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Tsai, Rong-Feng. "Sources and control of combustion oscillation." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265120.
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Dench, M. "Structural vibration control using multiple synchronous sources." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/349006/.
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The advantages of isolating vibrating machinery from its supporting structure are that the chances of vibration induced fatigue failure of structural components are reduced, the structure becomes more inhabitable for people due to less vibration exposure and the sound radiated by the structure into the environment is reduced. This last point is especially important for machinery operating in a marine environment because low frequency sound propagates very well underwater, and the machinery induced sound radiated from a ship or submarine is a primary detection and classification mechanism for passive sonar systems. This thesis investigates the control of vibration from an elastic support structure upon which multiple vibrating systems are passively mounted. The excitations are assumed to occur at discrete frequencies with a finite number of harmonic components and the machines are all assumed to be supplied with power from the same electrical supply. Active vibration control may be achieved by adjusting the phase of the voltage supplied to one or more of the machines, so that a minimum value of a measurable cost function is obtained. Adjusting the phase of a machine with respect to a reference machine is known as synchrophasing and is a well established technique for controlling the sound in aircraft cabins and in ducts containing axial fans. However, the use of the technique for reducing the vibration of machinery mounted on elastic structures seems to have received very little attention in the literature and would appear to be a gap in the current knowledge. This thesis aims to address that gap by investigating theoretically and experimentally how synchrophasing can be implemented as an active structural vibration control technique.
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Fabbiano, Ruggero. "Collaborative source-seeking control." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT038/document.
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Cette dissertation fait face au problème de la localisation de sources, un sujet qui a été largement étudié dans la littérature récente au vu de son grand nombre d'applications. En particulier, ce travail se concentre sur le pilotage de multiples capteurs, capables de prendre des mesures ponctuelles de la quantité émise, vers la source sans faire usage d'aucune information de position, qui se trouve être indisponible dans de nombreux cas pratiques (par exemple, sous l'eau ou dans l'exploration souterraine). En faisant quelques hypothèses sur le processus de diffusion, nous développons un modèle qui permet d'utiliser des outils mathématiques (l'intégrale de Poisson et ses dérivées) pour obtenir une simple approximation du gradient de la fonction décrivant le processus de diffusion, dont la source représente le maximum, ce qui permet d'utiliser l'algorithme du gradient et trouver l'emplacement de la source. Les contributions sont de trois ordres : d'abord, nous utilisons ces outils pour résoudre le problème de la recherche d'une source en deux dimensions à travers d'un contrôle centralisé, où un seul véhicule, équipé de multiples capteurs et sans information de position, se déplace dans un environnement planaire où se trouve une source. Ensuite, nous étendons cette recherche à un cadre en trois dimensions, en considérant un engin volant équipé de capteurs qui se déplace dans l'espace ; pour ce cas plus général, outre la validation par simulations, nous fournissons également une étude théorique des propriétes de convergence de la loi de commande proposée. Enfin, nous abordons le problème de la localisation de source de façon distribuée, compte tenu de plusieurs capteurs autonomes mobiles (en deux dimensions) ; outre le problème de mettre en oeuvre l'algorithme de localisation de source de manière distribuée, nous devons garantir un contrôle de la formation approprié pour assurer l'exactitude de l'estimation du gradient, et donc atteindre la source.}The dissertation faces the problem of source localisation, a topic which has been extensively studied in recent literature due to its large number of applications. In particular, it focuses on steering multiple sensors, able to take point-wise measurements of the emitted quantity, towards the source without making use of any position information, which happens to be unavailable in many practical cases (for example, underwater or underground exploration). By making some assumptions on the diffusion process, we develop a model which allows us to use some mathematical tools (the Poisson integral and its derivatives) for a simple approximation of the gradient of the function describing the diffusion process, whose source represents its maximum, making it possible to perform a gradient ascent to find the source location. The contributions are threefold: first, we use such tools to solve a 2-dimensional centralised source-seeking problem, where a single vehicle, equipped with multiple sensors and without position information, is moving in a planar environment where a source is supposed to emit. Then, we extend it to a 3-dimensional framework, considering a flying vehicle equipped with sensors moving in the space; for this more general case, in addition to simulation validation, we provide a theoretical study of the convergence properties of the proposed control law. Finally, we tackle the distributed source-localisation problem, considering several autonomous moving sensors (in two dimensions); in addition to the problem of implementing the source-localisation algorithm in a distributed manner, in this latter case we have also to guarantee a suitable formation control, to ensure the correctness of the gradient estimation and hence reach the source
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Ravindran, Vinoth Kumar. "Reactive power control functions for distributed PV sources." Thesis, Wichita State University, 2013. http://hdl.handle.net/10057/6835.
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The integration of distributed generation is one of the biggest changes facing the power
industry, with greenhouse gas mitigation and the smart grid initiative. With result of the
increasing penetration of grid-connected distributed generators, such as solar photovoltaic (PV)
sources the system voltage regulation becomes challenging. Specifically, capacitor banks and
step voltage regulators that normally boost voltage slightly may push utilization voltages either
above or below the adopted ANSI voltage limits because of the variable nature of PV sources.
This can adversely affect the expected reliability requirements for the utility and also decrease
the life span of voltage-regulating equipment due to excessive operations. This thesis work
studies the effects of large-scale penetration of distributed PV sources using several IEEE radial
distribution test feeders. Based on the simulation results, tap-changer excessive operations,
voltage fluctuations, and voltage rise in the feeders are identified, and the additional capacity of
reactive power control of inverters to minimize the voltage fluctuations is analyzed.
With the presence of a communication infrastructure, it is expected that distributed
generators could be more efficiently operated, especially the inverters, which will be able to
perform several grid support functions including voltage regulation and reactive power support.
Therefore, this work also focuses on developing a power loss minimization technique while
utilizing the additional benefits of dispatchable reactive power from a cluster of distributed
resources. The proposed technique is tested using IEEE 13- and 34-node test feeders, and the
results show that the proposed technique will minimize the real power loss in the radial
distribution feeders.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science
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Faridi, Azadeh. "Cross-layer distortion control for delay sensitive sources." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7417.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Blondel, Laurent Armand. "Compressed air acoustic sources for active noise control." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246196.
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Taylor, Chloe Eleanor. "Sources of variation in human blood pressure control." Thesis, Liverpool John Moores University, 2011. http://researchonline.ljmu.ac.uk/6025/.
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The control of blood pressure plays a vital part in homeostasis in humans. Poor regulation of blood pressure has been associated with an increased risk of events such as myocardial infarction, sudden cardiac death, and stroke. The studies in this thesis are designed to explore sources of variation in human BP control, and in particular to examine the interactions between BP status, activity and circadian variation. In study 1 the association between BP status and the acute exercise-mediated change in BP was investigated. A total of 32 participants, with pre-exercise MAP of 65-110mm Hg, cycled for 30 min at 70% peak oxygen uptake. Systolic and diastolic BP were measured (Portapres) before exercise and for 20 min after exercise. Changes in BP were regressed against pre-exercise values, and against the mean of pre- and post-exercise BP, an index known not to be prone to the influence of mathematical coupling and regression-to-the-mean artefacts. Correlations between pre-exercise BP and the exercise-mediated reductions were typical of those previously reported (r = 0.37-0.62, P < 0.05). Artefact-free indices of BP status (pre- and post-exercise mean) did not correlate with reductions in BP (P > 0.05), which were moderated more by maximal oxygen uptake and time of day (P < 0.05). These data indicate that, if statistical artefacts are not controlled for, the influence of BP status on the degree of PEH can be spuriously exaggerated to the extent that other more important moderators of BP change are masked. In study 2 meta-analytical methods were used to enhance the statistical power and precision with which to explore the association between BP status and exercise-mediated changes in ambulatory BP. Studies entered into the meta-analysis were required to meet inclusion criteria of ambulatory monitoring following exercise and comparisons to a control condition to minimize regression-to-the-mean artefacts. Blood pressure status was a significant moderator of PEH indicating that hypertensive patients will benefit from greater reductions in BP. Age, BMI and V02max were also identified as significant moderators PEH, indicating that older individuals with larger BMIs and lower fitness levels will benefit most from exercise. Pooled mean changes (95%CI) in daytime and nocturnal SBP were -3.8 (-5.4 to -2.3) and -3.0 (-4.7 to -1.3), respectively, and may be deemed as clinically significant reductions. Future meta-analyses should investigate the effects of chronic exercise on ambulatory BP and its cardioprotective effects. In study 3 the acute effects of PA on BP and symptoms of OSA were examined using blood pressure reactivity profiles during sleep and following waking. Ambulatory BP and actigraphy data were collected between 20:00-10:00h in 11 OSA patients and 18 healthy controls. Blood pressure reactivity indices were calculated (Jones et al., 2009) and compared between groups and over time using general linear models. The greatest mean (SD) systolic BP reactivity in the healthy controls was 15.4 (42.7) mmHg/activity count, occurring 0-2 hours after waking, whereas the peak systolic BP reactivity of 12.7(14.4) mmHg/activity count occurred during sleep in OSA patients (P < 0.05). This evidence of diminished nocturnal blood pressure control in response to activity may be associated with the peak incidence of MI in OSA, which occurs between 00:00 and 06:00 h (Kuniyoshi et al., 2008). In study 4 the focus moved from acute activity to chronic, with an investigation of leisure-time physical activity in OSA patients, in which the relationships with BP, OSA severity and daytime sleepiness were examined. Levels of leisure-time physical activity, estimated with self-reported activity questionnaires, were not significantly different between OSA patients (n=96) and a healthy control group (n=118). Compared with healthy controls, OSA patients displayed higher SBP, DBP and MAP (P < 0.05), but physical activity had no effect on BP in either group when adjusted for age and gender (P > 0.05). However, leisure-time physical activity was associated with reduced ODI and daytime sleepiness (Epworth Sleepiness Scale) in OSA patients (P < 0.05). The differences in daytime sleepiness between the lowest and highest activity groups were comparable to the reductions found with CPAP treatment. Physical activity would provide a useful treatment for OSA patients, potentially as an adjunct to traditional CPAP therapy. In study 5 the contribution of the mechanical and neural components of the cardiac baroreflex to diurnal variation in BP control were investigated. In 12 healthy participants, the modified Oxford method was used to quantify baroreflex gain for rising (Gup) and falling (Gdown) pressures in the morning (0700h) and afternoon (1600h). A novel analysis method based on linear mixed models (Atkinson et al., 2010) was employed to compare the integrated, mechanical and neural gains between the two times of day. There was significant diurnal variation in integrated gain, with an attenuated response in the morning (Gup= 13.0 ± 0.6; Gdown= 6.3 ± OA ms/mm Hg) when compared with the afternoon (Gup= 15.1 ± 0.6; Gdown= 12.6 ± OA ms/mm Hg). For rising pressures the diminished integrated gain in the morning was caused by a reduction in mechanical gain, whereas for falling pressures it was caused by a reduction in neural gain. It is proposed that the high prevalence of cardiovascular events in the morning is due to diminished mechanical transduction of pressure into arterial distension at this time. In study 6 postural influences on diurnal variation in cardiac baroreflex sensitivity were investigated, and the contribution of mechanical and neural baroreflex components were determined. Integrated baroreflex sensitivity was reduced in the morning and afternoon when an upright posture was assumed, and was primarily attributed to decreases in neural gain. Although observed at both times of day, reductions in baroreflex sensitivity due to the change in posture occurred to a greater extent in the afternoon. This caused the diurnal variation that was reported in the supine position to be attenuated for rising BP, and eliminated entirely for falling BP when participants changed to a standing position. The studies in this thesis have provided further knowledge and understanding of sources of variation in human BP control, including the effects of BP status, health status, fitness, physical activity, diurnal variation and postural changes. Methodological issues in BP research, clinical applications, and mechanisms responsible for BP regulation have also been addressed.
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Zenkert, Patrik, and Douglas Lowén. "Automatic control of renewable energy sources at varying load." Thesis, Uppsala universitet, Elektricitetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415098.
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With the current climate crisis with the global temperature increasing due to fossil fuels being used there are big investments in green energy. Wind power is a good alternative to fossil fueled power and already has a widespread use. One of the problems with wind poweris control and keeping the grid frequency stable during peaks and lows of power generation. In this master thesis there is a goal to implement a system which can regulate wind mills while always trying to use as much wind power as possible. A model was built in Matlab to represent the final product which was translated into a SCADA system. A fully integrated communication from SCADA computer to PLC to IED to wind mill and back was built. The simulation in the SCADA system gave satisfactory result where the wind power wasutilized to the maximum, and other conditions met. The laboratory experiment with an Arduino represented as the wind mill lacked in communication and the model did not achieveperfect results in every case. There is future work to be done, improved communication, additional or alternative automatic control and creating a bigger system with several powerproducers integrated.
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Mertens, Paulus Leonardus Johannus Marie. "Outbreaks: sources of epidemiological knowledge in communicable disease control." [S.l.] : Rotterdam : [The Author] ; Erasmus University [Host], 2008. http://hdl.handle.net/1765/10867.
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Pedrozo, Sonja P. "Oxides of nitrogen : their formation and control in stationary sources." Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/26146.
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Zahrn, Frederick Craig. "Studies of inventory control and capacity planning with multiple sources." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29736.
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Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010.Committee Co-Chair: John H. Vande Vate; Committee Co-Chair: Shi-Jie Deng; Committee Member: Anton J. Kleywegt; Committee Member: Hayriye Ayhan; Committee Member: Mark E. Ferguson. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Almada, Janaina Barbosa. "Modeling, Control and Management of Microgrids Operation with Renewable Sources." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11122.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoNowadays, the distribution networks of electricity are the segment of the electrical power systems that has experienced more changes, due in particular to the presence of distributed generation and the technological advances in the areas of instrumentation, automation, measurement, information technology and comunication. This work aims to present the modelling, the control and the operation management of a group of small-scale energy resources connected to the low voltage, which coordinated form a microgrid. The microgrid energy resources are solar photovoltaic sources, wind energy based on double fed induction generator and hydrogen fuel cell, and a storage system with batteries. Two conceptions are developed: a single-phase microgrid and a three-phase microgrid, both operating in connected mode and isolated from the utility. Each energy resource is connected to a point of common coupling through power converters. For each converter was designed a set of control loops. The master-slave strategy was used to control the converters and to microgrid management. In master-slave configuration only the master converter is designed to be the voltage reference and others operate as a current source. For managing the steady state operation of microgrids different operating scenarios were considered, with variation of load and generation levels, as well as changes in tariff flags, for load supply with economy and sources operating at maximum efficiency. The proposed systems operate satisfactorily fulfill the requirements of utility for synchronization and disconnection. The injected currents are below the allowed distortion level. In stand-alone mode, the system voltage remains within the appropriate level of amplitude and frequency.
Atualmente, as redes de distribuiÃÃo de energia elÃtrica sÃo o segmento dos siste-mas elÃtricos de potÃncia que mais tem experimentado mudanÃas, devido, em es-pecial, à presenÃa da geraÃÃo distribuÃda e aos avanÃos tecnolÃgicos nas Ãreas de instrumentaÃÃo, automaÃÃo, mediÃÃo, tecnologia da informaÃÃo e comunicaÃÃo. Este trabalho tem por objetivo apresentar a modelagem, o controle e o gerenciamento da operaÃÃo de um conjunto de recursos energÃticos de pequeno porte, conectados à baixa tensÃo, que coordenados formam uma microrrede. Os recursos energÃticos da microrrede sÃo fontes solar fotovoltaica, eolielÃtrica com gerador de induÃÃo de dupla alimentaÃÃo e cÃlula combustÃvel a hidrogÃnio, e um sistema de armazenamento de energia a baterias. Duas concepÃÃes de microrredes sÃo desenvolvidas: microrrede monofÃsica e microrrede trifÃsica, ambas operando em modo conectado e isolado da rede elÃtrica principal. Cada recurso energÃtico à conectado a um ponto comum de conexÃo atravÃs de conversores de potÃncia. Para cada conversor foi projetado um conjunto de malhas de controle. A estratÃgia mestre-escravo foi usada para o controle dos conversores e gerenciamento da microrrede. Na configuraÃÃo mestre-escravo apenas o conversor mestre à designado para ser a referÃncia de tensÃo que os outros conversores necessitam para operarem como fonte de corrente. Para o gerenciamento da operaÃÃo das microrredes em regime permanente, foram considerados diferentes cenÃrios de operaÃÃo, com variaÃÃo de nÃveis de carga e de geraÃÃo, bem como variaÃÃo de bandeiras e postos tarifÃrios, visando atender a carga com economicidade e fontes operando em mÃxima eficiÃncia. Os sistemas propostos operam de forma satisfatÃria obedecendo aos requisitos da concessionÃria para a sincronizaÃÃo e desconexÃo. As harmÃnicas de corrente injetada estÃo abaixo do nÃvel de distorÃÃo permitido. No modo isolado, a tensÃo dos sistemas permanece dentro do nÃvel adequado de amplitude e frequÃncia.
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Elrayyah, Ali Y. "Modeling and Control of Microgrid-Connected Photo-Voltaic Sources (MCPV)." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1384345552.
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Kelm, Jonathon. "Modeling and Control Strategies for Multiprocess Arc Welding Power Sources." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1574659504446931.
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Khazaei, Javad Khazaei. "Distributed Coordination and Control of Renewable Energy Sources in Microgrids." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6274.
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Microgrid is an emerging technology in the eld of electrical engineering which employs the concept of Distributed Energy Resources (DERs) in order to generate electricity in a small sized power system. The main objectives of this dissertation are to: 1- design a new control for lower level control of DERs in microgrids, 2- implement distributed upper level control for DERs in microgrids and 3- apply analytical approaches in order to analyze DERs in microgrids. The control in each DER can be divided into two main categories: lower and upper level. Lower level control is the main objective of control in each DER. For example, the lower level control in Photovoltaic (PV) is in charge of transferring the maximum power from sun into the main grid. Unlike the lower level control, the upper level control is an additional control loop on top of the lower level controls. For example, Voltage/Frequency (VF) controllers are installed on top of Active/Reactive (PQ) power controller in energy storage devices as upper level control. In this dissertation, for the lower level control improvements, two widely used DERs are selected (PV, and oshore wind farm) and new control algorithms are developed in order to improve the performance of lower level controllers in these DERs. For the PV lower level improvement, a new control methodology is proposed in order to minimize the maximum power tracking error in PV lower level controller. Second contribution in lower level control is for the oshore wind farm applications based on Multi-Terminal High Voltage Direct Current (MTDC) transmission; a new control is designed in order to minimize the losses in transmission lines through lower level control of High Voltage Direct Current (HVDC) converters.
For the upper level control, this dissertation considers the energy storage as another mostly used type of DER in microgrids. The lower level control for energy storage is in charge of controlling the PQ of the energy storage. The main contribution in the upper level control is to implement the distributed control algorithm based on consensus theory for battery energy storages in order to maximize the efficiency, energy management as well as synchronizing the performance of parallel energy storage devices in microgrids. In this case, the consensus based distributed control algorithm with limited information exchange between neighboring energy storage units is proposed and implemented to validate the claim.
The third contribution of this research is to apply advanced analysis techniques to evaluate the performance of the DERs in microgrids. Two approaches are introduced for microgrid modeling in this research. Firstly, an impedance modeling technique is used to model the oshore wind farm connected to the main AC grid through HVDC transmission line. Multiple Input Multiple Output (MIMO) Nyquist analysis and singular value analysis are used to assess the interactions between HVDC converter and grid. Secondly, an unbalanced microgrid is considered and Dynamic Phasor (DP) analysis is applied in order to nd the stability limitations under different scenarios.
This dissertation has led to seven journal papers (five published, one journal in revision process and one journal submitted recently) and four conference papers.
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Parsa, Maryam. "Optimum Decision Policy for Gradual Replacement of Conventional Power Sources by Clean Power Sources." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24015.
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With the increase of world population and industrial growth of developing countries, demand for energy, in particular electric power, has gone up at an unprecedented rate over the last decades. To meet the demand, electric power generation by use of fossil fuel has increased enormously thereby producing increased quantity of greenhouse gases. This contributes more and more to atmospheric pollution, which climate scientists believe can adversly affect the global climate, as well as health and the welfare of the world population. In view of these issues, there is global awareness to look for alternate sources of energy such as natural gas, hydropower, wind, solar, geothermal and biomass. It is recognized that this requires replacement of existing infrastructure with new systems, which cannot be achieved overnight.
Optimal control theory has been widely used in diverse areas of physical sciences, medicine, engineering and economics. The main motivation of this thesis is to use this theory to find the optimum strategy for integration of all currently available renewable energy sources with the existing electric power generating systems. The ultimate goal is to eliminate fossil fuels. Eight main energy sources namely, Coal, Petroleum, Natural Gas, Conventional Hydro, Wind, Solar, Geothermal and Biomass are considered in a dynamic model. The state of the dynamic model represents the level of energy generation from each of the sources.
Different objective functions are proposed in this thesis. These range from meeting the desired target level of power generation from each of the available sources at the end of a given plan period, to reducing the implementation and investment costs; from minimizing the production from polluted energy sources to meeting the electricity demand during a whole plan period. Official released data from the U.S. Energy Information Administration have been used as a case study. Based on real life data and the mathematics of optimal control theory, we present an optimal policy for integration of renewable energy sources to the national power grid.
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Fazeli, Meghdad. "Wind generator-energy storage control schemes for autonomous grid." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/11698/.
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Conventionally the power network operators were obliged to buy all the wind energy generated by wind farms. However, as the penetration of wind energy (or generally any other sort of renewable source) in a power system is increased, the ability of other generators to balance the demand becomes limited. This will necessitate the control of wind turbines in order to generate a given demand power rather than extracting the maximum wind power. This control approach is termed “Power Demand Control” in this thesis. In contrast to Power Demand Control, “Power Smoothing Control” utilizes energy storage systems in order to absorb high frequency wind fluctuations, hence, delivering a smoother version of wind power into the grid/load. The drawback of the Power Smoothing approach is that the average power into the grid/load is still determined by the available wind power rather than the system operator. The Power Demand Control approach, which has received little attention in literatures, is the main focus of this thesis. This research proposes control schemes with and without external energy storage for the Power Demand Control strategy. This thesis studies different possible methods of applying Power Demand Control, in particular the droop control method. It is shown that a droop-controlled wind farm does not need a central “Supervisory wind Farm Control” unit to determine the power demanded from each DFIG. Moreover, a droop-controlled wind farm has the advantage of controlling the local grid voltage and frequency. This means that no external voltage and frequency source is required which makes a droop-controlled wind farm a more suitable option for integration of wind energy at distribution level. The classical droop control is modified in order to make the DFIGs share the demand power not only according to their ratings but also to their associated available wind power. The applications of the control paradigm are discussed, including: integration into microgrids, AC grids and HVDC connection feeders. This work mainly concentrates on microgrid applications. An Energy Management System is proposed in order to keep the energy level of the energy storage (or the DFIG’s shaft speed) within its limits using an Auxiliary Generator and a Dispatchable Load. Different possible system configurations are introduced and their advantages and drawbacks are discussed. It is illustrated through simulation that the proposed control scheme can inherently ride-through a grid fault with no need for communication. Furthermore, it is shown that the control scheme can operate if the wind speed drops to zero. The simulations are carried out using the PSCAD/EMTDC software.
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Yan, Zuanhong. "Control of fluctuating renewable energy sources : energy quality & energy filters." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8568/.
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This doctoral study discusses how to control fluctuating renewable energy sources at converter, unit, and system layers to deliver smoothed power output to the grid. This is particularly relevant to renewable power generation since the output power of many kinds of renewable energy sources have huge fluctuations (e.g. solar, wind and wave) that needs to be properly treated for grid integration. In this research, the energy quality is developed to describe the friendliness and compatibility of power flows/waveforms to the grid, by contrast with the well-known concept of power quality which is used to assess the voltage and current waveforms. In Chapter 1 & 2, a background introduction and a literature review of studied subjects are presented, respectively. In Chapter 3, the problem of determining the PI parameters in dq decoupling control of voltage source converter (VSC) is studied based on a state-space model. The problems of the conventional method when there is insufficient interface resistance are addressed. New methods are proposed to overcome these drawbacks. In Chapter 4 & 5, energy quality and the energy filters (EFs) are proposed as tools to assess and manage power fluctuations of renewable energy sources. The proposed EFs are energy storage control systems that could be implemented on a variety of energy storage hardware. EFs behave like low-pass filters to the power flows. Finally, in Chapter 6, as an application example of renewable power plant with energy filter control and smoothed power output, a master-slave wave farm system is proposed. The wave farm system uses enlarged rotor inertia of electric machines as self-energy storage devices.
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Hansen, Stewart M. "Precision Current Control for Quantum Cascade Lasers as Flight Calibration Sources." DigitalCommons@USU, 2014. https://digitalcommons.usu.edu/etd/2022.
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The design of a precision current controller for quantum cascade lasers (QCLs) enables QCLs to be used for calibrating instruments in space-borne applications. This current controller design will enable constant wave (CW) or pulsed mode operation of QCL devices as calibration sources in a space environment. Any differences in the temperature between components of the current controller can result in an erroneous current through the QCL. This design will use previously demonstrated techniques from Pacific Northwest National Laboratory (PNNL) to minimize the effects of temperature changes on the desired current levels. A mathematical model is used to calculate what performance levels can be expected, and if the board can operate with a desired precision level of 0.1% of the desired power output of the QCL. This mathematical model shows the capability to control to the desired 0.1% output power stability with a change in the boards temperature of ±10◦C.
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Kulka, Arkadiusz. "Sensorless Digital Control of Grid Connected Three Phase Converters for Renewable Sources." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5578.
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Power electronic converters have become popular in the field of power transformation for renewable energy. Power electronics converters achieve high efficiency, and the price of their components is falling, thus making them even more beneficial for renewable energy applications. Those systems coupled to the grid need to withstand certain utility-defined circumstances which may occur during operation. Additionally the new net regulations for large generation plants specify that during specified severe grid disturbances the relatively delicate converters should stay connected supporting the system. For PV inverters the forthcoming standards may optionally add the possibility of reactive power compensation where for wind-power those standards are already in use. This thesis focuses on reliable, sensor-less control of the PWM converters coping with varying grid conditions and existing problems. The thesis presents a variety of digital control solutions for interfacing PWM converter with the grid, synchronization, sensorless operation and grid impedance detection. The introductory chapter gives the fundamental theory about three-phase converters and control.The following chapters deal with unbalanced condition and symmetric component decomposition, which is the tool to cope with unbalanced grid voltages or currents. A sensor-less operation method using dual frame virtual flux model is presented with good results. In addition sensor-less synchronization to the grid is shown. Moreover an algorithm based on virtual flux for grid inductance estimation is also successfully demonstrated. Knowing the grid inductance is important during weak grid operation, since it is needed in order to provide unity power factor to the point of common connection. At the end of the thesis, a control algorithm for voltage harmonic compensation during stand alone operation is presented. The presented algorithm gives the possibility to supply high quality power in isolated islands, where the load is unknown. Furthermore, this algorithm can be successfully used for UPS applications. The last chapter applies the voltage harmonic control to the Z-source converter having the possibility of achieving higher ac voltage than in conventional VSI, results are promising.
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Okonkwo, J. "An overview of exposure and management of persistent organic pesticides in Swaziland." International Journal of Environment Studies, 2003. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000900.
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Available information in Swaziland indicates that there are stocks of persistent organic pesticides that have been
discontinued elsewhere because of their carcinogenic, mutagenic and teratogenic properties. Some of these
pesticides, such as DDT and endosulfan, are still used in agriculture to protect crops and livestock from pests and
diseases, and in vector control especially mosquitoes. There has been an increase in the use of these pesticides
over the years. It is estimated that about 30–40% of the population may have already been exposed to these
pesticides. The cultural and lifestyle determinants of pesticide exposure are highlighted.
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Kusakana, Kanzumba. "Optimal operation control of hybrid renewable energy systems." Thesis, Bloemfontein: Central University of Technology, Free State, 2014. http://hdl.handle.net/11462/670.
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Thesis (D. Tech. (Electrical Engineering)) -- Central University of Technology, Free State, 2014For a sustainable and clean electricity production in isolated rural areas, renewable energies appear to be the most suitable and usable supply options. Apart from all being renewable and sustainable, each of the renewable energy sources has its specific characteristics and advantages that make it well suited for specific applications and locations. Solar photovoltaic and wind turbines are well established and are currently the mostly used renewable energy sources for electricity generation in small-scale rural applications. However, for areas in which adequate water resources are available, micro-hydro is the best supply option compared to other renewable resources in terms of cost of energy produced. Apart from being capital-cost-intensive, the other main disadvantages of the renewable energy technologies are their resource-dependent output powers and their strong reliance on weather and climatic conditions. Therefore, they cannot continuously match the fluctuating load energy requirements each and every time. Standalone diesel generators, on the other hand, have low initial capital costs and can generate electricity on demand, but their operation and maintenance costs are very high, especially when they run at partial loads. In order for the renewable sources to respond reliably to the load energy requirements, they can be combined in a hybrid energy system with back-up diesel generator and energy storage systems. The most important feature of such a hybrid system is to generate energy at any time by optimally using all available energy sources. The fact that the renewable resources available at a given site are a function of the season of the year implies that the fraction of the energy provided to the load is not constant. This means that for hybrid systems comprising diesel generator, renewable sources and battery storage in their architecture, the renewable energy fraction and the energy storage capacity are projected to have a significant impact on the diesel generator fuel consumption, depending on the complex interaction between the daily variation of renewable resources and the non-linear load demand. V This was the context on which this research was based, aiming to develop a tool to minimize the daily operation costs of standalone hybrid systems. However, the complexity of this problem is of an extremely high mathematical degree due to the non-linearity of the load demand as well as the non-linearity of the renewable resources profiles. Unlike the algorithms already developed, the objective was to develop a tool that could minimize the diesel generator control variables while maximizing the hydro, wind, solar and battery control variables resulting in saving fuel and operation costs. An innovative and powerful optimization model was then developed capable of efficiently dealing with these types of problems. The hybrid system optimal operation control model has been simulated using fmincon interior-point in MATLAB. Using realistic and actual data for several case studies, the developed model has been successfully used to analyse the complex interaction between the daily non-linear load, the non-linear renewable resources as well as the battery dynamic, and their impact on the hybrid system’s daily operation cost minimization. The model developed, as well as the solver and algorithm used in this work, have low computational requirements for achieving results within a reasonable time, therefore this can be seen as a faster and more accurate optimization tool.
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Aljaism, Wadah A., University of Western Sydney, and School of Engineering and Industrial Design. "Control method for renewable energy generators." THESIS_XXX_EID_Aljaism_W.xml, 2002. http://handle.uws.edu.au:8081/1959.7/796.
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This thesis presents a study on the design method to optimise the performance for producing green power from multiple renewable energy generators. The design method is presented through PLC (Programmable Logic Controller) theory. All the digital and analogue inputs are connected to the input cards. According to different operations conditions for each generator, the PLC will image all the inputs and outputs, from these images; a software program has been built to create a control method for multiple renewable energy generators to optimise production of green power. A control voltage will supply the output contractor from each generator via an interface relay. Three renewable generators (wind, solar, battery bank) have been used in the model system and the fourth generator is the back up diesel generator. The priority is for the wind generator due to availability of wind 24 hours a day, then solar, battery bank, and LPG or Diesel generators. Interlocking between the operations of the four contractors has been built to prevent interface between them. Change over between contractors, according to the generator's change over has also been built, so that it will delay supplying the main bus bar to prevent sudden supply to the load. Further study for controlling multiple renewable energy generators for different conditions such as controlling the multi-renewable energy generators from remote, or supplying weather forecast data from bureau of meteorology to the PLC directly as recommended.Master of Electrical Engineering (Hons)
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Jansen, Malte [Verfasser]. "Economics of control reserve provision by fluctuating renewable energy sources / Malte Jansen." Flensburg : Zentrale Hochschulbibliothek Flensburg, 2016. http://d-nb.info/1138586668/34.
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Sasangohar, Farzan. "A holistic investigation of complexity sources in nuclear power plant control rooms." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68516.
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Thesis (S.M.)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, September 2011."July 2011." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 99-104).
The nuclear power community in the United States is moving to modernize aging power plant control rooms as well as develop control rooms for new reactors. New generation control rooms, along with modernized control rooms, will rely more heavily on automation and computerized procedures. Of particular importance to the Nuclear Regulatory Commission (NRC) is the impact such modernizations or new technologies will have upon operator performance and reliability in these safety-critical control room environments. One specific area of interest is the effect that various complexities in the control room have on operator performance and reliability. This research identifies various definitions of complexity and characterizes complexity in the nuclear power plant (NPP) domain, focusing on the common complexity dimensions of number, variety, and interconnections. Based on this characterization of complexity, a comprehensive list of complexity sources within the NPP control room is presented, along with a novel approach to describe complexity source interconnections. Understanding the sources of complexity in advanced NPP control rooms and the associated effects on human reliability is critical for ensuring safe performance of both operators and the entire system. However, most of the previous approaches in investigating complexity typically focus on either objective or subjective views of complexity, and a systematic approach that considers both views is missing from previous approaches. This research provides a novel methodology to assess the sources of complexity in NPP control rooms both objectively and subjectively while understanding the difference between the two and introduces a systems theoretic descriptive model of these sources of complexity, leveraging network theory. Finally a method is introduced to investigate the differences between the complexity views of different groups of NPP stakeholders. Incident report databases and in particular, 22 nuclear incidents in the Human Event Repository and Analysis (HERA) database were parsed to find objective evidence for the identified sources. Using this evidence-based approach, some of the potential interactions between these sources could be captured. A network called "Complexity Source Network" (CSN) was created for each incident in HERA to present the sources (nodes) and potential interactions between them (links). An ensemble of networks was developed consisting of 22 CSNs, one for each of the incidents in HERA. A tool called CXViz was developed to visualize and analyze the CSNs. Using the aggregate network (22 CSNs combined) the most common sources and interactions were identified. The complexity views of three groups of stakeholders, namely Operators, Designers and NRC Reviewers, were collected using a survey tool called CXSurvey. Using this tool, the interviewees were asked to rate the identified sources of perceived complexity and to rank the top five in terms of contribution to perceived complexity. Data gathered from 16 operators, 8 designers and 3 NRC reviewers were collected and the top five sources identified by each group were compared to the top five most supported sources from the 22 incidents in HERA. The results show large variations between the subjective views of the operators and designers and the objective top five. In addition, the subjective source rating of the three groups of stakeholders were compared. The results show large variations between the complexity views between the stakeholders on some controversial sources such as boredom, and training.
by Farzan Sasangohar.
S.M.
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Righini, Simona <1976>. "The Enhanced Single-dish Control System and wide surveys of compact sources." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2634/.
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The Italian radio telescopes currently undergo a major upgrade period in response to the growing demand for deep radio observations, such as surveys on large sky areas or observations of vast samples of compact radio sources.
The optimised employment of the Italian antennas, at first constructed mainly for VLBI activities and provided with a control system (FS – Field System) not tailored to single-dish observations, required important modifications in particular of the guiding software and data acquisition system.
The production of a completely new control system called ESCS (Enhanced Single-dish Control System) for the Medicina dish started in 2007, in synergy with the software development for the forthcoming Sardinia Radio Telescope (SRT). The aim is to produce a system optimised for single-dish observations in continuum, spectrometry and polarimetry. ESCS is also planned to be installed at the Noto site.
A substantial part of this thesis work consisted in designing and developing subsystems within ESCS, in order to provide this software with tools to carry out large maps, spanning from the implementation of On-The-Fly fast scans (following both conventional and innovative observing strategies) to the production of single-dish standard output files and the realisation of tools for the quick-look of the acquired data.
The test period coincided with the commissioning phase for two devices temporarily installed – while waiting for the SRT to be completed – on the Medicina antenna: a 18-26 GHz 7-feed receiver and the 14-channel analogue backend developed for its use. It is worth stressing that it is the only K-band multi-feed receiver at present available worldwide.
The commissioning of the overall hardware/software system constituted a considerable section of the thesis work. Tests were led in order to verify the system stability and its capabilities, down to sensitivity levels which had never been reached in Medicina using the previous observing techniques and hardware devices.
The aim was also to assess the scientific potential of the multi-feed receiver for the production of wide maps, exploiting its temporary availability on a mid-sized antenna. Dishes like the 32-m antennas at Medicina and Noto, in fact, offer the best conditions for large-area surveys, especially at high frequencies, as they provide a suited compromise between sufficiently large beam sizes to cover quickly large areas of the sky (typical of small-sized telescopes) and sensitivity (typical of large-sized telescopes).
The KNoWS (K-band Northern Wide Survey) project is aimed at the realisation of a full-northern-sky survey at 21 GHz; its pilot observations, performed using the new ESCS tools and a peculiar observing strategy, constituted an ideal test-bed for ESCS itself and for the multi-feed/backend system. The KNoWS group, which I am part of, supported the commissioning activities also providing map-making and source-extraction tools, in order to complete the necessary data reduction pipeline and assess the general system scientific capabilities.
The K-band observations, which were carried out in several sessions along the December 2008-March 2010 period, were accompanied by the realisation of a 5 GHz test survey during the summertime, which is not suitable for high-frequency observations. This activity was conceived in order to check the new analogue backend separately from the multi-feed receiver, and to simultaneously produce original scientific data (the 6-cm Medicina Survey, 6MS, a polar cap survey to complete PMN-GB6 and provide an all-sky coverage at 5 GHz).
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Ahmed, Rana. "Energy management and control for hybrid renewable energy sources in rural area." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4353.
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Cette thèse propose principalement, un algorithme État-Flow MPPT basé P&O, amélioré avec deux degrés de liberté, dans lequel le système événementiel (MPPT) de comportement est modélisé par le décrivant en terme de transition entre les états, sous certaines conditions. Secondairement, un algorithme étendu MPPT, base d'exploitation en parallèle de l'état-débit est en outre proposé d'être une solution difficile pour le contrôle indépendant du système hybride, où la caractéristique de contrôle continu peut se présenter au cours d'un certain état de travail tout en discrète, est indiquée le long des transitions d'état. Deux configurations possibles pour le système hybride sont proposées : deux convertisseurs DC/DC séparés, et un convertisseur de sortie unique à double entrée (DISO) de configurations. Enfin, il est proposé, un comportement du système DC modélisation utilisant État-Flow, menant à l'ensemble de la conception de la stratégie de commande qui concernent RES MPPT, RES et la coordination BESS, la stabilité du système d'alimentation et de régulation de la tension du bus DC. La simulation et les résultats expérimentaux valident l'efficacité et l'applicabilité de l'algorithme proposé. Les deux résultats montrent la supériorité du MPPT basé proposé État-Flow pour réduire les oscillations de puissance RESs à l'état d'équilibre dans diverses conditions d'exploitation, en plus de son démarrage plus rapide, et l’opération de transition sans divergence de la MPP, selon des conditions météorologiques variablesThis thesis primarily proposes, an improved P&O based State-Flow MPPT algorithm featuring two degree of freedom, in which the event driven system (MPPT) behaviour is modelled by describing it in terms of transitions among states under certain conditions. Secondarily, an extended parallel operating State-Flowbased MPPT algorithm is further proposed to be a challenging solution for the independent control of the hybrid system, where continuous control characteristic can present during a certain working state while discrete one is indicated along state transitions. Two possible configurations for the hybrid system are proposed; two separate DC/DC converters and dual input single output converter (DISO) configurations. Finally it is proposed, DC system behaviour modelling using State-Flow leading to the whole control strategy design which concern RESs MPPT, RESs and BESS coordination, power system stability and DC bus voltage regulation.Simulation and experimental results validate the effectiveness and applicability of the proposed algorithm, both results show the superiority of the proposed State-Flow based MPPT in reducing the RESs power oscillations at steady-state in various operating conditions in addition to its faster start-up and transition operation without divergence from the MPP during sudden varying weather conditions
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Hughes, Thomas Carroll. "Sources of Adaptive Capacity during Multi-Unmanned Aerial Vehicle Operations." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354621762.
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Rust, Ryan Leonard. "Active Noise Control of a Two-Fan Exhaust-Mounted Array Using Near-Field Control Sources and Error Sensors." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2427.
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Multiple fans are sometimes used in an array configuration to cool various types of electronic equipment. In addition to adding another noise source, using two fans with closely spaced blade passage frequencies (BPF) can create an annoying beat frequency. A two fan array with each fan having a different BPF was considered. The fans were theoretically modeled at the BPF and first harmonics. Each fan has two acoustic paths to the far field. Thus, each fan was modeled as a two source array. The first control configuration consisted of one control filter using six control sources and six error sensors in a fully coupled control system designed to control both fans simultaneously. The second configuration used two independent controllers with three control sources and three error sensors, one controller per fan. Experimentally, the averaged narrow band reduction of the BPFs and the second harmonic of the two independent controllers were 15.6 and 7.4 dB respectively, compared to a reduction of 14.4 and 5.7 dB at the two frequencies using a single control loop. The results suggest that independent controllers perform better than the single control loop for the fan array studied. Optimization of active noise control systems has increased performance but sometimes with decreased robustness. Two control source configurations for the sound power reduction of a simple source were analyzed by modeling the control systems. The two control source configurations were four symmetric control sources surrounding the noise source and an optimized linear array of four control sources. Simulation results show the linear array control source configuration is more sensitive to microphone placement errors, with a 20-33 dB reduction in attenuation for a microphone placement error of 2 mm compared to a 0.8 dB drop in attenuation for the symmetric case. The linear array configuration was found to be more sensitive to the microphone placement errors compared to the symmetric configuration. A 2.5 mm change in one microphone position causes an average of 6 dB loss in attenuation for the linear array configuration compared to a 0.6 dB loss for the symmetric configuration.
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Addo, Douglas Kweku. "OPERATION AND PROCESS CONTROL DEVELOPMENT FOR A PILOT-SCALE LEACHING AND SOLVENT EXTRACTION CIRCUIT RECOVERING RARE EARTH ELEMENTS FROM COAL-BASED SOURCES." UKnowledge, 2019. https://uknowledge.uky.edu/mng_etds/50.
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The US Department of Energy in 2010 has identified several rare earth elements as critical materials to enable clean technologies. As part of ongoing research in REEs (rare earth elements) recovery from coal sources, the University of Kentucky has designed, developed and is demonstrating a ¼ ton/hour pilot-scale processing plant to produce high-grade REEs from coal sources. Due to the need to control critical variables (e.g. pH, tank level, etc.), process control is required. To ensure adequate process control, a study was conducted on leaching and solvent extraction control to evaluate the potential of achieving low-cost REE recovery in addition to developing a process control PLC system. The overall operational design and utilization of Six Sigma methodologies is discussed. Further, the application of the controls design, both procedural and electronic for the control of process variables such as pH is discussed. Variations in output parameters were quantified as a function of time. Data trends show that the mean process variable was maintained within prescribed limits. Future work for the utilization of data analysis and integration for data-based decision-making will be discussed.
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Brackett, Richard L. "A risk assessment of noise exposure sources within the Menomonie Fire Department /." Online version, 1998. http://www.uwstout.edu/lib/thesis/1999/1999brackettr.pdf.
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Brackett, Richard L. "A risk assessment of noise exposure sources within the Menomonie Fire Department." Online version, 1999. http://www.uwstout.edu/lib/thesis/1999/1999brackettr.pdf.
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Garcés, Javier, Sebastián Zúñiga, Laird Close, Jared Males, Katie Morzinski, Pedro Escárate, Mario Castro, José Marchioni, and Diego Rojas. "Vibrations in MagAO: resonance sources identification and first approaches for modeling and control." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622012.
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The Magellan Telescope Adaptive Optics System (MagAO) is subject to resonance effects induced by elements within the system instrumentation, such as fans and cooling pumps. Normalized PSDs are obtained through frequency-based analysis of closed-loop on-sky data, detecting and measuring vibration effects. Subsequently, a space-state model for the AO loop is obtained, using a standard AO loop scheme with an integrator-based controller and including the vibration effects as disturbances. Finally, a new control alternative is proposed, focusing on residual phase variance minimization through the design and simulation of an optimal LQG control approach.
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Schaab, Konstantin [Verfasser]. "Robust Hierarchical Control of Electrical Power Grids with Renewable Energy Sources / Konstantin Schaab." Kassel : Kassel University Press, 2018. http://d-nb.info/1161537236/34.
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Johansson, Marcus. "An indicative case-control study of noise perception due to environmental noise sources." Thesis, KTH, Marcus Wallenberg Laboratoriet MWL, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280546.
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The subject of the thesis was proposed by the acoustic consultancy firm Brekke & Strand, which is of relevance for their additional understanding and development of services and contribution to robust solutions. The aim with this thesis is to give indicative results and to dig deeper into the relation between environmental noise and the perception of the same, specially focusing on construction related noise but also permanent noise sources that originates from infrastructure. The area of interest to evaluate the study is a central location in Stockholm, specifically around Slussen.The importance of a study within this field is vital, especially when considering possible negative health effects that can be related to the perceived noise exposure. With that background it is worth to consider the amount of healthy-life-years lost in Europe each year, which is assumed to be one million. The correlation between lost life years and noise is one of many, but it is also proven to be a catalyst when it comes to stress related or cardiovascular diseases. For instance, if one is living closer than 50 meters from a major road the risk can be four times higher to be annoyed, which in extension can be coupled to the diseases mentioned above.The practical implementation of the study is conducted with a survey and field measurements, with a psychoacoustical perspective and within the frames of a case-control study. Partially this includes to inform the participants of the study at different stages regarding construction noise. The provided information, survey and field measurements aims to be a substantial part of the evaluation regarding the perceived noise whether it is due to construction work, infrastructure or other stochastic sources.The result is presented and distinguished based on distance to noise source, differentiated by gender as well as which type of source that tends to be most annoying. The implemented ranking is displayed as the ICBEN score of each category or source which aims to measure the perceived impact. Even though the results are indicative, the conclusion yields an information dependency as well as a noise source dependency. Further on, the result yields an interesting pattern between genders where women tend to be more disturbed by construction- and other-noise, whereas men tend to be more disturbed by rail- and road-noise.Ämnet för uppsatsen föreslogs av akustiskkonsultföretaget Brekke & Strand, vilket är av relevans för deras ytterligare förståelse och utveckling av tjänster och bidrag till robusta lösningar. Syftet är att ge vägledande resultat och gräva djupare i förhållandet mellan samhällsbuller och uppfattningen av detsamma, med särskilt fokus på konstruktionsrelaterat buller men också permanenta bullerkällor som härstammar från infrastruktur. Studien och utvärderingen av den samma har fokuserats till Slussenområdet i centrala Stockholm.Betydelsen av en studie inom detta område är avgörande, särskilt när man överväger eventuella negativa hälsoeffekter som kan relateras till den upplevda bullerexponeringen. Med den bakgrunden är det värt att ta hänsyn till hur många hälsosamma levnadsår som går förlorade i Europa varje år, vilket antas vara en miljon. Korrelationen mellan förlorade levnadsår och buller är en av många, men det har också visat sig vara en katalysator när det gäller stressrelaterade eller hjärt- och kärlsjukdomar. Om man till exempel bor närmare än 50 meter från en huvudväg kan risken vara fyra gånger högre för att bli störd och påverkad av buller, vilket i förlängning kan kopplas till ovan nämnda sjukdomar.Det praktiska genomförandet av studien utförsmed en enkätundersökning, fältmätningar,med ett psyko-akustiskt perspektiv och inom ramen för en fallkontrollstudie. Detta inkluderar delvis att informera deltagarna i studien i olika stadier beträffande konstruktionsrelaterat buller. Den tillhandahållna informationen, undersökningen och fältmätningarna syftar till att vara en väsentlig del av utvärderingen av det upplevda bullret oavsett om det beror på byggnadsarbete, infrastruktur eller andra stokastiska källor.Resultatet presenteras och skiljer sig utifrån avstånd till bullerkälla, uppdelat efter kön samt vilken typ av källa som tenderar att vara mest irriterande. Den implementerade rangordningen visas som ICBEN-skalan för varje kategori eller källa, som syftar till att mäta den upplevda effekten. Även om resultaten är vägledande så visar resultaten ett informationsberoende samt ett bullerkällaberoende. Vidare ger resultatet ett intressant mönster mellan könen, där kvinnor tenderar att bli mer störda av konstruktions- och andra-bullerkällor, medan män tenderar att bli mer störda av järnvägs- och väg-buller.
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Crawley, Michael B. "Understanding the Aeroacoustic Radiation Sources and Mechanisms in High-Speed Jets." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1446152138.
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Mohamed, Amgad. "Modélisation et contrôle des turbines hydrauliques pour l'intégration des sources d'énergies renouvelabless." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT027.
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Récemment, les sources d’énergie renouvelables telles que l’énergie éolienne et solaire, sont devenues des éléments essentiels des réseaux électriques en tant qu’alternatives d’énergie propre aux combustibles fossiles. Cependant, la qualité de la production de telles ressources énergétiques dépend de différents facteurs incertains, tels que les conditions météorologiques. Par conséquent, la gestion intermittente des sources d’énergie renouvelables est l’un des principaux défis à relever pour une utilisation à plus grande échelle.Une solution possible pour réduire les effets de l'intermittence des ressources énergétiques sur la production d'énergie et la stabilité du réseau consiste à utiliser les technologies de stockage d'énergie. Les stations de transfert d’énergie par pompage (STEP) semblent être la méthode de stockage propre unique qui peut être utilisée pour lutter contre la nature intermittente de l’énergie éolienne et solaire. Les STEP utilisent des pompes-turbines réversibles pouvant fonctionner comme des pompes pour stocker l'excès d'énergie électrique dans le réseau et comme des turbines pour générer de l'énergie électrique, lorsque davantage d'énergie électrique est nécessaire. Ainsi, les STEP aident à stabiliser le réseau en présence de ressources en énergies renouvelables intermittentes.Ce travail met l’accent sur les conditions de fonctionnement de la turbine pour le démarrage des STEP. Dans les STEP, la condition de fonctionnement de démarrage est généralement visitée plusieurs fois, à la suite d'un basculement entre les modes de pompage et de turbine. Ainsi, l'amélioration des performances des régulateurs de vitesse utilisés pour le démarrage devient plus importante lorsque l'on traite avec des STEP afin de permettre une récupération rapide de la tension.Cette thèse s'inscrit dans le cadre du projet pluridisciplinaire INNOVHYDRO, qui regroupe différents laboratoires et entreprises tels que, GIPSA-lab où cette thèse a été préparée, G2Elab, GE et EDF.Dans cette thèse, une architecture de contrôleur prenant en compte les limitations informatiques des microcontrôleurs existants utilisés chez GE est proposée. Elle apporte une solution au problème du démarrage rapide de la turbine tout en évitant l'excitation de fortes oscillations de pression. De plus, les contraintes de couple s'intègrent facilement pour permettre un démarrage en douceur, ce qui réduit la fatigue des composants mécaniques, résultant du démarrage répétitif des turbines.Des solutions sont proposées pour ajuster les gains du contrôleur, tout en tenant compte de la dynamique non linéaire de l'actionneur utilisé chez GE. Pour commencer, une méthodologie de réglage est décrite pour garantir la stabilité asymptotique et les performances en boucle fermée, tout en minimisant la limite supérieure de l'erreur de suivi en sortie. De plus, une approche d'optimisation systématique est développée pour sélectionner les gains du contrôleur afin de minimiser le temps nécessaire pour obtenir une connexion stable au réseau, tout en respectant les contraintes de couple maximales. De plus, des algorithmes sont utilisés pour choisir les paramètres du contrôleur de sorte que des certificats de robustesse soient obtenus sur le contrôleur résultant.De plus, un simulateur a été développé pour les centrales hydrauliques et utilisé pour tester le contrôleur proposé. Le simulateur est constitué d’un système d’équations différentielles continues qui modélisent systématiquement le comportement des différents composants de la centrale hydraulique, tels que les conduites forcées, les tunnels, les réservoirs et les cheminées d’équilibre. De plus, le comportement non linéaire et les caractéristiques en S des régions instables des turbines hydrauliques, généralement modélisées par des diagrammes de Hill, sont pris en compte avec succès. De plus, la dynamique non linéaire de l'actionneur est incluse dans le modèle mathématique completRecently, renewable energy resources such as, wind and solar energy, have become integral parts of electric grids as clean energy alternatives to fossil fuels. However, the quality of production of such resources of energy depends on different uncertain factors, for instance, weather conditions. Therefore, dealing with the intermittent nature of renewable energy resources is one of the main challenges when using them on a larger scale.A possible solution to reduce the effects of energy resources intermittency on energy production and grid's stability, is to use energy storage technologies. Pumped storage power plants (PSPs) seem to be the unique clean storage method that can be used to counteract the intermittent nature of wind and solar energy. PSPs make use of pumps-turbines which are capable of working as pumps to store excess electric energy in the grid, and as turbines to generate electric energy, when more electric energy is needed. Thus, PSPs help in stabilizing the grid in the presence of intermittent renewable energy resources.The emphasis in this work is on turbine start-up operating mode for PSPs. In PSPs, the start-up operating mode is usually visited multiple times, as a result of switching back and forth between pumping and turbine modes. Thus, enhancing the performance of the speed governors used for starting-up becomes more important when dealing with PSPs to enable a rapid voltage recovery.This PhD thesis is part of the multidisciplinary INNOVHYDRO project that includes different laboratories and enterprises such as, GIPSA-lab where this thesis was prepared, G2Elab, GE and EDF.In this thesis, a controller architecture that takes into account the computational limitations of existing microcontrollers in use at GE, is proposed. It provides a solution to the problem of fast turbine start-up, while avoiding the excitation of sharp pressure oscillations. In addition, torque constraints are easily integrated to achieve smoother start-up, which reduces the fatigue of the mechanical components, resulting from repetitive start-up of turbines.Different approaches are proposed to tune the controller gains, while taking into account the nonlinear dynamics of the actuator used at GE. To begin with, a tuning methodology is outlined to guarantee the asymptotic stability and the closed-loop performance, while minimizing the guaranteed upper bound on the output tracking error. In addition, a systematic optimization approach is developed to select the controller gains to minimize time needed to get a stable start-up, while respecting maximum torque constraints. Moreover, randomized algorithms are used to choose the controller parameters such that robustness certificates are obtained on the resulting controller.Furthermore, a simulator has been developed for hydraulic power plants and used to test the proposed controller. The simulator constitutes of a system of continuous differential equations, which systematically model the behavior of the different components of the hydraulic power plant such as, penstocks, tunnels, reservoirs and surge tanks. In addition, the nonlinear behavior and unstable regions 'S-characteristics' of hydraulic turbines, usually modeled by Hill charts, are successfully taken into consideration. Moreover, the actuator's nonlinear dynamics are included in the overall mathematical model
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Morcol, Tulin. "Potential sources for the large scale production of human protein C." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/39705.
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Sun, Yiming [Verfasser]. "Adaptive and Intelligent Temperature Control of Microwave Heating Systems with Multiple Sources / Yiming Sun." Karlsruhe : KIT Scientific Publishing, 2016. http://www.ksp.kit.edu.
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Stanbery, B. J. "Heteroepitaxy and nucleation control for the growth of metal chalcogenides using activated reactant sources." [Gainesville, Fla.] : University of Florida, 2001. http://etd.fcla.edu/etd/uf/2001/ank7129/Dissertation.pdf.
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Thesis (Ph. D.)--University of Florida, 2001.Title from first page of PDF file. Document formatted into pages; contains xix, 400 p.; also contains graphics. Abstract from separate . txt file supplied by author. Vita. Includes bibliographical references (p. 380-398).
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Cooke, Payton, and Payton Cooke. "Comparative Analysis of Multiple Data Sources for Travel Time and Delay Measurement." Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/622847.
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Arterial performance measurement is an essential tool for both researchers and practitioners, guiding decisions on traffic management, future improvements, and public information. Link travel time and intersection control delay are two primary performance measures that are used to evaluate arterial level of service. Despite recent technological advancements, collecting travel time and intersection delay data can be a time-consuming and complicated process. Limited budgets, numerous available technologies, a rapidly changing field, and other challenges make performance measurement and comparison of data sources difficult. Three common data collection sources (probe vehicles, Bluetooth media access control readers, and manual queue length counts) are often used for performance measurement and validation of new data methods. Comparing these and other data sources is important as agencies and researchers collect arterial performance data. This study provides a methodology for comparing data sources, using statistical tests and linear correlation to compare methods and identify strengths and weaknesses. Additionally, this study examines data normality as an issue that is seldom considered, yet can affect the performance of statistical tests. These comparisons can provide insight into the selection of a particular data source for use in the field or for research. Data collected along Grant Road in Tucson, Arizona, was used as a case study to evaluate the methodology and the data sources. For evaluating travel time, GPS probe vehicle and Bluetooth sources produced similar results. Bluetooth can provide a greater volume of data more easily in addition to samples large enough for more rigorous statistical evaluation, but probe vehicles are more versatile and provide higher resolution data. For evaluating intersection delay, probe vehicle and queue count methods did not always produce similar results.
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Aljaism, Wadah. "Control method for renewable energy generators /." View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20031223.093139/index.html.
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Cleland, Benjamin George. "Reinforcement Learning for Racecar Control." The University of Waikato, 2006. http://hdl.handle.net/10289/2507.
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This thesis investigates the use of reinforcement learning to learn to drive a racecar in the simulated environment of the Robot Automobile Racing Simulator. Real-life race driving is known to be difficult for humans, and expert human drivers use complex sequences of actions. There are a large number of variables, some of which change stochastically and all of which may affect the outcome. This makes driving a promising domain for testing and developing Machine Learning techniques that have the potential to be robust enough to work in the real world. Therefore the principles of the algorithms from this work may be applicable to a range of problems. The investigation starts by finding a suitable data structure to represent the information learnt. This is tested using supervised learning. Reinforcement learning is added and roughly tuned, and the supervised learning is then removed. A simple tabular representation is found satisfactory, and this avoids difficulties with more complex methods and allows the investigation to concentrate on the essentials of learning. Various reward sources are tested and a combination of three are found to produce the best performance. Exploration of the problem space is investigated. Results show exploration is essential but controlling how much is done is also important. It turns out the learning episodes need to be very long and because of this the task needs to be treated as continuous by using discounting to limit the size of the variables stored. Eligibility traces are used with success to make the learning more efficient. The tabular representation is made more compact by hashing and more accurate by using smaller buckets. This slows the learning but produces better driving. The improvement given by a rough form of generalisation indicates the replacement of the tabular method by a function approximator is warranted. These results show reinforcement learning can work within the Robot Automobile Racing Simulator, and lay the foundations for building a more efficient and competitive agent.
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Kurpad, Krishna Nagaraj. "Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources." Texas A&M University, 2004. http://hdl.handle.net/1969.1/2755.
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The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the imaging frequency, as determined by the static magnetic (B0) field strength. These coils are excited by one or more voltage sources. The distribution of currents on the coil elements or rungs is determined by the symmetry of the coil structure. At field strengths of 3T and above, electric properties such as the dielectric constant and conductivity of the load lead to B1 field inhomogeneity due to wavelength effects and perturbation of the coil current distribution from the ideal. The B1 field homogeneity under such conditions may be optimized by adjusting the amplitudes and phases of the currents on the rungs. However, such adjustments require independent control of current amplitudes and phases on each rung of the resonant coil. Due to both the strong coupling among the rungs of a resonant coil and the sensitivity to loading, such independent control would not be possible and B1 homogeneity optimization would involve a time consuming and impractical iterative procedure in the absence of exact knowledge of interactions among coil elements and between the coil and load.
This dissertation is based on the work done towards the design and development of a RF current source that drives high amplitude RF current through an integrated array element. The arrangement is referred to as a current element. Independent control of current amplitude and phase on the current elements is demonstrated. A non-resonant coil structure consisting of current elements is implemented and B1 field pattern control is demonstrated. It is therefore demonstrated that this technology would enable effective B1 field optimization in the presence of lossy dielectric loads at high field strengths.
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Du, Plooy Henri. "Comparative strategies for efficient control and storage of renewable energy in a microgrid." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2486.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016.Power fluctuations in a microgrid are caused by disturbances due to the connection and disconnection of Distributed Generators (DG’s), as well as the irregular input of the sun and wind renewable energy. Renewable penetration such as the sun, wind and tidal energy causes intermittency which directly affects the input and resultant output power of a microgrid. Control systems have to be implemented on three different levels to ensure the stability and reliability of the power supplied to the load. This can be achieved by implementing the following: 1) Primary control with mechanical valves and actuators to translate feedback signals through droop control. 2) Secondary control with power electronics to facilitate maximum power point tracking, phase lock loops and switch mode inverters to manipulate the electrical signals to a desired set points including PID control. 3) Tertiary control with software program management to monitor the power flow as well as to evaluate congregated logic and implement decision making. Energy storage systems like super capacitors can compensate for power imbalance by providing excess stored energy to the microgrid for short periods of time. The added advantage of capacitor banks is that it can facilitate power factor correction where inductive loads like rotating motors form large part of the total load. Battery banks can compensate for energy shortage for longer periods of time. The duration of the compensation can be determined by the size, topology and the type of batteries used. The objectives of this study is to improve the unstable power output responses of a renewable energy microgrid by designing and analysing control strategies intended at power wavering compensation which also includes energy storage. Sub control systems is created and simulated in Matlab/Simulink for analytical comparative observations. Results of the simulated model are discussed and recommendations are given for future works.
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Diaz, Matias. "Control of the modular multilevel matrix converter for wind energy conversion systems." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/47157/.
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The nominal power of single Wind Energy Conversion Systems has been steadily growing, reaching power ratings close to 10 MW. In the power conversion stage, medium-voltage power converters are replacing the conventional low-voltage back-to-back topology. Modular Multilevel Converters have appeared as a promising solution for Multi-MW WECSs due to their characteristics such as modularity, reliability and the capability to reach high nominal voltages. Thereby, this thesis discusses the application of the Modular Multilevel Matrix Converter to drive Multi-MW Wind Energy Conversion Systems (WECSs). The modelling and control systems required for this application are extensively analysed and discussed in this document. The proposed control strategies enable decoupled operation of the converter, providing maximum power point tracking capability at the generator-side, grid-code compliance and Low Voltage Ride Through Control at the grid-side and good steady-state and dynamic performance for balancing the capacitor voltages of the converter. The effectiveness of the proposed control strategies is validated through simulations and experimental results. Simulation results are obtained with a 10MW, 6.6 kV Modular Multilevel Matrix Converter based WECS model developed in PLECS software. Additionally, a 5 kVA downscale prototype has been designed and constructed during this Ph.D. The downscale prototype is composed of 27 H-Bridges power cells. The system is controlled using a Digital Signal Processor connected to three Field Programmable Gate Array which are equipped with 50 analogue-digital channels and 108 gate drive signals. Two programmable AMETEK power supplies emulate the electrical grid and the generator. The wind turbine dynamics is programmed in the generator-side power supply to emulate a generator operating in variable speed/voltage mode. The output port of the Modular Multilevel Matrix Converter is connected to another power source which can generate programmable grid sag-swell conditions. Simulation and experimental results for variable-speed operation, grid-code compliance, and capacitor voltage regulation have confirmed the successful operation of the Modular Multilevel Matrix Converter based WECSs. In all the experiments, the proposed control systems ensure proper capacitor voltage balancing, keeping the flying capacitor voltages bounded and with low ripple. Additionally, the performance of the generator-side and grid-side control system have been validated for Maximum Power Point Tracking and Low-Voltage Ride Through, respectively.
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Chen, Zhenwei. "Virtual Power Plant Simulation and Control Scheme Design." Thesis, KTH, Industriella informations- och styrsystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-116752.
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Virtual Power Plant (VPP) is a concept that aggregate Distributed Energy Resources (DER) together, aims to overcome the capacity limits of single DER and the intermit-ted natural characteristics of renewable energy sources like wind and solar. The whole system can be viewed as a single large-capacity power plant from the system‘s point of view. In this project, the literature review of VPP concept, architecture, existed project and the survey of VPP in Sweden are being conducted first. Secondly, the simplified VPP model is built on MATLAB/Simulink software. The simplified system contains a wind farm, a hydro power plant, a dynamic system load and an infinite bus representing the large transmission grid. During the simulation process, the generation and consump-tion unites are running according to the real history data located in external database. In the third place, optimized control schemes for the hydro unit in VPP model to decrease its effects on transmission grid are implemented in Simulink model. At the same time, hydro turbine should be controlled in an optimized way that without large turbulence. Basically, the hydro power plant is responsible for balancing the active power between the wind farm and dynamic load. Since there is a limit for the hydro turbine output, the rest of either power shortage or surplus power need to be com-pensated by the grid. This is the fundamental control scheme, so called run time con-trol scheme. The advanced control schemes here are based on the moving average control method and forecast compensation control method. The forecast compensa-tion control method use the 24 hours ahead load forecasting data generated by Artifi-cial Neural Network. Later on, analysis of those three control schemes will be pre-sented. The last part of the project is the conclusion of the different control schemes according to comparison of their control results.
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Etxeberria, Aitor. "Microgrid hybrid energy storage and control using a three-level NPC converter." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14695/document.
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L’intégration croissante de la Génération Distribuée basée sur des sources d’énergies renouvelables présente de nouveaux défis pour le réseau électrique centralisé actuel. Le micro-réseau est une des alternatives envisagées afin d’augmenter le taux de pénétration d’énergie renouvelable et d’améliorer la qualité de l’énergie. La stabilité d’un micro-réseau est fortement sensible aux variations de puissance venant des sources d’énergie ou des charges. Dans ce contexte, un système de stockage d’énergie joue un rôle essentiel et doit satisfaire deux conditions : disposer d’une capacité de stockage importante pour adapter la production à la demande et être capable de fournir rapidement une puissance instantanée suffisante pour pallier les problèmes de qualité d’énergie. L’objectif principal de cette thèse est de concevoir et valider expérimentalement un système de conversion de puissance et l’algorithme de contrôle associé pour la gestion du stockage dans un micro-réseau afin de satisfaire les deux conditions. Suite à l’analyse de différentes technologies de stockage, on peut conclure qu’il n’y a pas de système de stockage capable de satisfaire les conditions d’énergie et de puissance en même temps. Par conséquent, l’association d’un supercondensateur et d’une batterie Redox au Vanadium dans un Système de Stockage Hybride est utilisée pour satisfaire les conditions mentionnées. Le travail de recherche est axé sur la gestion du flux d’énergie et de puissance du Système de Stockage Hybride proposé à l’aide d’un système de conversion de puissance innovant et son algorithme de commande. Un convertisseur multi-niveaux 3LNPC a été choisi pour commander en même temps les deux systèmes de stockage, en raison de faibles pertes de puissance et de distorsions harmoniques réduites en comparaison avec d’autres topologies existantes. Un algorithme de commande capable d’exploiter les limites de fonctionnement du convertisseur sur toute sa plage de fonctionnement a été conçu afin de satisfaire de manière optimale les critères spécifiés. Le fonctionnement du système de conversion et la stratégie de commande proposée ont été validés d’abord en simulation et ensuite expérimentalement en utilisant le micro-réseau installé à l’ESTIAThe increasing penetration of Distributed Generation systems based on Renewable Energy Sources is introducing new challenges in the current centralised electric grid. The microgrid is one of the alternatives that is being analysed in order to increase the penetration level of renewable energy sources in electrical grids and improve the power quality. The microgrid stability is highly sensitive to power variations coming from the energy sources or loads. In this context, an energy storage system is essential and it must satisfy two criteria: to have a high storage capacity to adapt the generation to the demand and to be able to supply fast power variations to overcome the power quality problems that may arise. The main objective of this thesis has been to design a power conversion system and the associated control algorithm for a storage system management in order to satisfy the defined requirements, as well as to experimentally validate the proposed solution. After an analysis of different storage system technologies, it can be concluded that there is not any storage system capable of offering the energy and power requirements at the same time. Consequently, the association of a SuperCapacitor bank and a Vanadium Redox Battery is used to satisfy the mentioned requirements. This thesis has been focused on the power and energy flow management of the proposed Hybrid Energy Storage System through an innovative power conversion system and its control method. A Three-Level Neutral Point Clamped converter has been used to control at the same time the two storage systems, due to the reduced power losses and harmonic distortion compared to other existing topologies. A control algorithm that uses the operational limits of the converter in its entire operation range has been designed in order to allow selecting the best operation point according to the specified criteria. The operation of the power conversion system and the proposed control method have been first validated in simulations and then experimentally using the microgrid installed in ESTIA
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Alotaibi, Lafi. "Commande et optimisation d'une installation multi-sources." Thesis, Reims, 2012. http://www.theses.fr/2012REIMS039.
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Cette thèse traite la commande et l'optimisation d'une installation photovoltaïquepour un site isolé. Ainsi, nous avons proposé un algorithme par logique flouepermettant la poursuite du point de puissance maximal afin de remédier auxinconvénients des méthodes classiques. Ensuite, nous nous sommes intéressés àl'optimisation de la structure de l'installation. En effet, dans les installationsclassiques, dans le cas de défaillance d'un panneaux, tout le bloc série devientinutilisable, ce qui réduit considérablement les capacités de production del'installation. Pour résoudre ce problème, nous avons proposé un superviseur permettant la reconfiguration automatique de l'installation de telle sorte que seul lepanneaux défaillant est mis hors connexion. Par ailleurs, pour gérer le flux depuissance et pour répondre à la demande de l'utilisateur, nous avons développé un superviseur par logique floue. Ainsi, le surplus de production est stocké systématiquement dans la batterie pour l'utiliser ensuite en cas où la demandedépasse la production. De plus, la structure proposée permet de ne solliciter la batterie en cas de besoin de ce qui permet de prolonger considérablement sa duréede vieThis thesis addresses the control and optimization of a stand-alone photovoltaicsystem. Thus, we proposed a fuzzy logic algorithm for tracking the maximum powerpoint to overcome the disadvantages of classical methods. Then we focused onoptimizing the structure of the installation. Indeed, in conventional systems, in thecase of failure of a panel, the whole serie block becomes unusable, greatly reducingthe production capacity. To resolve this problem, we proposed a supervisor for theautomatic reconfiguration of the installation so that only the failed panels is takenoffline. Furthermore, to manage the power flow and to meet user demand, wedeveloped a fuzzy supervisor. Thus, the surplus production is systematically storedin the battery for later use in cases where demand exceeds production. In addition,the proposed structure can not draining the battery in case of need thereby greatlyextend its lifetime
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MELO, JOSE A. T. "Projeto e montagem de equipamento para controle de sistema de análise não destrutiva usando radiação nuclear." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11471.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP