abstract: Synthetic power system test cases offer a wealth of new data for research and development purposes, as well as an avenue through which new kinds of analyses and questions can be examined. This work provides both a methodology for creating and validating synthetic test cases, as well as a few use-cases for how access to synthetic data enables otherwise impossible analysis. First, the question of how synthetic cases may be generated in an automatic manner, and how synthetic samples should be validated to assess whether they are sufficiently ``real'' is considered. Transmission and distribution levels are treated separately, due to the different nature of the two systems. Distribution systems are constructed by sampling distributions observed in a dataset from the Netherlands. For transmission systems, only first-order statistics, such as generator limits or line ratings are sampled statistically. The task of constructing an optimal power flow case from the sample sets is left to an optimization problem built on top of the optimal power flow formulation. Secondly, attention is turned to some examples where synthetic models are used to inform analysis and modeling tasks. Co-simulation of transmission and multiple distribution systems is considered, where distribution feeders are allowed to couple transmission substations. Next, a distribution power flow method is parametrized to better account for losses. Numerical values for the parametrization can be statistically supported thanks to the ability to generate thousands of feeders on command. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019

Some of the challenges associated with the multi-objective optimization on a modern power system were addressed in this work. Optimization of reactive resources was performed in order to simultaneously optimize several criteria: transmission losses, distribution losses, voltage stability, etc. The optimization was performed simultaneously on the entire power system; transmission and distribution subsystems included. The inherent physical complexity of modeling together transmission and distribution systems was considered first. After considering all pros and cons for such a task, a model of the entire power system was successfully developed. The inherent mathematical complexity of high-dimensional optimization space was handled by introducing the decoupling principle. System is first decoupled in several independent models and optimizations were performed on each part of the system. An algorithm is developed that properly combines the independent solutions to reach the overall system optima. The principle of algorithm synthesis is used to reduce the size of the solution space. Deterministic algorithms are used to locate the local optima which are subsequently refined by probabilistic algorithm. The algorithm is applied on a "real-life" test system and it is shown that the obtained solutions outperform the solution obtained with the conventional algorithms.

Solar PV-based distributed generation has increased significantly over the last few years, and the rapid growth is expected to continue in the foreseeable future. As the penetration levels of distributed generation increase, power systems will become increasingly decentralized with bi-directional flow of electricity between the transmission and distribution networks. To manage such decentralized power systems, planners and operators need models that accurately reflect the structure of, and interactions between the transmission and distribution networks. Moreover, algorithms that can simulate the steady state and dynamics of power systems using these models are also needed. In this context, integrated transmission and distribution system modeling and simulation has become an important research area in recent years, and the primary focus so far has been on studying the steady state response of power systems using integrated transmission and distribution system models. The primary objective of this dissertation is to develop an analysis approach and a program that can simulate the dynamics of three phase, integrated transmission and distribution system models, and use the program to demonstrate the advantages of evaluating the impact of solar PV-based distributed generation on power systems dynamics using such models. To realize this objective, a new dynamic simulation analysis approach is presented, the implementation of the approach in a program is discussed, and verification studies are presented to demonstrate the accuracy of the program. A new dynamic model for small solar PV-based distributed generation is also investigated. This model can interface with unbalanced networks and change its real power output according to the incident solar irradiation. Finally, application of the dynamic simulation program for evaluating the impact of solar PV units using an integrated transmission and distribution system model is discussed. The dissertation presents a new approach for studying the impact of solar PV-based distributed generation on power systems dynamics, and demonstrates that the solar PV impact studies performed using the program and integrated transmission and distribution system models provide insights about the dynamic response of power systems that cannot be obtained using traditional dynamic simulation approaches that rely on transmission only models. / Ph. D.

Developments in measurement technology, communication and data storage have resulted in measurement systems that produce large amount of data. Together with the long existing need for characterizing the performance of the power system this has resulted in demand for automatic and efficient information-extraction methods. The objective of the research work presented in this thesis was therefore to develop new robust methods that extract additional information from voltage and current measurements in power systems. This work has contributed to two specific areas of interest.The first part of the work has been the development of a measurement method that gives information how voltage flicker propagates (with respect to a monitoring point) and how to trace a flicker source. As part of this work the quantity of flicker power has been defined and integrated in a perceptionally relevant measurement method. The method has been validated by theoretical analysis, by simulations, and by two field tests (at low-voltage and at 130-kV level) with results that matched the theory. The conclusion of this part of the work is that flicker power can be used for efficient tracing of a flicker source and to determine how flicker propagates.The second part of the work has been the development of a voltage disturbance classification system based on the statistical learning theory-based Support Vector Machine method. The classification system shows always high classification accuracy when training data and test data originate from the same source. High classification accuracy is also obtained when training data originate from one power network and test data from another. The classification system shows, however, lower performance when training data is synthetic and test data originate from real power networks. It was concluded that it is possible to develop a classification system based on the Support Vector Machine method with “global settings” that can be used at any location without the need to retrain. The conclusion is that the proposed classification system works well and shows sufficiently high classification accuracy when trained on data that originate from real disturbances. However, more research activities are needed in order to generate synthetic data that have statistical characteristics close enough to real disturbances to replace actual recordings as training data.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2016-11-18T11:35:11Z No. of bitstreams: 1 Reinaldo Augusto de Oliveira Ramos.pdf: 4385963 bytes, checksum: 2f3c319e5e8683bc29abfb9359b1a73f (MD5) / Made available in DSpace on 2016-11-18T11:35:11Z (GMT). No. of bitstreams: 1 Reinaldo Augusto de Oliveira Ramos.pdf: 4385963 bytes, checksum: 2f3c319e5e8683bc29abfb9359b1a73f (MD5) Previous issue date: 2016-09-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pontifícia Universidade Católica de São Paulo / This research aims to examine and analyze the evolution of the concept of linear television in the digital age and the impact that Netflix TV is provoking with Internet distribution of audiovisual content for streaming services. It intends to check how digital technology changes the transmission and distribution of video services, transforming the relationship between consumers and the traditional television industry. In this new paradigm, we have to understand how this mediation is transforming the experience and the perception of its subscribers, when media are understood as “extensions” of the body, taking also in consideration that hybridization or cross media completely changes the landscape of media industries, at times causing the extinction of these media, as in the case of the telegraph, and more recently of the music industry. Netflix took advantage of the opportunities of this new scenario, providing content in almost every screen. The television industry was slow to move in that direction. In this new scenario, we are witnessing the clash between the analog old TVs, cable and open, and new internetTVs, with Netflix as its greatest exponent and a present threat to the old linear programming model. The conclusion suggests a scenario for the emerging television and possible ways of development for this sector. Authors such as Henry Jenkins (2008), Amanda Lotz (2014), Chris Anderson (2006; 2009), Marshall McLuhan (1964/2005) e Lucia Santaella (2007) are the basis of the theoretical framework / Esta dissertação tem como objetivo de pesquisa examinar e analisar a evolução do conceito de televisão linear na era digital e o impacto produzido pelo serviço Netflix, “televisão por internet”, que distribui conteúdo audiovisual por streaming. Pretende verificar como as mudanças tecnológicas digitais de transmissão e distribuição de conteúdo televisivo vêm transformando as relações entre consumidores e a indústria de televisão tradicional. Sendo este um novo paradigma, trata-se de compreender: (a) como essa mediação vem modificando a experiência e a percepção de seus assinantes e usuários, na medida em que os novos serviços funcionam como “extensões” do próprio corpo; (b) como a hibridização ou cruzamento dos meios muda completamente o panorama das indústrias de mídia, por vezes causando até mesmo sua extinção, como ocorreu com o telégrafo e, mais recentemente, com a indústria fonográfica. A Netflix aproveitou as oportunidades desse novo cenário para disponibilizar seu conteúdo em praticamente todas as telas. Já a indústria de televisão demorou a se movimentar nessa direção. Com esse novo panorama, estamos presenciando o embate entre as antigas tevês analógicas, a cabo e aberta, e as novas tevês por internet, que têm na Netflix seu maior expoente, surgindo como ameaça ao antigo modelo de programação linear. Por fim, discute o cenário para onde caminha a emergente televisão, além das possibilidades de desenvolvimento para esse setor. Autores como Henry Jenkins (2008), Amanda Lotz (2014), Chris Anderson (2006; 2009), Marshall McLuhan (1964/2005) e Lucia Santaella (2007) são utilizados como referencial teórico

abstract: Two significant trends of recent power system evolution are: (1) increasing installa-tion of dynamic loads and distributed generation resources in distribution systems; (2) large-scale renewable energy integration at the transmission system level. A majority of these devices interface with power systems through power electronic converters. However, existing transient stability (TS) simulators are inadequate to represent the dynamic behavior of these devices accurately. On the other hand, simulating a large system using an electromagnetic transient (EMT) simulator is computationally impractical. EMT-TS hybrid simulation approach is an alternative to address these challenges. Furthermore, to thoroughly analyze the increased interactions among the transmission and distribution systems, an integrated modeling and simulation approach is essential. The thesis is divided into three parts. The first part focuses on an improved hybrid simulation approach and software development. Compared to the previous work, the pro-posed approach has three salient features: three-sequence TS simulation algorithm, three-phase/three-sequence network equivalencing and flexible switching of the serial and par-allel interaction protocols. The second part of the thesis concentrates on the applications of the hybrid simula-tion tool. The developed platform is first applied to conduct a detailed fault-induced de-layed voltage recovery (FIDVR) study on the Western Electricity Coordinating Council (WECC) system. This study uncovers that after a normally cleared single line to ground fault at the transmission system could cause air conditioner motors to stall in the distribu-tion systems, and the motor stalling could further propagate to an unfaulted phase under certain conditions. The developed tool is also applied to simulate power systems inter-faced with HVDC systems, including classical HVDC and the new generation voltage source converter (VSC)-HVDC system. The third part centers on the development of integrated transmission and distribution system simulation and an advanced hybrid simulation algorithm with a capability of switching from hybrid simulation mode to TS simulation. Firstly, a modeling framework suitable for integrated transmission and distribution systems is proposed. Secondly, a power flow algorithm and a diakoptics based dynamic simulation algorithm for the integrated transmission and distribution system are developed. Lastly, the EMT-TS hybrid simulation algorithm is combined with the diakoptics based dynamic simulation algorithm to realize flexible simulation mode switching to increase the simulation efficiency. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2016

Frequency scaling of attenuation is the prediction of attenuation at a desired frequency from attenuation values at a base frequency. The attenuation at the base frequency is often known from prior measurements. Frequency scaling of attenuation is of interest because of the eventual need to exploit higher frequency bands. Most satellite communications traffic now use C-band (4-8 GHz) and Ku-band (12-18 GHz). The next approved, yet largely unused, frequency allocation for domestic use is in the K-band (18-27 GHz) to Ka-band (27-40 GHz). At these higher frequencies, however, earth-space radio links suffer atmospherically induced impairments as frequency increases. In particular, rain causes severe fading. Consequently, satellite systems in these higher bands are very susceptible to outages due to rain-induced fades. Reliable frequency scaling models are needed in system design to estimate the effect of these rain-induced fades. Between August 1990 and August 1992, V.P.I. & S.U.'s SATCOM Group performed extensive measurements of slant path attenuation using the 12, 20, and 30 GHz beacon signals (in the Ku/Ka-bands) of the European OLYMPUS experimental satellite. The experimental results are used to evaluate the usefulness of scaling models proposed by other researchers, both for instantaneous and statistical purposes. New models are presented for accurate scaling of attenuation within the Ku/Ka-bands. / Master of Science

No description available.

Zur Umsetzung der Energiewende ist in den kommenden Jahren ein substantieller Netzausbau notwendig, der jedoch regional unterschiedlich stark ausfallen wird. Nach gegenwärtiger Gesetzeslage werden die folglich sehr unterschiedlich hohen Netzkosten von den Endkunden des jeweiligen Netzgebietes über die Netznutzungsentgelte getragen. Mittels eines detaillierten Modells der Kostenbestandteile der Netzkosten in den einzelnen Regionen wurden unter Berücksichtigung des erwarteten Netzausbaus sowie der demographischen Entwicklung die Netznutzungsentgelte, geschlüsselt nach den Kundengruppen Haushalt und Gewerbe sowie Industrie bis zum Jahr 2023 prognostiziert. Die anschließende Analyse eines bundesweiten Wälzens von Übertragungs- und Verteilungsnetzbestandteilen der Entgelte kommt zu dem Ergebnis, dass in Zukunft neben den ostdeutschen Flächenländern auch die Küstenländer Schleswig-Holstein und Niedersachsen sowie Teile Bayerns von einem bundeseinheitlichen Entgelt profitieren würden. Dabei stellt sich eine asymmetrische Verteilung von Be- und Entlastungen dar. Den zum Teil erheblichen jährlichen Entlastungen von bis zu 130 EUR pro 3-Personenhaushalt stehen in den süd- und westdeutschen Flächenländern vergleichsweise geringe Mehrbelastungen von maximal 30 EUR gegenüber. Gleichzeitig zeigt die Analyse, dass ein alleiniges Wälzen der Übertragungsnetzkosten zum heutigen Stand für Industriekunden in Ostdeutschland zwar merkliche Entlastungen mit sich bringen würde, diese aber zukünftig abnehmen und im Haushaltskundenbereich sehr gering ausfallen. Insgesamt lässt sich aus den Ergebnissen der Analyse schlussfolgern, dass die regionale Ungleichverteilung der Netzkosten tendenziell zunimmt und es Regionen in Deutschland gibt, in denen hohe Netzausbaukosten, eine negative demographische Entwicklung und eine geringe Kaufkraft zusammentreffen und so Privathaushalte sowie Industriebetriebe stark belasten.:1 Zusammenfassung und Schlussfolgerungen 2 Gegenstand und Ziel der Analyse 3 Rahmenbedingungen der Bestimmung der Netznutzungsentgelte 4 Kostenmodell des Übertragungsnetzes 5 Kostenmodell der Verteilungsnetze 6 Auswirkungen des demographischen Wandels auf Stromverbrauch und Netzentgelte 7 Abschätzung der Netznutzungsentgelte und ihrer Zusammensetzung 8 Skizze eines Netzkostenstrukturausgleichs 9 Quellen 10 Anhang

Zur Umsetzung der Energiewende ist in den kommenden Jahren ein substantieller Netzausbau notwendig, der jedoch regional unterschiedlich stark ausfallen wird. Nach gegenwärtiger Gesetzeslage werden die folglich sehr unterschiedlich hohen Netzkosten von den Endkunden des jeweiligen Netzgebietes über die Netznutzungsentgelte getragen. Mittels eines detaillierten Modells der Kostenbestandteile der Netzkosten in den einzelnen Regionen wurden unter Berücksichtigung des erwarteten Netzausbaus sowie der demographischen Entwicklung die Netznutzungsentgelte, geschlüsselt nach den Kundengruppen Haushalt und Gewerbe sowie Industrie bis zum Jahr 2023 prognostiziert. Die anschließende Analyse eines bundesweiten Wälzens von Übertragungs- und Verteilungsnetzbestandteilen der Entgelte kommt zu dem Ergebnis, dass in Zukunft neben den ostdeutschen Flächenländern auch die Küstenländer Schleswig-Holstein und Niedersachsen sowie Teile Bayerns von einem bundeseinheitlichen Entgelt profitieren würden. Dabei stellt sich eine asymmetrische Verteilung von Be- und Entlastungen dar. Den zum Teil erheblichen jährlichen Entlastungen von bis zu 130 EUR pro 3-Personenhaushalt stehen in den süd- und westdeutschen Flächenländern vergleichsweise geringe Mehrbelastungen von maximal 30 EUR gegenüber. Gleichzeitig zeigt die Analyse, dass ein alleiniges Wälzen der Übertragungsnetzkosten zum heutigen Stand für Industriekunden in Ostdeutschland zwar merkliche Entlastungen mit sich bringen würde, diese aber zukünftig abnehmen und im Haushaltskundenbereich sehr gering ausfallen. Insgesamt lässt sich aus den Ergebnissen der Analyse schlussfolgern, dass die regionale Ungleichverteilung der Netzkosten tendenziell zunimmt und es Regionen in Deutschland gibt, in denen hohe Netzausbaukosten, eine negative demographische Entwicklung und eine geringe Kaufkraft zusammentreffen und so Privathaushalte sowie Industriebetriebe stark belasten.:1 Zusammenfassung und Schlussfolgerungen 2 Gegenstand und Ziel der Analyse 3 Rahmenbedingungen der Bestimmung der Netznutzungsentgelte 4 Kostenmodell des Übertragungsnetzes 5 Kostenmodell der Verteilungsnetze 6 Auswirkungen des demographischen Wandels auf Stromverbrauch und Netzentgelte 7 Abschätzung der Netznutzungsentgelte und ihrer Zusammensetzung 8 Skizze eines Netzkostenstrukturausgleichs 9 Quellen 10 Anhang