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The increasing penetration of electric vehicles (EVs) and other distributed energy resources (DERs) offers enhanced flexibility and resilience. During extreme conditions, grid-connected EVs and DERs can provide electricity service and restore critical loads when the utility system is unavailable. On the other hand, during normal operation, these proactive devices can provide ancillary services to alleviate voltage fluctuations and support frequency regulation. In comparison with other DERs, EVs are more flexible in providing ancillary services due to their mobile nature. However, the proliferation of EVs and DERs also introduces operational challenges to the distribution grid. For instance, EVs primarily fulfill their transportation needs. Uncoordinated charging of a large number of EVs can increase the burden on the distribution system. Due to the limited charging rate and battery size, it is generally impractical for a single EV to directly participate in the ancillary service market. A conventional distribution system is designed for unidirectional flow of electric energy. With the growing installation of DERs on the distribution system, the flow of electric energy is bi-directional and, therefore, there is a higher risk of protection miscoordination due to the fault currents resulting from DERs. With limited communication capability, these undetected protective device (PD) actuations can cause uncertainties and delay the service restoration process. This dissertation makes contributions to the coordination of EVs and DERs. It introduces four innovative models for EV coordination: 1) A transactive energy (TE) trading mechanism is proposed to coordinate EVs and aggregators. 2) Optimal tools are provided to assist EVs and aggregators in optimal decision making while participating in TE. 3) A charging station model is developed to allow EVs to provide ancillary service aligned with their mobile nature. 4) A utility function model is presented to capture the EV owners' behaviors for providing ancillary services and charging vehicles. Charging stations can estimate the electric energy demand and optimize ancillary service provision to meet their goals. Simulation cases validated that the proposed optimization tools can align EV owners' preferences in providing ancillary service to enhance distribution system operation flexibility. To enhance the resilience of distribution systems, two novel optimization strategies are presented: 1) An advanced outage management (AOM) is proposed to utilize smart meters and fault indicators (FIs) to identify the most credible outage scenario and fault locations. 2) An advanced feeder restoration (AFR) is developed to provide an optimal restoration strategy to enhance system resilience. The proposed optimization models have been validated with realistic simulation cases. / Doctor of Philosophy / As Electric Vehicles (EVs) and other Distributed Energy Resources (DERs) become more common, they are changing how our distribution systems work. For example, during power outages, grid-connected DERs and EVs can be deployed to sustain essential electricity services such as hospitals and communications. On the other hand, during a normal operating condition, they can help maintain the stability of our electricity systems. It is a technical challenge to integrate these new EV and DER devices into the existing power grid. For example, EVs are mainly designed for transportation. Their clustered charging patterns can significantly increase the electrical demand if they are not managed properly. Also, the limited battery capacity and charging speed make it difficult for a single vehicle to provide meaningful support to the grid operation. For the EV management side, this research is concerned with how to better integrate EVs and similar technologies into the power grid. Four key contributions of this dissertation are: 1) Developing a trading mechanism for EVs and aggregators of EVs to exchange energy and ancillary services efficiently; 2) Creating computational technologies to help these entities optimize their decisions while meeting their requirements; 3) Structuring charging station operations that cater to the preferences of EV owners while supporting grid operation; and 4) Modeling EV owners' decision-making to set optimal pricing and service strategies at charging stations. These mechanisms and strategies will allow EV owners to support the power grid while meeting their transportation needs. Moreover, the study addresses the issue of enhancement of the distribution system's capability to restore services under extreme conditions. It provides an advanced outage management method that utilizes remote monitoring and control technologies, including smart meters and fault indicators, to identify the location of electrical faults and reduce the outage areas. The advanced feeder restoration method determines an optimal strategy to restore the electricity service efficiently while keeping the distribution grid stable.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-07-19T18:40:00Z No. of bitstreams: 1 victorfernandes.pdf: 1092306 bytes, checksum: 4a32aa04ed1256ce18768180de089629 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-09T12:20:45Z (GMT) No. of bitstreams: 1 victorfernandes.pdf: 1092306 bytes, checksum: 4a32aa04ed1256ce18768180de089629 (MD5) / Made available in DSpace on 2017-08-09T12:20:45Z (GMT). No. of bitstreams: 1 victorfernandes.pdf: 1092306 bytes, checksum: 4a32aa04ed1256ce18768180de089629 (MD5) Previous issue date: 2017-02-23 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Essa dissertação tem por objetivo mostrar os benefícios em termos de desempenho e confiabilidade de um modelo de canal híbrido de baixa taxa de dados que pode ser aplicado a smart grids e internet das coisas. Esse modelo é chamado de hybrid power line communication-wireless single-relay channel (HSRC), que consiste do uso paralelo e mútuo dos modelos single-relay channel baseado em transmissão de dados via rede elétrica e sem fio. Para mostrar os benefícios do mesmo, foi considerado que a posição do nó de retransmissão é variável, também foi assumida alocação de potência uniforme e ótima sob restrição de potência, bem como o uso de dois protocolos de cooperação: amplify-andforward (AF) e decode-and-forward (DF). Além disso, essa dissertação discute o modelo HSRC incompleto, que é caracterizado pela perda de um enlace de comunicação de dados ou uma interface de comunicação de um nó no modelo HSRC. Primeiramente, foi apresentada a formulação matemática no que tange a taxa de dados ergódica e probabilidade de outage dos dois modelos mencionados. Em seguida, foi realizada a análise numérica dos mesmos. Por fim, os resultados numéricos foram analisados e mostraram que tanto o HSRC quanto o HSRC incompleto têm performance melhores do que o single-relay channel baseado em transmissão de dados via rede elétrica ou sem fio para todas as posições do nó de retransmissão e protocolos de cooperação considerados. Também, os resultados mostraram que a posição relativa entre os nós de fonte, destino e de retransmissão impactam significativamente na taxa de dados ergódica bem como na probabilidade de outage. Ainda, foi mostrado o impacto da perda de cada enlace de comunicação de dados ou interface de comunicação de um nó (HSRC incompleto) quando a posição relativa do nó de retransmissão muda. Por último, é mostrado que a diferença de desempenho entre os protocolos de cooperação AF e DF reduz quando o modelo HSRC é utilizado e que a melhor posição para o nó de retransmissão é entre os nós fonte e destino em termos de taxa de dados ergódica. / This dissertation aims at discussing improvements of performance and reliability of lowbit rate data communication technologies applied to smart grids and internet of things. In this regard, a comprehensive analysis of the ergodic achievable data rate and the outage probability of the so-called low-bit rate hybrid power line communication-wireless singlerelay channel (HSRC) model, which jointly and in parallel uses power line and wireless channels for data transmission, is presented. In order to highlight the benefits of such hybrid channel model for the target applications when the relative position of relay node changes, optimal and uniform power allocations under sum power constraint, amplifyand-forward (AF) and decode-and-forward (DF) cooperative protocols are taken into account. Moreover, this dissertation discusses the so-called incomplete HSRC which is characterized by the loss of one data communication link or node communication interface in a HSRC. Numerical results show that the HSRC and incomplete HSRC remarkably outperform power line or wireless single-relay channels for all considered positions of the relay node and the chosen cooperative protocols. Furthermore, these results show that the relative distances among source, relay and destination nodes significantly impact the achievable data rate and outage probabilities. In addition, the impact of each missing data communication link or node communication interface (incomplete HSRC) when the relay position, relative to source and destination nodes, changes is quantified. Finally, but not the least, it is shown that the performance difference between AF and DF protocols reduces when the HSRC model is taken into account and that the best relay position is in the middle between source and destination nodes.

This thesis concerns communication across channels with multiple inputs and multiple outputs. Specifically, we consider the closed-loop scenario in which knowledge of the state of the multiple-input multiple-output (MIMO) channel is available at the transmitter. We show how this knowledge can be exploited to optimize performance, as measured by the zero-outage capacity, which is the capacity corresponding to zero outage probability. On at-fading channels, a closed-loop transmitter allocates different powers and rates to the multiple channel inputs so as to maximize zero-outage capacity. Frequency-selective fading channels call for a combination of orthogonal-frequency-division multiplexing (OFDM) and MIMO known as MIMO-OFDM. This exacerbates the allocation problem because it multiplies the number of allocation dimensions by the number of OFDM tones. Fortunately, this thesis demonstrates that simple allocations are sufficient to approach the zero-outage capacity. These simple strategies exploit the tendency for random MIMO channels to behave deterministically as the number of inputs becomes large.

A proposal for the spinning reserve assessment and allocation for El Salvador¡¦s Deregulated Electricity Market is formulated. Traditionally, the Independent System Operator calculates the spinning reserve as percentage of the forecast demand. And Automatic Generation Control (AGC) is allocated based on the partition factor. The reserve calculation neither reflects consistency achieving its main objective, reliability, nor is optimum performance control reached by the allocating mechanism. In the proposed method, the spinning reserve is estimated taking into account the generators outage ratio and AGC is allocated based on the North American Electric Reliability Corporation¡¦s Control Performance Standard-1. The allocation problem is solved with an improved Particle Swarm Optimization algorithm with a technique to modify the inertial factor on each iteration. The proposed method exhibits better results and it matches the Salvadorian technical requirements and market characteristics.

Wind generating resources have been increasing more rapidly than any other renewable generating resources. Wind power forecasting is an important issue for deploying higher wind power penetrations on power grids. The existing work on power output forecasting for wind farms has focused on the temporal issues. As wind farm outputs depend on natural wind resources that vary over space and time, spatial analysis and modeling is also needed. Predictions about suitability for locating new wind generating resources can be performed using spatial modeling. In this dissertation, we propose a new approach to spatial prediction of wind farm outputs for grid integration based on Kriging techniques. First, we investigate the characteristics of wind farm outputs. Wind power is variable, uncontrollable, and uncertain compared to traditional generating resources. In order to understand the characteristics of wind power outputs, we study the variability of wind farm outputs using correlation analysis. We estimate the Power Spectrum Density (PSD) from empirical data. Following Apt[1], we classify the estimated PSD into four frequency ranges having different slopes. We subsequently focus on phenomena relating to the slope of the estimated PSD at a low frequency range because our spatial prediction is based on the period over daily to monthly timescales. Since most of the energy is in the lower frequency components (the second, third, and fourth slope regions have much lower spectral density than the first), the conclusion is that the dominant issues regarding energy will be captured by the low frequency behavior. Consequently, most of the issues regarding energy (at least at longer timescales) will be captured by the first slope, since relatively little energy is in the other regions. We propose the slope estimation model of new wind farm production. When the existing wind farms are highly correlated and the slope of each wind farm is estimated at a low frequency range, we can predict the slope with low frequency components of a new wind farm through the proposed spatial interpolation techniques. Second, we propose a new approach, based on Kriging techniques, to predict wind farm outputs. We introduce Kriging techniques for spatial prediction, modeling semivariograms for spatial correlation, and mathematical formulation of the Kriging system. The aim of spatial modeling is to calculate a target value of wind production at unmeasured or new locations based on the existing values that have already been measured at locations considering the spatial correlation relationship between measured values. We propose the multivariate spatial approach based on Co-Kriging to consider multiple variables for better prediction. Co-Kriging is a multivariate spatial technique to predict spatially distributed and correlated variables and it adds auxiliary variables to a single variable of interest at unmeasured locations. Third, we develop the Augmented Kriging-based Model, to predict power outputs at unmeasured or new wind farms that are geographically distributed in a region. The proposed spatial prediction model consists of three stages: collection of wind farm data for spatial analysis, performance of spatial analysis and prediction, and verification of the predicted wind farm outputs. The proposed spatial prediction model provides the univariate prediction based on Universal Kriging techniques and the multivariate prediction based on Universal and Co-Kriging techniques. The proposed multivariate prediction model considers multiple variables: the measured wind power output as a primary variable and the type or hub height of wind turbines, or the slope with low frequency components as a secondary variable. The multivariate problem is solved by Co-Kriging techniques. In addition, we propose $p$ indicator as a categorical variable considering the data configuration of wind farms connected to electrical power grids. Although the interconnection voltage does not influence the wind regime, it does affect transmission system issues such as the level of curtailments, which, in turn, affect power production. Voltage level is therefore used as a proxy to the effect of the transmission system on power output. The Augmented Kriging-based Model (AKM) is implemented in the R system environments and the latest Gstat library is used for the implementation of the AKM. Fourth, we demonstrate the performance of the proposed spatial prediction model based on Kriging techniques in the context of the McCamey and Central areas of ERCOT CREZ. Spatial prediction of ERCOT wind farms is performed in daily, weekly, and monthly time scales for January to September 2009. These time scales all correspond to the lowest frequency range of the estimated PSD. We propose a merit function to provide practical information to find optimal wind farm sites based on spatial wind farm output prediction, including correlation with other wind farms. Our approach can predict what will happen when a new wind farm is added at various locations. Fifth, we propose the Augmented Sequential Outage Checker (ASOC) as a possible approach to study the transmission system, including grid integration of wind-powered generation resources. We analyze cascading outages caused by a combination of thermal overloads, low voltages, and under-frequencies following an initial disturbance using the ASOC. / text

Electric energy is part of our lives. We use electric energy everyday in our lives at home or work. The use ranges from home lighting to using computers or traffic lights. Electric energy became the indispensable part of our days. Electric energy is included in the fields of critical infrastructure which is essential to maintain safety and running the country. Power cut of critical infrastructure jeopardize the common being of inhabitants and also the safety of this region. Critical infrastructure is based in the Czech law of crisis management nb. 240/2000Cl and also in government regulation nb. 432/2010Cl about criteria of dealing crisis infrastructure. It is necessary to be prepared for every aspect of power cuts in the critical infrastructure field thoroughly as power cut can endanger human society and state. Because of the serious threat human society and state is essential to the individual areas of critical infrastructure failures to adequately prepare.Readiness to electrical power outage is a main theme of this thesis. The thesis focus on region of Cesky Krumlov located in South Bohemia, Czech Republic. Theoretical part of thesis named Power outage from the perspective of the crisis staff ORP Cesky Krumlov deals the aspects of electric energy and critical infrastructure. Reader learns about production, transport and distribution of electrical energy. Reader can also find information about power outages black outs. The thesis explains the meaning of word Infrastructure and also clarifies critical infrastructure and following protection of critical infrastructure. The thesis includes more information about critical infrastructure i.e. which documents deals with the problem of critical infrastructure, when and why the protection of critical infrastructure started and who was pioneer of the field problem. The thesis also describes the field of blackouts and gives the examples of the biggest blackouts which have every occurred in the world. The thesis reveals the cause of mentioned blackouts if the cause was human error, technical problem or overload of transmission system. The thesis shows the impact of blackouts on suffering population time they spent without electricity and how many people was affected with blackout, to complete the picture of blackouts. The last chapter is about crises staff. Reader learns about meaning of crisis staff and why and in which situations is the crisis staff in session. The thesis names and describes the crisis staffs at every level and describes the structure of crisis staff on every level government crises staff, county crisis staff and region crisis staff. The researcher part of this thesis is focused on region of Cesky Krumlov. The region is divided in municipalities and its belonging townships.The thesis gives picture about region population and its average age. The thesis also gives information about main water reservoirs and watercourses in region. The thesis mentions the leading farm economies which can be jeopardize during electric power outage. The thesis defines and analyses secondary crisis situations, which can occur during long lasting electrical power outage. The conclusion focus on the thesis research question "Is crises staff of region CeskýKrumlov prepared for the crises of electrical power outage?" The answer for the research question was ascertain by methods of risk analysing-the Checklist analysis and SWOT analysis. The research question was answered, based on these two analyses. One method was used to check the readiness for electrical power outage and following protection of region population of crisis staff of region CeskýKrumlov. The second method marks off strong and weak parts, opportunities and threats from the electrical power cut point of view. Following percentage calculation shows, what is the biggest danger for region of Cesky Krumlov in the moment of electrical power outage.

Indispensability of electricity in all areas of life, including industry, requires enterprises to be prepared for possible power outages, which would minimize impacts on the population. The aim of this thesis titled "Impacts of a power outage in great food - processing companies in the South Bohemia county" is to analyze possible impacts of power cuts in the awareness system of large food enterprises and to assess the effects it would have on the protection of the population when power outage occurs. To obtain the data for the thesis, I used a qualitative research in the form of structured interviews with employees of five large food enterprises, who are responsible for the given area. SWOT analyse was used to evaluate the interviews and a KARS method was used for the analysis of the most significant impacts of an electric power outage in the system of awareness of enterprises and in the protection of the population. The results of the research revealed a basic fact that electricity outage would mean an immediate interruption of production for the food enterprises in South Bohemia. None of the enterprises surveyed owns a standby electric power source, so the sustainability of the standby energy supply does not exist. This fact is alarming mainly from the point of view of the crisis management, because two of the surveyed enterprises are included in the Crises plan of South Bohemia and implement corresponding measures. An important factor influencing the current state of food enterprises awareness for electricity outage is undoubtedly the fact that there is no legislation in the Czech Republic at the moment, which would impose an obligation for food enterprises to prepare for electric power outages. To increase the awareness of the food enterprises for electricity outage, for example in the form back up power sources, would require considerable investments. I hope that this thesis will serve not only as a study material, but also will be a subject of discussion for food enterprises, presenting a model for a case of electric power outage.

Today's globalized world is much more vulnerable than we are often willing to admit. We live in a society which is considerably dependent on a stable supply of electricity. Potential large power outage also called blackout may be a very dangerous situation for our community. Usually we don't realize all consequences there can be for our everyday life, people's health, the security and the economy of the country. Despite the efforts of the responsible authorities, the complications for the population can be very serious. The effects of such unfortunate event can be reduced in a variety of ways. An option is to support an informed society that can take care of itself in times of crisis. This text is focused on the current approach to raising and maintaining awareness of the people for masive power outage not only in the Czech Republic. The aim of the thesis is to compare the information environment of the Czech Republic with the situation in neighboring Germany. It is important to keep on mind that many important systems serving under normal conditions to inform the population will not work when such an event occurs. It can be necessary to proceed with alternative solutions and communication channels. In the education context, it's realisic to inform the majority of the population only about the most important measures and appropriate patterns of blackout behavior. With the restoration of energy supplies, the task of informing the population doesn't end. By selecting key information, this work could contribute to the society.