Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaf 89). Also available online.

Power systems have evolved significantly during the last two decades with the advent of Distributed Energy Resources (DERs) like solar PV. Traditionally, large power plants were considered as the sole source of energy in the power systems. However, DERs connected to the transmission and the distribution systems are creating a paradigm shift from a centralized generation to a distributed one. Though the variable power output from these DERs poses challenges to the reliable operation of the grid, it also presents opportunities to design control and coordination approaches to improve system efficiency and operational reliability. Moreover, building new transmission lines to meet ever-increasing load demand is not always viable. Thus, the industry is leaning towards developing non-wires alternatives. Considering the existing limitations of the transmission system, line congestions, and logistic/economic constraints associated with its capacity expansion, leveraging DERs to supply distribution system loads is attractive and thus capturing the attention of researchers and the electric power industry. The primary objective of this dissertation is to develop a framework that enables DERs to supply local area load by co-simulating the power system and transactive system representations of the network. To realize this objective, a novel distributed optimization and game theory-based network representation is developed that optimally computes the power output of the Home Microgrids/DER aggregators. Moreover, the optimum operational schedules of the DERs within these Home Microgrids/DER aggregators are also computed. The novel electrical-transactive co-simulation ensures that the solution is optimum in the context of power systems i.e. power flow constraints are not violated while the payoffs are maximized for the Home Microgrids/DER aggregators. The transactive mechanism involves two-way iterative signaling. The signaling is modeled as an infinite strategy, multiplayer, non-cooperative game, and a novel theory is developed for the game model. The dissertation also introduces a novel concept of ranking the Home Microgrids/DER aggregators according to their historic performance, thus leading to fairness, higher participation, and transparency. Significant advantages offered by the framework include consumption of local generation, transmission upgrade deferral, mitigation of line congestions in peak periods, and reduced transmission systems losses. / Doctor of Philosophy / In past, electricity was primarily produced by the large fossil fuel-based and nuclear power plants, usually located farther away from the populated areas where the bulk of the electricity consumption occurs. The electricity from the power plants is carried by the transmission lines to the populated areas where it is distributed to end-users via a distribution network. However, during the last two decades, issues like global warming and depleting fossil fuels have led to the development and increased adoption of renewable energy resources like solar photovoltaics (PV), wind turbines, etc. These resources are commonly known as Distributed Energy Resources (DERs), and they are connected to both the transmission and the distribution systems. Initially, they were mainly used to supply the load within the facility in which they are installed. However, the electric load (demand) continues to grow while adding new fossil fuel-based plants and transmission lines are becoming logistically/economically challenging. Thus, researchers are working on developing techniques that can enable DERs to supply the loads in the distribution system to which they are connected. This dissertation develops a method to use DERs for load support in the distribution systems. Specifically, the buildings that house the DERs can use the energy generated by the DERs to supply the local load (building load), and once the total generation exceeds the load demand, the building can inject the power into the distribution system to support the local area load. The proposed framework considers the electric network constraints like limits of lines supplying the power and limits of the transformers. The proposed work also develops a new method to maximize the benefit (in terms of profit) for the DER owners. A ranking system is introduced for the DER owners that enhances the transparency and fairness of the process. The key benefits offered by the proposed work include reduced losses in the transmission system, more energy consumed closer to the point of generation, and avoidance of transmission line and large central generation additions.

<p> In North America, heat treating adds about $15 billion per year in value to metal goods by imparting specific properties that are required if parts are to function successfully. Heat treating is an energy-intensive industry, requiring about 500 trillion BTUs (~ 0.5 trillion ft3 of natural gas) per year, which accounts for about 20% of the total cost ofthe business. Considering this huge demand on energy resources and its significant impact on the environment, in the year 1996, members of the heat treating industry represented by the ASM Heat Treating Society and the Metal Treating Institute (MTI) met and discussed the future of the heat treating industry in North America. A vision was developed known as "Heat Treating Industry Vision-2020". In that vision, the industry identified key research areas among which was the development of integrated process models. The industry recognized that most current heat-treating procedures are based on the experience of the heat treater. Trial-and-error often results in operations or components that are functional but not optimized. </p> <p> The present study is concerned with the development of process models of gas nitriding operations using Artificial Neural Networks (ANNs). Data required for the development of ANN s have been acquired from experiments carried out at the industrial partner site, V AC AERO International, Oakville, Ontario. Two types of ANNs have been developed and tested using the experimental data. The two models were able to predict various case depths produced by the nitriding process with reasonable accuracy in the ± 20% range. Predictions of the white layer thickness were in the ± 40% range. The sensitivity of predictions due to measurement errors has been investigated. The range of measurement error of the current study did not have a significant effect on the ANNs predictions. The effect of rate of cooling after the nitriding operation on the developed case depths has also been investigated. Cooling rates in the range of3° F/min to about 20 °F/min were tested. Results indicated that this range of cooling rates do not have a significant effect on the developed case depths. </p> <p> The present study has confirmed that ANNs models have the ability to be trained and applied to multivariable systems which renders ANNs the most suitable tool to develop integrated models for heat treating processes. </p> / Thesis / Master of Applied Science (MASc)

