demonstrator MeerKAT are being designed to operate over a wide frequency range and are expected to achieve greater sensitivity and resolution than existing telescopes. The radio astronomy community is well aware of the negative impact that radio frequency interference (RFI) has on observations in the proposed frequency band. This is because weak radio signals such as those from pulsars and distant galaxies are difficult to detect on their own. The presence of RFI sources in the telescope’s operating area can severely corrupt observation data, leading to inaccurate or misleading results. Power-line interference and radiation from electric fences are examples of RFI sources. Mitigation techniques for these interference sources in the SKA system’s electromagnetic environment are essential to ensure the success of this project. These techniques can be achieved with appropriate understanding of the characteristics of the noise sources. Overhead power-line interference is known to be caused mainly by corona and gap-type (commonly known as sparking noise) discharges. Sparking noise is the dominant interference for the SKA. It is mainly encountered on wooden pole lines, which are usually distribution lines operated at up to 66 kV AC in the South African network. At this voltage level, the voltage gradients on the lines are insufficient to generate conductor corona. The power requirements for SKA precursors will be below this voltage level. The aim of the research in this dissertation is to evaluate the power line sparking characteristics through measurements and simulation of line radiation and propagation characteristics. An artificially made sparking noise generator, which is mounted on a power line, is used as noise source and the radiation characteristics are measured. Measurements were carried out in different environments, which included a high-voltage laboratory (HV-Lab), a 40m test-line, and another 22-kV test line of approximately 1.5 km. The key sparking noise parameters of interest were the temporal and spectral characteristics. The time domain features considered were the pulse shape and the repetition rate. The lateral, longitudinal and height attenuation profiles were also quantified. Since sparking noise current pulses are injected or induced onto power line conductors, the line will act as an unintentional antenna. The far-field radiation characteristics of the line were evaluated through measurements on physical scale-model structures and simulations. 1/120th and 1/200th scaled lines, using an absorbing material and metallic ground planes, respectively, were simulated in FEKO. The measurements of the constructed scale models were taken in the anechoic chamber. Both measurements and simulations showed that the line exhibits an end-fire antenna pattern mode. Line length, pulse injection point and line configuration were some of the parameters found to affect the radiation patterns. The findings from this study are used to determine techniques to identify the sparking noise, and locate and correct the sources when they occur on the line hardware. Appropriate equipment is recommended to be used for the location and correction of sparking noise. / AFRIKAANSE OPSOMMING: Die Vierkante Kilometer Reeks (SKA) en sy demonstrasie projek, die Karoo Reeks Teleskoop (KAT), word ontwerp om oor 'n wye frekwensie-bereik te funksioneer. Beide sal na verwagting beter sensitiwiteit en resolusie as bestaande radioteleskope he. Die radio-astronomie-gemeenskap is deeglik bewus van die negatiewe impak wat radio-frekwensie steurnisse (RFS) op waarnemings in die voorgestelde frekwensieband het. Die rede hiervoor is dat swak radio-seine soos die van pulsars en verafgelee sterrestelsels inherent moeilik is om te bepaal. Die teenwoordigheid van RFS bronne in die teleskoop se onmiddellike operasionele gebied kan waarnemings nadelig beinvloed. Dit lei uiteindelik tot onakkurate of misleidende resultate. Kraglyne en uitstralings van elektriese heinings is voorbeelde van RFS bronne. Metodes om die oorsake van die steurnisse van die SKA se elektromagnetiese omgewing te verminder is noodsaaklik om die sukses van hierdie projekt te verseker. Dit vereis egter deeglike begrip van die eienskappe van hierdie bronne. Steurnisse as gevolg van oorhoofse kraglyne word hoofsaaklik veroorsaak deur korona en gapingtipe ontladings (algemeen bekend as vonkontladings). Vonkontladings word hier beskou as die belangrikste oorsaak van steurnisse vir die SKA. Dit word in die Suid-Afrikaanse netwerk hoofsaaklik aangetref op houtpaal-installasies, wat gewoonlik bestaan uit distribusie lyne wat tot en met 66 kV wisselstroom (WS) bedryf word. By hierdie operasionele spanning is die spanningsgradient op die lyn onvoldoende om korona op te wek. Die kragvereistes vir die SKA se voorafgaande projekte sal sodanig wees dat hierdie spanningsvlak nie oorskry sal word nie. Die doel van die navorsing omskryf in hierdie proefskrif is om die eienskappe van vonkontladings rondom kraglyne te evalueer. Dit word gedoen met behulp van metings en simulasies van uitstralings- en voortplantingspatrone wat met 'n spesifieke lyn geassosieer kan word. 'n Kunsmatige vonkontladingsopwekker word op 'n kraglyn geplaas en dien as bron om die uitstralingspatrone te meet. Metings is uitgevoer in verskillende omgewings, insluitende 'n hoogspanningslaboratorium (HV-Lab), 'n 40 m toetslyn en 'n 22 kV WS toetslyn van ongeveer 1.5 km lank. Die hoof vonkontladings eienskappe van belang is die temporale en spektrale eienskappe. Die tydgebiedeienskappe wat ondersoek is, is die pulsvorm asook die pulsherhalingskoers. Die laterale, longitudinale en hoogte-attenuasie profiele word ook gekwantifiseer. Aangesien stroompulse deur vonkontladings op die kraglyn geplaas of geinduseer word, sal die lyn as 'n ongewenste antenna optree. Die ver-veld uitstralingskenmerke van die lyn is ook geëvalueer deur gebruik te maak van fisiese skaalmodelstrukture en -simulasies. 1/120ste en 1/200ste geskaleerde lynmodelle, wat onderskeidelik 'n absorberende- en metaalgrondvlak bevat, was gebruik om 'n 3 spanlengte kraglyn te simuleer met behulp van FEKO. Metings van die fisiese skaalmodel strukture is in 'n anegoise kamer geneem. Beide die metings en die simulasies toon dat die lyn 'n endpunt uitstralingspatroon het. Lynlengte, die opwekkingsposisie van die stroompuls en die lynkonfigurasie is 'n paar van die parameters wat die uitstralingpatroon beïnvloed, soos in die navorsing aangedui. Die bevindinge van hierdie studie word gebruik om steurnisse as gevolg van vonkontladings op die kraglyn te identifiseer, op te spoor en uiteindelik reg te stel. Toepaslike toerusting word voorgestel wat gebruik kan word vir die identifisering en opsporing van vonkontladings.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2017-12-21T11:52:32Z No. of bitstreams: 1 luisguilherrmedasilvacosta.pdf: 2910682 bytes, checksum: da61cee3e668dc7356aa3ab54ff0c28c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-12-22T11:58:44Z (GMT) No. of bitstreams: 1 luisguilherrmedasilvacosta.pdf: 2910682 bytes, checksum: da61cee3e668dc7356aa3ab54ff0c28c (MD5) / Made available in DSpace on 2017-12-22T11:58:44Z (GMT). No. of bitstreams: 1 luisguilherrmedasilvacosta.pdf: 2910682 bytes, checksum: da61cee3e668dc7356aa3ab54ff0c28c (MD5) Previous issue date: 2017 / Esta tese de doutorado apresenta, inicialmente, uma revisão sobre acopladores para power line communication (PLC), utilizados para acoplar o sinal dos transceptores PLC à rede de energia elétrica. As questões predominantes para o projeto de acopladores e, consequentemente, os diferentes tipos de acopladores são discutidos. Uma classificação dos acopladores PLC baseada nos tipos de acoplamentos (capacitivo, indutivo, resistivo e por antenas), níveis de tensão, largura de banda de frequência, modos de propagação e números de conexões com a rede de energia elétrica é apresentada. Em seguida, o projeto de circuitos PLC de acoplamento capacitivo não adaptativos, single input single output (SISO) de baixa tensão para aplicações banda larga e banda estreita são discutidos. O acoplador PLC banda estreita é projetado para a banda de frequência de 9 kHz-500 kHz, enquanto os acopladores banda larga são projetados para a banda de frequência de 1.7-50 MHz, 1.7-100 MHz e 1.7-500 MHz. Além disso, discute-se as especificações e o projeto dos protótipos desses circuitos de acoplamento PLC medindo seus parâmetros de espalhamento. A seguir, é discutida a medida da impedância de acesso da rede de energia elétrica de baixa tensão na banda de frequência 2- 500 MHz, visando apresentar prévio conhecimento da impedância de acesso da rede de energia elétrica no Brasil com base em uma campanha de medição realizada em várias instalações em três cidades brasileiras diferentes. Além disso, é proposto um procedimento para obter um modelo estatístico da impedância de acesso na referida faixa de frequência. Com base em uma série de medidas de impedâncias de acesso da rede de energia elétrica e critérios para a escolha de modelos estatísticos, esta tese sugere duas distribuições para modelar as componentes resistência e reatância da impedância de acesso da rede de energia elétrica. Uma vez que, os parâmetros de tais modelos mudam com a frequência e que a impedância de acesso é um processo aleatório no domínio da frequência, um modelo simples para gerar amostras em função desse processo aleatório, que leva em consideração as distribuições sugeridas, é