Dissertations / Theses on the topic 'Virtual Power System'

This dissertation develops a modeling and simulation methodology for design, verification, and testing (DVT) power supply system using a virtual prototype. The virtual prototype is implemented before the hardware prototyping to detect most of the design errors and circuit deficiencies that occur in the later stage of a standard hardware design verification and testing procedure. The design iterations and product cost are reduced significantly by using this approach. The proposed modeling and simulation methodology consists of four major parts: system partitioning, multi-level modeling of device/function block, hierarchical test sequence, and multi-level simulation. By applying the proposed methodology, the designer can use the virtual prototype effectively by keeping a short simulation CPU time as well as catching most of the design problems. The proposed virtual prototype DVT procedure is demonstrated by simulating a 5 V power supply system with a main power supply, a bias power supply, and other protection, monitoring circuitry. The total CPU time is about 8 hours for 780 tests that include the basic function test, steady stage analysis, small-signal stability analysis, large-signal transient analysis, subsystem interaction test, and system interaction test. By comparing the simulation results with the measurements, it shows that the virtual prototype can represent the important behavior of the power supply system accurately. Since the proposed virtual prototype DVT procedure verifies the circuit design with different types of the tests over different line and load conditions, many circuit problems that are not obvious in the original circuit design can be detected by the simulation. The developed virtual prototype DVT procedure is not only capable of detecting most of the design errors, but also plays an important role in design modifications. This dissertation also demonstrates how to analyze the anomalies of the forward converter with active-clamp reset circuit extensively and facilitate the design and improve the circuit performances by utilizing the virtual prototype. With the help of the virtual prototype, it is the first time that the designer is able to analyze the dynamic behavior of the active-clamp forward converter during large-signal transient and optimize the design correspondingly.
Ph. D.

As the European Union is on track to meet its 2020 energy targets on raising the share of renewable energy and increasing the efficiency in the energy consumption, considerable attention has been given to the integration of distributed energy resources (DERs) into the restructured distribution system. This thesis proposes market-oriented operations of micro virtual power prosumers (J.lVPPs) in the distribution system operator framework, in which the J.lVPPs evolve from home-oriented energy management systems to price-taking prosumers and to price-making prosumers. Considering the diversity of the DERs installed in the residential sector, a configurable J.l VPP is proposed first to deliver multiple energy services using a fuzzy logic-based generic algorithm. By responding to the retail price dynamics and applying load control, the J.lVPP achieves considerable electricity bill savings, active utilisation of energy storage system and fast return on investment. As the J.lVPPs enter the distribution system market, they are modelled as price-takers in a two-settlement market first and a chance-constrained formulation is proposed to derive the bidding strategies. The obtained strategy demonstrates its ability to bring the J.l VPP maximum profit based on different composition of DERs and to maintain adequate supply capacity to meet the demand considering the volatile renewable generation and load forecast. Given the non-cooperative nature of the actual market, the J.l VPPs are transformed into price-makers and their market behaviours are studied in the context of electricity market equilibrium models. The resulted equilibrium problems with equilibrium constraints (EPEC) are presented and solved using a novel application of coevolutionary approach. Compared with the roles of home-oriented energy management systems and price-taking prosumers, the J.lVPPs as price­ making prosumers have an improved utilisation rate of the installed DER capacity and a guaranteed profit from participating in the distribution system market.

Renewable energy resources are projected to claim a larger part of the Swedish power mix in coming years. This could potentially increase frequency fluctuations in the power grid due to the intermittency of renewable power generating resources. These fluctuations can in turn cause issues in the power grid if left unchecked. In order to resolve these issues, countermeasures are employed. One such countermeasure is for private actors to regulate power; in exchange they are financially compensated through reserve markets. The reserve market studied in this thesis is called Frequency Containment Reserve – Normal (FCR-N). Currently hydroelectric power provides almost all regulated power within this market. As the need for power regulation is expected to increase in the coming years, there exists a need to study other technologies capable of power regulation. This thesis focuses on one such technology called, virtual power plants. While virtual power plants are operating in other parts of the world, there were no virtual power plants operating in Sweden. As a result, the nature of an optimized virtual power plant and the economic benefits of optimization had not been previously investigated. To answer such questions, this thesis modelled and optimized the revenue of a virtual power plant. The examined virtual power plant consisted of cooling chillers, lighting, ventilation fans and a battery energy storage system. Where varying their total power demand allowed for them to provide power regulation. With the virtual power plant market in Sweden being in its infancy, this thesis serves as a first look into how an optimized virtual power plant using these components could function. To put the economic results of the optimization into context, a comparative model was constructed. The comparative model was based on a semi-static linear model. This is what the thesis’s industry partner Siemens currently uses. For the simulated scenarios, the optimized model generated at least 85% higher net revenues than the semi-static linear model. The increase in revenue holds potential to increase the uptake of virtual power plants on the Swedish market, thus increasing stability in the power grid and easing the transition to renewable energy.
Då förnyelsebara energiresurser antas omfatta en större roll av den svenska elproduktionen inom kommande år, så kan detta leda till att frekvensfluktueringar i elnätet ökar. Detta sker på grund av att den oregelbundna elproduktionen från förnyelsebara energiresurser inte matchas med konsumtion. Om dessa fluktueringar inte hanteras kan det i sin tur leda till skadliga störningar inom elnätet. För att motverka detta och således stabilisera elnätet används diverse lösningar. Ett sätt att åstadkomma ökad stabilisering i elnätet är att låta privata aktörer kraftreglera. De privata aktörerna som står för kraftregleringen gör detta i utbyte mot ekonomisk kompensation, genom att delta i reservmarknader. Den reservmarknad som studerades inom detta examensarbete kallas Frequency Containment Reserve – Normal (FCR-N). I nuläget står vattenkraft för nästan all reglerad kraft inom den här marknaden. Men då behovet av kraftreglering antas öka inom kommande år så behövs nya teknologier studeras som kan bistå med kraftregleringen. Den studerade teknologin inom detta examensarbete var ett virtuellt kraftverk. Då inga virtuella kraftverk var i bruk i Sverige då denna uppsats skrevs fanns det osäkerheter kring hur man optimalt styr ett virtuellt kraftverk och de ekonomiska fördelarna som detta skulle kunna leda till. Detta examensarbete modellerade och optimerade ett virtuellt kraftverk ur ett vinstperspektiv. Det virtuella kraftverket var uppbyggt utav kylmaskiner, ljus, ventilationsfläktar och ett batterisystem. Deras kraftkonsumtion styrdes på ett sådant sätt som lätt de bidra till kraftreglering på reservmarknaden. För att kunna analysera de ekonomiska resultaten från det optimerade virtuella kraftverket, så byggdes en jämförelsemodell. Denna jämförelsemodell är baserad på en semistatisk linjär modell, vilket är det som examensarbetets industripartner Siemens använder. Den ekonomiska jämförelsens resultat påvisade att inkomsten från den optimerade modellen var minst 85% högre än den semistatiskt linjära modellen, inom de studerade scenarierna. Denna inkomstökning skulle potentiellt kunna öka användningen av virtuella kraftverk på den svenska reservmarknaden vilket i sin tur skulle medföra högre stabilitet på elnätet. Genom att öka stabiliteten på elnätet kan således förnyelsebara energiresurser i sin tur lättare implementeras.

The output power variability of intermittent renewable sources can cause significant fluctuations in distribution system voltages. A local linear controller that exploits the capability of a photovoltaic inverter to provide both real and reactive power is described. This controller substitutes reactive power for real power when fluctuations in the output of the photovoltaic source are experienced. In this way, the inverter can help mitigate distribution system voltage fluctuations. In order to provide real and reactive to the grid, a three-phase grid-connected single-stage photovoltaic system with maximum power point tracking and power control is described. A method of reducing the current harmonic caused by resonance of the LC filter and transformer is presented. The local linear controller is examined using an example distribution system, and it is found that the controller is effective at mitigating voltage violations. The photovoltaic control system is examined using three-phase single-stage PV inverter system. The power control and damping system show good performance and stability under rapid change of irradiance.

Several trends can be observed in modern microprocessor design. Architectures have become increasingly complex while design time continues to dwindle. As feature sizes shrink, wire resistance and delay increase, limiting architects from scaling designs centered around a single thread of execution. Where previous decades have focused on exploiting instruction-level parallelism, emerging applications such as streaming media and on-line transaction processing have shown greater thread-level parallelism. Finally, the increasing gap between processor and off-chip memory speeds has constrained performance of memory-intensive applications. The Single-Chip Message Passing (SCMP) parallel computer sits at the confluence of these trends. SCMP is a tiled architecture consisting of numerous thread-parallel processor and memory nodes connected through a structured interconnection network. Using an interconnection network removes global, ad-hoc wiring that limits scalability and introduces design complexity. However, routing data through general purpose interconnection networks can come at the cost of dedicated bandwidth, longer latency, increased area, and higher power consumption. Understanding the impact architectural decisions have on cost and performance will aid in the eventual adoption of general purpose interconnects. This thesis covers the design and analysis of the on-chip network and its integration with the SCMP system. The result of these efforts is a framework for analyzing on-chip interconnection networks that considers network performance, circuit area, and power consumption.
Master of Science

Context. Industrial Decision Support System(DSS) traditionally relies on 2D approach to visualize the scenarios. For some abstract information, like chronological sequence of tasks or data trend, it provides a good visualization. For concrete information, such as location and spatial relationships, 2D visualizations are too abstract. Techniques from Game design, 3D modeling, virtual reality(VR) and animation provides many inspiration to develop a DSS tools for industrial applications. Objectives. The work in our research was to develop a unique prototype for data visualization in wind power systems, and compare it with traditional ones. The product combined 3D VR, 2D graphics, user navigation, and Human Machine Interaction(HMI). It was developed with a game engine, Unity3D. The study explored how much usability can be improved when using applied gamificaion 3D approaches in industrial monitoring and control systems. Methods. The research methods included Literature Review, Commercial Example Analysis, Development, and Evaluation. In the evaluation phase, Systematic Usability Scale(SUS) tests were performed with two independent groups, the testing results were analyzed with statistical method, t-test. Results. The evaluation results showed that an interface developed with 3D virtual reality can provide better usability(include learnability) than traditional 2D industrial interface in wind power system. The difference between them is significant. Conclusions. The study indicates that, compared with the traditional 2D interfaces, the gamification 3D approach in industrial DSS can provide user more comprehensive information visualization, better usability and learnability . It also gives more effective interactions to enhance the user experience.
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Numerous countries are trying to reach almost 100\% renewable penetration. Variable renewable energy (VRE), for instance wind and PV, will be the main provider of the future grid. The efforts to decrease the greenhouse gasses are promising on the current remarkable growth of grid connected photovoltaic (PV) capacity. This thesis provides an overview of the presented techniques, standards and grid interface of the PV systems in distribution and transmission level. This thesis reviews the most-adopted grid codes which required by system operators on large-scale grid connected Photovoltaic systems. The adopted topologies of the converters, the control methodologies for active - reactive power, maximum power point tracking (MPPT), as well as their arrangement in solar farms are studied. The unique L(LCL)2 filter is designed, developed and introduced in this thesis. This study will help researchers and industry users to establish their research based on connection requirements and compare between different existing technologies. Another, major aspect of the work is the development of Virtual Inertia Emulator (VIE) in the combination of hybrid energy storage system addressing major challenges with VRE implementations. Operation of a photovoltaic (PV) generating system under intermittent solar radiation is a challenging task. Furthermore, with high-penetration levels of photovoltaic energy sources being integrated into the current electric power grid, the performance of the conventional synchronous generators is being changed and grid inertial response is deteriorating. From an engineering standpoint, additional technical measures by the grid operators will be done to confirm the increasingly strict supply criteria in the new inverter dominated grid conditions. This dissertation proposes a combined virtual inertia emulator (VIE) and a hybrid battery-supercapacitor-based energy storage system . VIE provides a method which is based on power devices (like inverters), which makes a compatible weak grid for integration of renewable generators of electricity. This method makes the power inverters behave more similar to synchronous machines. Consequently, the synchronous machine properties, which have described the attributes of the grid up to now, will remain active, although after integration of renewable energies. Examples of some of these properties are grid and generator interactions in the function of a remote power dispatch, transients reactions, and the electrical outcomes of a rotating bulk mass. The hybrid energy storage system (HESS) is implemented to smooth the short-term power fluctuations and main reserve that allows renewable electricity generators such as PV to be considered very closely like regular rotating power generators. The objective of utilizing the HESS is to add/subtract power to/from the PV output in order to smooth out the high frequency fluctuations of the PV power, which may occur due to shadows of passing cloud on the PV panels. A control system designed and challenged by providing a solution to reduce short-term PV output variability, stabilizing the DC link voltage and avoiding short term shocks to the battery in terms of capacity and ramp rate capability. Not only could the suggested system overcome the slow response of battery system (including dynamics of battery, controller, and converter operation) by redirecting the power surges to the supercapacitor system, but also enhance the inertial response by emulating the kinetic inertia of synchronous generator.

This thesis describes a combined 1-D numerical and experimental analysis of a GDI injection system. The aim is to design the GDI injection system to have the minimum injection variability between injectors. This is possible analysing the rail pressure waves that affect the injections. Thanks to a MATLAB numerical code the results coming from a first calibration attempt were compared with experimental data to verify the reliability of the acquired results. They were calculated after specific tests made on the hydraulic test bench developed at Lamborghini. Different configurations were studied changing the system geometry, such as rail diameter, high pressure pipe length and inlet position inside the rail, flow-restrictor diameter at the end of high pressure pipe. Eight different configurations were analysed and the one that showed the lowest CoV of injection was proposed as a final design. Then a 1-D numerical analysis of the GDI injection system was developed on the chosen configuration with the aim of predicting pressure waves propagation phenomena and the injected mass flow rate. The focus of the 1-D analysis is to verify through the comparison between simulated values and experimental ones if the model predicts accurately the physics of the system, in order to use it on a wider range of operating points. The following step consisted in controlling the GDI pump in MIL environment through a cosimulation between high pressure system model built in GT-ISE and control model made with Simulink. The high pressure control model was developed and validated. The aim was to have a closed loop control of the rail pressure using the same ECU control strategy. The main task of the control is to actuate the angle, respect to pump TDC, the MSV valve had to be closed to make the actual pressure follow the target one. The control model and the simulation in MIL environment are very useful since they help on the precalibration of ECU functions, reducing testing activities.

The diploma thesis is dealing with possible approaches to control distributed energy resources and storage systems. One of these approaches is a virtual power plant and its concept is described in the first part of the thesis. The virtual power plant is a controlled system of distributed energy resources, storage systems and controllable loads interconnected via communication network, that can act as a conventional power plant. The theoretical part contains a survey of control system's topologies, a brief summary of available communication infrastructures and standards. The second part of the thesis is focused on the description of operation and control of hybrid system that represents an inseparable component of virtual power plant. A Matlab Simulink model was created for this purpose. A simulation of hybrid inverter's step response is realised to test the operation of the hybrid system and it is compared with the real measurements in the laboratory. A comparison of control approaches of hybrid system implemented on the basis of measurements is also included in this thesis and was published in the scientific paper attached in the appendix.

In this study, an examination regarding what benefits an aggregatedpopulation of Battery Energy Storage Systems (BESSs) could result incompared to when the individual units in the population are being usedseparately has been executed. The increased flexibility and reducedsafety margins as results of the aggregation was also examined. Thestudy was executed on behalf of the smart energy service companyCheckWatt AB and the study furthermore rests upon results of earlierperformed master theses on behalf of the company. By investigating previous work and studies through a literature study,the enabling of anumerical study was done. The numerical study wasbased on a simple model of a Virtual Power Plant (VPP) where severalBESSs are smartly controlled in order to be used for both local peakshaving and as common providers of the frequency reserve FrequencyContainment Reserve - Normal (FCR-N). The study involved the formation of a numerical model which simulated cases of both aggregated and non-aggregated populations of up to 45 load profile units, this in order for advantages and differences to be distinguished. The data used inthe simulations was received mainly from the CheckWatt AB andconsisted of photovoltaic (PV) electricity production and load data of 45 customers of the company. A sensibility analysis of the numericalstudy was also performed, which showed that the studied model andsystem were quite stable. The results of the simulations of the case of the study proved thatthere are some advantages connected to aggregation of several BESSs,and that the aggregation enabled an added value and a higher level offlexibility within the system. The safety margins connected todelivery of FCR-N could be reduced when aggregating several BESS,while a more extensive study is requested regarding safety marginsconnected to peak shaving. The study’s results further showed that anaggregator can be used as a sustainable and flexible solution forbalancing the electrical grid in the transition to a sustainableenergy system allowing a higher penetration of intermittentenergy sources.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
This paper presents a study about the electric power systems visualization presenting as results: the implementation of the main visualization techniques used in the operation and control of these systems; a new representation of electrical magnitudes with the use of Thiessen polygons; and finally, the presentation of a new paradigm in information management and manipulation of the power system graphics in a three-dimensional environment. Moreover, it presents the architecture used in the construction of this threedimensional viewing environment, which in our work, enabled the creation of a virtual control room where operators can build and add to the virtual environment the wanted and available visualization in the management of the electric system, enabling the analysis of the problem from several di erent aspects.
Este trabalho apresenta um estudo sobre visualização de sistemas elétricos de potência e tem como resultados: a implementação das principais técnicas de visualização utilizadas no controle e operação destes sistemas; uma nova representação de grandezas elétricas com a utilização dos polígonos de Thiessen; e por fim, a apresentação de um novo paradigma no gerenciamento das informações e manipulação dos gréficos dos sistemas de potência em um ambiente tridimensional. Ademais, apresenta-se a arquitetura utilizada na construção deste ambiente de visualização tridimensional que, em nosso trabalho, possibilitou a criação de uma sala virtual de controle, na qual os operadores podem construir e adicionar ao ambiente virtual as visualizações desejadas e disponíveis no gerenciamento do sistema elétrico, possibilitando a análise do problema sob vários aspectos diferentes.

Mestrado em Engenharia Electrónica e Telecomunicações
Por razões de potência, linearidade e e ciência o ampli cador é um componente limitador de performance em qualquer tipo de aplicações relacionadas com estações base de voz e dados, motivando a indústria das telecomunica ções a investir em sistemas capazes de ajudar o projetista de Ampli cador de Potência (AP) a obter o máximo deste elemento ativo. O sistema de 'load-pull' é uma ferramenta essencial para auxiliar o projeto de ampli cadores de potência, permitindo determinar as condições ideais de impedância que maximizam a sua performance. Esta dissertação insere-se na área de caracterização e projeto de AP, em rádio frequência e visa a concepção, implementação e validação de um sitema automático de 'load-pull' passivo. Neste trabalho, realizou-se um estudo sobre os mais diversos tipos de sistemas de 'load-pull' utilizados na caracterização de transistores de alta potência. De modo a cumprir a nalidade desta dissertação, construí-se um sistema passivo automatizado de 'load-pull' capaz de lidar com potência 250W forma de onda contínua (CW) e 2.5 kWde potência de pico em relação a envolvente de modulação (PEP), onde a repetibilidade da malha de saída deste sistema é -60dB a uma frequência correspondente de 1.8GHz, garantindo uma boa precisão das impedâncias apresentadas ao transístor de microondas.
Due to power, linearity and e ciency reasons the PA is the performance limiting component in any state-of-the-art mobile voice and data base station, motivating the telecommunications industry to invest in systems capable of helping the designer of PA to get the most of the active devices. The load-pull system is an essential tool to assist the design of PA, allowing to determine the optimum matching conditions that maximizes the PA performance parameters. This dissertation ts in the area of radio frequency characterization and PA design, aiming the artful conception, implementation and validation of an automated passive load-pull system. In this work a study was also performed on the most diverse types of load-pull systems that are used in the characterization of high power transistors. In order to ful ll the purpose of this dissertation, an automated load-pull system was built, being capable to handle 250W of power in continuous wave (CW) and 2.5kW in peak-to-envelope (PEP), where the system repeatability of its output network is -60dB at a frequency of 1.8GHz, granting a good accuracy of impedances presented to the microwave transistor.

This thesis concerns with design of micro sources and their implementation in Micro grid system. In the first part the work is aimed at definition of smart - grid, where describes their advantages, disadvantages and necessary changes, which has to be made in current distribution network for implementation this system. Further on the thesis concerns with detailed description of Micro grid, configuration of this kind of network, the issues in implementation and possibilities to provide ancillary services. The work also describes marginally virtual power plants, presents definition, components and types of virtual power plants. The final chapter describes the creation of micro sources in System modeler and subsequent testing of consumption cover to operate in island mode.

With deregulation, diagnosis and maintenance of power equipment, especially power transformers, become increasingly important to keep power systems in reliable operation. This dissertation systematically studied two kinds of transformer failure and abnormality cases, and then developed a new Internet based Virtual Hospital (VH) for power equipment to help power equipment diagnosis and maintenance. A practical case of generator-step-up (GSU) transformer failures in a pumped storage plant was extensively studied. Abnormal electrical phenomena associated with GSU transformers, including switching transients and very fast transients (VFT), and lightning, were analyzed. Simulation showed that circuit breaker restriking could be a major cause of transformer successive failures, and current surge arrester configuration did not provide enough lightning protection to GSU transformers. Mitigation of abnormal electrical phenomena effects on GSU transformers was proposed and discussed. The study can be a complete reference of troubleshooting of other similar transformer failures. Geomagnetically induced current (GIC) is another possible cause of transformer abnormality. A simplified method based on the equivalent magnetizing curve for transformers with different core design was developed and validated to estimate harmonic currents and MVar drawn by power transformers with a given GIC. An effective indicator was proposed using partial harmonic distortion, PHD, to show when the transformer begins saturating with the input GIC. The developed method has been applied to a real time GIC monitoring system last year for a large power network with thousands of transformers. A new Internet based Virtual Hospital (VH) for Power Equipment was conceptually developed to share experience of power equipment diagnosis and maintenance, and update the existing diagnostic techniques and maintenance strategies, and a comprehensive information model was developed for data organization, access, and archiving related to equipment diagnosis and maintenance. An Internet based interactive fault diagnostic tool has been launched for power transformers based on dissolved gas analysis (DGA). The above results and findings can help improving power equipment diagnosis and utility maintenance strategies.
Ph. D.

Virtual prototyping is a relatively new concept in the field of power electronics that intends to allow the integrated electrical, mechanical and thermal design of power electronic systems. Virtual prototyping uses coupled, multidisciplinary simulations to evaluate potential designs and aims to allow a designer to easily arrive at the optimum system design for any given set of performance targets and design space constraints using an iterative design approach. This work explores the current, established simulation options and identities advantages and weaknesses of these approaches and subsequently a set of requirements that must be met for an improved simulation approach suitable for virtual prototyping of power electronic systems. This required approach is determined to be based around coupled simulation of a number of compact, reduced order models and a fundamental weakness in all similar existing approaches is identified: the lack of a suitable method for the systematic extraction of the compact dynamic thermal models. This is then addressed by the proposal of novel method for the automatic extraction of compact thermal models of multi chip power modules from design data that would be readily available in a virtual prototyping design process. This thermal model extraction method is validated through simulation and experimental results and is implemented as a software tool for later use. A software design framework is then developed. centred on the thermal extraction utility, which implements the previously highlighted virtual prototyping approach in the form or a systematic design methodology suitable for the coupled, multidisciplinary simulation and evaluation 01" multi-chip power module based systems. The operation of the methodology is validated using design examples which demonstrate the ability of the thermal extraction utility, and the framework in which it is implemented, for use in virtual prototyping and highlight their potential weaknesses and limitations.

In the novel smart grid configuration of power networks, Energy Storage Systems (ESSs) are emerging as one of the most effective and practical solutions to improve the stability, reliability and security of electricity power grids, especially in presence of high penetration of intermittent Renewable Energy Sources (RESs). This PhD dissertation proposes a number of approaches in order to deal with some typical issues of future active power systems, including optimal ESS sizing and modelling problems, power ows management strategies and minimisation of investment and operating costs. In particular, in the first part of the Thesis several algorithms and methodologies for the management of microgrids and Virtual Power Plants, integrating RES generators and battery ESSs, are proposed and analysed for four cases of study, aimed at highlighting the potentialities of integrating ESSs in different smart grid architectures. The management strategies here presented are specifically based on rule-based and optimal management approaches. The promising results obtained in the energy management of power systems have highlighted the importance of reliable component models in the implementation of the control strategies. In fact, the performance of the energy management approach is only as accurate as the data provided by models, batteries being the most challenging element in the presented cases of study. Therefore, in the second part of this Thesis, the issues in modelling battery technologies are addressed, particularly referring to Lithium-Iron Phosphate (LFP) and Sodium-Nickel Chloride (SNB) systems. In the first case, a simplified and unified model of lithium batteries is proposed for the accurate prediction of charging processes evolution in EV applications, based on the experimental tests on a 2.3 Ah LFP battery. Finally, a dynamic electrical modelling is presented for a high temperature Sodium-Nickel Chloride battery. The proposed modelling is developed from an extensive experimental testing and characterisation of a commercial 23.5 kWh SNB, and is validated using a measured current-voltage profile, triggering the whole battery operative range.

Virtual inertia is known as an inevitable part of the modern power systems. Recent trend of research is oriented in different methods of emulating virtual inertia in different part of the systems. This dissertation is focused on modelling, analysing and application of virtual inertia concept in frequency control and Automatic Generation Control (AGC) issue in high level control AC/DC interconnected power systems. Since the virtual inertia is provided by advanced control concepts of power electronic based components, the HVDC links are the main focus of this dissertation for emulating inertia. AGC in a multi-area power system during load and resource variation is known as a very important mechanism that could facilitate various tasks like: frequency restoration, tie-line power control between authority areas and economic dispatch of generation units. The AGC concept is known as higher level control at the transmission level. This higher level control will generate the set-points for all the local components, like generators or power converter stations, which are under control by their local controllers. In this thesis two different methods for emulating virtual inertia are proposed and introduced in AGC modelling and control of AC/DC interconnected power systems. The first method which is one of the common methods for emulating inertia in various filed of applications, is derivative control technique. In this thesis, derivative control technique is used for higher level application of inertia emulation. This method of inertia emulation is developed for two-area AGC system which is connected by parallel AC/DC transmission lines. Based on the proposed technique, the dynamic effect of inertia emulated for frequency and active power control of interconnected systems are evaluated. The effects of frequency measurements delay and Phase Locked Loop (PLL) effects are also considered by introducing a second-order function. Simulations performed by Matlab software demonstrate how virtual inertia emulation can effectively improve the performance of the power system. A detailed eigenvalue and sensitivity analyses have been also performed to support the positive effects of the proposed method. Since the first method is based on derivation for grid frequency, the measurement of frequency is very important and application of different method for frequency measurements like PLL will bring some limitations for this method. Therefore, as an ultimate solution, the second method for virtual inertia emulation is introduced in this thesis. The second method is based on Virtual Synchronous Power (VSP) concept. The concept of VSP to simulate the dynamic effects of inertia emulations by HVDC links for higher level control applications is introduced and reflected in the multi-area AGC model. By using this proposed combination in AGC model, the dynamic performance of the systems shows a significant improvement. The active power loop control on VSP based HVDC link has second-order characteristic which make a simultaneous enabling of damping and inertia emulations into the system. Trajectory sensitivities and eigenvalue analyses are used to analyse the effects of VSP on the system stability. The effectiveness of proposed concept on dynamic improvements is tested through Matlab simulation of multi-area test system. Finally, it became clear that virtual inertia will add additional degree of freedom to the system dynamics which makes a considerable improvement in first overshoot in addition to damping characteristics of HVDC links. Comparing the results of these two different methods of inertia emulation shows that VSP technique has better performance with several advantages for emulating the inertia. In the VSP technique, PLL and frequency estimation are not required. Also considering the fact that simultaneous damping and inertia could be emulated, a powerful method based on VSP for improving the system dynamics during the contingencies is proposed.
El concepto de inercia virtual se está convirtiendo en una parte imprescindible de los sistemas de energía modernos y en la actualidad hay diferentes líneas de investigación orientadas a estudiar diferentes métodos de emulación de inercia virtual en diferentes partes del sistema.Esta tesis doctoral se centra en el modelado, análisis y aplicación del concepto de inercia virtual en el control de frecuencia y en el control automático de generación (AGC), los cuales son elementos clave en el control de alto nivel de los sistemas eléctricos interconectados AC / DC.Dada la evolución tanto en las topologías, como en las prestaciones de control de los convertidores electrónicos de potencia, los enlaces HVDC y el control a alto nivel de los dispositivos implicados para emular inercia constituirán el foco principal de esta tesis doctoral.El AGC es un mecanismo muy útil en un sistema de potencia multi-zona durante, sobre todo cuando hay variaciones en la carga o en la generación, ya que puede facilitar diversas tareas como: la restauración de frecuencia, control de potencia de líneas de enlace entre las áreas y el despacho económico de los sistemas de generación. En este contexto en AGC, dada su condición de control a alto nivel, generará las consignas para todos los elementos locales, tales como generadores o estaciones de conversión de energía, que están bajo el control de sus controladores locales.En esta tesis se proponen dos métodos diferentes para emular inercia virtual, los cuales se introducirán, se modelarán y se aplicarán al control de sistemas de potencia AC / DC interconectados. El primer método, que es uno de los métodos más comunes para la emulación de inercia en otras aplicaciones, es la técnica del control derivativo. En esta tesis, esta técnica se utiliza para llevar a cabo la emulación de inercia a alto nivel. Éste método de emulación de inercia se ha desarrollado para un sistema AGC de dos área que está interconectado mediante líneas de transmisión de CA / CC en paralelo. Sobre la base de la técnica propuesta, el efecto dinámico de la inercia emulada sobre el control de frecuencia y potencia activa será formulado y evaluado. Los efectos del retardo mediciones de frecuencia y los efectos del bucle de sincronización (PLL) también se consideran en el análisis y posterior ensayo. Las simulaciones llevadas a cabo demostrarán cómo la emulación de inercia virtual puede mejorar efectivamente el rendimiento del sistema de potencia.Dado que el primer método se basa en la derivación de la frecuencia de red, la medición de la frecuencia es muy importante y la aplicación de los métodos de medida de la misma, como las PLL, conlleva algunas limitaciones en la aplicación y respuesta del mismo. Por lo tanto, como una solución definitiva, se introduce el segundo método para la emulación de inercia virtual en esta tesis. El segundo método se basa en el concepto de energía síncrona virtual (VSP). El concepto de VSP, el cual permite simular los efectos dinámicos de las emulaciones de inercia por enlaces HVDC, se presentará y aplicará en sistemas de control de alto nivel, aplicándolo finalmente en el modelo AGC multi-zona. Tal y como se demostrará, mediante el uso de esta combinación propuesta en el modelo de AGC, el comportamiento dinámico de los sistemas muestra una mejora significativa. El control de bucle de potencia activa en el enlace HVDC basado en el VSP tiene una característica de segundo orden que genera una respuesta instantánea y permite controlar la amortiguación y la inercia en el sistema. La eficacia de concepto propuesto en las mejoras dinámicas se probará en plataformas de simulación que representarán un sistema multi-zona. Por último, se demostrará que la inercia virtual añade un grado de libertad adicional a la dinámica del sistema, lo cual ayuda a controlar el sobre pico así como el amortiguamiento en los transitorios en los enlaces HVDC.

Orientadores: Sigmar Maurer Deckmann, Fernando Pinhabel Marafão
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e Computação
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Resumo: O presente trabalho avalia a possibilidade da aplicação de instrumentação virtual para a análise de problemas da qualidade da energia elétrica (QEE). Aproveitando-se da grande flexibilidade, elevada capacidade de processamento e da facilidade de reconfiguração oferecida por tal tipo de instrumento, são desenvolvidos algoritmos para medição digital e análise de grandezas elétricas. No modo de medição, é feita uma análise comparativa entre os dois principais métodos apresentados na literatura, para o cálculo de potência e fator de potência em sistemas trifásicos com condutor de retorno (neutro). Para comparar esses métodos, foram implementadas sub-rotinas para identificação das componentes fundamentais, de seqüência positiva das tensões e correntes, potências ativa e não-ativa, além de algoritmos para calcular o fator de desequilíbrio da componente fundamental e o nível de distorção harmônica total. No modo de análise, foi implementado um algoritmo que realiza uma varredura nos indicadores de QEE, calculados de minuto em minuto e salvos em arquivos, através do instrumento de medição para uma análise estatística diária (baseada na função de distribuição de amostras).Tal algoritmo permite identificar os principais distúrbios que ocorrem em determinada instalação como também permite avaliar a duração das violações dos limites pré-fixados
Abstract: This work explores the possibility of applying virtual instrumentation to analyze power quality problems. Based on the great flexibility, increased processing capacity and the possibility of reconfiguration, offered by such type of instrumentation, several digital algorithms have been developed for digital measurement and analysis of electrical quantities. In the case of measurement mode, a comparison is made between the two main methods reported in the literature concerning power and power factor calculation in three-phase systems with return conductor (neutral). To compare those methods, sub-routines have been implemented to identify the fundamental components, positive sequence of voltages and currents, active and non-active powers, as well as to calculate the unbalanced factor of the fundamental component and the total harmonic distortion. In the case of analysis mode, an algorithm was implemented that realizes a sweeping of the power quality indices, obtained minute by minute, and automatically stored in files by the instrument, for daily statistical analysis (based on distribution function). Such algorithm helps to identify the main disturbing causes in a specific installation, and permits to evaluate the violation time of the prescribed limits
Mestrado
Energia Eletrica
Mestre em Engenharia Elétrica

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Com o aumento na demanda de energia elÃtrica e a exigÃncia de maior confiabilidade, seguranÃa e eficiÃncia na operaÃÃo de sistemas elÃtricos de potÃncia por parte dos ÃrgÃos reguladores, aumentou a necessidade por profissionais cada vez mais qualificados em planejamento e operaÃÃo dos sistemas de potÃncia. No entanto, com a necessidade de atualizaÃÃo tÃcnica continuada e em decorrÃncia da polÃtica de racionalizaÃÃo de custos e de disponibilizaÃÃo de pessoal, as tÃcnicas de ensino a distÃncia tÃm evoluÃdo e alcanÃado abrangÃncia nas mais diferentes Ãreas do conhecimento. Este trabalho apresenta um Simulador para Treinamento Presencial e a DistÃncia em OperaÃÃo e ProteÃÃo de Sistemas ElÃtricos (STOP). O simulador STOP à desenvolvido em Java, podendo ser utilizado em ambientes: Unix, Linux, Windows, MacOS. O STOP pode ser aplicado em treinamento presencial e a distÃncia e està voltado à capacitaÃÃo de estudantes de engenharia, tÃcnicos e profissionais da Ãrea de sistemas elÃtricos de potÃncia. O STOP està integrado a um Ambiente Virtual de Aprendizagem (AVA), o Moodle. A integraÃÃo enriquece o ensino-aprendizado tornando-o mais efetivo com o uso de uma ferramenta capaz de simular situaÃÃes reais. Os simuladores em ambientes virtuais sÃo alternativas para a reduÃÃo de custos em empresas e instituiÃÃes de ensino. O simulador STOP à um software composto de diagramas unifilares, com a representaÃÃo dos principais componentes do sistema de proteÃÃo, tornando possÃvel ao usuÃrio simular faltas e reconfigurar o sistema elÃtrico, por meio de ajustes de relÃs para coordenaÃÃo da proteÃÃo e redefiniÃÃo de parÃmetros.
As the demand for electrical energy increases and requirements from regulatory agencies for improved reliability, security and efficiency on the operation of electric power systems, the need for professionals ever more qualified on planning and operation power systems also increases. However, with the need for continued technical update and as a result of rationalization policies of costs and provision of personnel for training, the distance learning techniques have evolved and reached different areas of knowledge. This work presents a Simulator for Presence and Distance Learning about Operation and Protection of Electric Systems (STOP). The STOP Simulator is developed in Java, which enables it to be used in the following systems: Unix, Linux, Windows, MacOS. The STOP can be applied in class as well as distance training and is directed to the training of engineering students, technicians and professionals specialized on electric power systems. The STOP is integrated to a Learning Virtual Environment (AVA), the Moodle. The integration enhances the teaching-learning process making it more effective by using a tool able to simulate real life situations. Simulators in virtual environments are an alternative to reducing costs in companies and educational institutions. The STOP is a software tool featuring one-line diagrams with the main components of the protection system, short-circuits simulation and reconfiguration of the system by setting relays for coordination of the system protection and redefinition of parameters.

This research addresses some of the difficulties faced when operating voltage controlled inverters with synchronous generators in microgrids. First, an overview of microgrid value propositions is provided, and the problems faced when attempting to use microgrids to provide improved power quality are discussed. Design considerations for different types of microgrids are provided to enable microgrids to deliver the desired functionality without adding unnecessary cost. The main body of this research investigates the poor transient load sharing encountered between voltage controlled inverters and synchronous generators in islanded operation. Poor transient load sharing results in high peak inverter rating requirements and high cost. The tradeoff between power quality and power sharing is highlighted, and methods to improve transient load sharing are proposed. The use of current limiting to protect inverters during faults and overloads is also investigated. Stability problems are identified when using simple inverter current limiting methods when operating in parallel with synchronous generators. Virtual impedance current limiting is proposed to improve transient stability during current limiting. The methods proposed in this thesis for mitigating inverter overloads and faults will allow for more reliable and cost effective application of inverter based distributed energy resources with synchronous generators in microgrids.

The unconventional improvements in the power electronics field have been the primary reason for massive deployment of renewable energy sources in the electrical power grid over the past several decades. This needed trend, together with the increasing penetration of micro-, and nano- grids, is bringing significant improvements in system controllability, performance, and energy availability, but is fundamentally changing the nature of electronically-interfaced sources and loads, altering their conventionally mild aggregate dynamics, and inflicting low- and high- frequency dynamic interactions that never before existed at this magnitude. This problem is not restricted only to the grid; modern electronic power distribution systems built for airplanes, ships, electric vehicles, data-centers, and homes, comprise dozens, even hundreds of power electronics converters, produced by different manufacturers, who provide very limited details on converters' dynamic behavior - distinctiveness that has the highest impact on how two converters, or converter and a system interact. Consequently, substantial dispersion of power electronics into the future grid will significantly depend on engineers' capability to understand how to model and dynamically control power flow and subsystem interactions. It is therefore essential to continue developing innovative methods that allow easier system-level modeling, continuous monitoring of dynamic interactions, and advanced control concepts of power electronics converters and systems. The dissertation will start with a "black box" approach to modeling of three-phase power electronics converters, introducing a method to remove source and load dynamics from in-situ measured terminated frequency responses. It will be then shown how converter, itself, can perform an online stability assessment knowing its own unterminated dynamics, and being able to measure all terminal immittances. The dissertation will further advance into an approach to control power electronics converters based on the electro-mechanical duality with synchronous machines, and end with selected examples of system-level operation, where small-signal instability in multi-source power systems can be mitigated using this concept.
Ph. D.