There is an increasing integration of distributed energy resources (DER), controllable loads, and other technologies that are making the grid more robust, reliable, and decentralized. Communication is a major aspect that enables this decentralization and can improve control of important system parameters by allowing different grid components to communicate their states with each other. This information exchange requires a reliable and fast communication infrastructure. Different communication techniques can be used towards this objective, but with recent technological advancements, 5G communication is proving to be a very viable option. 5G is being widely deployed throughout the world due to its high data rates combined with increased reliability compared with its predecessor technologies. This thesis focuses on application and performance analysis of a 5G network for different power system test cases. These test cases are microgrids, and consist of DERs that use distributed control for efficient operation. Under distributed control, the DERs communicate with each other to achieve fast and improved dynamic response. This work develops a co-simulation platform to analyze the impact that a 5G network has in this distributed control objective. This offers key insights on 5G's capability to support critical functions. Different scenarios including set point changes and transients are evaluated. Since distributed control is a time-critical application and DERs rely on the availability of up-to-date information, the scheduling aspect of 5G becomes very important and is given more focus. Information freshness measured using age of information (AoI) is used in this work. Information freshness is a measure of how recent and updated the information communicated by DERs is. This thesis compares the performance of AoI-based schedulers against standard schedulers. These different schedulers are then used on test systems employing distributed control. / Master of Science / Communication has become an important aspect of modern power systems due to increased integration of distributed energy resources (DER), controllable loads and other components that have communication capabilities for improved grid performance. Of the various communication techniques available for power systems, 5G is very promising due to its advantages over its predecessors and other wired communication methods. This work develops a cosimulation framework to implement a 5G network for different microgrid test cases that employ distributed control. Under distributed control, the DERs communicate with each other to achieve fast and improved dynamic response. Due to the time-critical nature of distributed control, DERs rely on the availability of up-to-date information. Hence the scheduling aspect of 5G becomes very important and is given more focus in this work. 5G schedulers that account for the availability of up-to-date information, also referred to as information freshness, are compared with standard 5G schedulers and their performance in distributed control test systems is analyzed.

The future of the electric grid requires advanced control technologies to reliably integrate high level of renewable generation and residential and small commercial distributed energy resources (DERs). Flexible loads are known as a vital component of future power systems with the potential to boost the overall system efficiency. Recent work has expanded the role of flexible and controllable energy resources, such as energy storage and dispatchable demand, to regulate power imbalances and stabilize grid frequency. This leads to the DER aggregators to develop concepts such as the virtual energy storage system (VESS). VESSs aggregate the flexible loads and energy resources and dispatch them akin to a grid-scale battery to provide flexibility to the system operator. Since the level of flexibility from aggregated DERs is uncertain and time varying, the VESSs’ dispatch can be challenging. To optimally dispatch uncertain, energy-constrained reserves, model predictive control offers a viable tool to develop an appropriate trade-off between closed-loop performance and robustness of the dispatch. To improve the system operation, flexible VESSs can be formulated probabilistically and can be realized with chance-constrained model predictive control. The large-scale deployment of flexible loads needs to carefully consider the existing regulation schemes in power systems, i.e., generator droop control. In this work first, we investigate the complex nature of system-wide frequency stability from time-delays in actuation of dispatchable loads. Then, we studied the robustness and performance trade-offs in receding horizon control with uncertain energy resources. The uncertainty studied herein is associated with estimating the capacity of and the estimated state of charge from an aggregation of DERs. The concept of uncertain flexible resources in markets leads to maximizing capacity bids or control authority which leads to dynamic capacity saturation (DCS) of flexible resources. We show there exists a sensitive trade-off between robustness of the optimized dispatch and closed-loop system performance and sacrificing some robustness in the dispatch of the uncertain energy capacity can significantly improve system performance. We proposed and formulated a risk-based chance constrained MPC (RB-CC-MPC) to co-optimize the operational risk of prematurely saturating the virtual energy storage system against deviating generators from their scheduled set-point. On a fast minutely timescale, the RB-CC-MPC coordinates energy-constrained virtual resources to minimize unscheduled participation of ramp-rate limited generators for balancing variability from renewable generation, while taking into account grid conditions. We show under the proposed method it is possible to improve the performance of the controller over conventional distributionally robust methods by more than 20%. Moreover, a hardware-in-the-loop (HIL) simulation of a cyber-physical system consisting of packetized energy management (PEM) enabled DERs, flexible VESSs and transmission grid is developed in this work. A predictive, energy-constrained dispatch of aggregated PEM-enabled DERs is formulated, implemented, and validated on the HIL cyber-physical platform. The experimental results demonstrate that the existing control schemes, such as AGC, dispatch VESSs without regard to their energy state, which leads to unexpected capacity saturation. By accounting for the energy states of VESSs, model-predictive control (MPC) can optimally dispatch conventional generators and VESSs to overcome disturbances while avoiding undesired capacity saturation. The results show the improvement in dynamics by using MPC over conventional AGC and droop for a system with energy-constrained resources.

