Dissertations / Theses on the topic 'Automatic control- Power system'
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Falkner, Catherine M. "Robust output feedback controllers for power system stabilization." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14802.
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Uurtonen, Tommi. "Optimized Power Control for CDMA System using Channel Prediction." Thesis, Linköping University, Department of Science and Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3697.
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In an optimal power control scheme for a Code Division Multiple Access (CDMA) system all mobile stations signals should arrive to the base station at equal power. If not, stronger singals may cause too much interference and block out weaker ones. Commonly used power control schemes utilizes the Signal to Interference Ratio (SIR) to design a Power Control Command (PCC) to adjust the transmit power of the mobile station. A significant problem within the conventional methods is the slow SIR recovery due to deep channel fades. Conventional methods base the PCC on the previous channel state when in fact, the channel state may have significantly changed when transmission occurs. These channel changes may cause the SIR to drop or rise drastically and lead to uncontrollable Multi Access Interference (MAI) resulting in power escalation and making the system unstable. In order to overcome power escalation and improve the recovery from deep fades a novel power control method has been developed. Based on Linear Quadratic Control and Kalman filtering for channel prediction this method designs the PCC based on the coming channel state instead of the current. This optimizes the PCC for the channel state where transmission occurs. Simulations show that this control scheme outperforms previous methods by making the impacts of the deep fades less severe on the SIR and also improves the overall SIR behaviour.
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Hicks, Glenn V. "An investigation of automatic generation control for an isolated power system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0011/MQ34184.pdf.
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Prinsloo, Gerhardus Johannes. "Automatic positioner and control system for a motorized parabolic solar reflector." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96137.
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Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Most rural African villages enjoy high levels of sunlight, but rolling out solar power generation technology to tap into this renewable energy resource at remote rural sites in Africa pose a number of design challenges. To meet these challenges, a project has been initiated to design, build and test/evaluate a knock down 3 kW peak electrical stand-alone self-tracking dual-axis concentrating solar power system. This study focusses on the mechatronic engineering aspects in the design and development of a dynamic mechatronic platform and digital electronic control system for the stand-alone concentrating solar power system. Design specifications require an accurate automatic positioner and control system for a motorized parabolic solar reflector with an optical solar harnessing capacity of 12 kWt at solar noon. It must be suitable for stand-alone rural power generation. This study presents a conceptual design and engineering prototype of a balanced cantilever tilt-and-swing dual-axis slew drive actuation means as mechatronic solar tracking mobility platform for a ∼12 m2 lightweight parabolic solar concentrator. Digital automation of the concentrated solar platform is implemented using an industrial Siemens S7-1200 programmable logic controller (PLC) with digital remote control interfacing, pulse width modulated direct current driving, and electronic open loop/closed loop solar tracking control. The design and prototype incorporates off-the-shelf components to support local manufacturing at reduced cost and generally meets the goal of delivering a dynamic mechatronic platform for a concentrating solar power system that is easy to transport, assemble and install at remote rural sites in Africa. Real-time experiments, conducted in the summer of South Africa, validated and established the accuracy of the engineering prototype positioning system. It shows that the as-designed and -built continuous solar tracking performs to an optical accuracy of better than 1.0◦ on both the azimuth and elevation tracking axes; and which is also in compliance with the pre-defined design specifications. Structural aspects of the prototype parabolic dish are evaluated and optimized by other researchers while the Stirling and power handling units are under development in parallel projects. Ultimately, these joint research projects aim to produce a locally manufactured knock down do-it-yourself concentrated solar power generation kit, suitable for deployment into Africa.
AFRIKAANSE OPSOMMING: Landelike gebiede in Afrika geniet hoë vlakke van sonskyn, maar die ontwerp van betroubare sonkrag tegnologie vir die benutting van hierdie hernubare energie hulpbron by afgeleë gebiede in Afrika bied verskeie uitdagings. Om hierdie uitdagings te oorkom, is ’n projek van stapel gestuur om ’n afbreekbare 3 kW piek elektriese alleenstaande selfaangedrewe dubbel-as son-konsentreeder te ontwerp, bou en te toets. Hierdie studies fokus op die megatroniese ingenieurs-aspekte in die ontwerp en ontwikkeling van ’n dinamiese megatroniese platform en ’n digitale elektroniese beheerstelsel vir die alleenstaande gekonsentreerde sonkrag stelsel. Ontwerp spesifikasies vereis ’n akkurate outomatiese posisionering en beheer stelsel vir ’n motor aangedrewe paraboliese son reflekteerder met ’n optiesekollekteer- kapasiteit van 12 kWt by maksimum sonhoogte, en veral geskik wees vir afgeleë sonkrag opwekking. Hierdie studie lewer ’n konsepsuele ontwerp en ingenieurs-prototipe van ’n gebalanseerde dubbelas swaai-en-kantel swenkrat aandrywingsmeganisme as megatroniese sonvolg platform vir ’n ∼12 m2 liggewig paraboliese son konsentreerder. Digitale outomatisering van die son konsentreerder platform is geimplementeer op ’n industriële Siemens S7-1200 programmeerbare logiese beheerder (PLB) met ’n digitale afstandbeheer koppelvlak, puls-wydte-gemoduleerde gelykstroom aandrywing en elektroniese ooplus en geslote-lus sonvolg beheer. Die ontwerp en prototipe maak gebruik van beskikbare komponente om lae-koste plaaslike vervaardiging te ondersteun en slaag in die algemeen in die doel om ’n dinamiese megatroniese platform vir ’n gekonsentreerde sonkrag stelsel te lewer wat maklik vervoer, gebou en opgerig kan word op afgeleë persele in Afrika. Intydse eksperimente is gedurende die somer uitgevoer om die akkuraatheid van die prototipe posisionering sisteem te evalueer. Dit toon dat die sisteem die son deurlopend volg met ’n akkuraatheid beter as 1.0◦ op beide die azimut en elevasie sonvolg asse, wat voldoen aan die ontwerp spesifikasies. Strukturele aspekte van die prototipe paraboliese skottel word deur ander navorsers geëvalueer en verbeter terwyl die Stirling-eenheid en elektriese sisteme in parallelle projekte ontwikkel word. Die uiteindelike doel met hierdie groepnavorsing is om ’n plaaslik vervaardigde doen-dit-self sonkrag eenheid te ontwikkel wat in Afrika ontplooi kan word.
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Zhou, Huafeng, and 周華鋒. "Design of grid service-based power system control centers for future electricity systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687429.
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Zhou, Huafeng. "Design of grid service-based power system control centers for future electricity systems." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687429.
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Oukati, Sadegh Mahmoud. "Control of power electronic devices (FACTS) to enhance power system stability." Thesis, University of Strathclyde, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275177.
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Zonetti, Daniele. "Energy-based modelling and control of electric power systems with guaranteed stability properties." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS118/document.
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Pour traiter les systèmes non linéaires, à grande échelle, multi-domaine tels que les systèmes électriques de puissance, nous avons remarqué dans les dernières années un intérêt croissant pour les techniques de modélisation, analyse et contrôle basées sur la notion d'énergie. L'énergie est en fait un concept fondamental en science et en ingénierie, où typiquement les systèmes dynamiques sont regardés comme des dispositifs de transformation d'énergie. Cette perspective est particulièrement utile pour étudier des systèmes non linéaires assez complexes, qui peuvent être décomposés en sous-systèmes plus simples, caractérisés au niveau énergétique, et qui, à travers leurs interconnexions, déterminent le comportement global du système tout entier. Il représente bien évidemment le langage le plus naturel et intuitif pour représenter les systèmes électriques de puissance. En particulier, l'utilisation de systèmes Hamiltoniens à Ports a eu un impact très fort dans différentes applications, plus précisément dans le cas de systèmes mécaniques, électriques et électromécaniques. Dans ce contexte alors, l'approche Hamiltonien à Ports représentent sans doute une base solide qui montre une nouvelle fac{c}on d'aborder les problèmes d'analyse et contrôle de systèmes électriques de puissance. Basée sur cette approche, la thèse est structurée en trois étapes fondamentales:1 - Modélisation d'une classe très générale de systèmes électriques de puissance, basée sur la théorie des graphes et la formulation en Systèmes Hamiltoniens à Ports des composantes.2 - Modélisation, analyse et commande de systèmes de transmission de courant continu haute tension. Avec l'intention de construire un pont entre la théorie et les éventuelles applications, un des objectifs fondamentaux consiste à établir des relations évidentes entre les solutions adoptées dans la pratique et les solutions obtenues à travers une analyse mathématique précise.3 - Travaux apparentés de l'auteur, dans différents domaines des systèmes électriques de puissance: systèmes ac conventionnels et micro réseauxTo deal with nonlinear, large scale, multidomain, systems, as power systems are, we have witnessed in the last few years an increasing interest in energy–based modeling, analysis and controller design techniques. Energy is one of the fundamental concepts in science and engineering practice, where it is common to view dynamical systems as energy-transformation devices. This perspective is particularly useful in studying complex nonlinear systems by decomposing them into simpler subsystems which, upon interconnection, add up their energies to determine the full systems behavior. This is obviously the most natural and intuitive language to represent power systems. In particular, the use of port–Hamiltonian (pH) systems has been already proven highly successful in many applications, namely for mechanical, electrical and electromechanical systems. The port-Hamiltonian systems paradigm theremore provides a solid foundation, which suggests new ways to look at power systems analysis and control problems.Based on this framework, this thesis is structured in three main steps.1 - Modelling of a generalized class of electric power systems, based on graph theory and port-Hamiltonian representation of the individual components.2 - Modelling, analysis and control of multiterminal hvdc transmission systems. With the intention to bridge the gap between theory and applications, one of the main concerns is to establish connections between existing engineering solutions, usually derived via ad hoc considerations, and the solutions stemming from theoretical analysis.3 - Additional contributions of the author in other fields of electric power systems, including traditional ac power systems an microgrids
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Yoon, Hyungjoo. "Spacecraft Attitude and Power Control Using Variable Speed Control Moment Gyros." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4850.
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A Variable Speed Control Moment Gyro (VSCMG) is a recently
introduced actuator for spacecraft attitude control.
As its name implies, a VSCMG is essentially a single-gimbal
control moment gyro (CMG) with a flywheel allowed to have variable spin
speed. Thanks to its extra degrees of freedom, a
VSCMGs cluster can be used to achieve additional objectives, such
as power tracking and/or singularity avoidance, as well as
attitude control.
In this thesis, control laws for an integrated power/attitude
control system (IPACS) for a satellite using VSCMGs are
introduced.
The power tracking objective is achieved by storing or releasing the kinetic energy
in the wheels. The proposed control algorithms perform both the attitude
and power tracking goals simultaneously.
This thesis also provides a singularity analysis and avoidance method using
CMGs/VSCMGs. This issue is studied for both the cases of attitude tracking with and without a power
tracking requirement. A null motion method to avoid singularities is
presented, and a criterion is developed to determine the momentum region
over which this method will successfully avoid singularities.
The spacecraft angular velocity and attitude control problem using a single
VSCMG is also addressed.
A body-fixed axis is chosen to
be perpendicular to the gimbal axis, and it is controlled to aim at an arbitrarily given inertial direction,
while the spacecraft angular velocity is stabilized.
Finally, an adaptive control algorithm for the spacecraft attitude tracking in case
when the actuator parameters, for instance the spin axis directions, are uncertain is developed.
The equations of motion in this case
are fully nonlinear and represent a Multi-Input-Multi-Output (MIMO) system.
The smooth projection algorithm is applied to keep the parameter estimates inside
a singularity-free region.
The design procedure can also be easily applied to general MIMO dynamical systems.
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Choi, Sungyun. "Autonomous state estimation and its application to the autonomous operation of the distribution system with distributed generations." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50250.
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The objective of this thesis is to propose guidelines for advanced operation, control, and protection of the restructured distribution system by designing the architecture and functionality for autonomous operation of the distribution system with DGs. The proposed architecture consists of (1) autonomous state estimation and (2) applications that enable autonomous operation; in particular, three applications are discussed: setting-less component protection, instant-by-instant management, and short-term operational planning. Key elements of the proposed approach have been verified: (1) the proposed autonomous state estimation has been experimentally tested using laboratory test systems and (2) the feasibility of the setting-less component protection has been tested with numerical simulations.
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Al-Busaidi, Adil G. "Automatic generation control of the Petroleum Development Oman (PDO) and the Oman Electricity Transmission Company (OETC) interconnected power systems." Thesis, Teesside University, 2012. http://hdl.handle.net/10149/263268.
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Petroleum Development Oman (PDO) and Oman Electricity Transmission Company (OETC) are running the main 132kV power transmission grids in the Sultanate of Oman. In the year 2001, PDO and OETC grids were interconnected with a 132kV Over head transmission line linking Nahada 132kV substation at PDO's side to Nizwa 132kV sub-station at OETC's side. Since then the power exchange between PDO and OETC is driven by the natural impedances of the system and the frequency and power exchange is controlled by manually re-dispatching the generators. In light of the daily load profile and the forecasted Gulf Cooperation Council (GCC) states electrical interconnection, it is a great challenge for PDO and OETC grids operators to maintain the existing operation philosophy. The objective of this research is to investigate Automatic Generation Control (AGC) technology as a candidate to control the grid frequency and the power exchange between PDO and OETC grid. For this purpose, a dynamic power system model has been developed to represent PDO-OETC interconnected power system. The model has been validated using recorded data from the field which has warranted the requirement of refining the model. Novel approaches have been followed during the course of the model refining process which have reduced the modelling error to an acceptable limit. The refined model has then been used to assess the performance of different AGC control topologies. The recommended control topologies have been further improved using sophisticated control techniques like Linear Quadratic Regulator (LQR) and Fuzzy Logic (FL). Hybrid Fuzzy Logic Proportional Integral Derivative (FLPID) AGC controller has produced outstanding results. The FLPID AGC controller parameters have then been optimised using Multidimensional Unconstrained Nonlinear Minimization function (fminsearch) and Particle Swarm Optimisation (PSO) method. The PSO has been proved to be much superior to fminsearch function. The robustness of the LQR, the fminsearch optimized FLPID and the PSO FLPID optimized AGC controllers has been assessed. The LQR robustness found to be slightly better than the FLPID technique. However the FLPID supercedes the LQR due to the limited number of field feedback signals in comparison to the LQR. Finally, a qualitative assessment of the benefits of the ongoing GCC interconnection project on PDO and OETC has been done through modelling approach. The results proved that the GCC interconnection will bring considerable benefits to PDO and OETC but the interconnection capacity between PDO and OETC needs to be enhanced. However, the application of AGC on PDO and OETC will alleviate the PDO-OETC interconnection capacity enhancement imposed by the GCC interconnection.
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Brus, Linda. "Nonlinear Identification and Control with Solar Energy Applications." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8594.
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Liu, Kai, and 劉愷. "Optimal dispatch and management for smart power grid." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46336680.
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Bladh, Johan. "Hydropower generator and power system interaction." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182188.
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After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. At the same time, an extensive reinvestment programme has commenced where many old components and apparatus are being refurbished or replaced. Introduction of new technical solutions in existing power plants requires good systems knowledge and careful consideration. Important tools for research, development and analysis are suitable mathematical models, numerical simulation methods and laboratory equipment. This doctoral thesis is devoted to studies of the electromechanical interaction between hydropower units and the power system. The work encompasses development of mathematical models, empirical methods for system identification, as well as numerical and experimental studies of hydropower generator and power system interaction. Two generator modelling approaches are explored: one based on electromagnetic field theory and the finite element method, and one based on equivalent electric circuits. The finite element model is adapted for single-machine infinite-bus simulations by the addition of a network equivalent, a mechanical equation and a voltage regulator. Transient simulations using both finite element and equivalent circuit models indicate that the finite element model typically overestimates the synchronising and damping properties of the machine. Identification of model parameters is performed both numerically and experimentally. A complete set of equivalent circuit parameters is identified through finite element simulation of standard empirical test methods. Another machine model is identified experimentally through frequency response analysis. An extension to the well-known standstill frequency response (SSFR) test is explored, which involves measurement and analysis of damper winding quantities. The test is found to produce models that are suitable for transient power system analysis. Both experimental and numerical studies show that low resistance of the damper winding interpole connections are vital to achieve high attenuation of rotor angle oscillations. Hydropower generator and power system interaction is also studied experimentally during a full-scale startup test of the Nordic power system, where multiple synchronised data acquisition devices are used for measurement of both electrical and mechanical quantities. Observation of a subsynchronous power oscillation leads to an investigation of the torsional stability of hydropower units. In accordance with previous studies, hydropower units are found to be mechanically resilient to subsynchronous power oscillations. However, like any other generating unit, they are dependent on sufficient electrical and mechanical damping. Two experimentally obtained hydraulic damping coefficients for a large Francis turbine runner are presented in the thesis.
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Ferreira, Castellane Silva [UNESP]. "Sistema de gerenciamento automático de reatores eletrônicos com ajuste do nível de luminosidade para múltiplas lâmpadas fluorescentes." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/87118.
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Este trabalho trata do desenvolvimento e implementação de um sistema de iluminação fluorescente com gerenciamento automático baseado em reatores eletrônicos aplicados a múltiplas lâmpadas fluorescentes. O foco desta pesquisa é direcionado ao desenvolvimento de uma plataforma automática de gerenciamento e supervisão, propiciando o controle de luminosidade, acionamento remoto e também acionamentos programáveis de acordo com o expediente de trabalho do local e condições de iluminação natural do ambiente, além de prover aumento de vida útil das lâmpadas fluorescentes, em função de protocolo proposto para préaquecimento e ignição. Foram acoplados ao sistema sensores de luminosidade e de presença, permitindo a obtenção dos dados necessários para a atuação automática. O controle por calha das lâmpadas fluorescentes é feito por um microcontrolador AtMega8 da ATMEL, o qual é responsável pela automação do sistema. A plataforma de gerenciamento e monitoração utiliza um microcomputador para que seja executado o aplicativo desenvolvido, o qual provê uma interface amigável ao usuário. Assim, um protocolo de comunicação foi desenvolvido para que haja uma comunicação de dados confiável, oferecendo robustez e alta confiabilidade ao controle do sistema de iluminação. Para o processamento dos dados, foi utilizado o barramento serial de comunicação full duplex com padrão RS232 e RS485 com transmissão assíncrona. Adicionalmente, o sistema funciona no sistema mestre-escravo, sendo o microcomputador responsável por enviar endereçamentos e ordens de ação aos microcontroladores, os quais identificam os endereçamentos e dados, executam a ação programada e envia dado de monitoramento ao microcomputador, quando requisitado pelo usuário.
In this work, the development and implementation of an illumination fluorescent system with automatic management based on electronic ballast applied to multiple fluorescent lamps are presented. This research is directed in the development of the management and supervision of an automatic platform, allowing the control of luminosity, the remote actuation and also the programmable actuation according with the local business work and conditions of natural light of the environment. In addition, the ballast will provide the increase in the average lifetime for fluorescent lamps, considering a proposed protocol to pre-heating and ignition. The automatic actuation of the system is allowed by the coupling, of the luminosity and presence sensors. The control of fluorescent lamps by channel is executed by an ATMEL’s AtMega8 microcontroller, which is responsible for the system automation. The management and monitoring platform uses a microcomputer with purpose to execute the implemented application, which will provide a friendly interface to the user. Thus, a protocol of communication was developed to allow a reliable communication of data, providing robustness and high reliability to the control of lighting system. Considering the processing of data acquired, was used a Serial Bus of communication with full duplex standard RS232 and RS485, with asynchronous transmission. Additionally, the system works in the master-slave mode, and the microcomputer is responsible for sending addresses and orders of action to microcontrollers, which identify and address data, in order to perform the programmed action to it, and in order to send data to the microcomputer, when requested by the user.
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Ma, Tan. "Hybrid Power System Intelligent Operation and Protection Involving Plug-in Electric Vehicles." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/1760.
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Two key solutions to reduce the greenhouse gas emissions and increase the overall energy efficiency are to maximize the utilization of renewable energy resources (RERs) to generate energy for load consumption and to shift to low or zero emission plug-in electric vehicles (PEVs) for transportation. The present U.S. aging and overburdened power grid infrastructure is under a tremendous pressure to handle the issues involved in penetration of RERS and PEVs. The future power grid should be designed with for the effective utilization of distributed RERs and distributed generations to intelligently respond to varying customer demand including PEVs with high level of security, stability and reliability. This dissertation develops and verifies such a hybrid AC-DC power system. The system will operate in a distributed manner incorporating multiple components in both AC and DC styles and work in both grid-connected and islanding modes.
The verification was performed on a laboratory-based hybrid AC-DC power system testbed as hardware/software platform. In this system, RERs emulators together with their maximum power point tracking technology and power electronics converters were designed to test different energy harvesting algorithms. The Energy storage devices including lithium-ion batteries and ultra-capacitors were used to optimize the performance of the hybrid power system. A lithium-ion battery smart energy management system with thermal and state of charge self-balancing was proposed to protect the energy storage system. A grid connected DC PEVs parking garage emulator, with five lithium-ion batteries was also designed with the smart charging functions that can emulate the future vehicle-to-grid (V2G), vehicle-to-vehicle (V2V) and vehicle-to-house (V2H) services. This includes grid voltage and frequency regulations, spinning reserves, micro grid islanding detection and energy resource support.
The results show successful integration of the developed techniques for control and energy management of future hybrid AC-DC power systems with high penetration of RERs and PEVs.
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Ng, Kwok-kei Simon, and 吳國基. "Optimal planning and management of stochastic demand and renewable energy in smart power grid." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B50434299.
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To combat global climate change, the reduction of carbon emissions in different industries, particularly the power industry, has been gradually moving towards a low-carbon profile to alleviate any irreversible damage to the planet and our future generations. Traditional fossil-fuel-based generation is slowly replaced by more renewable energy generation while it can be harnessed. However, renewables such as solar and wind are stochastic in nature and difficult to predict accurately. With the increasing content of renewables, there is also an increasing challenge to the planning and operation of the grid.
With the rapid deployment of smart meters and advanced metering infrastructure (AMI), an emerging approach is to schedule controllable end-use devices to improve energy efficiency. Real-time pricing signals combined with this approach can potentially deliver more economic and environmental advantages compared with the existing common flat tariffs. Motivated by this, the thesis presents an automatic and optimal load scheduling framework to help balance intermittent renewables via the demand side.
A bi-level consumer-utility optimization model is proposed to take marginal price signals and wind power into account. The impact of wind uncertainty is formulated in three different ways, namely deterministic value, scenario analysis, and cumulative distributions function, to provide a comprehensive modeling of unpredictable wind energy. To solve the problem in off-the-shelf optimization software, the proposed non-linear bi-level model is converted into an equivalent single-level mixed integer linear programming problem using the Karush-Kuhn-Tucker optimality conditions and linearization techniques. Numerical examples show that the proposed model is able to achieve the dual goals of minimizing the consumer payment as well as improving system conditions. The ultimate goal of this work is to provide a tool for utilities to consider the demand response model into their market-clearing procedure.
As high penetration of distributed renewable energy resources are most likely applied to remote or stand-alone systems, planning such systems with uncertainties in both generation and demand sides is needed. As such, a three-level probabilistic sizing methodology is developed to obtain a practical sizing result for a stand-alone photovoltaic (PV) system. The first-level consists of three modules: 1) load demand, 2) renewable resources, and 3) system components, which comprise the fundamental elements of sizing the system. The second-level consists of various models, such as a Markov chain solar radiation model and a stochastic load simulator. The third-level combines reliability indices with an annualized cost of system to form a new objective function, which can simultaneously consider both system cost and reliability based on a chronological Monte Carlo simulation and particle swamp optimization approach. The simulation results are then tested and verified in a smart grid laboratory at the University of Hong Kong to demonstrate the feasibility of the proposed model.
In summary, this thesis has developed a comprehensive framework of demand response on variable end-use consumptions with stochastic generation from renewables while optimizing both reliability and cost. Smart grid technologies, such as renewables, microgrid, storage, load signature, and demand response, have been extensively studied and interactively modeled to provide more intelligent planning and management for the smart grid.published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
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Ratshitanga, Mukovhe. "Investigation and design of an integrated monitoring, protection, and control system of a power reticulation network." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2710.
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Thesis (Master of Engineering in Electrical Engineering))--Cape Peninsula University of Technology, 2018.As far as substation automation systems are concerned, one of the prime requirements of most utilities today is the interoperability between Intelligent Electronic Devices (IEDs) of different manufacturers. The standard IEC 61850 - Communication Networks and Systems in Substations - allows such interoperability between IEDs for protection and automation of substations. Presently, many manufacturers have implemented, or are in the process of implementing this standard in their IEDs. This has encouraged some utilities to specify IEC is to ensure that both system requirements are met and the features and benefits of the standard are fully exploited. The author of this thesis investigated and brought forward the design of an integrated monitoring protection and control system of a network in Cape Peninsula University of Technology (CPUT) campus based of the IEC 61850 standard. A method of testing the physical IED based on Hardware-In-Loop (HIL) configuration with the Real-Time Digital Simulator (RTDS) is developed and implemented. Mapping of IED Substation Configuration Language (SCL) with that of the RTDS GTNET cards is discussed and implemented to further exploit the use of realtime testing with Generic Object Oriented Substation Event messages (GOOSE). The thesis highlight the benefits of interconnecting the reticulation IEDs into a standardised communication network for protection, control and monitoring of each substation event. This improves the access to information and reduces maintenance cost on the reticulation network.
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Lindén, Annica, and Anna Ågren. "Load flow control and optimization of Banverket’s 132 kV 16 2/3 Hz high voltage grid." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4583.
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The purpose of this thesis was to investigate the possibility of power flow control, on a section of a railway grid fed by rotary converters, using an extra feeding line. Two possible solutions for the power flow control were examined. The first using a series reactance in connection to each converter station and the second by changing the tap changer level of the transformer between the converter station and the feeding line.
In the two models a distance, comparable to the distance between Boden and Häggvik, in Stockholm, was used. The simulations were performed using the software SIMPOW.
The results from the performed simulations show that series reactances, under the stated conditions, can essentially improve the power flow. To implement this air coils with inductances in the approximate size of 10 to 45 mH could be used. Further, the tap changer levels of the transformer may be used, for individual converter stations, as a way to control the reactive power flow.
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Нікуліна, Олена Миколаївна, Валерій Петрович Северин, and Ніна Вікторівна Трубчанова. "Математичні моделі систем управління парогенератором енергоблоку АЕС." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33421.
Full textAbstract:
Розроблена математична модель системи автоматичного управління продуктивністю парогенератора, яка представлена в просторі станів з відносними змінними у вигляді системи диференціальних рівнянь. Розв’язані задачі ідентифікації параметрів моделей систем керування за експериментальними даними процесів в парогенераторі ПГВ-1000.The mathematical model of the system of automatic control of the efficiency of a steam generator, which is presented in the space of states with relative variables in the form of a system of differential equations, is developed. Problems of parameters identification of control systems models based on experimental data of processes in steam generator PGV-1000 were solved.
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Sastry, Jyoti. "Direct AC control of grid assets." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41109.
Full textAbstract:
The objective of the proposed research is to investigate feasible approaches to dynamic control of the power grid. Growth in the demand for electric power, and an increase in the penetration of renewable energy resources are causing congestion on an already aging power grid. Conventional grid control involves the use of static assets that operate on long time scales. These assets provide no dynamic control on the grid, and are typically used for scheduled support. Existing solutions (FACTS devices) to dynamic grid control have seen minimal market penetration because of high cost and low reliability. The proposed research provides a solution for dynamic control of the power grid that augments existing grid assets with a thin AC converter (TACC) to realize enhanced dynamic control. The TACC is a direct AC converter with filter elements and no bulk energy storage that dynamically reflects the asset value on the grid. The converter has a fail-normal mode of operation that returns the asset to its initial operating state, thereby not degrading system reliability. Some applications of TACCs include Inverter-Less STATCOMs and Controllable Network Transformers, which are realized by augmenting shunt VAR capacitors and load tap changers respectively. The principle of virtual quadrature sources is proposed to enable conditioning of AC voltages and currents. The concept is a novel method to realize control of phase angle and, or harmonics in single-phase AC converters, with no bulk energy storage. This concept is used to control the TACC and provides the asset with significantly enhanced control capabilities. Scaling of the TACC to utility voltage and power levels has been addressed by proposing a novel multilevel direct AC converter. The concept proposes the use of commercially available low cost semiconductor devices to realize high power converters. The specific application chosen to validate the concept of TACCs, through a medium voltage design, is the Inverter-less STATCOM.
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Алексієвський, Дмитро Геннадійович. "Синтез електромеханічних систем вітроенергетичних установок з аеродинамічним мультиплікуванням." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2020. http://repository.kpi.kharkov.ua/handle/KhPI-Press/47742.
Full textAbstract:
Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.09.03 "Електротехнічні комплекси та системи" (14 - Електрична інженерія) - Запорізький національний університет, Запоріжжя, 2020. Подана до захисту до спеціалізованої вченої ради Д 64.050.04 у Національному технічному університеті "Харківський політехнічний інститут". Дисертація присвячена вирішенню актуальної наукової проблеми, що полягає у розвитку теоретичних засад синтезу електромеханічних систем вітроенергетичних установок (ВЕУ) з аеродинамічним мультиплікуванням (АДМ), які забезпечують максимальну ефективність роботи ВЕУ з точки зору відбору потужності від вітрового потоку та підвищення їх експлуатаційної надійності. Запропонована узагальнена математична модель вітроелектрогенеруючої системи ВЕУ з аеродинамічним мультиплікуванням, яка дозволяє отримувати теоретичні залежності, що описують властивості даної системи, в узагальненій формі з метою їх використання при проектуванні даних систем. Запропоновано графоаналітичний метод аналізу ефекту автооптимізації, який дозволив: дати теоретичне пояснення причин появи цього ефекту та виявити умови, що необхідні для його виникнення, намітити шляхи його більш ефективного використання. Запропоновано спосіб декомпозиції електромеханічної системи та методику побудови схем трактів перетворення енергії в цих системах, які дозволяють розглядати широкий клас електромеханічних систем ВЕУ з аеродинамічним мультиплікуванням з єдиних теоретичних позицій, проводити їх аналіз та класифікацію за структурними ознаками, виявляти ці ознаки завдяки наочній візуалізації. Запропоновано спосіб синтезу візуально-блочних моделей електромеханічних систем ВЕУ з АДМ, який значно скорочує терміни проведення даного синтезу та значно зменшує ймовірність помилок при моделюванні. Розроблено формалізований алгоритм перетворення візуально-блочної моделі електротехнічного комплексу ВЕУ з АДМ, який дозволяє значно скоротити створення математичного опису електромеханічної системи ВЕУ з АДМ як об'єкту управління, що використовується при синтезі її систем управління. Розроблено алгоритм моментного керування електромеханічною системою ВЕУ з АДМ, який дозволяє використовувати аеромеханічну систему ВЕУ з АДМ з жорсткою аеродинамічною конструкцією первинного вітроколеса, що значно зменшує капітальні та експлуатаційні витрати на ВЕУ та підвищує її експлуатаційну надійність. Шляхом математичного моделювання отримано залежності величини перевищення потужності, під час перехідного процесу при реалізації алгоритму моментного управління електромеханічною системою ВЕУ з АДМ, від середнього значення, амплітуди та частоти коливання вітрового потоку, що дозволяє проводити розрахунок встановленої потужності компонентів електрообладнання ВЕУ. В результаті модельного експерименту отримано характеристики впливу параметрів системи на величину вихідної потужності, що дозволило визначити оптимальні режими керування електромеханічною системою ВЕУ з АДМ. За допомогою експериментальної ВЕУ було підтверджено працездатність запропонованого способу моментного управління ВЕУ з АДМ. Розроблено схему та алгоритм функціонування імітатору аеромеханічної підсистеми, який дозволяє створити стенд для випробування електрообладнання ВЕУ з АДМ в лабораторних або цехових умовах як на стадії розробки нового електрообладнання, так і при випробуванні електрообладнання при серійному виробництві цих систем. Результати роботи було використано при проектуванні електрообладнання ВЕУ з АДМ ТГ-750, ТГ-1000 ВАТ «НДІ «Перетворювач» (м. Запоріжжя) і КБ «Конкорд» (м. Дніпро) та в перспективній розробці КБ «Голубенко» ВАТ «Згода» (м. Дніпро) ВЕУ з АДМ ТГ-2100 потужністю 2100 кВт.Dissertation on achieving the scientific degree Doctor of Technical Science by specialty 05.09.03 "Electrotechnical Complexes and Systems" (14 - Electrical engineering) - Zaporizhzhya National University, Zaporizhzhia, 2020. Filed for defense at a specialized academic council D 64.050.04 at the National Technical University «Kharkiv Polytechnic Institute». The development of the synthesis theoretical base of the wind power plants electromechanical systems with aerodynamic multiplication (ADM), provide the maximum efficiency of wind turbines in power take-off from the wind flow terms and increase their operational reliability, was the dissertation subject. A generalized wind turbine with aerodynamic multiplication mathematical model was proposed. This model allows one to obtain theoretical dependencies describing the properties of a given system in a generalized form for the purpose of its use in the design of these systems. The graph analytical method for analyzing the effect of auto-optimization is proposed in the thesis. This method allowed us to give a theoretical explanation of the reasons for the appearance of the auto-optimization effect, discovered the conditions for its occurrence, and outlined the ways for its more efficient use. The decomposition method of the electromechanical system and the methodology for constructing circuits of energy conversion paths in these systems are also proposed in the paper. These methods allow us to consider a wide class of wind turbines with aerodynamic multiplication from a single theoretical point of view analyze and classify them according to structural features, and identify these features through visualization. A method of visual-block models synthesis of wind turbines with ADM is proposed. This method significantly shortens synthesis time and significantly reduces the probability of modeling errors. A formalized algorithm for the transformation of the visual-block model of the electrotechnical complex of wind turbines with ADM has been developed. An algorithm for the instantaneous control of a wind turbines electromechanical system with ADM was developed. The algorithm allows using the wind system with the rigid aerodynamic design of the primary wind wheel, which significantly reduces the capital and operational costs of the wind turbine and increases its operational reliability. The excess power amount dependence, during the transition process, when implementing the algorithm for instant control of the wind turbine electromechanical system with ADM, on the amplitude and frequency of the wind flow oscillations, which allows you to calculate the installed power in the elements of electrical equipment, are got as the result by mathematical modeling. As the result of the model experiment, the influence of the system parameters characteristics on the output power was obtained, which made it possible to determine the optimal control modes for the electromechanical system of wind turbines with ADM. With the help of an experimental wind turbine, the efficiency of the proposed method of instantaneous control of wind turbine with ADM was confirmed. The scheme and algorithm of functioning of the simulator of the aeromechanical subsystem are developed. This allows creating a stand for electrical equipment testing of wind turbines with ADM in laboratory or workshop conditions both at the development stage of new electrical equipment and during testing of electrical equipment during the batch production of these systems. The results of the work were used in the design of wind turbine electrical equipment with ADM TG-750, TG-1000 of OJSC "Preobraxovatel" Research Institute (Zaporizhzhya) and Concord CB (Dnipro) and in the prospective development of Golubenko CB of OJSC "Zgoda" (Dnipro) Wind turbine with ADM TG-2100 capacity of 2100 kW.
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Oda, George. "Aplicação do software scicoslab para análise do controle automático de geração de sistemas elétricos de potência." Universidade Federal de Uberlândia, 2012. https://repositorio.ufu.br/handle/123456789/14492.
Full textAbstract:
The purpose of this paper is to show that the software ScicosLab can be used as an interesting and effective computational tool to analyze the automatic generation control of electric power systems.
Firstly it is presented the software and, afterwards, the concepts and definitions of rotational movements in order to develop mathematical models for the generators equipped with steam turbines or hydraulic turbines and speed governors, and for their electrical loads.
For the studies it is used a system comprised by two distinct interconnected areas where a load increase in one area is simulated without/with the tieline, ignoring, and then considering the primary and supplementary controls.
Finally, it is analyzed a more realistic system with three distinct areas extracted from the Brazilian power system.
The computational results show graphically the variations of the two main quantities of interest: the frequency of each area of the system and the tieline power. These quantities allow the evaluation of the system behavior after a disturbance that affects the generation-load balance.
Within the above context, it is verified that the ScicosLab computer package effectively models and simulates the load-frequency control of power systems, qualifying, therefore, as an excellent alternative to replace any similar program which requires license payment.A proposta deste trabalho é mostrar que o software ScicosLab pode ser utilizado como uma ferramenta computacional, interessante e eficaz, para analisar o controle automático de geração de sistemas elétricos de potência. Inicialmente é apresentado o software e, em seguida, os conceitos de movimentos rotativos que permitem desenvolver os modelos matemáticos para os geradores equipados com turbinas a vapor ou hidráulica e reguladores de velocidade, e para suas cargas elétricas. Para possibilitar os estudos é utilizado um sistema constituído por duas áreas distintas interligadas, onde é simulado um aumento de carga em uma destas áreas, sem e com a linha de interligação, desconsiderando e, em seguida, considerando os controles primário e suplementar. Finalmente, analisa-se um sistema mais realístico com três áreas distintas extraído do sistema elétrico brasileiro. Os resultados computacionais mostram graficamente as variações das duas principais grandezas de interesse: a frequência de cada área do sistema e a potência da linha de interligação. Estas grandezas permitem avaliar o comportamento do sistema após uma perturbação que afeta o balanço geração-carga. Considerando o exposto acima, constata-se que o pacote computacional ScicosLab modela e simula eficazmente o controle carga-frequência de sistemas elétricos de potência, qualificando-se, portanto, como uma excelente alternativa para substituir qualquer programa similar que exige pagamento de licença.
Mestre em Ciências
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Алексієвський, Дмитро Геннадійович. "Синтез електромеханічних систем вітроенергетичних установок з аеродинамічним мультиплікуванням." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2020. http://repository.kpi.kharkov.ua/handle/KhPI-Press/47741.
Full textAbstract:
Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.09.03 "Електротехнічні комплекси та системи" - Запорізький національний університет, Запоріжжя, 2020.
Дисертація присвячена вирішенню актуальної наукової проблеми, що полягає у розвитку теоретичних засад синтезу електромеханічних систем вітроенергетичних установок з аеродинамічним мультиплікуванням, які забезпечують максимальну ефективність роботи ВЕУ з точки зору відбору потужності від вітрового потоку та підвищення їх експлуатаційної надійності. Запропонована узагальнена математична модель вітроелектрогенеруючої системи ВЕУ з аеродинамічним мультиплікуванням, яка дозволяє отримувати теоретичні залежності, що описують властивості даної системи, в узагальненій формі з метою їх використання при проектуванні даних систем. Запропоновано графоаналітичний метод аналізу ефекту автооптимізації, який дозволив: дати теоретичне пояснення причин його появи та виявити умови, що необхідні для виникнення цього ефекту, намітити шляхи його більш ефективного використання. Запропоновано спосіб декомпозиції електромеханічної системи та методику побудови схем трактів перетворення енергії в цих системах, які дозволяють розглядати широкий клас електромеханічних систем ВЕУ з аеродинамічним мультиплікуванням з єдиних теоретичних позицій, проводити їх аналіз та класифікацію за структурними ознаками, виявляти ці ознаки завдяки наочній візуалізації. Запропоновано спосіб синтезу візуально-блочних моделей електромеханічних систем ВЕУ з АДМ, який значно скорочує терміни проведення даного синтезу та значно зменшує ймовірність помилок при моделюванні. Розроблено формалізований алгоритм перетворення візуально-блочної моделі електротехнічного комплексу ВЕУ з АДМ, який дозволяє значно скоротити створення математичного опису електромеханічної системи ВЕУ з АДМ як об'єкту управління, що використовується при синтезі її систем управління. Розроблено алгоритм моментного управління електромеханічною системою ВЕУ з АДМ, який дозволяє використовувати аеромеханічну систему ВЕУ з АДМ з жорсткою аеродинамічною конструкцією первинного вітроколеса, що значно зменшує капітальні та експлуатаційні витрати на ВЕУ та підвищує її експлуатаційну надійність. Шляхом математичного моделювання отримано залежності величини перевищення потужності під час перехідного процесу, при реалізації алгоритму моментного управління електромеханічною системою ВЕУ з АДМ, від середнього значення, амплітуди та частоти коливання вітрового потоку, що дозволяє проводити розрахунок встановленої потужності компонентів електрообладнання ВЕУ. В результаті модельного експерименту отримано характеристики впливу параметрів системи на величину вихідної потужності, що дозволило визначити оптимальні режими управління електромеханічною системою ВЕУ з АДМ. За допомогою експериментальної ВЕУ було підтверджено працездатність запропонованого способу моментного управління ВЕУ з АДМ.
Розроблено схему та алгоритм функціонування імітатору аеромеханічної підсистеми, який дозволяє створити стенд для випробування електрообладнання ВЕУ з АДМ в лабораторних або цехових умовах як на стадії розробки нового електрообладнання, так і при випробуванні електрообладнання при серійному виробництві цих систем. Результати роботи було використано при проектуванні електрообладнання ВЕУ з АДМ ТГ-750 та ТГ-1000 ВАТ «НДІ «Перетворювач» (м. Запоріжжя) і КБ «Конкорд» (м. Дніпро) та у перспективній розробці КБ «Голубенко» ВАТ «Згода» (м. Дніпро) ВЕУ з АДМ ТГ-2100 потужністю 2100 кВт.Dissertation on achieving the scientific degree Doctor of Technical Science by specialty 05.09.03 "Electrotechnical Complexes and Systems" - Zaporizhzhya National University, Zaporizhzhia, 2020. The development of the synthesis theoretical base of the wind power plants electromechanical systems with aerodynamic multiplication, provide the maximum efficiency of wind turbines in power take-off from the wind flow terms and increase their operational reliability, was the dissertation subject. A generalized wind turbine with aerodynamic multiplication mathematical model was proposed. This model allows one to obtain theoretical dependencies describing the properties of a given system in a generalized form for the purpose of its use in the design of these systems. The graph analytical method for analyzing the effect of auto-optimization is proposed in the thesis. This method allowed us to give a theoretical explanation of the reasons for the appearance of the auto-optimization effect, discovered the conditions for its occurrence, and outlined the ways for its more efficient use. The decomposition method of the electromechanical system and the methodology for constructing circuits of energy conversion paths in these systems are also proposed in the paper. These methods allow us to consider a wide class of wind turbines with aerodynamic multiplication from a single theoretical point of view analyze and classify them according to structural features, and identify these features through visualization. A method of visual-block models synthesis of wind turbines with ADM is proposed. This method significantly shortens synthesis time and significantly reduces the probability of modeling errors. A formalized algorithm for the transformation of the visual-block model of the electrotechnical complex of wind turbines with ADM has been developed. An algorithm for the instantaneous control of a wind turbines electromechanical system with ADM was developed. The algorithm allows using the wind system with the rigid aerodynamic design of the primary wind wheel, which significantly reduces the capital and operational costs of the wind turbine and increases its operational reliability. The excess power amount dependence, during the transition process, when implementing the algorithm for instant control of the wind turbine electromechanical system with ADM, on the amplitude and frequency of the wind flow oscillations, which allows you to calculate the installed power in the elements of electrical equipment, are got as the result by mathematical modeling. As the result of the model experiment, the influence of the system parameters characteristics on the output power was obtained, which made it possible to determine the optimal control modes for the electromechanical system of wind turbines with ADM. With the help of an experimental wind turbine, the efficiency of the proposed method of instantaneous control of wind turbine with ADM was confirmed. The scheme and algorithm of functioning of the simulator of the aeromechanical subsystem are developed. This allows creating a stand for electrical equipment testing of wind turbines with ADM in laboratory or workshop conditions both at the development stage of new electrical equipment and during testing of electrical equipment during the batch production of these systems. The results of the work were used in the design of wind turbine electrical equipment with ADM TG-750, TG-1000 of OJSC "Preobrazovatel" Research Institute (Zaporizhzhya) and Concord CB (Dnipro) and in the prospective development of Golubenko CB of OJSC "Zgoda" (Dnipro) Wind turbine with ADM TG-2100 capacity of 2100 kW.
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Северин, Валерій Петрович, Олена Миколаївна Нікуліна, and Дарина Андріївна Лютенко. "Модель системи автоматичного управління для маневрування потужністю реактора ВВЕР-1000." Thesis, НТУ "ХПІ", 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33462.
Full textAbstract:
Представлена багатозонна математична модель реактора ВВЕР-1000 з зосередженими параметрами як об’єкта автоматичного управління. Модель реактора доповнена рівняннями регуляторів та приведена до відносних змінних стану. Розраховано аксіальний офсет як кількісну міру сталості реактора.The multi-zone mathematical model of WWER-1000 reactor with lumped parameters as an object of automatic control is presented. The model of the reactor is supplemented by the equations of the regulators and is brought to the relative variables of the state. The axial offset is calculated as a quantitative measure of the reactor constancy.
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Ferreira, Castellane Silva. "Sistema de gerenciamento automático de reatores eletrônicos com ajuste do nível de luminosidade para múltiplas lâmpadas fluorescentes /." Ilha Solteira : [s.n.], 2008. http://hdl.handle.net/11449/87118.
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Resumo: Este trabalho trata do desenvolvimento e implementação de um sistema de iluminação fluorescente com gerenciamento automático baseado em reatores eletrônicos aplicados a múltiplas lâmpadas fluorescentes. O foco desta pesquisa é direcionado ao desenvolvimento de uma plataforma automática de gerenciamento e supervisão, propiciando o controle de luminosidade, acionamento remoto e também acionamentos programáveis de acordo com o expediente de trabalho do local e condições de iluminação natural do ambiente, além de prover aumento de vida útil das lâmpadas fluorescentes, em função de protocolo proposto para préaquecimento e ignição. Foram acoplados ao sistema sensores de luminosidade e de presença, permitindo a obtenção dos dados necessários para a atuação automática. O controle por calha das lâmpadas fluorescentes é feito por um microcontrolador AtMega8 da ATMEL, o qual é responsável pela automação do sistema. A plataforma de gerenciamento e monitoração utiliza um microcomputador para que seja executado o aplicativo desenvolvido, o qual provê uma interface amigável ao usuário. Assim, um protocolo de comunicação foi desenvolvido para que haja uma comunicação de dados confiável, oferecendo robustez e alta confiabilidade ao controle do sistema de iluminação. Para o processamento dos dados, foi utilizado o barramento serial de comunicação full duplex com padrão RS232 e RS485 com transmissão assíncrona. Adicionalmente, o sistema funciona no sistema mestre-escravo, sendo o microcomputador responsável por enviar endereçamentos e ordens de ação aos microcontroladores, os quais identificam os endereçamentos e dados, executam a ação programada e envia dado de monitoramento ao microcomputador, quando requisitado pelo usuário.Abstract: In this work, the development and implementation of an illumination fluorescent system with automatic management based on electronic ballast applied to multiple fluorescent lamps are presented. This research is directed in the development of the management and supervision of an automatic platform, allowing the control of luminosity, the remote actuation and also the programmable actuation according with the local business work and conditions of natural light of the environment. In addition, the ballast will provide the increase in the average lifetime for fluorescent lamps, considering a proposed protocol to pre-heating and ignition. The automatic actuation of the system is allowed by the coupling, of the luminosity and presence sensors. The control of fluorescent lamps by channel is executed by an ATMEL's AtMega8 microcontroller, which is responsible for the system automation. The management and monitoring platform uses a microcomputer with purpose to execute the implemented application, which will provide a friendly interface to the user. Thus, a protocol of communication was developed to allow a reliable communication of data, providing robustness and high reliability to the control of lighting system. Considering the processing of data acquired, was used a Serial Bus of communication with full duplex standard RS232 and RS485, with asynchronous transmission. Additionally, the system works in the master-slave mode, and the microcomputer is responsible for sending addresses and orders of action to microcontrollers, which identify and address data, in order to perform the programmed action to it, and in order to send data to the microcomputer, when requested by the user.
Orientador: Carlos Alberto Canesin
Coorientador: Fábio Toshiaki Wakabayashi
Banca: Falcondes Jose Mendes de Seixas
Banca: Ricardo Nederson do Prado
Mestre
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Pieters, Willem Diederick. "Monitoring, protection, and voltage control of parallel power transformers based on IEC 61850-9-2 process bus." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/3067.
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Thesis (MEng (Electrical Engineering)--Cape Peninsula University of Technology, 2019The purpose of an electrical power system is to supply electrical energy to the customers. Power transformers are required to transform the system voltage from generation to transmission and distribution levels. Protection and control systems must ensure that power system high voltage equipment such as transformers operate and deliver save, reliable and secure electricity supply. The aim of the project research work is to develop and implement a strategy, methods and algorithms for monitoring, protection and voltage control of parallel power transformers based on IEC 61850-9-2 process bus standard. NamPower is a power utility in Namibia. The IEC 61850 protocol for electrical substation automation system is used for the protection and control of 5 power transformers operated in parallel in an existing substation system. The IEC 61850-9-2 process bus standard is however not used in regards of Sampled Values (SV). Protection and control devices are connected to a substation communication network, routers and switches using fibre optic linked Ethernet. Inductive Current Transformers (CTs) and Voltage Transformers (VTs) secondary circuits are hardwired to Intelligent Electronic Devices (IEDs) and fibre optic links are not used for this purpose at process level communication. The research focuses on the implementation of the IEC 61850 standard with Merging Units (MUs) and sampled values to improve the existing implemented protection and control system at NamPower. This includes substation communication networks and MUs used for transformer protection, voltage regulator control and cooling fan control. At the present the CTs located at the transformer bushings and switchgear and the VTs located at the switchgear are hardwired to the inputs on protection and control IEDs. The research focuses on issues with the copper wires for voltage and currents signals and how these issues can be eliminated by using the MUs and the SV protocol. The MUs which are considered in this Thesis is to improve the voltage regulator control and the control of the cooling fan motors. The voltage regulator control IED is situated at the tap change motor drive of the On-Load Tap Changer (OLTC). The IED of each transformer is required to regulate the voltage level of the secondary side bus bar it is connected to. All the regulating IEDs are required to communicate with each other and collectively to control the bus bar voltage depending on the switching configuration of the parallel transformers. The control circuit for controlling the cooling fan motors is hardwired. Temperature analogue signal input into a programmable automation controller IED can be used for controlling the transformer cooling fans. A strategy, methods and algorithms for transformer protection, voltage regulator control and cooling fan motor control of parallel power transformers need to be developed and implemented based on IEC 61850-9-2 process bus. Power utilities and distributors can benefit from interpretation of the IEC 61850-9-2 standard and implementing MUs and SV in substations. MUs can be included in the power transformer protection, automation and control systems. A cost reduction in high voltage equipment, substation installation and commissioning costs and better performance of protection and control system are anticipated.
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Северин, Валерий Петрович, Елена Николаевна Никулина, and Дарина Андреевна Лукинова. "Многокритериальный синтез систем управления энергоблока АЭС с реактором ВВЭР-1000 для эксплуатации в маневренных режимах." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33422.
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Для многокритериального синтеза нелинейных систем управления использована упрощенная векторная целевая функция, которая учитывает ограничения переменных параметров, ограничения перерегулирования и размаха колебаний, а также требования минимальности времени регулирования. Как пример задачи синтеза системы управления энергоблока при работе в маневренных режимах рассматривается задача многокритериального синтеза системы управления турбиной с нечеткими регуляторами.For a multicriterion synthesis of nonlinear control systems, a simplified vector objective function is used that takes into account the limitations of the variable parameters, the limitations of overshoot and swing of the oscillations, and also the requirements for the minimum of the control time. As an example of the task of synthesizing the power unit control system during operation in maneuvering modes, the task of multi-criteria synthesis of the turbine control system with fuzzy regulators is considered.
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Nduku, Nyaniso Prudent. "Development of methods for distribution network power quality variation monitoring." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1144.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009The purpose of this project is to develop methods for distribution network power quality' variations monitoring. Power quality (PO) has become a significant issue for both power suppliers and customers. There have been important changes in power system regarding to power quality requirements. "Power quality" is the combination at voltage quality and current quality. The main research problem of the project is to investigate the power quality of a distribution network by selection of proper measurement, applying and developing the existing classic and modern signal conditioning methods for power disturbance's parameters extracting and monitoring. The research objectives are: To study the standard lEC 61000-4-30 requirements. to investigate the common couplings in the distribution network. To identity the points for measurement, to develop MySQL database for the data from the measurement and to develop MATLAB software tor simulation of the network To develop methods based on Fourier transforms for estimation of the parameters of the disturbances. To develop software for the methods implementation, The influence of different loads on power quality disturbances are considered in the distribution network. Points on the network and meters according to the lEC power quality standards are investigated and applied for the CPUT Bellville campus distribution network. The implementation of the power quality monitoring for the CPUT Bellville campus helps the quality of power supply to be improved and the used power to be reduced. MATLAB programs to communicate with the database and calculate the disturbances and power quality parameters are developed.
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Mahmoud, Thair. "Optimal power generation in microgrids using agent-based technology." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/599.
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The existing power grids that form the basis of the respective electrical power infrastructures for various states and nations around the world, are expected to undergo a period of rapid change in the near future. The key element driving this change is the emergence of the Smartgrid. The Smartgrid paradigm represents a transition towards an intelligent, digitally enhanced, two-way power delivery grid. The aim of the Smartgrid is to promote and enhance the e_cient management and operation of the power generation and delivery facilities, by incorporating advanced communications, information technology, automation, and control methodologies into the power grid proper. Smartgrid's are currently an active topic for research, where the research is strongly focused on developing new technologies such as: demand response, power generation management, pricing modelling and energy markets participation, power quality, and self-healing scenarios. In recent times, in both the United States of America and Europe, many new projects have begun which are specifically directed towards developing “Smartgrid” technologies. In Australia, the Federal Government has recently initiated funding plans to promote the commercialisation of renewable energy. In order to exploit these developments, Edith Cowan University (ECU); which is a High Voltage (HV) customer for the major utility network of Western Australia, and which owns its own transformers and Low Voltage (LV) network; is planning to integrate renewable energy suppliers within its LV network.
The aim of this research is to introduce a smart decision making system, which can manage the operation of disparate power generation sources installed on a LV network (microgrid); such as that owned by ECU on its campuses. The proposed energy management system is to gather data in real-time, and it must be capable of anticipating and optimising energy needs for each operational scenario that the microgrid might be expected to experience. The system must take into account risk levels, while systematically favouring low economic and environmental costs. A management system application, based on autonomous and distributed controllers, is investigated in a virtual environment. The virtual environment being a full-scale simulation of ECU's microgrid; with solar panels, wind turbines, storage devices, gas gen-sets, and utility supply. Hence the simulation studies were conducted on the basis of realistic demand trends and weather conditions data.
The major factors for reducing the cost of generation in the case study, were identified as being: 1) demand forecasting; 2) generation scheduling; 3) markets participation; and 4) autonomous strategies configuration, which is required to cope with the unpredictable operation scenarios in LV networks. Due to the high uncertainty inherent within the operational scenarios; an Artificial Intelligence (AI) deployment for managing the distributed sub-systems was identified as being an ideal mechanism for achieving the above mentioned objectives. Consequently it is proposed that Multi-Agent System (MAS) technology be deployed, to enable the system to respond dynamically to the unpredictable operational conditions by updating the method of analysis. The proposed system is to behave in a strategic manner when dealing with the expected operational scenarios, by aiming to achieve the lowest possible cost of power generation for the microgrid. The simulated system is based on realistic operational scenarios, which have been scaled to suit the size and type of load in the case study. The distributed intelligent modules have proven to be successful in achieving the potential benefits of the dynamic operational conditions, by minimising the cost of power generation.
The distributed intelligent modules, which form the basis of the proposed management systems, have been designed to perform the following functions:
1. Provide accurate demand forecasts through the utilisation of an AI-based adaptive demand forecasting model. The novel demand-forecast modelling technique, which was introduced to model demand in the case study, has been utilised to supply reasonably accurate demand forecasts to other stages of processing in the management system. The forecasts are generated from this model, by monitoring and controlling the forecasting error to ensure consistent and satisfactory forecasts.
2. Make optimum decisions concerning the operation of the power generators by considering the economic and the environmental costs. In order to deal with the complexity of the operational conditions, a smart and adaptive generation scheduling method was implemented for the case study. The method was primarily applied to control the charging/ discharging process of the Storage Devices (SDs) among the other generators. The proposed method aims at controlling the resources, and extracting the benefit of having an hourly based variable generation cost.
3. Integrate the microgrid into the electricity market, in order to enable the microgrid to offer its spinning and non-spinning power generation reserve as Ancillary Services (AS) to the grid. To this end, studying the operational mechanisms of the Australian market was essential prior to building the proposed market participation rules which form an integral part of the proposed management system. As a result we used the market data, by approaching the market operators to create a semi-realistic competitive market environment for our simulations. Consequently, a smart and adaptive pricing mechanism, that adapts the AS prices to the amount of electricity on offer, and the level of demand in the market has been presented.
The motivation for introducing the proposed management system, is to achieve a transition plan for current microgrids, so that they can have a commercial connection to the future Smartgrid. The results obtained in this work show that there is a signi_cant economic and environmental advantage to be gained from utilising intelligence when managing electricity generation within a power grid. As a consequence, selecting the appropriate management strategy is fundamental to the success of the proposed management system. In conclusion, modelling of the proposed strategies using MAS technology has proven to be a successful approach, and one that is able to reflect the human attitude; in making critical decisions and in reducing the cost of generation.
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Северин, Валерий Петрович. "Синтез систем управления энергоблока АЭС в лаборатории оптимизации OPTLAB." Thesis, ТЕС, 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/43189.
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Рассмотрена лаборатория методов оптимизации, которая построена на принципах модульности, простоты и надежности. Выполнен синтез оптимальных систем управления для ядерного реактора, парогенератора и паровой турбины, а также систем автоматического поддержания нейтронной мощности и давления пара перед турбиной для нормальных режимов эксплуатации энергоблока.Consideration was given to the laboratory of optimization methods based on the principles of the modularity, simplicity and reliability. Optimal automatic control systems for the nuclear reactor, steam generator, steam turbine and automatic maintenance of the neutron power and the pressure before the turbine for normal operation modes were synthesized.
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Sari, Ibrahim. "Design, Fabrication And Implementation Of A Vibration Based Mems Energy Scavenger For Wireless Microsystems." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12610096/index.pdf.
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This thesis study presents the design, simulation, micro fabrication, and testing steps of microelectromechanical systems (MEMS) based electromagnetic micro power generators. These generators are capable of generating power using already available environmental vibrations, by implementing the electromagnetic induction technique. There are mainly two objectives of the study: (i) to increase the bandwidth of the traditional micro generators and (ii) to improve their efficiency at low frequency environmental vibrations of 1-100 Hz where most vibrations exist.
Four main types of generators have been proposed within the scope of this thesis study. The first type of generator is mainly composed of 20 parylene cantilevers on which coils are fabricated, where the cantilevers are capable of resonating with external vibrations with respect to a stationary magnet. This generator has dimensions of 9.5×8×
6 mm3, and it has been shown that 0.67 mV of voltage and 56 pW of power output can be obtained from a single cantilever of this design at a vibration frequency of 3.45 kHz. The second type generator aims to increase the bandwidth of the traditional designs by implementing cantilevers with varying length. This generator is sized 14×
12.5×
8 mm3, and the mechanical design and energy generation concept is similar to the first design. The test results show that by using 40 cantilevers with a length increment of 3 &
#956
m, the overall bandwidth of the generator can be increased to 1000 Hz. It has also been shown that 9 mV of constant voltage and 1.7 nW of constant power output can be obtained from the overall device in a vibration frequency range of 3.5 to 4.5 kHz. The third type is a standard large mass coil type generator that has been widely used in the literature. In this case, the generator is composed of a stationary base with a coil and a magnet-diaphragm assembly capable of resonating with vibrations. The fabricated device has dimensions of 8.5×
7×
2.5 mm3, and it has been considered in this study for benchmarking purposes only. The test results show that 0.3 mV of voltage and 40 pW of power output can be obtained from the fabricated design at a vibration frequency of 113 Hz. The final design aims to mechanically up-convert low frequency environmental vibrations of 1-100 Hz to a much higher frequency range of 2-3 kHz. This type of generator has been implemented for the first time in the literature. The generator is composed of two parts
a diaphragm-magnet assembly on the top, and 20 cantilevers that have coils connected in series at the base. The diaphragm oscillates by low frequency environmental vibrations, and catches and releases the cantilevers from the tip points where magnetic nickel (Ni) areas are deposited. The released cantilevers then start decaying out oscillations that is at their damped natural frequency of 2-3 kHz. It has been shown with tests that frequency up-conversion is realized in micro scale. The fabricated device has dimensions of 8.5×
7×
2.5 mm3, and a maximum voltage and power output of 0.57 mV and 0.25 nW can be obtained, respectively, from a single cantilever of the fabricated prototype at a vibration frequency of 113 Hz.
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Beneux, Gaëtan. "Développement de stratégies de contrôle pour le pilotage des convertisseurs avec prise en compte des aspects dynamiques événementiels." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0123/document.
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Les travaux de cette thèse portent sur l’analyse de stabilité et la synthèse de commandes robustes pour les systèmes affines à commutation en temps continu en présence d’incertitudes paramétriques constantes. On propose deux méthodes de commande permettant de garantir la stabilité asymptotique globale des systèmes affines à commutation avec paramètres inconnus. La première approche est basée sur l’estimation des paramètres inconnus et la reconstruction de l’état d’équilibre associée pour permettre d’appliquer une commande robuste adaptative. La seconde méthode est basée sur une augmentation d’état par l’ajout d’une action intégrale dans la boucle de commande qui garantit une erreur statique nulle. Pour chaque approche, deux lois de commande sont proposées. Une méthode du type « min switching » qui sélectionne la commutation la plus apte à stabiliser le système et une méthode de type « Embedded » permettant de générer une commande polytopique des différents modes possibles. Les résultats sont appliqués aux convertisseurs de puissance de topologie Flyback avec preuve de stabilité dans les deux modes de conduction (continue et discontinue)This PhD thesis is focused on stability analysis and robust control synthesis for continuous time switching affine systems in presence of constant parametric uncertainties. Two control methods are proposed to guarantee global asymptotic stability of switching affine systems with unknown parameters. The first approach is based on the estimation of the unknown parameters and the reconstruction of the related equilibrium state to allow the application of a robust adaptive control. The second method is based on a state augmentation by adding an integral action in the control loop that guarantees a null steady state error. For each approach, two control laws are proposed. A "min switching" method that selects the most suitable mode to stabilize the system and an "Embedded" method that generates a polytopic control of the different possible modes. The results are applied to Flyback topology power converters with proof of stability in both conduction modes (continuous and discontinuous)
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Asbery, Christopher W. "SMART GRID COMMUNICATIONS." UKnowledge, 2012. http://uknowledge.uky.edu/ece_etds/10.
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Smart grid technologies are starting to be the future of electric power systems. These systems are giving the utilities detailed information about their systems in real time. One of the most challenging things of implementing smart grid applications is employing the communications into the systems. Understanding the available communications can help ease the transition to these smart grid applications. Many of the utility personnel are spending too much time trying to figure out which communication is better for their application or applications. So this thesis presents the different communication types available with discussing the different attributes in which these communication types are going to offer to the utility. Then these communication types are looked such that utilities can quickly understand how to approach the difficult task of obtaining the information from the different smart grid applications by the use of different communication options.
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Северин, Валерий Петрович, Елена Николаевна Никулина, and Дарина Андреевна Лютенко. "Анализ и синтез систем управления энергоблока АЭС для маневренных режимов эксплуатации." Thesis, Сумський державний університет, 2016. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33429.
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Усовершенствованы модели и методы для анализа и синтеза систем автоматического управления энергоблоков атомных электростанций на основании методов оптимизации. Построены нелинейные математические модели систем управления энергоблока и проведен синтез оптимальных регуляторов для маневренных режимов эксплуатации.Models and methods for analysis and synthesis of automatic control systems of power units of nuclear power plants were improved on the basis of optimization methods. Nonlinear mathematical models of control systems of power unit were built and synthesis of optimal controllers was carried out for maneuvering modes of operation.
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Stavinoha, Jakub. "Informační a komunikační technologie v energetice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217603.
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The thesis is focused on the information and communication technologies used in the energetic. Problematic areas in energetic which are regulation, metering, control of waste minimalizations, expense and maximalization of earnings. These aspects lead to implementing expert systems, which have to process this bulk of information necessary for increasing efficiency and economization of single processes. Systems used in practice have their own hierarchical structure, where every application requires specific access of selection of used components that suit to the application. First of all it is about acceptable device selection in single level of the system: metering and regulation, data acquisition out of the process and informative layer. Suitable choice flowing from previous, already settled up application is possible to reach maximum efficiency of the whole system. In the thesis there are introduced systems used in practice and possibilities of increase the effectiveness of generation, transmission and distribution with ICT usage in distributed power generation. We are mainly talking about upgrade processes joined with power generation of energy, diagnostics, isolation states on the power line and usage of expert systems for distribution.
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Лукинова, Дарина Андреевна, Валерий Петрович Северин, and Елена Николаевна Никулина. "Оптимизация показателей качества систем автоматического управления ядерным реактором ВВЭР-1000." Thesis, Національний університет біоресурсів і природокористування України, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33125.
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Представлены результаты математического моделирования систем автоматического регулирования мощности ядерного реактора ВВЭР-1000. Применены методы оптимизации прямых показателей качества систем автоматического регулирования мощности ядерного реактора с различными типами регуляторов.The results of mathematical modeling of automatic control systems of power of the nuclear reactor WWER-1000 are presented. The technique of optimization of direct quality indexes of automatic regulation system of power of a nuclear reactor with various types of regulators is applied.
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Gomes, Ricardo Borges. "Resolução do problema de fluxo de carga para redes de distribuição utilizando o metodo desacoplado rapido com rotação automatica de eixos." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261715.
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Orientador: Carlos Alberto de Castro JuniorDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-06T19:37:05Z (GMT). No. of bitstreams: 1 Gomes_RicardoBorges_M.pdf: 725231 bytes, checksum: e24b9811f14e33910092b2f639a89050 (MD5) Previous issue date: 2006
Resumo: O método desacoplado rápido (MDR) [2] é uma variante do tradicional método de Newton [1] para a resolução do problema de fluxo de carga (obtenção do estado de operação de redes elétricas de potência). Sabe-se que o MDR apresenta desempenho insatisfatório quando aplicado a redes de distribuição, devido à desfavorável relação r/x dos ramos, resultando num processo de cálculo que pode apresentar divergência ou convergência lenta (grande número de iterações). Há algum tempo foi proposta uma alteração no MDR, chamada de rotação de eixos[4], que melhora as características de convergência do método. A idéia consiste em obter uma rede fictícia para a qual o MDR funcione bem e cujo estado de operação (magnitudes e ângulos de tensão) seja o mesmo da rede original. O valor do ângulo de rotação de eixos, único para toda a rede, é determinado empiricamente. Recentemente uma outra proposta de rotação ótima de eixos[5] foi apresentada, sugerindo modificações ao método que trouxeram maior automação aos cálculos, apesar de efeitos desfavoráveis em relação à manipulação de matrizes e ao significado físico da rede elétrica durante o processo iterativo. O presente trabalho traz um novo algoritmo de rotação de eixos que supera algumas desvantagens dos métodos apresentados em [4, 5], com bom desempenho. Além disso, traz uma interessante contribuição sobre a rotação de barras do tipo PV, não abordado anteriormente
Abstract: The fast decoupled loadflow (FDLF) [2] is a variant of the traditional Newton method [1] for solving the loadflow problem (find the operational state of electrical power networks). It is well-known that FDLF presents unsatisfactory performance when applied to distribution systems. Their unfavourable r/x branch ratios may lead to divergence or slow convergence (large number of iterations). A modification to the FDLF, called axesrotation[4], was proposed some time ago, which improves convergency of the method. The idea is to obtain a fictitious network for which the FDLF performs better and which operational state (voltage magnitudes and angles) is the same as the original network. However, the rotation angle is determined empirically. Recently the optimal axes rotation[5] was presented, suggesting some modifications that led to more automated calculations, despite of some undesirable effects on matrices handling and also to the physical meaning of networks during the iterative process. This research work presents a new algorithm for axes rotation that overcomes some disadvantages found in [4, 5], with good performance. Moreover, it brings an interesting contribution on the rotation of PV buses, not previously considered.
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica
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Conficoni, Christian <1983>. "Nonlinear constrained and saturated control of power electronics and electromechanical systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5576/1/Conficoni_Christian_tesi.pdf.
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Power electronic converters are extensively adopted for the solution of timely issues, such
as power quality improvement in industrial plants, energy management in hybrid electrical
systems, and control of electrical generators for renewables. Beside nonlinearity, this systems
are typically characterized by hard constraints on the control inputs, and sometimes
the state variables. In this respect, control laws able to handle input saturation are crucial
to formally characterize the systems stability and performance properties. From a practical
viewpoint, a proper saturation management allows to extend the systems transient
and steady-state operating ranges, improving their reliability and availability.
The main topic of this thesis concern saturated control methodologies, based on modern
approaches, applied to power electronics and electromechanical systems. The pursued
objective is to provide formal results under any saturation scenario, overcoming the
drawbacks of the classic solution commonly applied to cope with saturation of power converters,
and enhancing performance. For this purpose two main approaches are exploited
and extended to deal with power electronic applications: modern anti-windup strategies,
providing formal results and systematic design rules for the anti-windup compensator, devoted
to handle control saturation, and “one step” saturated feedback design techniques,
relying on a suitable characterization of the saturation nonlinearity and less conservative
extensions of standard absolute stability theory results.
The first part of the thesis is devoted to present and develop a novel general anti-windup
scheme, which is then specifically applied to a class of power converters adopted for power
quality enhancement in industrial plants. In the second part a polytopic differential inclusion
representation of saturation nonlinearity is presented and extended to deal with a
class of multiple input power converters, used to manage hybrid electrical energy sources.
The third part regards adaptive observers design for robust estimation of the parameters
required for high performance control of power systems.
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Conficoni, Christian <1983>. "Nonlinear constrained and saturated control of power electronics and electromechanical systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5576/.
Full textAbstract:
Power electronic converters are extensively adopted for the solution of timely issues, such
as power quality improvement in industrial plants, energy management in hybrid electrical
systems, and control of electrical generators for renewables. Beside nonlinearity, this systems
are typically characterized by hard constraints on the control inputs, and sometimes
the state variables. In this respect, control laws able to handle input saturation are crucial
to formally characterize the systems stability and performance properties. From a practical
viewpoint, a proper saturation management allows to extend the systems transient
and steady-state operating ranges, improving their reliability and availability.
The main topic of this thesis concern saturated control methodologies, based on modern
approaches, applied to power electronics and electromechanical systems. The pursued
objective is to provide formal results under any saturation scenario, overcoming the
drawbacks of the classic solution commonly applied to cope with saturation of power converters,
and enhancing performance. For this purpose two main approaches are exploited
and extended to deal with power electronic applications: modern anti-windup strategies,
providing formal results and systematic design rules for the anti-windup compensator, devoted
to handle control saturation, and “one step” saturated feedback design techniques,
relying on a suitable characterization of the saturation nonlinearity and less conservative
extensions of standard absolute stability theory results.
The first part of the thesis is devoted to present and develop a novel general anti-windup
scheme, which is then specifically applied to a class of power converters adopted for power
quality enhancement in industrial plants. In the second part a polytopic differential inclusion
representation of saturation nonlinearity is presented and extended to deal with a
class of multiple input power converters, used to manage hybrid electrical energy sources.
The third part regards adaptive observers design for robust estimation of the parameters
required for high performance control of power systems.
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JÃnior, Josà Nilo Rodrigues da Silva. "Sintonia Ãtima de Regulador AutomÃtico de TensÃo e Estabilizador de Sistema de PotÃncia Utilizando Algoritmo de OtimizaÃÃo por Enxame de PartÃculas." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8831.
Full textAbstract:
nÃo hÃEste trabalho apresenta a aplicaÃÃo do algoritmo de OtimizaÃÃo por Enxame de PartÃculas (PSO â Particle Swarm Optimization) para sintonia Ãtima de controladores associados à regulaÃÃo de tensÃo e ao aumento do amortecimento de geradores sÃncronos utilizados em plantas termelÃtricas de ciclo combinado. Para representaÃÃo matemÃtica do gerador sÃncrono, utiliza-se o modelo linearizado de terceira ordem do sistema mÃquina conectada a uma barra infinita, vÃlido para estudos de estabilidade a pequenos sinais. Os parÃmetros do regulador automÃtico de tensÃo (AVR â Automatic Voltage Regulator) e do estabilizador de sistema de potÃncia (PSS â Power System Stabilizer) sÃo determinados de maneira Ãtima pela ferramenta computacional proposta. Os parÃmetros obtidos para o AVR e PSS sÃo comparados com valores calculados por tÃcnicas de sintonia convencionais, baseadas em aproximaÃÃes das equaÃÃes que descrevem o sistema. Os resultados de simulaÃÃes a variaÃÃes na tensÃo de referÃncia, considerando a anÃlise da resposta temporal do sistema controlado, demonstram que o PSO à uma tÃcnica eficiente na sintonia dos parÃmetros do AVR e PSS, destacando-se sua simplicidade, baixo esforÃo computacional e boa caracterÃsticas de convergÃncia.
This work presents the application of the Particle Swarm Optimization (PSO) algorithm for optimal tuning of controllers associated with voltage regulation and damping enhancement of synchronous generators used in combined cycle power station. For mathematic representation of the synchronous generator, the third order linearized model of a single machine connected to an infinite bus, valid for small signal stability studies, is used. The Automatic Voltage Regulator (AVR) and Power System Stabilizer (PSS) parameters are optimally determined by the proposed computational tool. The parameters obtained for AVR and PSS are compared with values calculated by conventional tuning techniques based on approximations of the equations that describe the system. The simulations results to reference voltage disturbances, considering the time response analysis of the controlled system, show that PSO is an efficient technique in the tuning of AVR and PSS parameters, with emphasis on its simplicity, low computational effort and good convergence characteristics.
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Erzini, Gabriel de Castro. "Automatic control of an aquaculture system." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16545.
Full textAbstract:
Mestrado em Engenharia MecânicaThis thesis covers the automated aquaculture scenario around the world and speci cally Portugal. With research done, a case study and laboratory work, the goal is to create a reliable remote control system capable of not only controlling the physical variables within an aquaculture system but monitor and rectify unwanted situations.
Esta tese trata-se de aquacultura pelo mundo e Portugal especi camente. Com uma pesquisa feita, um "case study" e trabalho laboratorial, o objetivo é criar um sistema de controlo remoto capaz de controlar as variáveis físicas dentro de um sistema de aquacultura e monitorizar e reti car situações indesejadas.
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Толбатов, А. В., Г. А. Смоляров, О. О. Толбатова, and С. В. Толбатов. "Підвищення ефективності функціонування газотурбінних електростанцій на основі автоматизованої системи керування з інформаційними технологіями." Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65202.
Full textAbstract:
Підвищення ефективності функціонування таких систем як газотурбінні електростанції (ГТЕ) забезпечується на базі сучасної підсистеми моніторингу з інформаційними технологіями.
Практичні дослідження функціонування ГТЕ підтверджують складні умови їх роботи: підвищений рівень інтенсивності завад в інформаційних трактах системи управління (СУ) через дію електромагнітних і віброакустичних полів.
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Manansala, Edgardo Celestino. "Adaptive power system control." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54391.
Full textAbstract:
This work presents a centralized control scheme applied to a power system. The scheme has adaptive characteristics which allow the controller to keep track of the changing power system operating point and to control nonlinear functions of state variables. Feedback to the controller is obtained from phasor measurements at chosen power system buses, generator field voltage measurements, and state estimators. Control effort is aimed at minimizing the oscillations and influencing the power system state trajectory through the control of linear and nonlinear functions of state variables during a power system disturbance.
The main contributions of this dissertation are the simultaneous introduction and utilization of measurement based terms in the state and output equations in the derivation and implementation of the control law, the study of limits on controller performance as the state residual vector becomes very large, and the simulation of the performance of local state estimators to prove the need for faster phasor measurement systems.
The test system is a hypothetical 39-Bus AC power system consisting of typical components which have been sufficiently modelled for the simulation of power system performance in a dynamic stability study.Ph. D.
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Bhatnagar, Rahul. "Dynamic dispatch of direct load control." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54736.
Full textAbstract:
Direct Load Control (DLC) -- the direct control of customer loads by an electric utility for the economic and reliable operation of the power system, is an important and active element of Load Management (LM). Currently attention has focussed on the integration of DLC into system operations. However, as yet, DLC is regarded as a discretionary resource to be used by the system operator based on informed judgment. The integration process has therefore, concentrated on improving the informational inputs to the operator.
This dissertation extends the integration from that of a discretionary resource to a dispatchable system resource. The concept of the dynamic dispatch of DLC is formulated and defined to be an online evaluation and utilization of DLC for optimum benefit to the utility, as system conditions change. The concept envisages the use of DLC in an automated mode and coordinated with other system resources for optimum benefit.
An important and integral part of the research effort is the development of a cost characterization of DLC. A closed form solution, using a dynamic programming framework, has been developed to estimate the costs of DLC dispatch. The derivation takes into account all operational constraints on the utilization of DLC -- payback characteristics, maximum on-times and minimum recovery times. The cost, defined as the difference in the fuel costs with and without DLC dispatch, were found to be dependent on the cost characteristics of the online generators and the load shape impacts of DLC dispatch.
The dynamic dispatch concept is concretized by a power system operations model which incorporates DLC dispatch for fuel cost minimization and peak load shaving. The two modes are toggled by the dispatch algorithm as system conditions change. Results from the model are presented for several combinations of system conditions and DLC system parameters.Ph. D.
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CAMPANER, RICCARDO. "VOLTAGE CONTROL SYSTEMS FOR TRANSMISSION AND DISTRIBUTION GRIDS." Doctoral thesis, Università degli Studi di Trieste, 2017. http://hdl.handle.net/11368/2908145.
Full textAbstract:
The research activities carried out for the present PhD dissertation concerns the increasingly evident and widespread set of problems related to the remarkable levels of distributed generation (DG) connected to electric networks. It has also included the proposal of applicable and performing control techniques, suitable to allow new connection of Renewable Energy Sources (RES) generators, able to assure adequate reliability and quality of service through the integration of electric networks with Information and Communication Technology (ICT) (process also known with the term “Smart Grid”).
The focus of the research activity was directed to voltage control of DG units based on RES, both connected to low voltage (LV) and medium voltage (MV) distribution networks and the ones directly connected to high voltage (HV) transmission system.
A short summary of the different chapters provides an overview of the present work:
- Chapter 1 describes the architecture of the national electric system, the on-going change from the traditional paradigm of energy production towards the DG model and the problems deriving from such change. To provide an idea of the dimension of the phenomenon some data about DG installed in the latest years both at international and national level are given, together with the results of studies on the economic and energetic advantage of photovoltaic technology carried out in view of a possible assessment of future impacts on energy distribution systems.
- Chapter 2 outlines the features of a Smart Grid apt to receive RES generation, at the same time guaranteeing suitable levels of reliability and quality service. The chapter summarizes the European and Italian Regulatory Environment for the connection of DG to distribution networks and electric transmission.
- Chapter 3 concentrates on voltage control for DG plants based on RES. The chapter reports a review of the control techniques proposed by literature and by recent connection rules, together with the control techniques collected and proposed by our research group.
- Chapter 4 presents the results of the studies carried out on some test electric networks presented in scientific literature and some really existing ones.
- Chapter 5 reports some final considerations.
- Appendix A1 provides a description of the software tools used to carry out the simulations. More specifically tests have been conducted with the aid of Matlab@ software, the toolbox open source PSAT and DOME software for steady state and dynamic simulations.
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Луцик, Артур Петрович, and Artur Lutsyk. "Розробка автономної системи електропостачання дослідної лабораторії навчального корпусу №7 ТНТУ ім. І. Пулюя." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, кафедра електричної інженерії,Тернопіль, Україна, 2021. http://elartu.tntu.edu.ua/handle/lib/36695.
Full textAbstract:
Уже сьогодні населення планети усвідомлює необхід-ність використання відновлюваних джерел енергії, оскільки відчуває проблеми з викопним паливом та зростанням попиту на стабільне постачання енергії. Сонячну енергетику можна вважати одним із найперспективніших напрямків відновлюваної енергетики, так як вона є простою, доступною, має великий потенціал та здатна задовольнити зростаючий попит на енергію [1].
На даний час системи на фотоелектричній основі набирають все більшої популярності завдяки великому попиту на електроенергію і в зв’язку з доволі несуттєвим забруднення навколишнього середовища. Енергія Сонця вважається безкоштовною і нею достатньо забезпечені більшість країн нашої планети. Земля отримує від Сонця протягом півгодини настільки величезну і потужну кількість енергії, яка еквівалентна повній споживаній енергія всього світу [2]. Перевагою сонячної енергії є те, що вона виступає чистим і відновлюваним джерелом енергії без шкідливих газів та токсичних відходів під час її використання. Крім переваг ця системи має і недоліки [3]:
низький коефіцієнт корисної вироблення електроенергії (біля 15%);
залежність від погодних умов.
Сучасні сонячні електростанції не генерують електроенергії вночі та є не-достатньо ефективними під час ранкових та вечірніх сутінків. Варто зауважити, що найбільше електроспоживання припадає якраз саме на цей період. Недоліком цієї електростанції є те, що її потужність може різко і несподівано коливатися від зміни погоди.У кваліфікаційній роботі розглянуто питання розробки автономної сис¬теми електропостачання дослідної лабораторії навчального корпусу №7 ТНТУ ім. І. Пулюя та її практичне впровадження. Базовим джерелом є сонячні панелі і акумуляторні батареї, а резервним додатковим джерелом – централізована система електропостачання. У пояснювальній записці кваліфікаційної роботи розглянуто cпособи під¬ви¬щення ефективності сонячних установок та їх аналіз на базі слідкуючих систем за Сонцем. Запропоновано методику розрахунку автономних сонячних установок, розроблено конструкцію автономної сонячної установки, побудо¬ва¬но її функці¬ональну схему, проведено експериментальні дослідження побудованої установки та розроблено алгоритм роботи зворотного зв’язку
The qualifying work considers the development of an autonomous of electricity supply system of research laboratory of the educational building № 7 of Ternopil Ivan Puluj National Technical University and its practical implementation. The basic source is solar panels and batteries, and the backup additional source is a centralized power supply system. In the explanatory note of qualification work ways of increase of efficiency of solar installations and their analysis on the basis of tracking systems on the Sun are considered. The method of calculation of autonomous solar installations is offered, the design of the autonomous solar installation is developed, its functional scheme is constructed, experimental researches of the constructed installation are carried out and the algorithm of work of feedback is developed.
ЗМІСТ ВСТУП 7 1 АНАЛІТИЧНИЙ РОЗДІЛ 11 1.1 Аналіз перспектив використання сонячної енергії 11 1.2 Аналіз передумов розвитку сонячних установок 12 1.3 Способи підвищення ефективності сонячних установок 17 1.4 Аналіз сонячних установок з слідкуючими системами за Сонцем 22 1.5 Висновки до розділу 29 2 РОЗРАХУНКОВО-ДОСЛІДНИЦЬКИЙ РОЗДІЛ 30 2.1 Методика розрахунку автономних сонячних установок 30 2.2 Розрахунок та вибір інвертора 32 2.3 Розрахунок кількості акумуляторних батарей та вибір їх типу 34 2.4 Розрахунок кількості сонячних панелей та вибір їх типу 38 2.5 Розрахунок та вибір контролера 41 2.4 Висновки до розділу 43 3 ПРОЕКТНО-КОНСТРУКТОРСЬКИЙ РОЗДІЛ 44 3.1 Шляхи підвищення ефективності автономних сонячних установок 44 3.2 Розробка конструкції автономної сонячної установки 45 3.3 Розробка функціональної схеми сонячної установки 46 3.4 Експериментальні дослідження сонячної установки 49 3.5 Висновки до розділу 57 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 58 4.1 Аналіз шкідливих і небезпечних факторів, які можуть виникнути при монтажі й експлуатації сонячної установки 58 4.2 Розрахунок струму при одно- і двохполюсному дотику до струмопро-відних частин сонячної установки 59 4.3 Заходи безпеки життєдіяльності для захисту працюючих 61 ЗАГАЛЬНІ ВИСНОВКИ 66 ПЕРЕЛІК ПОСИЛАНЬ 67
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Celanovic, Ivan. "A Distributed Digital Control Architecture for Power Electronics Systems." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/34998.
Full textAbstract:
This thesis proposes a novel approach to power electronics system design that is based on the open-architecture distributed digital controller and modular power electronics building blocks (PEBBs). The proposed distributed digital controller partitions the controller in three levels of control authority. The power stage controller, designated as hardware manager, is responsible for low-level hardware oriented tasks; the high level controller, designated as applications manager, performs higher-level application-oriented tasks; and the system level controller handles system control and monitoring functions.
Communications between the hardware-oriented controller and the higher-level controller are implemented with the previously proposed 125 Mbits/sec daisy-chained fiber optic communication protocol. Real-time control and status data are communicated by means of communication protocol. The distributed controller on the power converter level makes the system open, flexible and simple to use. Furthermore, this work gives an overview and comparison of current state-of-the-art communication protocols for real-time control applications with emphasis on industrial automation and motion control. All of the studied protocols have been considered as local area networks (LAN) for system-level control in power converter systems. The most promising solution has been chosen for the system level communication protocol.
This thesis also provides the details of design and implementation of the distributed controller. The design of both the hardware and software components are explained. A 100 kVA three-phase voltage source inverter (VSI) prototype was built and tested using the distributed controller approach to demonstrate the feasibility of the proposed concept.Master of Science
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Furmanik, Olga, and Alireza Famili. "Control system integration in ADAMS : With emphasis on hauler Automatic Traction Control system." Thesis, Linnéuniversitetet, Institutionen för maskinteknik (MT), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-45957.
Full textAbstract:
The thesis investigates control system integration in ADAMS and the thesis presents appropriate knowledge related to the topic as multi body system, acting forces between road and wheels, equation of motion regarding to the haulers, traction control system and differential locks. The emphasis of the thesis is to implement and test the automatic traction control (ATC) for the hauler into ADAMS and Simulink models. The ATC models are based on certain requirements provided by Volvo Construction Equipment. As expected, results indicate that the ATC model operates during simulation for various road conditions. Nevertheless, the ATC model includes a few defects which are observed in results. The significant achievement of the thesis is a great collaboration between ADAMS and Simulink model.
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Bansal, Ramesh Chand. "Automatic reactive power control of autonomous hybrid power systems." Thesis, 2002. http://localhost:8080/xmlui/handle/12345678/6491.
Full text