Les Microgrids sont une excellente solution aux problèmes actuels soulevés par la croissance constante de la demande de charge et la forte pénétration des sources d’énergie renouvelables, qui se traduisent par une modernisation du réseau grâce au concept de “Smart-Grids”. L’impact des sources d’énergie distribuées basées sur l’électronique de puissance est une préoccupation importante pour les systèmes d’alimentation, où la régulation naturelle de la fréquence du système est entravée en raison de la réduction de l’inertie. Dans ce contexte, les réseaux à courant continu (CC) sont considérés comme une solution pertinente, car la nature CC des appareils électroniques de puissance apporte des avantages technologiques et économiques par rapport au courant alternatif (CA). La thèse propose la conception et le contrôle d’une Microgrid hybride AC/DC pour intégrer différentes sources renouvelables, y compris la récupération d’énergie solaire et de freinage des trains, aux systèmes de stockage d’énergie sous forme de batteries et de supercondensateurs et à des charges telles que les véhicules électriques ou d’autres réseaux (AC ou DC), pour un fonctionnement et une stabilité fiables. La stabilisation des tensions des bus du Microgrid et la fourniture de services systèmes sont assurées par la stratégie de contrôle proposée, où une étude de stabilité rigoureuse est réalisée. Un contrôleur non linéaire distribué de bas niveau, basé sur une approche “Systemof- Systems”, est développé pour un fonctionnement correct de l’ensemble du Microgrid. Un supercondensateur est appliqué pour faire face aux transitoires, équilibrant le bus CC du Microgrid et absorbant l’énergie injectée par des sources d’énergie intermittentes et possiblement très fortes comme celle provenant du freinage régénératif de trains ou metros, tandis que la batterie réalise le flux de puissance à long terme. Un contrôle de linéarisation par bouclage dynamique basé sur une analyse par perturbation singulière est développé pour les supercondensateurs et les trains. Des fonctions de Lyapunov sont construites en tenant compte des dispositifs interconnectés au Microgrid pour assurer la stabilité de l’ensemble du système. Les simulations mettent en évidence les performances du contrôle proposé avec des tests de robustesse paramétriques et une comparaison avec le contrôleur linéaire traditionnel. L’approche VSM (Virtual Synchronous Machine) est implémentée dans le Microgrid pour le partage de puissance et l’amélioration de la stabilité de fréquence. Une inertie virtuelle adaptative est proposée, puis la constante d’inertie devient une variable d’état du système qui peut être conçue pour améliorer la stabilité de fréquence et le support inertiel, où l’analyse de stabilité est effectuée. Par conséquent, le VSM est la connexion de liaison entre les côtés DC et AC du Microgrid, où la puissance disponible dans le réseau DC est utilisée pour les services système dans les Microgrids AC. Les résultats de la simulation montrent l’efficacité de l’inertie adaptative proposée, où une comparaison avec la solution de statisme et le contrôle standard est effectuée
Microgrids are a very good solution for current problems raised by the constant growth of load demand and high penetration of renewable energy sources, that results in grid modernization through “Smart-Grids” concept. The impact of distributed energy sources based on power electronics is an important concern for power systems, where natural frequency regulation for the system is hindered because of inertia reduction. In this context, Direct Current (DC) grids are considered a relevant solution, since the DC nature of power electronic devices bring technological and economical advantages compared to Alternative Current (AC). The thesis proposes the design and control of a hybrid AC/DC Microgrid to integrate different renewable sources, including solar power and braking energy recovery from trains, to energy storage systems as batteries and supercapacitors and to loads like electric vehicles or another grids (either AC or DC), for reliable operation and stability. The stabilization of the Microgrid buses’ voltages and the provision of ancillary services is assured by the proposed control strategy, where a rigorous stability study is made. A low-level distributed nonlinear controller, based on “System-of-Systems” approach is developed for proper operation of the whole Microgrid. A supercapacitor is applied to deal with transients, balancing the DC bus of the Microgrid and absorbing the energy injected by intermittent and possibly strong energy sources as energy recovery from the braking of trains and subways, while the battery realizes the power flow in long term. Dynamical feedback control based on singular perturbation analysis is developed for supercapacitor and train. A Lyapunov function is built considering the interconnected devices of the Microgrid to ensure the stability of the whole system. Simulations highlight the performance of the proposed control with parametric robustness tests and a comparison with traditional linear controller. The Virtual Synchronous Machine (VSM) approach is implemented in the Microgrid for power sharing and frequency stability improvement. An adaptive virtual inertia is proposed, then the inertia constant becomes a system’s state variable that can be designed to improve frequency stability and inertial support, where stability analysis is carried out. Therefore, the VSM is the link between DC and AC side of the Microgrid, regarding the available power in DC grid, applied for ancillary services in the AC Microgrid. Simulation results show the effectiveness of the proposed adaptive inertia, where a comparison with droop and standard control techniques is conducted

Depuis quelques années, les systèmes embarqués n’ont pas cessé d’évoluer. Cette évolution a conduit à des circuits de plus en plus complexes pouvant comporter plusieurs centaines de processeurs sur une même puce.Si la progression des techniques de fabrication des systèmes intégrés, a permis l’amélioration des performances de ces derniers en terme de temps et de capacité de traitement, elle a malheureusement amené une nouvelle contrainte de conception. En effet, cette nouvelle génération de systèmes consomme plus d’énergie et nécessite donc la prise en compte, pendant la phase de conception, des caractéristiques énergétiques dans le but de trouver le meilleur compromis (performance / énergie). Des études montrent qu’une estimation précoce de la consommation – i.e. au niveau comportemental – permet une meilleure diminution de l’énergie consommée par le système.L’outil EDPE (Early Design Power Estimation), objet de cette thèse, propose en réponse à ce besoin, une procédure permettant la caractérisation énergétique précoce d’une architecture de type MPSoC (MultiProcessor System on Chip) dans la phase de prototypage virtuel en System C. EDEP s’appuie sur des modèles de consommation par composant pour en déduire l’énergie dissipée par le système global lorsque le système est simulé au niveau CABA(Cycle Accurate Byte Accurate) ou encore TLM (Transaction Level Model). Les modèles proposés par EDPE, ont été intégrés dans la bibliothèque de prototypage virtuel SoClib. Ainsi, pendant la phase d’exploration architecturale, le concepteur dispose en plus des caractéristiques temporelles et spatiales de son circuit, d’une estimation précise de sa consommation énergétique.L’élaboration de modèles de consommation pour les différents composants matériels d’un système, à l’aide d’EDPE, est simple, homogène et facilement généralisable.Les résultats obtenus montrent la capacité d’EDPE à prédire la consommation énergétique de différentes applications logicielles déployées sur une même architecture matérielle de manière précise et rapide
Technological trends towards high-level integration combined with the increasing operating frequencies, made embedded systems design become more and more complex.The increase in number of computing resources in integrated circuit (IC) led toover-constrained systems.In fact, SoC (System on Chip) designers must reduce overall system costs, including board space, power consumption and development time.Although many researches have developed methodologies to deal with the emerging requirements of IC design, few of these focused on the power consumption constraint.While the highest accuracy is achieved at the lowest level, estimation time increases significantly when we move down to lower levels.Early power estimation is interesting since it allows to widely explore the architectural design space during the system level partitioning and to early adjust architectural design choices.EDPE estimates power consumption at the system levels and especially CABA (Cycle Accurate Bit Accurate) and TLM (Transaction Level Modelling) levels.The EDPE have been integrated into SoCLib library.The main goal of EDPE (Early Design Power Estimation) is to compare the power consumption of different design partitioning alternatives and chooses the best trade-off power/ performance.Experimental results show that EDPE (Early Design Power Estimation) method provides fast, yet accurate, early power estimation for MPSoCs (MultiprocessorSystem on Chip).EDPE uses few parameters per hardware components and is based on homogeneous and easy characterization method.EDPE is easily generalized to any virtual prototyping library

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The Information Technology (IT) is increasing his applicability to business, both private and public companies. It is necessary the adequate use of the new technologies and get cooperation and technology acceptance of the system. People tend to resist to the changes, contributing so that the technology is rejected or even it is not recognized as promoting of the changes. This study is relevant and aim to evaluate the impacts of new technologies, considering their users as fundamental factors in the change process. The survey analyzed the advantages and the barriers of the system use in three federal special judicial of Rio Grande do Norte, with data collected in May of 2007, through the application of questionnaires to thirty eight users of the virtual system CRETA. The users' perception was evaluated, under the optics of five variables: efficiency, image, agility, ease of use and quality. Starting from the obtained results, it was evidenced that the implementation of the system felt accordingly the expected and it reached the objectives intended that were: the velocity and efficiency in the path of the lawsuits, larger productivity, resulting in a better quality of the final work introduced to the citizen and proportionate an improvement in the organizational image of the judiciary power
A Tecnologia da Informa??o (TI), frente aos constantes avan?os tecnol?gicos e sua aplicabilidade ?s t?cnicas de gest?o, se apresenta como uma grande aliada na busca pelo sucesso organizacional, tanto no ?mbito das empresas privadas quanto p?blicas. Uma das estrat?gias diferenciadoras utilizadas pelas organiza??es prov?m de usos inovadores de tecnologias, com ?nfase em TI. No entanto, ? necess?rio avaliar a percep??o dos usu?rios quanto aos impactos do uso das novas tecnologias. Por mais avan?ada que seja a tecnologia implantada, poder? haver resist?ncia das pessoas ?s mudan?as, contribuindo para que a tecnologia n?o seja plenamente aceita ou mesmo n?o seja reconhecida como fomentadora de mudan?as. Justifica-se, assim, a relev?ncia de estudos que busquem avaliar os impactos de novas tecnologias, considerando os seus usu?rios como fatores fundamentais no processo de mudan?a. Partindo desse princ?pio, esse estudo analisou os impactos, as vantagens e as limita??es da implanta??o de um sistema virtual de controle processual, denominado CRETA, no Juizado Especial Federal do Rio Grande do Norte. Por meio da aplica??o de question?rios a 38 usu?rios, foi avaliada a percep??o dos impactos do uso do CRETA sob a ?tica de cinco vari?veis: efici?ncia/produtividade, imagem, agilidade, facilidade e qualidade. A partir dos resultados obtidos, foi evidenciado que a implementa??o do sistema se deu conforme o esperado e atingiu os objetivos pretendidos, tais como celeridade e efici?ncia no tr?mite dos processos judiciais, maior produtividade, resultando numa melhor qualidade do trabalho final apresentado ao cidad?o e proporcionado uma melhora na imagem organizacional do poder judici?rio. No entanto, alguns impactos negativos foram destacados, principalmente ligados aos fatores humanos

La raréfaction des sources de production conventionnelles et leurs émissions nocives ont favorisé l’essor notable de la production renouvelable, plus durable et mieux répartie géographiquement. Toutefois, son intégration au système électrique est problématique. En effet, la production renouvelable est peu prédictible et issue de sources majoritairement incontrôlables, ce qui compromet la stabilité du réseau, la viabilité économique des producteurs et rend nécessaire la définition de solutions adaptées pour leur participation au marché de l’électricité. Dans ce contexte, le projet scientifique Winpower propose de relier par un réseau à courant continu les ressources de plusieurs acteurs possédant respectivement des fermes éoliennes offshore (acteurs EnR) et des centrales de stockage de masse (acteurs CSM). Cette configuration impose aux acteurs d’assurer conjointement la gestion du réseau électrique.Nous supposons que les acteurs participent au marché comme une entité unique : cette hypothèse permet aux acteurs EnR de tirer profit de la flexibilité des ressources contrôlables pour minimiser le risque de pénalités sur le marché de l’électricité, aux acteurs CSM de valoriser leurs ressources auprès des acteurs EnR et/ou auprès du marché et à la coalition de faciliter la gestion des déséquilibres sur le réseau électrique, en agrégeant les ressources disponibles. Dans ce cadre, notre travail s’attaque à la problématique de la participation au marché EPEX SPOT Day-Ahead de la coalition comme une centrale électrique virtuelle ou CVPP (Cooperative Virtual Power Plant). Nous proposons une architecture de pilotage multi-acteurs basée sur les systèmes multi-agents (SMA) : elle permet d’allier les objectifs et contraintes locaux des acteurs et les objectifs globaux de la coalition.Nous formalisons alors l’agrégation et la planification de l’utilisation des ressources comme un processus décisionnel de Markov (MDP), un modèle formel adapté à la décision séquentielle en environnement incertain, pour déterminer la séquence d’actions sur les ressources contrôlables qui maximise l’espérance des revenus effectifs de la coalition. Toutefois, au moment de la planification des ressources de la coalition, l’état de la production renouvelable n’est pas connue et le MDP n’est pas résoluble en l’état : on parle de MDP partiellement observable (POMDP). Nous décomposons le POMDP en un MDP classique et un état d’information (la distribution de probabilités des erreurs de prévision de la production renouvelable) ; en extrayant cet état d’information de l’expression du POMDP, nous obtenons un MDP à état d’information (IS-MDP), pour la résolution duquel nous proposons une adaptation d’un algorithme de résolution classique des MDP, le Backwards Induction.Nous décrivons alors un cadre de simulation commun pour comparer dans les mêmes conditions nos propositions et quelques autres stratégies de participation au marché dont l’état de l’art dans la gestion des ressources renouvelables et contrôlables. Les résultats obtenus confortent l’hypothèse de la minimisation du risque associé à la production renouvelable, grâce à l’agrégation des ressources et confirment l’intérêt de la coopération des acteurs EnR et CSM dans leur participation au marché de l’électricité. Enfin, l’architecture proposée offre la possibilité de distribuer le processus de décision optimale entre les différents acteurs de la coalition : nous proposons quelques pistes de solution dans cette direction
Renewable Energy Sources (RES) has grown remarkably in last few decades. Compared to conventional energy sources, renewable generation is more available, sustainable and environment-friendly - for example, there is no greenhouse gases emission during the energy generation. However, while electrical network stability requires production and consumption equality and the electricity market constrains producers to contract future production a priori and respect their furniture commitments or pay substantial penalties, RES are mainly uncontrollable and their behavior is difficult to forecast accurately. De facto, they jeopardize the stability of the physical network and renewable producers competitiveness in the market. The Winpower project aims to design realistic, robust and stable control strategies for offshore networks connecting to the main electricity system renewable sources and controllable storage devices owned by different autonomous actors. Each actor must embed its own local physical device control strategy but a global network management mechanism, jointly decided between connected actors, should be designed as well.We assume a market participation of the actors as an unique entity (the coalition of actors connected by the Winpower network) allowing the coalition to facilitate the network management through resources aggregation, renewable producers to take advantage of controllable sources flexibility to handle market penalties risks, as well as storage devices owners to leverage their resources on the market and/or with the management of renewable imbalances. This work tackles the market participation of the coalition as a Cooperative Virtual Power Plant. For this purpose, we describe a multi-agent architecture trough the definition of intelligent agents managing and operating actors resources and the description of these agents interactions; it allows the alliance of local constraints and objectives and the global network management objective.We formalize the aggregation and planning of resources utilization as a Markov Decision Process (MDP), a formal model suited for sequential decision making in uncertain environments. Its aim is to define the sequence of actions which maximize expected actual incomes of the market participation, while decisions over controllable resources have uncertain outcomes. However, market participation decision is prior to the actual operation when renewable generation still is uncertain. Thus, the Markov Decision Process is intractable as its state in each decision time-slot is not fully observable. To solve such a Partially Observable MDP (POMDP), we decompose it into a classical MDP and an information state (a probability distribution over renewable generation errors). The Information State MDP (IS-MDP) obtained is solved with an adaptation of the Backwards Induction, a classical MDP resolution algorithm.Then, we describe a common simulation framework to compare our proposed methodology to some other strategies, including the state of the art in renewable generation market participation. Simulations results validate the resources aggregation strategy and confirm that cooperation is beneficial to renewable producers and storage devices owners when they participate in electricity market. The proposed architecture is designed to allow the distribution of the decision making between the coalition’s actors, through the implementation of a suitable coordination mechanism. We propose some distribution methodologies, to this end

Cette thèse aborde les formalismes pour la modélisation multi-physique en support au cycle en V deconception. Ce travail a été réalisé dans le cadre du projet ANR-MoCoSyMec, selon la méthodologie duprototypage virtuel fonctionnel (PVF) et illustré sur des systèmes électromagnétiques.Nous nous sommes principalement intéressés au langage VHDL-AMS, en tant que support aux différentsniveaux de modélisation apparaissant dans le cycle en V de conception. Cela nous a conduits à traiter laportabilité et l'interopérabilité en VHDL-AMS de diverses méthodes et outils de modélisation. Nous avonsproposé et validé, via le formalisme des composants logiciels ICAr, des solutions aux limites de l'utilisation deVHDL-AMS pour modéliser certains phénomènes physiques reposants sur des calculs numériques.Nous avons étendu la norme ICAr pour supporter des modèles dynamiques décrits par des équationsdifférentielles algébriques (DAE) ; et pour des besoins de co-simulation, nous pouvons également y associer unsolveur. Ces développements sont désormais capitalisés dans le framework CADES.Enfin, nous avons proposé une architecture pour le portage de modèles d'un formalisme à un autre. Elle a étédéfinie et mise en oeuvre plus particulièrement pour des modèles magnétiques réluctants (Reluctool) et desMEMS magnétiques (MacMMems) vers le VHDL-AMS.Ces formalismes et méthodologies sont mis en oeuvre autour du PVF d'un contacteur électromagnétique.

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This research proposes a methodology for development of Virttual Reality (VR) and Augmented Reality (AR) aplications, using natural markers for industrial scenarios. The proposed methodology uses the object annotation concept and visualization proposals are presented both for development of VR as for AR environments. In VR environments, the methodology is applied for object detection step of the semi-automatic environment development. On the other hand, in AR environments, is presented the concept of georreferenced natural markers, which use the georreferenced data integrated with object detection process using image processing techniques. The energy substations scenarios were used as case study for both approaches. Architectures are presented for construction and data visualization in industrial environments. Both for VR as for AR approaches, this work proposes using 3D natural markers based in Haar-like features for object training and detection process. The results enable the equipment detection at different points of view, within the operating scenario. Besides that, in AR, it enables the pose estimation in real-time using ORB features, while in VR it enables the semi-automatic object detection, which are used as information points for inclusion of virtual information. Several industrial scenarios, and especially the energy sector, has a high degree of complexity in the information processing and visualization. In this sense, beyond the 3D natural markers methodology, this work presents new visualization applications for industrial scenario visualization in VR and AR approaches.
Esta pesquisa propõe uma metodologia para construção de aplicações de Realidade Virtual (RV) e Realidade Aumentada (RA) com uso de marcadores naturais em cenários industriais. A metodologia usa o conceito de anotação de objetos e são apresentadas propostas de visualização para ambientes industriais tanto em formato de RV quanto de RA. Nos ambientes de RV, a metodologia é aplicada através da detecção de objetos no processo de construção semiautomática dos ambientes. Por outro lado, nos ambientes de RA, apresenta-se o conceito de marcadores naturais georreferenciados, que associam dados georreferenciados ao processo de detecção de objetos com técnicas de processamento de imagens. O cenário de subestações de energia elétrica foi utilizado como estudo de caso para as duas abordagens. São apresentadas arquiteturas para construção e visualização de dados em ambientes industriais. Tanto sob a forma de RV quanto de RA, este trabalho propõe o uso de marcadores naturais 3D baseados em Haar-like features para o processo de treinamento e detecção de objetos. Os resultados permitem a detecção de equipamentos a partir de diferentes pontos de vista no cenário de operação. Além disso, em RA, esta abordagem permite a estimativa de pose em tempo real com uso de ORB features e permite, em RV, a detecção semiautomática de objetos que são utilizados como pontos de informação para adição de informações virtuais. Diversos cenários industriais, principalmente o setor elétrico, possuem grau elevado de complexidade no tratamento e visualização das informações. Nesse sentido, além da metodologia de marcadores naturais 3D, este trabalho apresenta novas aplicações de visualização no cenário industrial com abordagens em RV e RA.

High-power microwave, HPM, systems can be used as non-lethal weapons with the ability to destroy or disturb electronics, by damaging internal circuits and inducing high currents. Today microwave sources are being developed with peak powers exceeding 1 GW, one of these devices is the vircator, a narrowband source which is unique to the HPM community. In order to understand and develop microwave sources like the vircator it is necessary to have computer models, as simulations gives an invaluable understanding of the mechanisms involved during operation, saving time and development costs.                                                                  This thesis presents the results from a theoretical analysis and a simulation study using a well known electromagnetic particle-in-cell code, Computer Simulation Technology Particle Studio. The results are then compared to measured data from a HPM system, the Bofors HPM Blackout. The results show that CST PS can be used to design and study the coaxial vircator with good results.

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.

Esta dissertação apresenta uma contribuição aos estudos de planejamento do sistema elétrico do Estado de São Paulo, ressaltando os benefícios que se obteria, com uma maior integração das fontes renováveis à matriz elétrica desse estado (notadamente as fontes de energia solar fotovoltaica, eólica, aproveitamento dos resíduos sólidos urbano RSU e vinhaça), visando o aumento da segurança e independência energética, redução de perdas, e benefícios ambientais. Para tanto, apresenta-se o conceito das usinas virtuais, cujo propósito é obter um melhor e maior aproveitamento dos recursos energéticos normalmente dispersos espacialmente - incluindo nesse rol a microgeração distribuída, a autoprodução e cogeração, e mesmo as fontes não renováveis que se encontram perto dos centros de consumo - com o objetivo de coordenar o seu funcionamento conjunto para satisfazer os requisitos da demanda de energia, por meio do uso da Tecnologia da Informação e Telecomunicações ou das Redes Inteligentes (Smart Grid), e, além disso, configurando a usina virtual de maneira que ela atue , no que diz respeito ao sistema interconectado de energia elétrica, rede de transmissão ou distribuição, como se fosse uma planta de geração de grande porte. Apresenta-se uma análise e projeções da operação e do suprimento do subsistema Sudeste/Centro Oeste (SE/CO), com foco especial no Sistema Elétrico do Estado de São Paulo, com suas interações com o SIN.
This Thesis presents contributions for the planning of the electrical system of São Paulo State Brazil, emphasizing benefits obtained with a better integration of renewables (mainly solar photovoltaics, wind energy, from municipal solid waste and sugarcane vinasse) aiming energy security and independence, loss reduction and environmental benefits. For this, the concept of VPP Virtual Power Plant is introduced, in which a better and broader use of energetic resources, geographically dispersed, including distributed microgeneration, autoproduction, cogeneration, and even nonrenewable sources, is facilitated. Those disperse energy resources, in general located near the consumer, are grouped and jointly managed, in order of to satisfy the demand requirements, using Smart Grid and Information and Telecommunication Technologies, and making the VPP to act, for the transmission or distribution system point of view, as a conventional large electrical power plant. An analysis and forecasts of the operation of the Brazilian Southeast/Center West (SE/CO) subsystem, with special focus on São Paulo State electrical system, and its interactions with the Brazilian Interconnected Electrical System (SIN), is presented.

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.14.02 - електричні станції, мережі і системи (141 – електроенергетика, електротехніка та електромеханіка). – Національний технічний університет «Харківський політехнічний інститут» МОН України, Харків, 2019. Зміст анотації. Дисертація присвячена розв’язанню актуальної науково- прикладної задачі у галузі забезпечення заявлених графіків видачі потужності у вузлі генерації електричних станцій на відновлювальних джерелах енергії (ВДЕ), шляхом використання систем акумуляції та концепції віртуальних електричних станцій. Актуальність теми дисертаційної роботи полягає у наступному, сучасні тенденції в розвитку електроенергетичних систем передбачають суттєве збільшення частки електричних станцій на відновлювальних джерелах енергії в загальній структурі генерації розвинутих країн, що призводить до необхідності їх додаткового резервування. З гідно статті 71.5 закону про «Ринок електричної енергії України», Гарантований покупець повинен придбати всю енергію від виробників з ВДЕ, що працюють за «Зеленим тарифом». Особливістю режимів роботи електричних станцій на відновлювальних джерелах є майже пряма залежність від погодних умов, що призводить до відхилень значення потужності в точках генерації від заявлених значень. Отже виникає необхідність в компенсації виникаючих небалансів. Використовуючи концепцію віртуальних електричних станцій, що поєднують електричні станції на ВДЕ, активних споживачів та системи акумуляції в єдину станцію зі спільною системою управління, можливо зменшити небаланси в точці генерації. Це потребує створення методів вибору оптимальної компоновки систем накопичення; алгоритмів систем управління для віртуальних електричних станцій та розподілених систем акумулювання; рекомендацій по їх застосуванню для електричних мереж, які тільки починають перехід від традиційних до інтелектуальних і мають дефіцит маневрових потужностей. Розробка технічних заходів для забезпечення заявлених графіків роботи сонячних електростанцій (СЕС) та вітряних електростанцій (ВЕС) дозволить їх інтегрувати до графіку генерації в якості базових станцій. Це дасть можливість виконати зобов‘язання всіх учасників процесу та не порушувати заплановані режими роботи інших станцій. Мета і задачі дослідження. Мета дослідження полягає у забезпеченні заявлених графіків видачі потужності у вузлі генерації електричних станцій на відновлювальних джерелах енергії, шляхом використання систем акумуляції та концепції віртуальних електричних станцій. Для досягнення поставленої мети визначені задачі дослідження: – проаналізувати основні методи та засоби забезпечення графіків видачі потужності електричних станцій на відновлювальних джерелах енергії в Україні та світі і фактори, що впливають на них; – розробити математичну модель для дослідження режимів роботи електричних станцій гібридної генерації на основі сонячної та вітроелектростанції та провести перевірку адекватності розробленої математичної моделі; – уточнити методику розрахунку вартості електричної енергії від систем акумулювання у вузлі генерації з урахуванням втрат при передачі та перетворенні енергії; – вдосконалити методику оптимізації конфігурації систем акумулювання для балансування генерації СЕС та ВЕС за умови мінімізації питомої вартості електричної енергії; – провести комп‘ютерне моделювання роботи електричних станцій на відновлювальних джерелах енергії на основі погодних даних обраного адміністративного району України з метою визначення необхідної конфігурації системи акумулювання на основі розробленої методики; – розробити комп‘ютерну модель віртуальної електричної станції, що поєднує в собі удосконалені математичні моделі генерації активної потужності СЕС і ВЕС, комп‘ютерні моделі систем накопичення енергії, імітацію активних споживачів і енергетичного ринку, а також елементи апаратно-комп‘ютерного моделювання. – розробити алгоритм роботи інформаційно-керуючої системи віртуальної електричної станції, на основі уточненого методу розрахунку вартості електричної енергії та провести його апробацію на комп‘ютерній моделі віртуальної електричної станції. – дослідити можливість застосування концепції віртуальних електричних станцій для забезпечення добових графіків генерації з урахуванням вимог Гарантованого покупця. Об’єктом досліджень – електромагнітні процеси в мережах з електричними станціями на основі відновлювальних джерел енергії. Предметом досліджень – електричні та інформаційні параметри режимів обладнання електричних станцій на відновлюваних джерелах енергії. Наукова новизна одержаних результатів: 1) Отримала подальший розвиток математична модель віртуальної електричної станції, яка відрізняється від існуючих тим, що додано елементи для зв‘язку з реальним програмованим логічним контролером ОВЕН 110-60 та на основі регресійного аналізу враховано додатковий коефіцієнт співвідношення вхідних погодних умов та результуючої потужності для встановлення відповідності з реальними характеристиками обладнання, що дозволило застосувати апаратно-програмне моделювання, збільшити точність розрахунку вихідної активної потужності сонячної електричної станції на 5% та проводити моделювання роботи вітряної електричної станції на швидкостях вітру більших за номінальні. 2) Отримав подальший розвиток метод розрахунку вартості електричної енергії яка використовується для забезпечення добових графіків генерації ВДЕ на основі акумуляції в межах однієї віртуальної електричної станції, який відрізняється від відомих врахуванням витрат пов‘язаних з розташуванням, встановленням та роботою додаткового обладнання, що дозволяє підвищити точність виконання розрахунків і підвищити енергоефективність таких систем за рахунок задіяння найбільш доцільних їх елементів. 3) Науково і технічно обґрунтовано використання концепції віртуальних електричних станцій для забезпечення добових графіків генерацій сонячних та вітроелектростанцій в умовах енергетичного ринку України, що дозволить забезпечити функціонування механізму Гарантованого покупця з мінімальним застосуванням додаткових маневрових потужностей. Практичне значення одержаних результатів. Для електроенергетичної галузі України полягає в тому, що на підставі виконаних досліджень визначені способи оптимізації режимів роботи електричних станцій на відновлювальних джерелах енергії за допомогою акумуляції. Такий підхід дозволить встановити відповідність між діючим та прогнозним значенням потужності у точці генерації, сформувати графік навантаження для традиційних електричних станцій без необхідності додаткового їх маневрування для компенсацій електростанцій на відновлювальних джерелах енергії. Окрім того, результати досліджень допоможуть збільшити точність розрахунків вартості електричної енергії у точці генерації від систем акумулювання. Розроблена методика вибору конфігурації систем акумуляції дозволяє визначити мінімально необхідну ємність накопичувачів енергії та їх потужність, що забезпечить мінімізацію вартості устаткування. Запропонований алгоритм управління розподіленою системою акумулювання дозволяє вирішити задачу розподіленого балансування, а також враховує можливість залучення активних споживачів та енергетичного ринку до процесу балансування. Результати дисертаційної роботи були впроваджені: - у ТОВ «ЛЕО» для розрахунку мінімально необхідного об’єму систем накопичення енергії, що будуть рекомендовані для забезпечення заявлених графіків генерації електричних станцій на ВДЕ які працюють за зеленим тарифом; - у навчальному процесі кафедри електричних станцій Національного технічного університету “Харківський політехнічний інститут” для студентів спеціальностей 141 спеціальності за спеціалізаціями: 141-01 «Електричні станції» та 141-05 «Енергетичний менеджмент та енергоефективні технології» під час викладання курсів лекцій з дисциплін «Електрична частина станцій та підстанцій», «АСУТП станцій та підстанцій», «Системи відновлюваної енергетики та вторинні енергоресурси» , під час написання дипломних проектів, випускних кваліфікаційних робіт. Дисертація виконана згідно планів наукових досліджень кафедр електричних станцій та загальної електротехніки Національного технічного університету «Харківський політехнічний інститут» у відповідності до договору «Методи удосконалення електроенергетичних систем» (ДР № 0116U000885).
Dissertation for the degree of candidate of technical sciences (doctor of philosophy) in specialty 05.14.02 - Electric power stations, networks and systems (141 - Power engineering, electrical engineering and electromechanics). – National Technical University "Kharkiv Polytechnic Institute", Ministry of Education and Science of Ukraine, Kharkiv, 2019. Annotation content. The dissertation is devoted to solving the actual scientific and applied problem in the providing the stated schedules of power generation at renewable energy sources (RES) through the use of storage systems and the concept of virtual power plants. According to the legislation of Ukraine, the Guaranteed Buyer must purchase all energy from renewable energy producers operating under the Green Tariff. The peculiarity of the operating modes of power plants on renewable sources is almost a direct dependence on weather conditions, which leads to deviations of the power value at the points of generation from the declared values. Therefore, there is a need to compensate for emerging imbalances. Using the concept of virtual power plants that combine RES, active consumers and storage systems into a single station with a common control system, it is possible to reduce imbalances at the generation point. This requires the creation of methods for selecting the optimal layout of the accumulation systems; control systems algorithms for virtual power plants and distributed storage systems; recommendations for their application to power grids that are just beginning to transition from traditional to intelligent and have a lack of maneuverability. The development of technical measures to ensure the declared schedules of solar power plants (SPP) and wind power plants (WPP) will allow them to be integrated into the generation schedule as base stations. This will make it possible to fulfill the obligations of all participants of the process and not violate the planned operating modes of other stations. The purpose and tasks of the study. The purpose of the study is to provide the stated schedules of power generation at the generation site of renewable energy sources through the use of storage systems and the concept of virtual power plants. To achieve the goal, the research objectives are defined: – to analyze the basic methods and means of providing the schedules of power outputs of renewable energy sources in Ukraine and the world and the factors that influence them; – to develop a mathematical model for the study of operating modes of hybrid power plants based on solar and wind power plants and to check the adequacy of the developed mathematical model; – clarify the methodology for calculating the cost of electricity from storage systems at the generation site, taking into account losses in energy transmission and conversion; – improve the method of optimization of the configuration of accumulation systems for balancing the generation of SES and WPP, while minimizing the specific cost of electricity; – carry out computer simulation of the operation of renewable energy power plants based on the weather data of the selected administrative district of Ukraine in order to determine the required configuration of the accumulation system based on the developed methodology; – to develop a computer model of a virtual power plant that combines advanced mathematical models of SES and WPP power generation, computer models of energy storage systems, imitation of active consumers and the energy market, as well as elements of hardware and computer modeling. – to develop an algorithm of operation of the information and control system of the virtual power plant, based on the specified method of calculating the cost of electricity, and to test it on a computer model of the virtual power plant. – explore the possibility of applying the concept of virtual power plants to provide daily generation schedules, taking into account the requirements of the Guaranteed Buyer. The object of research is the electromagnetic processes in grids with power plants based on renewable energy sources. Subject of research – electrical and information parameters of modes of equipment of power plants on renewable energy sources. Scientific novelty: 1) The mathematical model of the virtual power plant has been further developed, which differs from the existing ones by adding elements for communication with the real programmable logic controller OVEN 110-60 and based on the regression analysis the additional coefficient of the ratio of incoming weather conditions and the resulting power is taken into account the real characteristics of the equipment, which allowed to apply hardware and software modeling, to increase the accuracy of the calculation of the output active power of solar panels at 5% and conduct simulations of wind power station at wind speeds greater than nominal. 2) The method of calculating the cost of electricity, which is used to provide daily schedules of generation of RES on the basis of accumulation within one virtual power station, which differs from the known costs related to the location, installation and operation of additional equipment, which improves the accuracy of calculations, was further developed. and to increase the energy efficiency of such systems by utilizing their most relevant elements. 3) It is scientifically and technically grounded to use the concept of virtual power plants for providing daily schedules of generation of solar and wind power plants in the conditions of the energy market of Ukraine, which will allow to ensure the functioning of the Guaranteed Buyer mechanism with minimal use of additional maneuvering capacities. Practical value: The practical value of the work lies in the fact that methods of optimization of modes of operation of power plants on renewable energy sources by means of accumulation are determined on the basis of the performed researches. This approach will allow to establish the correspondence between the current and the predicted value of power at the point of generation, to form a schedule of load for traditional power plants without the need for additional maneuvering for compensation of power plants on renewable energy sources. In addition, research findings will help to increase the accuracy of electricity cost calculations at the point of generation from storage systems. The developed method of choosing the configuration of accumulation systems allows to determine the minimum required capacity of energy storage and their capacity, which will minimize the cost of equipment. The proposed algorithm for managing a distributed accumulation system allows to solve the problem of distributed balancing, and also takes into account the possibility of involving active consumers and the energy market in the balancing process. The results of the dissertation work were introduced: - at LEO LLC to calculate the minimum required volume of energy storage systems that will be recommended to provide the stated generation schedules of power plants than work based on green tariff; - in the educational process of the National Technical University "Kharkiv Polytechnic Institute" for students of specialties 141 specialties in specialization: 141- 01 "Power Plants" and 141-05 "Energy Management and Energy Efficient Technologies" during the teaching of lectures on disciplines "Electrical part of stations and substations "," ACTSP of stations and substations "," Renewable energy systems and secondary energy resources ", during writing of diploma projects, final qualification works. The dissertation is executed according to the plans of scientific researches of the National Technical University "Kharkiv Polytechnic Institute" of the Department of Power stations and general electrical engineering in accordance with the economic agreement « Methods of improvement of power systems» (state registration number - 0116U000885).

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.14.02 - електричні станції, мережі і системи. – Національний технічний університет «Харківський політехнічний інститут», Харків, 2019. Дисертаційна робота присвячена розв’язанню актуальної науково-прикладної задачі у напрямку забезпечення заявлених графіків генерації електричних станцій на відновлюваних джерелах енергії на основі концепції віртуальних електричних станцій. У дисертаційній роботі досліджено методи забезпечення заявлених графіків генерації електричних станцій на ВДЕ та обґрунтована доцільність використання концепції віртуальних електричних станцій для вирішення поставленої задачі. Досліджено застосування різних типів систем акумуляції, як одного з елементів віртуальної електричної станції. Проведено аналіз існуючих методів впровадження інтелектуальних мереж, що дозволило вибрати шаблон Smart Grid Architecture Model за основу для створення необхідної інфраструктури. Проведено аналіз існуючих методів визначення оптимальної ємності систем акумуляції та їх компоновки. Розроблено комп‘ютерну модель для дослідження роботи віртуальних електричних станцій, що дозволяє оцінити потенційні небаланси при генерації, перевірити достатність обсягу систем акумуляції для різних задач, а також провести апробацію роботи системи управління. Уточнено методику розрахунку вартості електричної енергії від систем акумулювання з урахуванням вартості втрат енергії при передачі та трансформації, а також додаткових факторів пов‘язаних з орендою та обслуговуванням. Розроблено, реалізовано та апробовано алгоритм управління віртуальною електричною станцією, що базується на задіянні найбільш дешевого джерела енергії для балансування з урахуванням обмежень електричних мереж, доступу до енергетичного ринку та можливості залучення активних споживачів. Показана можливість забезпечення заявлених графіків генерації електричних станцій на основі концепції віртуальних електричних станцій на прикладі умов одного з адміністративних центрів України.
Dissertation for the degree of candidate of technical sciences in specialty 05.14.02 - power plants, networks and systems. - National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The thesis is devoted to the solution of the current scientific and applied problem in the field of providing the declared schedules of generating power plants with renewable energy sources based on the concept of virtual power plants. In the dissertation work, the methods of providing the declared schedules of generating power plants on renewable energy sources are investigated. The expediency of using the concept of virtual power plants to solve the problem is justified. The use of various types of accumulation systems as one of the elements of a virtual power plant is investigated. The analysis of existing methods and state-of-the-art-practices of implementing intelligent networks was carried out, which made it possible to select the Smart Grid Architecture Model pattern as the basis for creating the necessary infrastructure. The analysis of existing methods for determining the optimal capacity of accumulation systems and their layout has been carried out that was used to calculate minimal capacity for providing the declared schedules of generation of PV and wind power plant each 1 MW for one of the administrative centers of Ukraine. The developed computer model for studying the operation of virtual power plants that include PV and wind power with energy storage and connections to PLC allows assessing potential unbalances during generation, checking the sufficiency of the capacity of accumulation systems for various tasks, as well as testing the operation of the control system. The methodology for calculating the cost of electrical energy from storage systems has been refined, taking into account the cost of energy losses during transmission and transformation, as well as additional factors associated with renting and servicing. An algorithm for managing a virtual power plant was developed, implemented and tested with real PLC connected to mathematical model, based on using the cheapest energy source for balancing taking into account the limitations of electrical networks, power lines and transforming equipment, access to the energy market for buying and selling energy and the ability to attract active consumers. The possibility of providing the declared schedules of generation of power plants based on the concept of virtual power plants on the example of conditions of one of the administrative centers of Ukraine is shown.

Avec en perspective l’application à la robotique ou à l’étude des milieux granulaires, nous discutons la formulation des problèmes de contacts avec frottement en dynamique et pour les systèmes constitués de solides rigides. L’approche usuelle est event driven et ne permet pas d’écrire de manière systématique un problème d’évolution. Ceci a motivé l’émergence d’une nouvelle approche dans le cas sans frottement que nous généralisons au cas avec frottement. Suivant le point de vue de Lagrange sur l’équation de la dynamique, nous mettons en exergue l’usage systématique des puissances virtuelles et de la dualité. Ce parti-pris suggère de mettre l’accent sur l’effort généralisé de réaction dans la formulation et non sur les forces de réactions locales dans le monde réel, comme il est usuel. Ce point de vue permet d’échapper à des pathologies connues sous le nom de paradoxe de Painlevé
In the view of robotics or granular media mechanics, we question the statement of the dynamical evolution problem for multibody systems with contacts and friction. The usual approach is event driven and does not allow to state an evolution problem in a systematic way. This matter of fact gave rise to a new approach in the frictionless case we generalize to the case with friction. Sticking to the point of view of Lagrange on the equation of the dynamics, we emphasize the systematic use of virtual powers and duality. This bias suggests to put emphasis on generalized reaction forces in the statement of the evolution problem and not on local reaction forces of the real world, as it is usual in practice. This point of view allows to escape from pathologies known as Painlevé paradox

碩士
國立成功大學
機械工程學系
86
In recent years, virtual reality (VR) is sprouting as a particular computer technology, which is applied in many aspects such as engineering, science, business applications, entertainment, and so on. In this dissertation, we develop a simulation system for power machine operation which integrated digital controller, computer network and virtual reality techniques. This system consists of three main parts: an operation platform, a monitor platform and a VR platform. The operation platform provides the user the sense of presence. The monitor platform controls the signal transmission. The VR platform illustrates overall simulations that combine virtual scenes and the virtual power machine operation. A forklift operation system is built for simulation in the dissertation. The virtual forklift machine is controlled by the operation platform. By using the helmet display, the user would immerse himself in the virtual environment. Finally, we discuss incomplete parts and unsolved programs of this dissertation for the future work.

碩士
國立中山大學
電機工程學系研究所
107
With the increase of power demand, rising concern of environment protection and decommission of nuclear and fossil fuel power plants, the utility companies are facing with various challenges. Renewable energy, such as solar photovoltaic, wind power in conjunction with energy storage system are integrated to the network in a rapid speed. Effective Coordination of these distributed energy resources could not only reduce the impacts to the system but also provide supports to system operations. This research uses the concept of virtual power plant to integrate the distributed resources in the distribution system to provide ancillary services to distribution system operator. Mathematical formulations of several ancillary services, including line losses optimization, congestion relief, voltage regulation and service restoration support, are presented. The dispatch of virtual power plant resources in a feeder level network during normal and emergency situations are studied and the enhancement of system efficiency and reliability due to the dispatch of the distributed energy resources is demonstrated.

碩士
國立臺灣科技大學
電子工程系
105
Many diseases or accidents lead to physical disabilities, for example, stroke, sport injuries, or traffic accidents. Those whom suffered from physical disabilities may have to go to the hospital for rehabilitation to recover from sequela of diseases or injuries. However, the place for rehabilitation is limited to the hospital may leads to patient’s inconvenience, and the results of the range of motion obtained from the goniometry may diverse from different therapists. To improve the inconvenience and disadvantages above, a wearable movement monitoring system is derived in this study to monitor user’s range of motion. The system can automatically provide the information about the range of motion and allows users to conduct the physical treatment at home. Besides, four benefits also come out: the extension of multi-node to extend the monitoring for more limbs, small and light-weighted low-power wearable device to improve the portability and the endurance, a fast calibration of the sensor to increase the accuracy under different environmental conditions, and a virtual-reality based real-time application to provide feedbacks of the movement information. The results of the proposed wearable monitoring device have been compared to the optical motion capture system (Qualisys). In the motor-based experiment, a maximum mean error of 0.44°±0.161°, 0.368°±0.338°, and 0.193°±0.287° is obtained in the rotation of X-, Y-, and Z-axes, respectively. Furthermore, the power consumption of our device is about 5.44mA based on the power consumption test, which is much smaller than the commercial device x-IMU of 50mA ~ 150mA.

碩士
國立東華大學
資訊工程學系
105
With the rapid development of the emerging technologies and significant cost reduction of the deployment for solar energy and wind power, the replacement of traditional power generation by renewable energy becomes feasible in the future. However, different from currently deployed centralized power sources, renewables are categorized as one kind of intermittent energy sources, and the scale of renewables is small and scattered. In the recent literature, the architecture of virtual power plant was proposed to replace the current smart grid in the future. However, the energy sharing concept and the uncertainties of intermittent energy sources will cause the short-term energy management for the future virtual power plant much more complicated than current centralized control energy management for traditional power generation system. To the best of our knowledge, no researcher has addressed on the above-mentioned short-term energy management problems for the future virtual power plant so far. Accordingly, a hierarchical day-ahead energy management system based on the architecture of virtual power plant is proposed in this work to tackle the complex energy management problems. We first collect electricity consumption data from smart appliances used in households and predict power-generating capacity of renewable energy sources at the prosumer level. Then, the proposed hierarchical energy management system is employed to schedule the usage of electricity for the customers by considering the efficiency of the use of distributed renewables. Notably, a reallocation mechanism is presented in this work to allocate excess electricity generated in a community virtual power plant to others facing with power supply shortage, and the maximal usage of renewables and reduction of the burden on community virtual power plants during time period of peak load can be achieved accordingly. The experimental results show that the hierarchical day-ahead energy management system proposed in this work can mitigate the dependency on community virtual power plants effectively, and balance peak and off-peak period load of electricity market.

Modern day power systems present an open access environment, inspiring participation from small scale and large power suppliers. With multiple players in the system driven by the market, proper monitoring and control of system becomes a major concern. This transformation is accompanied by dynamic consumption patterns and rising power demands. The expanding network encompassing EHV/AC network, HVDC and FACTS devices, along with increased penetration of renewable sources, viz. solar and wind energy at medium and low voltage levels, adds to the problem. Independent System Operators (ISO) are entrusted with ensuring smooth operation, and employing proper preventive measures to eliminate a possible cascade tripping leading to a partial or large-scale blackout. To aid the operator in the process of ensuring secure operation of the grid, there are many tools that provide required information and guidance. Power flow tracing is one such tool that aids the operator in congestion management, transmission pricing, transaction evaluation, loss allocation and reactive power optimization. In this thesis, a novel active power flow tracing approach is proposed that takes into account, the real-time operating conditions and network topology. It provides the decomposition of active power flow in a line into respective components injected by various generators in the system. It also provides the contribution of the generators to various loads in the system. The approach is simple and computationally fast, making it an ideal tool to aid preventive control decisions. Based on the proposed active power flow tracing, a congestion management approach is developed. The approach indicates the least number of generators that need to be coordinated for generation rescheduling, so as to alleviate overloading in affected transmission lines and transformers. The approach also takes into consideration the operating constraints on the system, while computing the optimal rescheduling amongst selected generators using LP technique. The thesis also presents a real power loss allocation approach based on the proposed power flow tracing. Loss allocation is an important part of tariff design as the cost associated with losses amounts to a sizable fraction of total revenue collected from the loads. The approach provides information as to how losses are distributed among loads and how much each generator is providing for the loss share of each load. The approaches developed in the thesis are illustrated on a sample 10-bus equivalent system, IEEE 30-bus, and IEEE 39-bus systems. Results for typical case studies are presented for practical systems of 72-bus equivalent and 203-bus equivalent of Indian Southern grid.

碩士
遠東科技大學
機械工程研究所
105
In the thesis, a machine learning based intelligent gateway for the collabration system of virtual green power generation is proposed. It works for power dispatching of virtual green power plants. The intelligent gateway for the collabration system is developed by using supervising machine learning method. It can reduce the risk of power supply instability caused by poor loading distribution of green power plants. So it will effectively improve the performance of power dispatching. The intelligent gateway for the collaboration system contains: (1) Communication Module (2) Coordination Module (3) Cooperation Module (4) Shared Creation Module. Multiclass decision jungle algorithm is choosed for machine learning in the communication module and the coordination module. And supervised neural network regression algorithm is choosed for machine learning in the cooperation module and the shared creation module. These modules are integrated into the intelligent gateway for the collaboration system. Finally, the design of the intelligent gateway for the collabration system is verified by the results of simulation and implementation. The experimental results of the system showed the good performance and feasibility of power dispatching for virtual green power plants.

碩士
亞洲大學
資訊工程學系
103
This thesis aims to propose a simple way to develop a low-cost and high-efficiency frequency estimation system for power signal. Arduino DAQ is utilized to extract the power signal and then perform the analysis by using a virtual-instrument software, LabVIEW. First , the analysis is performed by using Fourier algorithm as a digital filter to fetch the fundamental signal of the acquired signals, and then a zero crossing algorithm technology is applied to sine or cosine signal of the fundamental signal to calculate the frequency of the fundamental signal. The RMS algorithm is also implemented to monitor the voltage variation of the power signal so as to monitor the power quality. LabVIEW is implemented to simulat a signal source with high-order harmonics and noise signal combined together, and the program can be used to estimate the frequency of fundamental sinusoidal signals with high accuracy. Experiments show Arduino can be utilized to complete the task of the data acquisition.

碩士
國立臺北教育大學
數位科技設計學系(含玩具與遊戲設計碩士班)
102
With the advanced developments recently made in all kinds of technology, teaching material has become more and more diversified. Many studies have been done on the application of virtual reality to interactive learning and it is seen as a most effective teaching technique. However, this learning only involves “watching” and “imagining” and visual stimulation can be over emphasized in a virtual reality environment. The importance of “learning by doing” or by “hands-on experience” is often neglected. This study proposes a concept of physical-virtual integration in teaching where a virtual reality environment is integrated with physical material, including a 3D printer, and applied in energy education. To evaluate the proposed teaching method, tests were carried out in a study involving elementary school students. Three classes, selected at random, participated in the research, and three different teaching methods were used in each: the virtual reality teaching method, a physical materials method, and a virtual-physical integration method. After the teaching sessions written tests completed by the students were used to assess the learning outcome. The results showed that students from the virtual reality class performed the worst with an average score of 73.1, the physical material group was better with an average score of 78.5, and students who were exposed to integrated virtual-physical teaching were the best performers with an average score of 89.6. The virtual-physical integration teaching method was also found to effectively improve learning motivation, extend the attention span, and enhance the overall learning process. If the method is adopted for general use, with a combination of virtual and physical material, this will maximize the student’s learning outcome.

碩士
中原大學
電機工程研究所
91
Following the grown of the industry, it is increase in use of the any kinds of the load equipment, so the large power system will become more complication, and it will be increase in cost of the load monitoring. The virtual instrument (VI) application, which integrates all data acquisition, processing, display, and database management in one metering system, enhances the convenience, efficiency, flexibility, and economy of the power monitoring task. Because the power systems become more complication, how to ensure that the data of power waveform transfer is fast and correct, the chosen of the transfer interface is more important. However, the overall performance of the VI system is specifically limited by the bandwidth of the communication interface between the power meters and the host computer, when conventional serial communications are applied. The distributed VI power monitoring system will significantly enhance its real-time performance by interfacing the VI host computer via the universal serial bus (USB). LOW-COST power monitors are in great demand for industrial and commercial applications to assess power quality and manage demand and energy. Observing the energy consumption of electric loads, convectional load monitoring system needs to install hardware circuit on each load to be monitored. However, non-intrusive load monitoring system (NILMS) only needs to install a monitoring device on the electric power entrance point to collect the data for energy consumption of the loads by analyzing the signal waveforms collected and identifying the loads accordingly. And non-intrusive load monitoring system can be combined with the virtual instrument power monitoring system, so the cost is less than those of the conventional one. The thesis aims at developing the virtual instrument power monitoring meter, which transferred the data or command via universal serial bus (USB) interface. However, the techniques needed for load identification are more sophisticated as compared with the convectional one. So, how to choose the load feature is very important. In the convectional feature extraction method, one of the statistics method is principal component analysis（PCA）, the PCA method can solve the linear problem. Nevertheless, to solve the nonlinear problem, we should use nonlinear method, like nonlinear principal analysis（NLPCA）. The decision boundary feature extraction（DBFE） method is available for the nonlinear problem. In the thesis, we will compare with three kinds of feature extraction method, and which method can identify the load combination the highest, and the computer time and floats is the minimization, the method we will be proposed.