With the adoption of the Act on Promotion of Use of Renewable Energy Resources in 2005, the Czech Republic took a significant step forward to examine the economic field of energy in general in light of environmental and climate protection. With this act, the Czech Republic followed the example of other European Union member states in asserting the goal of reducing greenhouse gas emissions and seeking alternative energy resources in the spirit of the Kyoto Protocol obligations. The goal of this Master's thesis is to present and logically analyze the relevant legal legislation concerning renewable resources passed in the Czech law. The emphasis of this analysis of the Act No. 180/2005 Sb. on the Promotion of the Use of Renewable Energy Resources in the context of energy law, whereby the attention is placed on promotion of energy production, those in the Czech Republic represent two alternative schemes: "feed-in tariff" and "green bonus certificates." With the broad definition of renewable energy resources in the introduction, this thesis comprises a basic overview of this comprehensive legal problem. This thesis consists of five separate chapters, which are closely related.

The United States leads the world in per capita production of Municipal Solid Waste (MSW), generating approximately 200 million tons per year. By 2000 A.D. the US EPA predicts a 20% rise in these numbers. Currently the major strategies of MSW disposal are (i) landfill and (ii) incineration. The amount of landfill space in the US is on a rapid decline. There are -10,000 landfill sites in the country, of which only 65-70% are still in use. The Office of Technology Assessment (OTA) predicts an 80% landfill closure rate in the next 20 years. The development of a viable energy resource from MSW, in the form of densified Refuse Derived Fuel (dRDF), provides solutions to the problems of MSW generation and fossil fuel depletions. Every 2 tons of MSW yields approximately 1 ton of dRDF. Each ton of dRDF has an energy equivalent of more than two barrels of oil. At current production rates the US is "throwing away" over 200,000,000 barrels of oil a year. In order to be considered a truly viable product dRDF must be extensively studied; in terms of it's cost of production, it's combustion properties, and it's potential for environmental pollution. In 1987 a research team from the University of North Texas, in conjunction with the US DOE and Argonne National Laboratory (ANL), cofired over 550 tons of dRDF and bdRDF with a high sulfur Kentucky coal in a boiler at ANL. This work examines the emission rates of polychlorinated dioxins (PCDDs) and furans (PCDFs) during the combustion of the dRDF, bdRDF, and coal. Even at levels of 50% by Btu content of dRDF in the fuel feedstock, emission rates of PCDDs and PCDFs were below detection limits. The dRDF is shown to be an environmentally acceptable product, which could help resolve one of the major social and environmental problems facing this country today.

M. Tech. (Engineering: Electrical, Department Electronic Engineering, Faculty of Engineering and Technology), Vaal University of Technology, / “If we think oil is a problem now, just wait 20 years. It’ll be a nightmare.” — Jeremy Rifkin, Foundation of Economic Trends, Washington, D.C., August 2003. This statement harmonises with the reality that human civilisation faces today. As a result, humankind has been forced to look for alternatives to fossil fuels. Among possible solutions, fuel cell (FC) technology has received a lot of attention because of its potential to generate clean energy. Fuel cells have the advantage that they can be used in remote telecommunication sites with no grid connectivity as the majority of telecommunication equipment operates from a DC voltage supply. Power plants based on phosphoric acid fuel cell (PAFC) have been installed worldwide supplying urban areas, shopping centres and medical facilities with electricity, heat and hot water. Although these are facts regarding large scale power plants for on-site use, portable units have been explored as well. Like any other fuel cell, the PAFC output power is highly unregulated leading to a drastic drop in the output voltage with changing load value. Therefore, various DC–DC converter topologies with a wide range of input voltages can be used to regulate the fuel cell voltage to a required DC load. An interleaved synchronous buck converter intended for efficiently stepping down the energy generated by a PAFC was designed and developed. The design is based on the National Semiconductor LM5119 IC. A LM5119 evaluation board was redesigned to meet the requirements for the application. The measurements were performed and it was found that the converter achieved the expectations. The results showed that the converter efficiently stepped down a wide range of input voltages (22 to 46 V) to a regulated 13.8 V while achieving a 93 percent efficiency. The conclusions reached and recommendations for future research are presented. / Telkom Centre of Excellence, TFMC, M-Tech, THRIP.

Os reservatórios são utilizados pelo homem há milhares de anos e são fundamentais em países que apresentam uma matriz energética predominantemente hidrelétrica como o Brasil. Desta forma, há uma preocupação relacionada à vida útil de um reservatório que é influenciada diretamente pelo transporte e deposição de sedimentos. No entanto, a maioria dos reservatórios nacionais não apresenta atualmente estudos hidrossedimentológicos consistentes para auxiliar seus gestores no planejamento e gerenciamento dos mesmos. Uma das principais justificativas apresentadas para a ausência destes estudos se refere à dificuldade na aplicação de metodologias relacionadas à sedimentologia nos recursos hídricos. Neste contexto, a tese apresenta o desenvolvimento de uma ferramenta computacional (NH Sediment) de livre acesso que poderá auxiliar os gestores de reservatórios no monitoramento e análise dos parâmetros hidrossedimentológicos. A ferramenta computacional é fundamentada em metodologias consolidadas na literatura técnica e acadêmica. Ela permite que o usuário estime parâmetros hidrossedimentólogicos, como a descarga sólida total, o peso específico aparente, a eficiência de retenção, além do volume assoreado e do tempo de vida útil de reservatórios. A ferramenta foi aplicada no Reservatório da Pequena Central Hidrelétrica de Mogi-Guaçu (SP) e foi possível observar que os resultados estavam condizentes com os parâmetros obtidos no levantamento de campo (dados primários) e com os dados fornecidos pela empresa que administra a PCH. Desse modo, a ferramenta computacional é mais uma alternativa para auxiliar o acompanhamento do processo de assoreamento em reservatórios, principalmente das pequenas centrais hidrelétricas onde este problema tende a ser maior. Além disso, ela também poderá ajudar na escolha das melhores medidas para prevenção ou minimização de parte dos problemas causados pelos sedimentos nos reservatórios. / Reservoirs have been used by people for thousands of years and are essential in countries with a predominantly hydroelectric energy matrix, such as Brazil. Although, there is a concern about the life of a reservoir, which is directly influenced by transport and deposition of sediments, most national reservoirs have not conducted consistent hydrosedimentological studies to assist their managers in their planning and managing. One of the main justifications for such a lack is the difficulty of application of methodologies related to sedimentology in water resources. This thesis addresses the development of a computational tool (NH Sediment) of free access that can assist reservoir managers in monitoring and analyzing hydrosedimentological parameters. The tool is based on methodologies consolidated in the technical and academic literature and enables users to estimate hydrosedimentological parameters, such as total solid discharge, apparent specific weight, retention efficiency, silting volume and lifetime of reservoirs. It was applied to the reservoir of the Small Hydropower Plant (SHP) of Mogi-Guaçu (SP) and the results were consistent with the parameters obtained in a field survey conducted and data provided by the company that manages SHP. It has proven an alternative to help users in monitoring the silting process in reservoirs, especially in small hydropower plants, where this problem tends to be more serious. It can also be employed for the choice of best measures for the prevention or minimization of problems caused by sediments in reservoirs.

This study is performed as a partial aid to a larger study that aims to determine if electromagnetic fields produced by underwater power cables have any effect on marine species. In this study, a new numerical method for calculating magnetic fields around subsea power cables is presented and tested. The numerical method is derived from electromagnetic theory, and the program, Matlab, is implemented in order to run the simulations. The Matlab code is validated by performing a series of tests in which the theoretical code is compared with other previously validated magnetic field solvers. Three main tests are carried out; two of these tests are physical and involve the use of a magnetometer, and the third is numerical and compares the code with another numerical model known as Ansys. The data produced by the Matlab code remains consistent with the measured values from both the magnetometer and the Ansys program; thus, the code is considered valid. The validated Matlab code can then be implemented into other parts of the study in order to plot the magnetic field around a specific power cable. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection