270 research outputs found
Automatic fault location in electrical distribution networks with distributed generation
Nowadays the electrical network is continuously evolving due to the increasing deployment of Information Technologies and the Distribution Energy Resources. This scenario affects directly to the quality of service in the electrical distribution networks. For this reason, the Power Quality is a key important concern to make the electrical network evolve towards a Smart Grid.
Power quality is defined through three important focal points: availability, wave quality and commercial quality. The presence of the Distribution Energy Resources in the current electrical distribution network is showing a new scenario where the fault detection is more complex due to the flow current is in both directions.
This thesis is focused in the analysis of several methods to locate a fault in electrical distribution network and also how the current communication standards can improve considerably this fault location. It is important to remark that the main contribution of this thesis is in the analysis of several propositions and algorithms to enhance the fault location in a distribution network using the current Intelligent Electronic Device with international standards such as IEC 61850. All of these algorithms have been focused to work in a mesh distribution networks.
Another important contribution of this thesis is in the adaptive protection system in order to isolate correctly the fault in a ring system distribution. Although this proposition could be extended to a mesh network where the elements of the network can operate under a fault.
Finally, the thesis concludes that the use of communication standards and Internet of Things with current developed Intelligent Electronic Devices technology can contribute significantly to enhance the current and future electrical network distribution.La xarxa elèctrica evoluciona contínuament a causa del creixent desplegament de les Tecnologies de la Informació i dels Recursos Energètics Distribuïts. Aquest escenari afecta directament a la qualitat de servei de les xarxes de distribució elèctrica. Per aquest motiu, el mantenir i millorar el nivell de qualitat d'energia és un punt clau per fer evolucionar la xarxa elèctrica cap a una xarxa Smart Grid. Aquesta qualitat de l'energia es defineix per medi de de tres punts importants: disponibilitat, qualitat d'ona i qualitat comercial. La presència dels Recursos Energètics Distribuïts mostra un nou escenari en què la detecció de defectes es complica afectant a la disponibilitat del servei. Aquesta tesi es centra principalment en l'anàlisi de diversos mètodes per localitzar un defecte a la xarxa de distribució elèctrica i també en com l'ús dels estàndards de comunicació actuals poden contribuir considerablement a la localització del defecte. És important remarcar que la principal contribució d'aquest document ha estat en l'anàlisi de diverses proposicions i algoritmes per millorar la localització de faltes en una xarxa de distribució utilitzant Dispositius Electrònics Intel·ligents amb estàndards internacionals com l'IEC 61850. Tots aquests algoritmes han estat definits per treballar en xarxes de distribució mallades. Una altra contribució important d'aquesta tesi es troba en el sistema de protecció adaptatiu per tal d'aïllar correctament el defecte en una distribució del sistema d'anell amb interruptors automàtics. Aquesta proposta es podria ampliar a una xarxa mallada. Finalment, la tesi conclou amb que l'ús d'estàndards de comunicació i l'Internet of Things en combinació amb Dispositius Electrònics Intel·ligents, desenvolupats actualment, poden contribuir significativament a millorar la distribució de la xarxa elèctrica actual i futura.Postprint (published version
Automatic fault location in electrical distribution networks with distributed generation
Nowadays the electrical network is continuously evolving due to the increasing deployment of Information Technologies and the Distribution Energy Resources. This scenario affects directly to the quality of service in the electrical distribution networks. For this reason, the Power Quality is a key important concern to make the electrical network evolve towards a Smart Grid.
Power quality is defined through three important focal points: availability, wave quality and commercial quality. The presence of the Distribution Energy Resources in the current electrical distribution network is showing a new scenario where the fault detection is more complex due to the flow current is in both directions.
This thesis is focused in the analysis of several methods to locate a fault in electrical distribution network and also how the current communication standards can improve considerably this fault location. It is important to remark that the main contribution of this thesis is in the analysis of several propositions and algorithms to enhance the fault location in a distribution network using the current Intelligent Electronic Device with international standards such as IEC 61850. All of these algorithms have been focused to work in a mesh distribution networks.
Another important contribution of this thesis is in the adaptive protection system in order to isolate correctly the fault in a ring system distribution. Although this proposition could be extended to a mesh network where the elements of the network can operate under a fault.
Finally, the thesis concludes that the use of communication standards and Internet of Things with current developed Intelligent Electronic Devices technology can contribute significantly to enhance the current and future electrical network distribution.La xarxa elèctrica evoluciona contínuament a causa del creixent desplegament de les Tecnologies de la Informació i dels Recursos Energètics Distribuïts. Aquest escenari afecta directament a la qualitat de servei de les xarxes de distribució elèctrica. Per aquest motiu, el mantenir i millorar el nivell de qualitat d'energia és un punt clau per fer evolucionar la xarxa elèctrica cap a una xarxa Smart Grid. Aquesta qualitat de l'energia es defineix per medi de de tres punts importants: disponibilitat, qualitat d'ona i qualitat comercial. La presència dels Recursos Energètics Distribuïts mostra un nou escenari en què la detecció de defectes es complica afectant a la disponibilitat del servei. Aquesta tesi es centra principalment en l'anàlisi de diversos mètodes per localitzar un defecte a la xarxa de distribució elèctrica i també en com l'ús dels estàndards de comunicació actuals poden contribuir considerablement a la localització del defecte. És important remarcar que la principal contribució d'aquest document ha estat en l'anàlisi de diverses proposicions i algoritmes per millorar la localització de faltes en una xarxa de distribució utilitzant Dispositius Electrònics Intel·ligents amb estàndards internacionals com l'IEC 61850. Tots aquests algoritmes han estat definits per treballar en xarxes de distribució mallades. Una altra contribució important d'aquesta tesi es troba en el sistema de protecció adaptatiu per tal d'aïllar correctament el defecte en una distribució del sistema d'anell amb interruptors automàtics. Aquesta proposta es podria ampliar a una xarxa mallada. Finalment, la tesi conclou amb que l'ús d'estàndards de comunicació i l'Internet of Things en combinació amb Dispositius Electrònics Intel·ligents, desenvolupats actualment, poden contribuir significativament a millorar la distribució de la xarxa elèctrica actual i futura
Communication technology selection method for smart energy metering based on analytic hierarchy process
As new communication technologies continue to emerge and the integration of these
technologies into the modernization of the electricity grid becomes increasingly necessary,
a variety of communication protocols and combinations are being explored for their
potential use in the smart grid domain. However, given the multitude of technological
possibilities available, choosing the optimal technology capable of adequately addressing
the communication requirements of the intelligent grid remains a challenge for utilities.
This is due, on the one hand, to the fact that different intelligent grid applications have
different qualitative and quantitative communication requirements. Moreover, on the
other hand, each technology has advantages and disadvantages concerning its performance
characteristics in such requirements. This work uses the AHP (Analytic Hierarchy Process)
methodology to select the wireless technology that presents the best performance
characteristics concerning determined requirements. For this, a computational algorithm
was developed in the Matlab programming environment, through which criteria such
as data rate, latency, range, security, reliability, and interoperability were compared to
select the best technological alternative among Wi-Fi, ZigBee, Z-Wave, and Bluetooth.
Data collected from the literature review, with the performance characteristics of these
technologies, were applied in a single case study simulating the practical implementation
of this work. Among the analyzed criteria, simulations demonstrated that Wi-Fi was the
winning technology alternative with 32.353%, followed by Z-Wave with 29.865% in second
place, and ZigBee and Bluetooth were ranked third and fourth with 25.255% and 12.527%,
respectively. In addition, sensitivity analysis shows how the AHP methodology can be a
feasible alternative to assist decision-making in the smart grid domain.À medida que novas tecnologias de comunicação continuam a surgir e a integração destas
tecnologias na modernização da rede elétrica se torna cada vez mais necessária, uma
variedade de protocolos e combinações de tecnologias de comunicação vem sendo explorados
para a sua potencial utilização no domínio da rede inteligente. No entanto, dada a multiplicidade
de possibilidades tecnológicas disponíveis, a escolha da melhor tecnologia capaz
de responder, adequadamente, aos requisitos de comunicação da rede elétrica inteligente
continua sendo um desafio para diferentes atores interessados. Isto se deve, por um lado, ao
fato de diferentes aplicações de rede inteligente terem diferentes requisitos de comunicação,
quer sejam quantitativos ou qualitativos. Além disso, por outro lado, cada tecnologia tem
vantagens e desvantagens relacionadas com as suas características de desempenho em
tais requisitos. Este trabalho, portanto, utiliza a metodologia AHP (Analytic Hierarchy
Process) para selecionar a tecnologia sem fios que apresenta as melhores características
de desempenho relativamente a determinados requisitos. Para tal, foi desenvolvido um
algoritmo computacional no ambiente de programação Matlab, através do qual critérios
tais como taxa de dados, latência, alcance, segurança, confiabilidade e interoperabilidade
foram comparados para selecionar a melhor alternativa tecnológica entre Wi-Fi, ZigBee,
Z-Wave e Bluetooth. Os dados coletados na revisão de literatura, com as características de
desempenho destas tecnologias, foram aplicados num único estudo de caso simulando a
implementação prática deste método em ambiente residencial. Dentre os critérios analisados,
as simulações demonstraram que o Wi-Fi foi a alternativa tecnológica vencedora
com 32,353%, seguido pelo Z-Wave com 29,865% em segundo lugar, e ZigBee e Bluetooth
ficaram em terceiro e quarto lugar com 25,255% e 12,527%, respectivamente. Além disso,
a análise de sensibilidade, dos resultados, mostra como a metodologia AHP pode ser uma
alternativa viável para auxiliar na tomada de decisões no domínio da rede inteligente
Advanced Communication and Control Methods for Future Smartgrids
Proliferation of distributed generation and the increased ability to monitor different parts of the electrical grid offer unprecedented opportunities for consumers and grid operators. Energy can be generated near the consumption points, which decreases transmission burdens and novel control schemes can be utilized to operate the grid closer to its limits. In other words, the same infrastructure can be used at higher capacities thanks to increased efficiency. Also, new players are integrated into this grid such as smart meters with local control capabilities, electric vehicles that can act as mobile storage devices, and smart inverters that can provide auxiliary support. To achieve stable and safe operation, it is necessary to observe and coordinate all of these components in the smartgrid
Energy Efficiency
This book is one of the most comprehensive and up-to-date books written on Energy Efficiency. The readers will learn about different technologies for energy efficiency policies and programs to reduce the amount of energy. The book provides some studies and specific sets of policies and programs that are implemented in order to maximize the potential for energy efficiency improvement. It contains unique insights from scientists with academic and industrial expertise in the field of energy efficiency collected in this multi-disciplinary forum
Power Quality
Electrical power is becoming one of the most dominant factors in our society. Power
generation, transmission, distribution and usage are undergoing signifi cant changes
that will aff ect the electrical quality and performance needs of our 21st century industry.
One major aspect of electrical power is its quality and stability – or so called Power
Quality.
The view on Power Quality did change over the past few years. It seems that Power
Quality is becoming a more important term in the academic world dealing with electrical
power, and it is becoming more visible in all areas of commerce and industry, because
of the ever increasing industry automation using sensitive electrical equipment
on one hand and due to the dramatic change of our global electrical infrastructure on
the other.
For the past century, grid stability was maintained with a limited amount of major
generators that have a large amount of rotational inertia. And the rate of change of
phase angle is slow. Unfortunately, this does not work anymore with renewable energy
sources adding their share to the grid like wind turbines or PV modules. Although the
basic idea to use renewable energies is great and will be our path into the next century,
it comes with a curse for the power grid as power fl ow stability will suff er.
It is not only the source side that is about to change. We have also seen signifi cant
changes on the load side as well. Industry is using machines and electrical products
such as AC drives or PLCs that are sensitive to the slightest change of power quality,
and we at home use more and more electrical products with switching power supplies
or starting to plug in our electric cars to charge batt eries. In addition, many of us
have begun installing our own distributed generation systems on our rooft ops using
the latest solar panels. So we did look for a way to address this severe impact on our
distribution network. To match supply and demand, we are about to create a new, intelligent
and self-healing electric power infrastructure. The Smart Grid. The basic idea
is to maintain the necessary balance between generators and loads on a grid. In other
words, to make sure we have a good grid balance at all times. But the key question that
you should ask yourself is: Does it also improve Power Quality? Probably not!
Further on, the way how Power Quality is measured is going to be changed. Traditionally,
each country had its own Power Quality standards and defi ned its own power
quality instrument requirements. But more and more international harmonization efforts
can be seen. Such as IEC 61000-4-30, which is an excellent standard that ensures
that all compliant power quality instruments, regardless of manufacturer, will produce of measurement instruments so that they can also be used in volume applications and
even directly embedded into sensitive loads. But work still has to be done. We still use
Power Quality standards that have been writt en decades ago and don’t match today’s
technology any more, such as fl icker standards that use parameters that have been defi
ned by the behavior of 60-watt incandescent light bulbs, which are becoming extinct.
Almost all experts are in agreement - although we will see an improvement in metering
and control of the power fl ow, Power Quality will suff er. This book will give an
overview of how power quality might impact our lives today and tomorrow, introduce
new ways to monitor power quality and inform us about interesting possibilities to
mitigate power quality problems.
Regardless of any enhancements of the power grid, “Power Quality is just compatibility”
like my good old friend and teacher Alex McEachern used to say.
Power Quality will always remain an economic compromise between supply and load.
The power available on the grid must be suffi ciently clean for the loads to operate correctly,
and the loads must be suffi ciently strong to tolerate normal disturbances on the
grid
Operations Management
Global competition has caused fundamental changes in the competitive environment of the manufacturing and service industries. Firms should develop strategic objectives that, upon achievement, result in a competitive advantage in the market place. The forces of globalization on one hand and rapidly growing marketing opportunities overseas, especially in emerging economies on the other, have led to the expansion of operations on a global scale. The book aims to cover the main topics characterizing operations management including both strategic issues and practical applications. A global environmental business including both manufacturing and services is analyzed. The book contains original research and application chapters from different perspectives. It is enriched through the analyses of case studies
Risk-based decision support system for life cycle management of industrials plants
Dissertação para obtenção do Grau de Doutor em
Engenharia Electrotécnica e de ComputadoresThe objective of this thesis is to contribute for a better understanding of the decision making process in industrial plants specifically in situations with impact in the long term performance of the plant.
The way decisions are made, and especially the motivations that lead to the selection of a specific course of action, are sometimes unclear and lack on justification. This is particularly critical in cases where inappropriate decisions drive to an increase on the production costs. Industrial plants are part of these cases, specifically the ones that are still lacking enhanced monitoring technologies and associated decision support systems.
Maintenance has been identified as one of the critical areas regarding impact on performance.
This is due to the fact that maintenance costs still represent a considerable slice of the production costs. Thus, understanding the way maintenance procedures are executed, and more important, the methods used to decide when maintenance should be developed and how, have been a concern of decision makers in industrial plants.
This thesis proposes a methodology to efficiently transform the existing information on the plant behaviour into knowledge that may be used to support the decision process in maintenance activities. The development of an appropriate knowledge model relating the core aspects of the
process enables the extraction of new knowledge based on the past experience. This thesis proposes also a methodology to calculate the risk associated to each maintenance situation and, based on the possible actions and on the impacts they may have in the plant costs performance,
suggests the most appropriate course. The suggestion is made aiming the minimization of the life cycle costs.
Results have been validated in test cases performed both at simulation and real industrial environments. The results obtained at the tests cases demonstrated the feasibility of the developed methodology as well as its adequateness and applicability in the domain of interest
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