Indiana University-Purdue University Indianapolis (IUPUI) / In this research, a Split-Shaft Wind Energy Conversion System (SS-WECS) is investigated to improve the performance and cost of the system and reduce the wind power uncertainty influences on the power grid. This system utilizes a lightweight Hydraulic Transmission System (HTS) instead of the traditional gearbox and uses a Doubly-Fed Induction Generator (DFIG) instead of a synchronous generator. This type of wind turbine provides several benefits, including decoupling the shaft speed controls at the turbine and the generator. Hence, maintaining the generator’s frequency and seeking maximum power point can be accomplished independently. The frequency control relies on the mechanical torque adjustment on the hydraulic motor that is coupled with the generator. This research provides modeling of an SS-WECS to show its dependence on mechanical torque and a control technique to realize the mechanical torque adjustments utilizing a Doubly-Fed Induction Generator (DFIG). To this end, a vector control technique is employed, and the generator electrical torque is controlled to adjust the frequency while the wind turbine dynamics influence the system operation. The results demonstrate that the generator’s frequency is maintained under any wind speed experienced at the turbine. Next, to reduce the size of power converters required for controlling DFIG, this research introduces a control technique that allows achieving MPPT in a narrow window of generator speed in an SS-WECS. Consequently, the size of the power converters is reduced significantly. The proposed configuration is investigated by analytical calculations and simulations to demonstrate the reduced size of the converter and dynamic performance of the power generation. Furthermore, a new configuration is proposed to eliminate the Grid- Side Converter (GSC). This configuration employs only a reduced-size Rotor-Side Converter (RSC) in tandem with a supercapacitor. This is accomplished by employing the hydraulic transmission system (HTS) as a continuously variable and shaft decoupling transmission unit. In this configuration, the speed of the DFIG is controlled by the RSC to regulate the supercapacitor voltage without GSC. The proposed system is investigated and simulated in MATLAB Simulink at various wind speeds to validate the results. Next, to reduce the wind power uncertainty, this research introduces an SS-WECS where the system’s inertia is adjusted to store the energy. Accordingly, a flywheel is mechanically coupled with the rotor of the DFIG. Employing the HTS in such a configuration allows the turbine controller to track the point of maximum power (MPPT) while the generator controller can adjust the generator speed. As a result, the flywheel, which is directly connected to the shaft of the generator, can be charged and discharged by controlling the generator speed. In this process, the flywheel energy can be used to modify the electric power generation of the generator on-demand. This improves the quality of injected power to the grid. Furthermore, the structure of the flywheel energy storage is simplified by removing its dedicated motor/generator and the power electronics driver. Two separate supervisory controllers are developed using fuzzy logic regulators to generate a real-time output power reference. Furthermore, small-signal models are developed to analyze and improve the MPPT controller. Extensive simulation results demonstrate the feasibility of such a system and its improved quality of power generation. Next, an integrated Hybrid Energy Storage System (HESS) is developed to support the new DFIG excitation system in the SS-WECS. The goal is to improve the power quality while significantly reducing the generator excitation power rating and component counts. Therefore, the rotor excitation circuit is modified to add the storage to its DC link directly. In this configuration, the output power fluctuation is attenuated solely by utilizing the RSC, making it self-sufficient from the grid connection. The storage characteristics are identified based on several system design parameters, including the system inertia, inverter capacity, and energy storage capacity. The obtained power generation characteristics suggest an energy storage system as a mix of fast-acting types and a high energy capacity with moderate acting time. Then, a feedback controller is designed to maintain the charge in the storage within the required limits. Additionally, an adaptive model-predictive controller is developed to reduce power generation fluctuations. The proposed system is investigated and simulated in MATLAB Simulink at various wind speeds to validate the results and demonstrate the system’s dynamic performance. It is shown that the system’s inertia is critical to damping the high-frequency oscillations of the wind power fluctuations. Then, an optimization approach using the Response Surface Method (RSM) is conducted to minimize the annualized cost of the Hybrid Energy Storage System (HESS); consisting of a flywheel, supercapacitor, and battery. The goal is to smooth out the output power fluctuations by the optimal size of the HESS. Thus, a 1.5 MW hydraulic wind turbine is simulated, and the HESS is configured and optimized. The direct connection of the flywheel allows reaching a suitable level of smoothness at a reasonable cost. The proposed configuration is compared with the conventional storage, and the results demonstrate that the proposed integrated HESS can decrease the annualized storage cost by 71 %. Finally, this research investigates the effects of the reduced-size RSC on the Low Voltage Ride Through (LVRT) capabilities required from all wind turbines. One of the significant achievements of an SS-WECS is the reduced size excitation circuit. The grid side converter is eliminated, and the size of the rotor side converter (RSC) can be safely reduced to a fraction of a full-size excitation. Therefore, this low-power-rated converter operates at low voltage and handles the regular operation well. However, the fault conditions may expose conditions on the converter and push it to its limits. Therefore, four different protection circuits are employed, and their effects are investigated and compared to evaluate their performance. These four protection circuits include the active crowbar, active crowbar along a resistorinductor circuit (C-RL), series dynamic resistor (SDR), and new-bridge fault current limiter (NBFCL). The wind turbine controllers are also adapted to reduce the impact of the fault on the power electronic converters. One of the effective methods is to store the excess energy in the generator’s rotor. Finally, the proposed LVRT strategies are simulated in MATLAB Simulink to validate the results and demonstrate their effectiveness and functionality.

Several cascading outages that have occurred in the past have shown the importance of performing appropriate and coordinated transmission system planning between the different Planning Coordinators and Transmission Planners in a power system. In very large, interconnected systems, this coordinated planning is necessary due to the inherent complexity that characterizes non-lineal electric power systems. A major task in transmission system planning is to conduct contingency studies that would determine the consequences in the system when single or multiple of its elements trip due to failure or are disconnected during scheduled maintenance outages. This work develops general programs aimed at facilitating the performance of such contingency studies based on the latest Transmission System Planning Performance Requirement standard issued by NERC, TPL-001-4. The focus of this work is on the requirements for the steady state analysis described in the standard, which includes specific steady state performance planning events. The developed programs have been tested in a few base cases and have demonstrated their ability to facilitate contingency studies with any system regardless of its size. / Master of Science

No description available.

Svenska kraftnät is the transmission system operator in Sweden, their responsibilities include renewing and expanding the existing transmission system to keep up with the rising demand for electricity. The ongoing climate crisis demands the process of expanding the transmission system to be as sustainable as possible. One way to do this is to use CEEQUAL, a point based, third party sustainability assessment tool for construction projects. The aim of this project is to estimate what CEEQUAL score the projects of Svenska kraftnät could achieve based on their current sustainability work. The aim also includes to determine what actions needs to be taken to improve that score, together with a cost analysis and interviews of the experiences from other CEEQUAL users.  By studying the sustainability work of Svenska kraftnät and translating this to CEEQUALs credits, a calculation of the current level of sustainability was determined as 44 percent. This equals the CEEQUAL level Pass. Further investigation revealed that to improve to the level Good, there needs to be more clear goals for a project sustainability and a business model for a circular economy among other things. For a higher score, reaching the level Very Good, there needs to be a life cycle analysis for new construction projects and better CO2-emission calculations.  A cost analysis revealed that it is hard to determine the cost of using CEEQUAL beforehand due to unforeseeable costs. Interviewing external users of CEEQUAL shows that using CEEQUAL is beneficial to improve the sustainability of a project and creates a common goal for the team members. A downside to using CEEQUAL is the administrative work it demands as well as the bureaucracy.  All in all, using CEEQUAL in all Svenska kraftnäts construction project could not be seen as beneficial. It would be beneficial to create a decision report tool for projects that help teams make sustainable choices for the projects. This would preferably be done together with distribution system operators in Sweden and transmission system operators in neighboring countries for a tool adapted to their operations and aspirations.

Esta pesquisa tem por finalidade propor um modelo de automação e padronização do processo de controle da prescrição médica e dispensação de medicamentos no Brasil, baseado no Sistema Autenticador e Transmissor (SAT) aplicado ao controle fiscal do comércio varejista e implementado no Estado de São Paulo, Brasil. Busca-se analisar o cenário atual de prescrição médica no país, suas características operacionais, os problemas cada vez mais frequentes ligados ao comércio irregular de medicamentos e o uso abusivo de substâncias controladas. São apresentadas as medidas adotadas para o controle do setor no Brasil, em Portugal e nos Estados Unidos da América, bem como seus requisitos e grau de operacionalização. Com base na lacuna encontrada nas ações adotadas pelo Brasil, apresenta-se a motivação do presente trabalho, a busca pelas características do cenário brasileiro e a respectiva não aderência do mesmo às propostas internacionais, principalmente pelo fato dessas demandarem infraestrutura técnica, ordenamento jurídico e disponibilidade de investimentos incompatíveis. Diante de referida necessidade, buscou-se em outras áreas um modelo de controle de processos que fosse aderente à realidade brasileira apresentada, razão pela qual uma solução encontrada foi a utilizada para o controle do comércio varejista, por meio do equipamento SAT (Sistema Autenticador Transmissor), que é responsável pela geração de Cupons Fiscais Eletrônicos. Assim, o trabalho consiste em utilizar os conceitos traçados para o modelo fiscal e adaptar às necessidades da prescrição médica, propondo um novo modelo de automação e controle do processo de prescrição e dispensa de medicamentos baseado na Receita Médica Eletrônica (RM-e). / This research aims to propose a model of automation and standardization of the process of control of medical prescription and dispensing of medicines in Brazil, based on the Authentication and Transmission System (Sistema Autenticador Transmissor - SAT) applied to the fiscal control of the retail trade and implemented in the State of São Paulo, Brazil. The aim is to analyze the current scenario of medical prescription in the country, its operational characteristics, the increasingly frequent problems related to irregular drug trade and the abusive use of controlled substances. The measures adopted to control the sector in Brazil, Portugal and the United States of America, as well as their requirements and degrees of operation are presented. Based on the gap found in the actions adopted by Brazil, the motivation of the present study is the search for the characteristics of the Brazilian scenario and its non-adherence to the international proposals, mainly because they require technical infrastructure, legal order and availability Incompatible investments. In view of this need, a process control model was searched in other areas that adhered to the Brazilian reality presented, which is why a solution found was used to control the retail trade, through the SAT (Authentication and Transmission System), which is responsible for the generation of Electronic Tax Coupons. Thus, the work consists of using the concepts outlined for the fiscal model and adapting to the needs of the medical prescription, proposing a new model of automation and control of the prescription and dispensing process based on Electronic Medical Prescription (Receita Médica Eletrônica RM-e).

Esta pesquisa tem por finalidade propor um modelo de automação e padronização do processo de controle da prescrição médica e dispensação de medicamentos no Brasil, baseado no Sistema Autenticador e Transmissor (SAT) aplicado ao controle fiscal do comércio varejista e implementado no Estado de São Paulo, Brasil. Busca-se analisar o cenário atual de prescrição médica no país, suas características operacionais, os problemas cada vez mais frequentes ligados ao comércio irregular de medicamentos e o uso abusivo de substâncias controladas. São apresentadas as medidas adotadas para o controle do setor no Brasil, em Portugal e nos Estados Unidos da América, bem como seus requisitos e grau de operacionalização. Com base na lacuna encontrada nas ações adotadas pelo Brasil, apresenta-se a motivação do presente trabalho, a busca pelas características do cenário brasileiro e a respectiva não aderência do mesmo às propostas internacionais, principalmente pelo fato dessas demandarem infraestrutura técnica, ordenamento jurídico e disponibilidade de investimentos incompatíveis. Diante de referida necessidade, buscou-se em outras áreas um modelo de controle de processos que fosse aderente à realidade brasileira apresentada, razão pela qual uma solução encontrada foi a utilizada para o controle do comércio varejista, por meio do equipamento SAT (Sistema Autenticador Transmissor), que é responsável pela geração de Cupons Fiscais Eletrônicos. Assim, o trabalho consiste em utilizar os conceitos traçados para o modelo fiscal e adaptar às necessidades da prescrição médica, propondo um novo modelo de automação e controle do processo de prescrição e dispensa de medicamentos baseado na Receita Médica Eletrônica (RM-e). / This research aims to propose a model of automation and standardization of the process of control of medical prescription and dispensing of medicines in Brazil, based on the Authentication and Transmission System (Sistema Autenticador Transmissor - SAT) applied to the fiscal control of the retail trade and implemented in the State of São Paulo, Brazil. The aim is to analyze the current scenario of medical prescription in the country, its operational characteristics, the increasingly frequent problems related to irregular drug trade and the abusive use of controlled substances. The measures adopted to control the sector in Brazil, Portugal and the United States of America, as well as their requirements and degrees of operation are presented. Based on the gap found in the actions adopted by Brazil, the motivation of the present study is the search for the characteristics of the Brazilian scenario and its non-adherence to the international proposals, mainly because they require technical infrastructure, legal order and availability Incompatible investments. In view of this need, a process control model was searched in other areas that adhered to the Brazilian reality presented, which is why a solution found was used to control the retail trade, through the SAT (Authentication and Transmission System), which is responsible for the generation of Electronic Tax Coupons. Thus, the work consists of using the concepts outlined for the fiscal model and adapting to the needs of the medical prescription, proposing a new model of automation and control of the prescription and dispensing process based on Electronic Medical Prescription (Receita Médica Eletrônica RM-e).

Large interruptions of power supply in the transmission system have considerable impact on modern society. The goal for the transmission system operator (TSO) is to prevent and mitigate such events with optimal decisions in design, planning, operation and maintenance. Identifying critical power components for system reliability provides one important input to this decision-making. This thesis develops quantitative component reliability importance indices applicable for identifying critical components in real transmission systems. Probabilistic models with component failure statistics are combined with detailed power system models evaluated with the AC power flow technique. In the presented method each system component is assigned three importance indices based on outage events expected probability and consequence to (i) reduced system security margin, (ii) interrupted load supply and (iii) disconnected generation units. By ranking components by each of the three interests, a more complete view of the risks to system reliability can be assessed than if, as traditionally, only (ii) is modelled. The impact on security margin is studied in well established critical transfer sections (CTS) supervised by the TSO. TSOs set the CTSs limits [MW] based on deterministic security criteria, with regard to thermal, voltage level, and system stability limits, and the CTSs' condition at post-contingency state is in the method used as an indicator of the system security margin. The methodology is extended with three indices modified to quantify the component importance for common-cause events initiated by acts of sabotage. The developed methods are applied on a significant part of the Great Britain transmission system, modelling 7000 components and 107 substation layouts. The study includes several load demand scenarios, 200 million initiating outage events and non-functioning protection equipment. The resulting component ranking provides an important input to the TSO's decision-making, and could be implemented as a complement to the existing deterministic N-1 criterion. With the methods applied a TSO can perform further and more detailed assessments on a few critical components in order to enhance system reliability for equipment failures and strengthen the system vulnerability against sabotage. / QC 20110920

abstract: After a power system blackout, system restoration is the most important task for the operators. Most power systems rely on an off&ndashline; restoration plan and the experience of operators to select scenarios for the black start path. Using an off&ndashline; designed restoration plan based on past experience may not be the most reliable approach under changing network configurations and loading levels. Hence, an objective restoration path selection procedure, including the option to check constraints, may be more responsive in providing directed guidance to the operators to identify the optimal transmission path to deliver power to other power plants or to pick up load as needed. After the system is subjected to a blackout, parallel restoration is an efficient way to speed up the restoration process. For a large scale power system, this system sectionalizing problem is quite complicated when considering black&ndashstart; constraints, generation/load balance constraints and voltage constraints. This dissertation presents an ordered binary decision diagram (OBDD) &ndashbased; system sectionalizing method, by which the splitting points can be quickly found. The simulation results on the IEEE 39 and 118&ndashbus; system show that the method can successfully split the system into subsystems satisfying black&ndashstart; constraints, generation/load balance constraints and voltage constraints. A power transfer distribution factor (PTDF)&ndashbased; approach will be described in this dissertation to check constraints while restoring the system. Two types of restoration performance indices are utilized considering all possible restoration paths, which are then ranked according to their expected performance characteristics as reflected by the restoration performance index. PTDFs and weighting factors are used to determine the ordered list of restoration paths, which can enable the load to be picked up by lightly loaded lines or relieve stress on heavily loaded lines. A transmission path agent can then be formulated by performing the automatic path selection under different system operating conditions. The proposed restoration strategy is tested on the IEEE&ndash39; bus system and on the Western region of the Entergy system. The testing results reveal that the proposed strategy can be used in real time. / Dissertation/Thesis / Ph.D. Electrical Engineering 2010

This paper examines the possibilities for further integration of day-ahead electricity market in Central Europe. The contemporary situation is locked due to the existence of the German-Austria bidding zone. However, compliance of this bidding zone with European legislative is questionable. Therefore, the author makes a thorough legal analysis to assess the compatibility of both analysed projects for market coupling with the recent legal development in the European Union. Further, the examined projects are technically deconstructed in order to evaluate their conformity or differences between each other as well as in relation towards the EU Target Model. It is assessed, that both projects are relatively well technically compatible, however, their merger is not possible until the definite and binding decision on the issue of German-Austrian bidding zone will be found.

The topic of the present thesis is an analysis of a sample data archive containing measured values of real and reactive power. The measurement in question took place in late 2006 and early 2007 using MEg40 recording measurement devices disposed in a station for transforming high voltage to low voltage in the Pražská energetika distribution network. The procedure of processing measured values, the preparation thereof for a subsequent processing by a neural network, and a final statistical evaluation of determined individual clusters -- typical daily take-off diagrams -- will be described. The results of the present thesis may be applied in the making of predictions of electrical energy consumption at a particular transformer station.