Please read the abstract in the section 00front of this document / Dissertation (MSc ( Electronic Engineering))--University of Pretoria, 2005. / Electrical, Electronic and Computer Engineering / unrestricted

The presence of information and communication technologies in the field of energy is increasing every day. Smart grid subject which aims to increase the percentage of energy generation through renewable resources and to make consumers to be involved in grid actively, is gaining importance day by day. In order to provide an effcient and reliable operation of smart grid network, it is necessary to collect relevant parameters from network components via communication infrastructure and to evaluate collected information. Also, with the inclusion of distributed energy sources in the power lines, collection of relevant data becomes important in order to ensure the quality of power. In the scope of this study, to measure current parameters, two DSP based electronic circuits and necessary embedded software have been developed. Data acquisition card is a fixed device which is to be installed to a point on the power line to gather current value samples. By means of being fed through magnetic induction from the line, this part of the system could stay on-line permanently and this allows taking measurements on demand. Sampling of line current is performed through principle of magnetic induction from the line on current sensing instrument which is connected to data-acquisition part. Also by utilization of clamp-on instruments, cutting of energy lines is not needed. Samples received by control card over radio frequency or infrared communication, are evaluated with the help of Discrete Fourier Transform (DFT). Control card can show information about Root mean square (RMS) value and harmonic components of line current and total harmonics distortion (THD) on graphic LCD. Present state of the system was tested in LV and MV environments and shown to be used on distribution lines. The system presented in this study is open to improvements and suggestions to make the system to be able to work on high voltage lines are made.

Orientador: Elnatan Chagas Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T07:37:40Z (GMT). No. of bitstreams: 1 Bacurau_RodrigoMoreira_M.pdf: 7520389 bytes, checksum: 2e88cad485dbbbdbd306a531c0ed2298 (MD5) Previous issue date: 2014 / Resumo: Neste trabalho é apresentado o desenvolvimento de um módulo medidor de energia residencial capaz de medir, além do consumo de energia total, os parâmetros elétricos necessários para a discriminação de consumo de energia por aparelho. Também é apresentado um levantamento de quais parâmetros elétricos derivados das curvas de tensão e corrente são úteis para a definição de assinatura de cargas residenciais. Os resultados dos experimentos realizados indicaram a potência ativa, a potência reativa, o fator de potência, a tensão e corrente eficazes e as cinco primeiras harmônicas ímpares do sinal de corrente como os parâmetros mais adequados para uso em sistemas não intrusivos para identificação de consumo por aparelho. Graças a técnicas de programação e decisões de projeto acertadas, foi possível desenvolver um módulo medidor de alta precisão e baixo custo, usando um microcontrolador simples e de baixo consumo. Este módulo é capaz de calcular todas as grandezas elétricas supramencionadas a frequência de 46 Hz. Os valores de tensão, corrente, fator de potência, potência ativa e potência aparente apresentaram erros inferiores a 0,3% (para cargas resistivas). O erro nas componentes harmônicas do sinal de corrente foi de 0,03% para a componente fundamental, 0,58% para a 3ª harmônica, 3,69% para a 5ª harmônica, 6,63% para a 7ª harmônica e 11,81% para a 9ª harmônica. O medidor desenvolvido será usado no projeto "Sistema Inteligente de Gestão Energética para Unidades Consumidoras de Baixa Tensão" o qual consistirá em um sistema completo de gestão de consumo de energia residencial / Abstract: We present in this project the development of a residential power meter module capable of measuring besides the total energy consumption, the electrical parameters needed for power consumption breakdown. We also present a study of which electrical features derived from current and voltage waveforms are more adequate to define signatures of residential loads. The experimental results indicated that the active power, reactive power, power factor, voltage, current and the first five odd harmonics of the current signal are good parameters to use in Non-Intrusive Load Monitoring Systems - NILM. Thanks to the use of advanced programming techniques and right design decisions, we developed, using a simple microcontroller, a high-precision, low-power and low cost smart meter. This module is capable to calculate all electrical parameters above mentioned at 46 Hz frequency. The voltage, current, power factor active and apparent power presented errors lower than 0.3% for resistive loads. The error in the harmonics of the current signal was 0.03% for the fundamental harmonic, 0.58% for the 3rd harmonic, 3.69% for the 5th harmonic, 6.63% for the 7th harmonic and 11.81% for the 9th harmonic. The smart meter presented here will be used in a larger project entitled "Intelligent Energy Management System for Consumer Units Low Voltage" which consists of a complete management system of residential energy consumption / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestre em Engenharia Elétrica

Orientador: Elnatan Chagas Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-26T21:41:11Z (GMT). No. of bitstreams: 1 Duarte_LuisFernandoCaparroz_D.pdf: 2460153 bytes, checksum: ff832dc604aa88b406f8f597eacaa933 (MD5) Previous issue date: 2015 / Resumo: A preocupação com o futuro dos recursos energéticos leva os pesquisadores a procurar formas mais eficientes de gerenciar estes recursos. Neste trabalho apresenta-se a implementação de um sistema não invasivo de monitoramento de consumo de energia elétrica baseado em conjuntos nebulosos, capaz de informar ao cliente, em período próximo de tempo real, sobre o consumo energético das principais cargas elétricas na unidade consumidora. Este trabalho parte da premissa de que a necessidade de se conhecer com detalhes como se dá o uso da energia elétrica em uma residência é primordial para se alcançar edificações com alto grau de eficiência energética. O conhecimento preciso de como a energia elétrica está sendo consumida é fundamental para que as pessoas entendam como é possível reduzir o desperdício e maximizar economia sem que haja prejuízo na qualidade de vida. O sistema proposto baseia-se em medição centralizada de energia elétrica. Para processar o consumo dos aparelhos em uso, utiliza a medição da tensão, da potência ativa e das cinco primeiras harmônicas ímpares da corrente elétrica como notação das assinaturas de cargas, medidas em nível de circuito, logo após os disjuntores de uma caixa de distribuição elétrica. A desagregação do consumo por aparelho é resolvida empregando técnicas de conjuntos nebulosos. Como o sistema possui conexão com a Internet, além de informar seus usuários sobre o consumo energético de suas cargas elétricas, ele também pode ser usado como ferramenta para enviar informações pertinentes às empresas geradoras e distribuidoras de energia elétrica, favorecendo o desenvolvimento de redes inteligentes de abastecimento energético / Abstract: Concerns about the future of energy resources lead the researchers to pursue more efficient ways to manage these resources. This work presents the implementation of a non-invasive power consumption monitoring system based on fuzzy sets, able to inform the customer, in a period close to real time, about the energy consumption of the main electrical appliances in their consumer units. This work relies on the premise that knowing in detail how do we make use of electricity in a residence is essential to achieve buildings with high degree of energy efficiency. The precise knowledge on how the electricity is being consumed is fundamental to understand how it is possible to reduce wastage and maximize savings without loss of quality of life. The proposed system is based on centralized measurement of electrical energy. To process the consumption of the appliances in use, it makes use of measurements of voltage, active power and the first five odd harmonics of the electrical current to constitute the load signatures, sensed at circuit level, just after the breakers at an electrical distribution box. The power consumption disaggregation is solved using fuzzy sets techniques. Since the system has Internet connection, in addition to informing its users about the energy consumption of their electrical loads, it is also possible to send relevant information to electric utilities, supporting the Smart Grid development / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho é proposto e apresentado um medidor inteligente de energia elétrica considerando os métodos de medição classe S especificados no PRODIST e na norma IEC 61000-4-30. O medidor proposto calcula os valores eficazes de tensão e corrente, as potências aparente, ativa e reativa, o fator de potência, a frequência, as distorções harmônicas e detecta a ocorrência de variações de tensão de curta duração. Como principais contribuições deste trabalho, pode-se citar a avaliação de métodos existentes e a proposta de um novo método para detectar a origem de distúrbios em relação à localização do medidor. Propôs-se também uma interface gráfica que permite o monitoramento dos parâmetros elétricos e de qualidade de energia, e ainda possibilita a interação do consumidor para a obtenção o de informações detalhadas sobre o estado da rede. O medidor pode ser utilizado como um registrador de dados e permite o acesso à sua interface gráfica por meio da utilização da porta de comunicação ethernet. Para a validação inicial, realizaram-se simulações computacionais, a partir de um modelo de consumidor residencial, em diferentes cenários de operação. Na etapa de validação experimental, foi utilizada uma fonte de geração de sinais e realizaram se testes com o medidor conectado à rede de distribuição de baixa tensão. A partir destas etapas foi possível verificar o funcionamento da interface gráfica e validar o funcionamento do medidor inteligente proposto. / In this study, a smart meter is presented, which considers the class S measurement methods specified at IEC 61000-4-30 standard and PRODIST. The proposed smart meter calculates RMS voltage and current values, active, reactive and apparent powers, power factor, frequency, harmonic distortions and detects short duration voltage variations. As main contributions of this study, it can be mentioned the evaluation of existing methods and the proposal of a new method to determine on which side of a recording device a disturbance originates. It’s also developed a graphical interface that allows the monitoring of electrical and power quality parameters and it enables consumer interaction to get detailed power grid information. The smart meter can also be used as a data logger and it allows access to its graphical interface through ethernet communication port. For the initial validation, computer simulations were performed through a residential consumer model in different operating scenarios. The experimental validation tests were carried out using an AC power source and the smart meter has been connected to low-voltage distribution grid. Through these steps, it was possible to verify the interface operation and to validate the proposed smart meter operation.

Orientador: Moacyr Trindade de Oliveria Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-05T19:49:11Z (GMT). No. of bitstreams: 1 Vieiralves_EduardodeXerez_M.pdf: 1874956 bytes, checksum: 4f79bc70e42ae0c47e0a35cde1327ad1 (MD5) Previous issue date: 2005 / Resumo: O equilíbrio econômico-financeiro garantido pelo contrato de concessão firmado pelas concessionárias junto ao poder concedente, tem como prerrogativa uma gestão atuante por parte do agente prestador do serviço, o que evidencia o seu controle técnico e comercial, bem como a promoção do desenvolvimento tecnológico dos serviços concedidos. Neste contexto, é de suma importância que a receita da concessionária, fruto de sua gestão na aquisição da energia a ser utilizada, bem como sua efetiva disponibilidade, seja dirigida ao mercado e aos consumidores com a qualidade requerida, a preços compatíveis com a renda média da população regional e com um percentual de perdas compatível com a tecnologia disponível. O controle das perdas técnicas e comerciais, em empresas do setor elétrico é fundamental para a consecução dos objetivos das concessionárias e da população a ser atendida. A falta de efetivo controle das perdas gera desperdício, ineficiência e redunda em custos elevados. Na região amazônica, as fontes energéticas são suportadas por parques térmicos que queimam material fóssil. Nessas condições o desperdício energético provoca, adicionalmente, danos desnecessários à natureza. As emissões de material particulado e de gases do efeito estufa, na condição de grandes perdas comerciais das empresas do setor elétrico, são mais elevadas, o que fatalmente vai agravar as condições ambientais da vida das gerações futuras. Na região Norte do Brasil, os sistemas elétricos isolados, em função do tipo das fontes energéticas e das grandes distâncias envolvidas, apresentam altos custos de operação e manutenção. As empresas apresentam índices de perdas elevadíssimos, que inviabilizam totalmente o negócio, razão pela qual, até hoje, vários são os mecanismos de subsídios associados ao mesmo, visando a viabilização do serviço de energia elétrica. O presente trabalho visa analisar a situação das perdas comerciais na região, dando ênfase ao ¿Caso Manaus¿, procurando identificar as suas causas e efeitos, tanto para a sociedade em geral como para os empresários do setor. Mais especificamente, se abordará o estudo de caso da empresa Manaus Energia S/A, por ser a maior dos sistemas isolados e por apresentar índices de perdas muito acima do admissível e da média das concessionárias do Setor Elétrico Nacional / Abstract: The financial-economical equilibrium guaranteed by the concession contract made by the concessionaries before the granting power, has as a prerogative an acting management by the service agent owner. That evidences its technical and commercial control, as well as the promotion of the technological development of the granted services. In such a context, it is of great importance that the concessionary receipt, product of its management in the acquisition of the energy to be used, as well as in its effective availability, be driven towards the market and the consumers with the quality requested with compatible prices at the middle income of the local population and with a loss percentage balanced to the technology available. The control of such technical and commercial loss in the companies of the electric field is fundamental to the accomplishment of the concessionary objectives and to the population attending.The lack of an effective control about the loss generates waste, non-efficiency and leads to elevated costs. In the Amazon area, the energetic sources are supported by thermic park which burn fossil matter. Besides, in such conditions the energetic waste provokes unnecessary waste to the nature. The emissions of particled material and gases from the greenhouse effect, in the condition of great commercial losses of the electric field companies are higher what will worsen the environmental conditions of the future generations life. In Brazil north region, the isolated electric systems due to the kind of the energetic sources and the great distances involved, lead to high costs of operation and maintenance. The companies show very high losses rates which make the business completely unfeasible, that is the reason, nowadays, due to many are the resources of subsidies associated attempting the availability of the electric energy service. The present work aims to analyze the state of the commercial losses in the region, emphasizing ¿Manaus case¿, searching the causes and effects identification, to the society in general, as to the sector entrepreneurs. More specifically, there will be approached the case study of Manaus Energia S/A company, for being the biggest of the isolated systems and for presenting a loss rate much higher from the admissible and the average of the National Electric Sector concessionaries / Mestrado / Energia Eletrica / Mestre em Engenharia Mecânica

Orientador: Maria Cristina Dias Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T00:34:34Z (GMT). No. of bitstreams: 1 Dias_OzenirFarahdaRocha_M.pdf: 5023742 bytes, checksum: b0fe9b9418551d927583a884fbec6e92 (MD5) Previous issue date: 2015 / Resumo: Este trabalho apresenta a implementação de um esquema de religamento monopolar adaptativo rápido baseado na medição do conteúdo harmônico da tensão da fase aberta nas extremidades da linha de transmissão. O objetivo principal deste esquema é controlar e reduzir o tempo compreendido entre a abertura e o religamento da fase em falta, como também bloquear a manobra em caso de faltas permanentes. O esquema proposto foi implementado em um relé de distância e um medidor de conteúdo harmônico. O método está baseado na identificação do instante de extinção da corrente de arco secundário para casos de faltas transitórias. Já para faltas permanentes é implementado o bloqueio da manobra automática e a abertura tripolar do disjuntor da linha protegida. A medição do conteúdo harmônico foi feita primeiramente utilizando um medidor de qualidade de energia comercial, que realiza a medição do conteúdo harmônico de acordo com a norma IEC 61000-4-3. Em seguida, foi utilizado outro método de medição do conteúdo harmônico, chamado de filtro de medição do conteúdo harmônico rápido, elaborado dentro do Simulador Digital em Tempo Real (RTDS). O sistema de transmissão utilizado foi modelado no RTDS e seus dados são dados reais do sistema interligado nacional (SIN). As faltas monofásicas transitórias foram simuladas utilizando o modelo de arco do próprio RTDS. Já para falta permanente utilizou-se uma resistência de 1 'ômega'. O esquema foi avaliado através de testes variando o ponto de aplicação do defeito e o valor da corrente de arco secundário / Abstract: This work presents the implementation of a scheme of fast adaptive single-phase reclosing based on measuring the voltage harmonic content at the opened faulty phase terminals. The main objective of this scheme is to control and to reduce the time between opening and reclosing of the phase in fault, and also to block the maneuver in case of permanent faults. The proposed scheme is implemented in a distance relay and a harmonic content meter. The method is based in the identification of the secondary arc current extinction moment for transient faults cases. For permanent faults an automatic blocking followed by circuit-breaker three-phase opening is implemented. The measurement of harmonic content was made initially using a commercial power quality meter, which performs the harmonic content measurement according to IEC 61000-4-3 standard. Another harmonic content measurement method was tested, the fast harmonic content filter measurement, elaborated within the real-time digital simulator (RTDS). The transmission system used was modeled on RTDS and the data corresponds to an actual Brazilian 500 kV system. To represent the transient single-phase fault it was used RTDS arc model. The permanent fault was modeled with an 1'ômega' resistance. The scheme was evaluated by varying the fault application point and the secondary arc current value / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2015 / The work presented extends and contributes to research in Non-Intrusive Load Monitoring (NILM), focussing on steady-state and transient power measurement disaggregation techniques for circuits containing household ap- pliances. Although previous work in this area has produced and evaluated a wide range of NILM approaches, much of it has involved the use of datasets captured from real-world household implementations. In such cases, the lack of accurate ground truth data makes it di cult to assess disaggregation tech- niques. In the research presented, three NILM techniques are comparatively evaluated using measurements from typical household appliances assembled within a laboratory environment, where accurate ground truth data could be compiled to complement the measurements. This allows for the accu- racy of the various disaggregation approaches to be precisely evaluated. It is demonstrated that the correlation of transient event edges in aggregated power measurements to individual appliance transient exemplars performs better than the matching of steady-state power levels against individual ap- pliance state combinations. Furthermore, the transient approach is shown to be the most appropriate technique for further development. / MT2017

Submitted in fulfillment of the requirement for the Degree of Master of Management Sciences Specialising in Business Administration, Durban University of Technology, Durban, South Africa, 2017. / In the electricity prepayment metering industry the continuous increase in customers’ expectations and technological innovation demand that leading firms in the industry differentiate themselves from the competition by going beyond customers’ present expectations. Thus, organizations which have set their goals on mere customer satisfaction are, from a customers’ perspective, deemed to be of limited value and may subsequently lack the anticipation and preparation essential to meet the demands of the future. Electricity prepayment metering market competition today is forcing organisations to seek the means to gain customer satisfaction, and thus aim to sustain their future in times of economic instability. The study revealed that the most effective way to retain customer satisfaction is consistent service quality that decreases the cost of attracting new customers and raises sales and market share. The quality of service is one of the most effective factors in creating competitive advantages and advance business. Factors that influence customer satisfaction in the electricity prepayment industry were investigated and tested. The study also attempted to identify the critical factors, as identified in the literature, among those investigated: service quality, customer expectations, customer perception and customer retention. Against this background, the study sought to determine the interrelationship between customer satisfaction and the critical factors of customer satisfaction with Conlog Electricity Prepayment Meters in KwaZulu-Natal. The research developed to ascertain subjects’ perceptions of the critical factors of customer satisfaction; determine the interrelationship among the critical factors of customer satisfaction; and explore the relationship between customer satisfaction and the critical factors of customer satisfaction. The research population comprising of Conlog electricity prepayment metering customers in KwaZulu-Natal was selected and interviewed. Questionnaires were distributed through electronic mail and self-administered for data collection and a sample of twelve respondents was selected for interview. Interviews were analysed using conversational analysis and the data collected from the interviews were merged with the questionnaire data, seeking depth as well as breadth. Data collected from respondents was analysed using descriptive and inferential statistical techniques. The tool utilised to analyze data was the Statistical Package for the Social Sciences (SPSS) version 22 (SPSS Inc., Chicago, Illinois, USA). A p value < 0.05 was considered as statistically significant. Conclusions and recommendations were drawn from the literature and the findings of the study. The results of the study revealed that service quality is the most significant critical factor of customer satisfaction. The study recommends that the management of Conlog can use the specific data obtained from the measurement of service quality in their strategies and plans. The study further recommends that Conlog allocates resources to this effect to provide better service to their customers. The results and findings of the study will provide further information concerning customer satisfaction and customer perception in the prepayment metering industry in KwaZulu-Natal. It will also contribute to future industry research, setting the ground for further research in measuring levels of customer satisfaction in the electricity prepayment industry in South Africa. / M