detalhado. Por fim, é proposto um circuito de acoplamento adaptativo PLC, capacitivo, SISO de baixa tensão. Estes circuitos de acoplamento adaptativos usam três diferentes filtros analógicos passa-baixa com diferentes impedâncias de entrada. A impedância de entrada de cada filtro analógico é projetado de acordo com os valores obtidos através da campanha de medição, e a impedância de saída é projetada para 50 Ω. A escolha do filtro analógico que proporciona melhor casamento de impedância com a rede de energia elétrica é obtido por um microcontrolador, que através de um conversor analógico digital, monitora a tensão fornecida por um circuito que mede a potência dos sinais injetados nos acopladores PLC pelos transceptores PLC. A monitoração da potência é realizada continuamente pelo conversor analógico digital do microcontrolador que escolhe qual o filtro analógico proporciona o melhor casamento de impedância com a rede de energia elétrica e comuta os filtros analógicos através de uma chave de analógica conectando os transceptores PLC a rede de energia elétrica através dos acopladores PLC. Além disso, as medições dos valores do parâmetro de espalhamento S11 confirmam que a componente resistiva da impedância de acesso da rede de energia elétrica apresentou melhor casamento de impedância entre 50 Ω e 100 Ω. Por fim, os valores medidos do parâmetro de espalhamento S12 mostram que a atenuação cresce com o aumento da frequência devido ao comportamento indutivo da rede de energia elétrica. / This work outlines a comprehensive review of PLC coupling circuits, which are required for narrowband and broadband PLC transceivers. Prevailing issues that protract the design of couplers and consequently subtended the inventions of different types of couplers are clearly described. Also, it provides a useful classification of PLC couplers based on the type of physical couplings, voltage levels, frequency bandwidth, propagation modes and a number of connections. Next, the focus is on the design of non-adaptive capacitive, SISO and low-voltage (LV) PLC coupling circuits for both broadband and narrowband applications. The narrowband cover the frequency band 9 kHz-500 kHz, while broadband frequency bands are 1.7-50MHz, 1.7-100MHz and 1.7- 500 MHz. Moreover, it discusses the specification and design of the prototypes of the PLC coupling circuits measuring their scattering parameters. The access impedance of Brazilian in-home, broadband and low-voltage electric power grid in the frequency band 2-500 MHz is taken into account. Based on the use of a measurement setup a large measurement campaign that was carried out in several facilities in three different Brazilian cities is discussed. Also, a procedure to obtain a statistical model of the access impedance in the aforementioned broadband frequency is outlined. Based on a number of measured access impedances and well-known criteria for choosing statistical models, two distributions to model the resistance and reactance components of the access impedance are suggested. Due to the fact that the parameters of such models change with the frequency and the access impedance is a random process in the frequency domain, a simple and effective model to generate samples function of such random process, which takes into account the suggested distributions, is addressed. Finally, adaptive capacitive, SISO and LV PLC coupling circuits are proposed for broadband power line communication. These adaptive coupling circuits use three different analog low-pass filter for impedance matching. This filter is an array of analog low-pass irregular filters that separate the input and output signal into three analog low-pass filters, each one matching the impedance between the electric power grid and PLC transceiver. The input impedance of each filter has a different impedance value, chosen according to the impedance of the measurement campaign, and the output impedance is fixed in 50 Ω for all analog low-pass filter. The choice of the analog filter that provides better impedance matching to the electrical power grid is obtained by a microcontroller, which through an analog-to-digital converter (ADC), measure the voltage provided by a circuit that measures the power of the signals injected into the PLC coupling circuit by the PLC transceivers. The power is continuously measured by an ADC of the microcontroller which chooses which analog filter provides the best impedance matching with the electric power grid and switches the analog filters through an analog switcher connecting the PLC transceivers to the electric power grid through the PLC coupling circuit. In addition, the measured values of the scattering parameter S11 show that the best impedance matching occurs when the resistive impedance component of the access impedance is between 50 Ω and 100 Ω . For the scattering parameter S12 it has been found that the attenuation increases as the frequency increases because of the inductive behavior of the electric power grid.

This master’s thesis deals with design and implementation of electric energy meter with support of automatic remote data collection. For the collecting of measured data is used narrowband PLC technology. The theoretical part describes the basic properties and standards of narrowband PLC technology, such as types of coupling circuits, modulations, frequency bands and interference problems. In the practical part, there is description of selected parts, such as control circuit power meter, modem, microcontroller and UART to USB converter. There are further described basic properties of narrowband PLC modem ST7570 by STMicroelectronics. The final chapter, implementation of the device, deals with designs of circuit PLC modem ST7570, power meter ADE7753 and converter USB to UART CP2102.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper introduces a study of the feasibility and initial hardware design for transmitting data over aircraft power lines. The intent of this design is to significantly reduce the wiring in the aircraft instrumentation system. The potential usages of this technology include Common Airborne Instrumentation System (CAIS) or clock distribution. Aircraft power lines channel characteristics are presented and Orthogonal Frequency Division Multiplexing (OFDM) is introduced as an attractive modulation scheme for high-speed power line transmission. A design of a full-duplex transceiver with accurate frequency planning is then discussed. A general discussion of what communications protocols are appropriate for this technology is also provided.

Non-Destructive Testing of industrial components carries vital importance, both financially and safety-wise. Among all Non-Destructive techniques, Long Range Ultrasonic Testing utilizing the guided wave phenomena is a young technology proven to be commercially valid. Owing to its well-documented analytical models, Ultrasonic Guided Waves has been successfully applied to cylindrical and plate-like structures. Its applications to complex structures such as multi-wire cables are fairly immature, mainly due to the high complexity of wave propagation. Research performed by the author approaches the long range inspection of overhead transmission line cables using ultrasonic guided waves. Existing studies focusing on guided wave application on power cables are extremely limited in inspection range, which dramatically degrades its chances of commercialization. This thesis consists of three main chapters, all of which approaches different problems associated with the inspection of power cables. In the first chapter, a thorough analysis of wave propagation in ACSR (most widely used power cable) cables is conducted. It is shown that high frequency guided waves, by concentrating the energy on the surface layers, can travel much further in the form of fundamental longitudinal wave mode, than previous studies have shown. Defect detection studies proved the system’s capability of detecting defects which introduce either increase or decrease in cross sectional area of the cable. Results of the chapter indicate the detectability of defects as small as 4.5% of the cross sectional area through a 26.5 meter long cable without any post-processing. In the second chapter, several algorithms are proposed to increase the inspection range and signal quality. Well-documented wavelet-denoising algorithm is optimized for power cables and up to 24% signal-to-noise ratio improvement is achieved. By introducing an attenuation correction framework, a theoretical inspection range of 75 meters is presented. A new framework combining dispersion compensation and attenuation correction is proposed and verified, which shows an inspection range of 130 meters and SNR improvement up to 8 dBs. Last chapter addresses the accurate localization of structural defects. Having proven the optimum excitation and related wave propagation in ACSR cables, a system having a more complex wave propagation characteristics is studied. A new algorithm combining pulse compression using Maximal Length Sequences and dispersion compensation is applied to multi-modal signals obtained from a solid aluminum rod. The algorithm proved to be able to improve signal quality and extract an accurate location for defects. Maximal Length Sequences are compared to chirp signals in terms of SNR improvement and localization, which produced favourable results for MLS in terms of localization and for chirp in terms of SNR improvement.

RSAT (Reticulation Sag And Tension) software is a tool available for use as part of the medium voltage Eskom Distribution standard. This software is scrutinised for its usability and for errors such that it can be revised to improve the usability of the tool. The type of software being studied is used to ensure optimum design performance and reduce the probability of a conductor failure on distribution lines. The algorithms for calculating tension, sag and clearance values take into account research into optimum design tensions. This ensures low bending forces due to conductor vibration. An algorithm for creep is designed based on common life expectancy of line conductors. The design methodology and algorithms were then put into software form as RSAT. Review and alterations include the changing of compiler, user interface, data storage mechanisms and the inclusion of options allowing the addition of new data.

A presente dissertação tem como objetivo principal a validação do modelo matemá- tico PI a partir da avaliação do seu desempenho tanto a nível de representação elétrica, como também nas transmissões de sinal de comunicação em alta frequência, usualmente utilizadas em tráfego conhecido como Power Line Communication (PLC). Para atingir este objetivo, inicialmente, foi realizado o estudo e avaliação dos modelos matemáticos utilizados para representar um segmento de distribuição de energia. Depois foi utilizado um emulador em escala de potência reduzida, validado para baixa frequência, objetivando avaliar o modelo matemático escolhido. Como o foco do trabalho é a rede de distribuição em baixa tensão, foi realizada a construção de um circuito elétrico representativo de um trecho real de uma concessionária de energia, no caso deste trabalho o DEMEI, que foi implementado computacionalmente utilizando a ferramenta matemática Matlab e sicamente em um dos laboratórios do Grupo de Automação Industrial e Controle (GAIC). Foi realizado um conjunto signi cativo de medições, de corrente e tensão, no circuito real e os resultados foram comparados com os dados obtidos a partir das simulações computacionais do modelo escolhido para representar o circuito real utilizando uma transmissão PLC, no caso o modelo PI. A partir da análise dos resultados reais com os obtidos das simulações computacionais foi possível comprovar que o modelo PI representa satisfatoriamente o trecho simulado em relação a transmissão em altas frequências, uma vez que o sinal PLC transmitido no trecho simulado no Matlab em relação ao trecho real teve um erro inferior a 1%. / 128 f.

No description available.

In this thesis, we studied the narrowband power line communication system. This system mainly utilizes the 60Hz power line as the medium to transmit network signals. In the beginning, we studied the power line channel characteristics and the coupling circuit structure, that was used to couple the signal to the power line. Impedance mismatch and signal attenuation may occur when the loading in the power line network changes. To this end we added a driver to the coupling circuit to reduce the output impedance, and hence enhance signal magnitude. In addition, we add the cross-phase coupling circuit with bandpass filter characteristics at the 220V socket. It was found that our cross-phase coupling circuit was able to improve the performance of the power line communication system when cross-phase transmission took place. Finally, we simulated the indoor power line network environment, measured several kinds of residential appliance noise and analyzed the influence on the power line communication system of the appliance noise.