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This thesis deals with a general investigation and comparison of methods of solution of the unit commitment problem for thermal generating units. An intensive mathematical model for this problem has been developed and presented. The most commonly implemented methods for solving the problem of unit commitment were reviewed and discussed. Every reviewed method had been coded in FORTRAN 77 on a VAX11/785 machine. On the basis of the results obtained, a comprehensive comparison of the different methods ha; been carried out. For the comparison to be realistic and practical, each method was tested on three power systems of different sizes. As a result of the comparison, the unit commitment problem for a case study system has been solved by using the most appropriate method(s) from those discussed in the thesis. A new approach for solving the problem has also been proposed and tested.

Transmission charges are levied against generators and suppliers for their use of transmission networks. The majority of existing transmission charging methods were designed for a system dominated by conventional and controllable generation. The resultant transmission charges reflect network users’ contribution to the system peak. The integration of renewable generation brings fundamental challenges in transmission planning and charging. Main criteria of transmission planning have changed from meeting system peak demand to the trade-offs between operational and investment costs. Transmission charging is required to effectively reflect these trade-offs. This research work aims to develop novel transmission charging methods for low carbon power systems, reflecting the contribution to transmission investments from different generation technologies, different locations, and critically different times. It firstly identifies the key drivers and key conditions of transmission investments under the economic criteria. In the second step, the key drivers and conditions are reflected in the developing of T-LRIC method, ToU-LRIC method and ToU-ICRP method. Major innovations of the proposed methods include 1. reflecting the trade-offs between operational and investments costs by employing investment time horizons to reflect the impacts of system operation on transmission investments (T-LRIC method and ToU-LRIC method). 2. differentiating various generation technologies by firstly quantifying their impacts on the time horizons of network investments, then translating these impacts to transmission charges (T-LRIC method and ToU-LRIC method). 3. providing time-specific transmission charges, in which Time-of-Use periods are identified by clustering time-series congestion costs or transmission charges, thus reflecting the typical conditions of system congestions and the required transmission investments (ToU-LRIC method and ToU-ICRP method). The main benefits from introducing these innovations are i) to guide the short-run behaviours of network users, thus mitigating transmission congestions and promoting efficient utilization of existing networks; ii) to incentivize appropriate generation expansion, thus reducing or deferring costly future transmission investments.

Submitted by LIVIA MARIA GONÇALVES ROSSI null (liv.rossi@yahoo.com) on 2016-01-25T14:04:25Z No. of bitstreams: 1 TESE_HCV Multi-region_LIVIA ROSSI.pdf: 6853283 bytes, checksum: d2ce231bc1292f9fa0469f971cf0856b (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-25T17:23:43Z (GMT) No. of bitstreams: 1 rossi_lmg_dr_sjrp.pdf: 6853283 bytes, checksum: d2ce231bc1292f9fa0469f971cf0856b (MD5) / Made available in DSpace on 2016-01-25T17:23:43Z (GMT). No. of bitstreams: 1 rossi_lmg_dr_sjrp.pdf: 6853283 bytes, checksum: d2ce231bc1292f9fa0469f971cf0856b (MD5) Previous issue date: 2016-01-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O vírus da Hepatite C (HCV) afeta cerca de 3% da população mundial. A cada ano, 3-4 milhões de novos casos são diagnosticados. A identificação de redes transmissão é complexa devido ao longo período de incubação, à falta de sintomas na fase aguda da doença e à heterogeneidade do HCV, que dificulta o estabelecimento de vínculos entre casos relacionados. Uma ampla caracterização das populações intra-hospedeiros pode ser realizada de forma eficiente através do sequenciamento de nova geração (NGS). Com base neste contexto, o sequenciamento de múltiplas regiões subgenômicas é uma solução às limitações impostas pela rápida evolução molecular do HCV. Variantes virais das regiões HVR1 e NS5A de 16 pacientes cronicamente infectados com o HCV, genótipos 1a e 1b, foram sequenciadas com a técnica de NGS. Os pacientes 1-7 compartilhavam fatores de risco, pertencendo ao mesmo grupo de usuários de drogas injetáveis, porém o parentesco genético desses casos não pode ser estabelecido com base apenas no sequenciamento da HVR1 (distância nucleotídica mínima entre 16-23). A amplificação de um fragmento maior (~450 pb), correspondente a um segmento da região NS5A, aprimorou a relação epidemiológica entre os pacientes 1-5, onde as distancias genéticas mínimas foram consideravelmente menores (9-13). Os pacientes 6 e 7 não compartilharam sequências com os outros cinco pacientes dessa rede, apresentando populações virais mais homogêneas. Adicionalmente, Median Joining Networks foram construídas para melhor analisar a variabilidade genética intra-hospedeiro. Em geral, observou-se que as sequências derivadas da NS5A formaram comunidades mais homogêneas e menos divergentes geneticamente. Assim, a tecnologia NGS e o sequenciamento das regiões subgenômicas HVR1 e NS5A podem ajudar a restaurar elos perdidos quando somente a região HVR1 é analisada, aprimorando portanto, a resolução de estudos de associação genética entre populações de HCV. / The hepatitis C virus (HCV) affects approximately 3% of the world's population. Each year 3-4 million new cases are diagnosed. The identification of transmission networks is complicated due to the characteristic long incubation period, the lack of symptoms during the acute phase of the disease and the heterogeneity of HCV, making it challenging to link related cases to a common source of infection. Extensive characterization of intra-host populations can be reliably archived using next generation sequencing (NGS) approaches. Sequencing of multiple and longer subgenomic regions has been proposed as an alternative to overcome the limitations imposed by the rapid molecular evolution of the HCV HVR1. Thus, the NS5A and HVR1 regions of 16 chronically infected individuals, genotypes 1a and 1b, were sequenced using a NGS platform. Patients 1-7 shared risk factors and belonged to the same injection drug users network. However, genetic relatedness could not be established based on the HVR1 sequences (minimal nucleotide distance ranging from 16-23). Amplification and sequencing of a larger PCR fragment (~450 bp) targeting the NS5A region reestablished lost epidemiological links between patients 1-5. The minimum genetic distances in those patients were considerable smaller than the HVR1 counterparts (9-13). Patients 6 and 7 displayed a rather homogeneous viral population and were clearly not sharing any sequences with all other five patients in this network. Additionally, Median Joining Networks analysis was carried out to further analyze the intrahost genetic variability of all seven patients. Overall, NS5A sequences were significantly less diverse than their HVR1 equivalents. Thus, NGS technology and use of both HVR1 and NS5A sequences might help restored otherwise lost links when the HVR1 region alone is analyzed, improving the resolution of HCV genetic relatedness studies. / CAPES: 33004153079P9

Orientador: Paula Rahal / Resumo: O vírus da Hepatite C (HCV) afeta cerca de 3% da população mundial. A cada ano, 3-4 milhões de novos casos são diagnosticados. A identificação de redes transmissão é complexa devido ao longo período de incubação, à falta de sintomas na fase aguda da doença e à heterogeneidade do HCV, que dificulta o estabelecimento de vínculos entre casos relacionados. Uma ampla caracterização das populações intra-hospedeiros pode ser realizada de forma eficiente através do sequenciamento de nova geração (NGS). Com base neste contexto, o sequenciamento de múltiplas regiões subgenômicas é uma solução às limitações impostas pela rápida evolução molecular do HCV. Variantes virais das regiões HVR1 e NS5A de 16 pacientes cronicamente infectados com o HCV, genótipos 1a e 1b, foram sequenciadas com a técnica de NGS. Os pacientes 1-7 compartilhavam fatores de risco, pertencendo ao mesmo grupo de usuários de drogas injetáveis, porém o parentesco genético desses casos não pode ser estabelecido com base apenas no sequenciamento da HVR1 (distância nucleotídica mínima entre 16-23). A amplificação de um fragmento maior (~450 pb), correspondente a um segmento da região NS5A, aprimorou a relação epidemiológica entre os pacientes 1-5, onde as distancias genéticas mínimas foram consideravelmente menores (9-13). Os pacientes 6 e 7 não compartilharam sequências com os outros cinco pacientes dessa rede, apresentando populações virais mais homogêneas. Adicionalmente, Median Joining Networks foram construídas para ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The hepatitis C virus (HCV) affects approximately 3% of the world's population. Each year 3-4 million new cases are diagnosed. The identification of transmission networks is complicated due to the characteristic long incubation period, the lack of symptoms during the acute phase of the disease and the heterogeneity of HCV, making it challenging to link related cases to a common source of infection. Extensive characterization of intra-host populations can be reliably archived using next generation sequencing (NGS) approaches. Sequencing of multiple and longer subgenomic regions has been proposed as an alternative to overcome the limitations imposed by the rapid molecular evolution of the HCV HVR1. Thus, the NS5A and HVR1 regions of 16 chronically infected individuals, genotypes 1a and 1b, were sequenced using a NGS platform. Patients 1-7 shared risk factors and belonged to the same injection drug users network. However, genetic relatedness could not be established based on the HVR1 sequences (minimal nucleotide distance ranging from 16-23). Amplification and sequencing of a larger PCR fragment (~450 bp) targeting the NS5A region reestablished lost epidemiological links between patients 1-5. The minimum genetic distances in those patients were considerable smaller than the HVR1 counterparts (9-13). Patients 6 and 7 displayed a rather homogeneous viral population and were clearly not sharing any sequences with all other five patients in this network. Additionally, Median Joining... (Complete abstract click electronic access below) / Doutor

<p>  </p> <p>This dissertation is composed of three main articles, which are detailed below.</p> <p>First article: The proliferation of prosumers generates the opportunity to have a more decentralized and open energy market. Given this opportunity, the Peer-to-Peer (P2P) trading energy paradigm appears, where consumers and prosumers can exchange energy without an intermediary. Because P2P energy trading plays a fundamental role in the proliferation of renewable energies and the system flexibility for a low-carbon energy transition, this article provides a review of the P2P energy trading that is necessary to understand the current approaches, challenges, and future research that should be conducted in this area. As a result, areas for consideration were identified and grouped into the following six topics: (1) trading platform, (2) blockchain, (3) game theory, (4) simulation, (5) optimization, and (6) algorithms. The study identified several challenges that may give way to future research, such as integrating generation, transmission, and distribution into studies, large-scale studies, and modeling consumer and prosumer complex behavior. Given that P2P energy trading is a relatively new topic, there is still much work to be done to implement the real-world model successfully.</p> <p>Second article: Along with the <a href="https://www.sciencedirect.com/topics/engineering/exponential-growth" target="_blank">exponential growth</a> of distributed energy sources in the last decade, net-metering programs have expanded to encourage investment in renewable energy. However, several countries and some states in the United States are ending these programs. Therefore, it is needed to explore alternatives to net-metering programs to continue encouraging the adoption of renewable energies. In this paper, Peer-to-Peer (P2P) models are studied as viable options to net-metering. In particular, the evaluation and comparison of the net-metering model to two P2P models is proposed. The first P2P model used the power grid for electricity exchange, and the other used electric vehicles. Simulations of a 50 household <a href="https://www.sciencedirect.com/topics/engineering/micro-grids" target="_blank">microgrid</a> with access to electric vehicles and <a href="https://www.sciencedirect.com/topics/engineering/photovoltaics" target="_blank">photovoltaic</a> generation were run to achieve this objective. Technical and economic indexes were established to measure the performance of the three models. The results indicated that the P2P model using the grid shows the best performance, followed by the P2P model using electric vehicles. </p> <p>Third article: Solar generation has increased rapidly in recent years worldwide, and it is projected to continue to grow exponentially. A problem exists in that the increase in solar energy generation will increase the probability of grid disturbances. This article focused on analyzing the grid disturbances caused by the massive integration to the transmission line utility-scale solar loaded to the balancing authority high voltage transmission lines in four regions of the United States electrical system: (1) California, (2) Southwest, (3) New England, and (4) New York. Statistical analysis of equality of means was carried out to detect changes in the energy balance and peak power. Results show that when comparing the difference between hourly net generation and demand, energy imbalance occurs in the regions with the highest solar generation: California and Southwest. No significant difference was found in any of the four regions in relation to the energy peaks. The results imply that regions with greater utility level solar energy adoption must conduct greater energy exchanges with other regions to reduce potential disturbances to the grid. It is essential to bear in mind that as the installed solar generation capacity increases, the potential energy imbalances created in the grid increase. </p>

Orientadores: Nelson Luis Saldanha da Fonseca, Marcos Rogerio Salvador / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-08T22:05:51Z (GMT). No. of bitstreams: 1 Uesono_MarceloMitsutoshi_M.pdf: 1126012 bytes, checksum: de8cfd74039d54886967b1fc3c6176d4 (MD5) Previous issue date: 2005 / Resumo: Em redes ópticas em anel com slotting, slots de tamanhos fixos circulam continuamente pelo anel transportando pacotes de dados entre os nós. Em tais redes, um slot, ocupado com pacotes de um nó, tem seu conteúdo removido somente pelo próprio nó de origem. Entretanto, é possível remover o conteúdo do slot no nó de destino, técnica conhecida como remoção no destino, o que permite que um slot seja utilizado mais de uma vez em cada ciclo, o que é conhecido como reutilização espacial. Esta prática aumenta consideravelmente a vazão do anel. Entretanto, se o acesso aos slots não for controlado, injustiças podem ocorrer devido a oportunidades desbalanceadas de acesso ao meio oferecido aos nós. Para previnir um acesso injusto ao meio, a ocupação dos slots é controlada pelos protocolos de controle de acesso ao meio (MAC), que distribuem os slots entre os nós, oferecendo oportunidades justas do acesso ao meio. Os protocolos MAC seguem políticas de justiça, que são regras que determinam a divisão justa dos recursos do anel. Os protocolos MAC que oferecem justiça entre nós são comuns na literatura, entretanto, estes protocolos ignoram a justiça entre conexões TCP (Transmission Control Protocol)o Nesta dissertação, três novos protocolos são apresentados: LCR-SD, TCP-Fair e RVQ. O protocolo LCR-SD distribui a largura de banda baseada na política de justiça entre pares origem-destino, o protocolo RVQ oferece justiça entre conexões TCP e o protocolo de TCP -Fair oferece a justiça entre as conexões TCP mantendo a justiça entre nós. Os protocolos são comparados através de simulações realizadas no Network Simulator (NS-2). Resultados indicam que os protocolos LCR-SD, TCP-Fair e RVQ oferecem uma vazão superior ao protocolo Metaring. Além disso, apresenta-se um estudo sobre o impacto do tamanho dos slots no transporte de tráfego da Internet / Abstract: In slotted ring networks, slots of fixed size continuously circulate the ring transferring data packets between nodes. In such networks, a slot occupied by packets from one node, has its content removed only by the source node. However, it is possible to remove the packet content in the destination node, technique known as destination removal, which allows a slot to be used more than once in each cycle, leading to spatial reuse, which increases considerably the throughput. However, if the access to the slots is not regulated, unfairness may occur due to unbalanced medium access opportunities offered to the nodes. To prevent unfair access to the medium, the occupation of the slots is regulated by a Medium Access Control protocol (MAC), which distributes the slots among the nodes, offering fair access opportunities to the medium. MAC protocols comply with fairness policies, which are rules that determine the fair distribution of the ring resources. MAC protocols that offer fairness among nodes are common in the literature, however, these protocols ignore the fairness among TCP (Transmission Control Protocol) connections. In this dissertation, three new protocols are presented: LCR-SD, TCP-Fair and RVQ. The LCR-SD protocol distributes the bandwidth based on the source-destination node fairness policy, the RVQ protocol offers fairness among TCP connections and the TCP-Fair protocol offers fairness among TCP connections and maintains fairness among nodes. The protocols are compared through simulations using the Network Simulator (NS- 2). Results indicate that the protocols LCR-SD, TCP-Fair and RVQ offer a superior throughput compared to the Metaring protocol. Moreover, a study on the impact of the slot size on the transport of Internet traffic is presented. / Mestrado / Redes de Computadores / Mestre em Ciência da Computação

Les gestionnaires des réseaux de transport d'électricité doivent adapter leurs outils d'aide à la décision aux avancées technologiques du XXIième siècle. Une opération sous-jacente à beaucoup d'outils est de calculer les flux en actif/réactif qui minimisent les pertes ou les coûts de production. Mathématiquement, il s'agit d'un problème d'optimisation qui peut être décrit en utilisant seulement l'addition et la multiplication de nombres complexes. L'objectif de cette thèse est de trouver des solutions globales. Un des aboutissements de ce projet doctoral hautement collaboratif est d'utiliser des résultats récents en géométrie algébrique pour calculer des flux optimaux dans le réseau Européen à haute tension. / Transmission system operators need to adapt their decision-making tools to the technological evolutions of the twenty first century. A computation inherent to most tools seeks to find alternating-current power flows that minimize power loss or generation cost. Mathematically, it consists in an optimization problem that can be described using only addition and multiplication of complex numbers. The objective of this thesis is to find global solutions, in other words the best solutions to the problem. One of the outcomes of this highly collaborative doctoral project is to use recent results from algebraic geometry to compute globally optimal power flows in the European high-voltage transmission network.

In the new global and local scenario, the advent of intelligent distribution networks or Smart Grids allows real-time collection of data on the operating status of the electricity grid. Based on this availability of data, it is feasible and convenient to predict consumption in the short term, from a few hours to a week. The hypothesis of the study is that the method used to present time variables to a prediction system of electricity consumption affects the results.

<p dir="ltr">The horizon for inclusion of data-driven algorithms in cyber-physical systems is rapidly expanding due to evermore availability of high-performance computing tools and the inception of novel mathematical models in the fields of deep learning and reinforcement learning. In this regard, energy systems are a suitable candidate for data-driven algorithms utilization due to rapid expansion of smart measuring tools and infrastructure. Accordingly, I decided to explore the capabilities of deep reinforcement learning in control, security, and restoration of smart energy systems to tackle well-known problems such as ensuring stability, adversarial attack avoidance, and the black start restoration. To achieve this goal, I employed various reinforcement learning techniques in different capacities to develop transfer learning modules based on a rule-based approach for online control of the power system, utilized reinforcement learning for procedural noise generation in adversarial attacks against contingency detection in a power system and exploited multiple reinforcement learning algorithms to fully restore an energy system in an optimal manner. Per the results of these endeavors, I managed to develop a rule-based transfer learning logic to control the power system under various disturbance types and intensities. Furthermore, I developed an optimal adversarial attack module using a reinforcement-learning-based procedural noise generation to avoid detection by conventional deep-learning-based detection. Finally for the system restoration, the proposed intelligent restoration module managed to provide sustainable results for the black start restoration in energy system.</p>