Virtual prototyping is today an essential technology for modeling, verification, and re-design of full HW/SW platforms. This allows a fast prototyping of platforms with a higher and higher complexity, which precludes traditional verification approaches based on the static analysis of the source code. Consequently, several technologies based on the analysis of simulation traces have proposed to efficiently validate the entire system from both the functional and extra-functional point of view. From the functional point of view, different approaches based on invariant and assertion mining have been proposed in literature to validate the functionality of a system under verification (SUV). Dynamic mining of invariants is a class of approaches to extract logic formulas with the purpose of expressing stable conditions in the behavior of the SUV. The mined formulas represent likely invariants for the SUV, which certainly hold on the considered traces. A large set of representative execution traces must be analyzed to increase the probability that mined invariants are generally true. However, this is extremely time-consuming for current sequential approaches when long execution traces and large set of SUV's variables are considered. Dynamic mining of assertions is instead a class of approaches to extract temporal logic formulas with the purpose of expressing temporal relations among the variables of a SUV. However, in most cases, existing tools can only mine assertions compliant with a limited set of pre-defined templates. Furthermore, they tend to generate a huge amount of assertions, while they still lack an effective way to measure their coverage in terms of design behaviors. Moreover, the security vulnerability of a firmware running on a HW/SW platforms is becoming ever more critical in the functional verification of a SUV. Current approaches in literature focus only on raising an error as soon as an assertion monitoring the SUV fails. No approach was proposed to investigate the issue that this set of assertions could be incomplete and that different, unusual behaviors could remain not investigated. From the extra-functional point of view of a SUV, several approaches based on power state machines (PSMs) have been proposed for modeling and simulating the power consumption of an IP at system-level. However, while they focus on the use of PSMs as the underlying formalism for implementing dynamic power management techniques of a SoC, they generally do not deal with the basic problem of how to generate a PSM. In this context, the thesis aims at exploiting dynamic assertion mining to improve the current approaches for the characterization of functional and extra-functional properties of a SoC with the final goal of providing an efficient and effective system-level virtual prototyping environment. In detail, the presented methodologies focus on: efficient extraction of invariants from execution traces by exploiting GP-GPU architectures; extraction of human-readable temporal assertions by combining user-defined assertion templates, data mining and coverage analysis; generation of assertions pinpointing the unlike execution paths of a firmware to guide the analysis of the security vulnerabilities of a SoC; and last but not least, automatic generation of PSMs for the extra-functional characterization of the SoC.

Transmission pricing and congestion management are two important aspects of modern power sectors working under a deregulated environment or moving towards a deregulated system (open access) from a regulated environment. The transformation of power sector for open access environment with the participation of private sector and potential power suppliers under the regime of trading electricity as a commodity is aimed at overcoming some of the limitations faced by the vertically integrated system. It is believed that this transformation will bring in new technologies, efficient and alternative sources of power which are greener, self sustainable and competitive. There is ever increasing demand for electrical power due to the changing life style of human beings fueled by modernization and growth. Augmentation of existing capacity, siting of new power plants, and a search for alternate viable sources of energy that have lesser impact on environment are being taken up. With the integration of power plants into the grid depending upon the type, loca- tion and technology used, the cost of energy production also differs. In interconnected networks, power can flow from one point to other point in infinite number of possible paths which is decided by the circuit parameters, operating conditions, topology of network and the connected loads. The transmission facility provided for power transfer has to recover the charges from the entities present in the network based on the extent of utilization. Since power transmission losses account for nearly 4 to 8% of the total generation, this has to be accounted for and shared properly among the entities depending upon the connected generation/load. In this context, this thesis aims to evaluate the shortcomings of existing tracing methods and proposes a tracing method based upon the actual operating conditions of the network taking into account the network parameters, voltage gradient among the connected buses and topology of the network as obtained by the online state estimator/load flow studies. The concept proposed is relatively simple and easy to implement in a given transactional period. The proposed method is compared against one of the existing tracing technique available in literature. Both active and reactive power tracing is handled at one go. The summation of partial contributions from all the sources in any given line of the system always matches with that of the respective base case ow. The AC power flow equations themselves are nonlinear in nature. Since the sum of respective partial flows in a given branch is always equal to the original ow, these are termed as virtual flows and the effect of nonlinearity is still unknown. The virtual flows in a given line are complex in nature and their complex sum is equal to the original complex power flows as in the base case. It is required to determine whether these are the true partial flows. To answer this, a DC equivalent of the original AC network is proposed and is called as the R - P equivalent model. This model consists of only the resistances as that of original network (the resistances of transformers and lines neglecting the series reactance and the shunt charging) only. The real power injections in a AC network i.e. sources into respective buses and loads (negative real power injections) are taken as injection measurements of this R P model and the bus voltages (purely real quantities) are estimated using the method of least squares. Complex quantities are absent in this model and only real terms which are either sums or differences are present. For this model, virtual flows are evaluated and it has been verified that the virtual real power contributions from sources are in near agreement with the original AC network. This implies that the virtual flows determined for the original network can be applied for day-to-day applications. An important feature of the virtual flows is that it is possible to identify counter ow components. Counter flow components are the transactions taking place in opposite direction to the net flow in that branch. If a particular source is produces counter flow in a given line, then it is in effect reducing congestion to that extent. This information is lacking in most of the existing techniques. Counter flows are useful in managing congestion. HVDC links are integrated with HVAC systems in order to transfer bulk power and for the additional advantages they offer. The incremental cost of a DC link is zero due to the closed loop control techniques implemented to maintain constant power transfer (excluding constant voltage or constant current control). Consequently, cost allocation to HVDC is still a problem. The proposed virtual power flow tracing method is extended to HVAC systems integrated with HVDC in order to determine the extent of utilization of a given link by the sources. Before evaluating the virtual contributions to the HVDC links, the steady state operating condition of the combined system is obtained by per-forming a sequential load flow. Congestion is one of the main aspects of a deregulated system, and is a result of several transactions taking place simultaneously through a given transmission facility. If congestion is managed by providing pricing signals for the transmission usage by the parties involved. It can also be due to the non-availability of transmission paths due to line outages as a result of contingencies. In such a case, generation active power redispatch is considered as a viable option in addition to other available controls such as phase shifters and UPFCs to streamline the transactions within the available corridors. The virtual power flow tracing technique proposed in the thesis is used as a guiding factor for managing congestions occurring due to transactions/contingencies to the possible extent. The utilization of a given line by the sources present in the network in terms of real power flow is thus obtained. These line utilization factors are called as T-coefficients and these are approximately constant for moderate increments in active power change from the sources. A simple fuzzy logic based decision system is proposed in order to obtain active power rescheduling from the sources for managing network congestions. In order to enhance the system stability after rescheduling, reactive power optimization has life systems to illustrate the proposed approaches. For secure operation of the network, the ideal proportion of active power schedule from the sources present in the network for a given load pattern is found from network [FLG] matrix. The elements of this matrix are used in the computation of static voltage stability index (L-index). This [FLG] matrix is obtained from the partitioned network YBUS matrix and gives the Relative Electrical Distance (RED) of each of the loads with respect to the sources present in the network. From this RED, the ideal proportion of real power to be drawn by a given load from different sources can be determined. This proportion of active power scheduling from sources is termed as Desired Proportion of Generation (DPG). If the generations are scheduled accordingly, the network operates with less angular separation among system buses (improved angular stability), improved voltage profiles and better voltage stability. Further, the partitioned K[GL] matrix reveals information about the relative proportion in which the loads should draw active power from the sources as per DPG which is irrespective of the present scheduling. Other partitioned [Y ′ GG] matrix is useful in finding the deviation of the present active power output from the sources with respect to the ideal schedule. Many regional power systems are interconnected to form large integrated grids for both technical and economic benefits. In such situations, Generation Expansion Planning (GEP) has to be undertaken along with augmentation of existing transmission facilities. Generation expansion at certain locations need new transmission networks which involves serious problems such as getting right-of-way and environmental clearance. An approach to find suitable generation expansion locations in different zones with least requirements of transmission network expansion has been attempted using the concept of RED. For the anticipated load growth, the capacity and siting generation facilities are identified on zonal basis. Using sample systems and real life systems, the validity of the proposed approach is demonstrated using performance criteria such as voltage stability, effect on line MVA loadings and real power losses.

In order to fulfil the goals set by EU and in the Swedish energy agreement an increased share of renewable electricity production, like wind and solar power, is necessary. Due to current legislations photovoltaic (PV) installations are usually limited to the 255 kWp energy taxation rule, or to fit the consumption profile of the building. There is also an uncertainty regarding subsidies from a long-term perspective. Three main questions are examined in this report: Firstly, whether or not a larger PV installation is more beneficial compared to a smaller one regarding LCOE, payback time and IRR. Secondly, if and how a larger PV installation can be optimized using virtual storage. Thirdly, how the virtual storage solution compares to a conventional storage method with a lithium-ion battery. Throughout the project, larger installations have proven more profitable by taking advantage of cost efficiencies. By increasing the size of the installation from 120 kWp to 314 kWp for the investigated pilot project, the LCOE is reduced from 0,938 to 0,767 SEK/kWh, payback time is reduced from 17 to 12 years, and IRR is increased from 8,1 to 10,8 %. To maintain the advantage of the largest installation in the current market, it is necessary to integrate and optimize the storage so that all produced electricity is self-consumed. Some buildings have the possibility to create a virtual storage through using existing possibilities within the facility. Virtual storage is still an unexplored area but has risen in interest since focus on energy efficiency has increased. The project includes a virtual storage solution where the refrigeration system in a grocery store is paired with a water tank to provide more storage capacity. To optimize the use of the virtual storage, it is necessary to maximize the use of the available capacity. Three main applications have been identified as optimization alternatives for the project and those are: 1) storing excess electrical energy from over-production, 2) load shifting from hours with high electricity prices, 3) providing demand response for the primary regulation market (FCR-N, FCR-D). By utilizing the storage capacity, the PV investment can improve with regards to the studied economic measures. When utilizing the most profitable options, 1) and 3), for a 314 kWp PV installation the payback time is reduced from 12 to 10 years and the IRR is increased from 10,8 % to 11,73 %. Compared with a conventional lithium-ion battery (Tesla Powerwall), the virtual storage solution is competitive with respect to initial cost and environmental impact. However, for electrical aspects the battery significantly outperforms the virtual storage with an efficiency of 90 % of the battery and 54 % of the virtual storage and an energy density of 0,108 kWh/kg for the battery and 0,0035 kWh/kg for the virtual storage.

Στο πρώτο κεφάλαιο, γίνεται μία αναφορά στις ανανεώσιμες πηγές ενέργειας και αναλύεται περισσότερο η αιολική. Αναφέρεται η πορεία αξιοποίησής της, και παραθέτονται πληροφορίες για την τωρινή χρήση της στην παραγωγή ηλεκτρικής ενέργειας αλλά και μελλοντικές βλέψεις. Στο δεύτερο κεφάλαιο παρουσιάζονται τα χαρακτηριστικά του ανέμου και οι εξισώσεις της ανεμογεννήτριας που μας επιτρέπουν να απομαστεύουμε ενέργεια από τον άνεμο μέσω των ανεμογεννητριών. Στο τρίτο κεφάλαιο παρουσιάζονται τα δομικά στοιχεία και ο τρόπος με τον οποίο γίνεται η κατηγοριοποίηση των ανεμογεννητριών, οι έλεγχοι που χρησιμοποιούνται και τα είδη των ανεμογεννητριών που χρησιμοποιούνται σήμερα στη βιομηχανία. Στο τέταρτο κεφάλαιο παρουσιάζονται οι τεχνικές απαιτήσεις για τους αιολικούς σταθμούς στο ελληνικό Σ.Η.Ε. Στο πέμπτο κεφάλαιο, γίνεται η προσομοίωση μέσω του προγράμματος Matlab - Simulink ενός μη γραμμικού ελέγχου ισχύος ανεμογεννητριών DFIG για ενσωμάτωση σε εικονικούς σταθμού ισχύος (V.P.P).
In the first chapter, there is a general description about renewable energy resources and more specific, about the wind energy. We present the current worldwide electrical power production and the future requirements for electrical power production in Europe and Greece. In the second chapter, we study the features of the wind performance and the equations that allows us to drain energy from the wind ,using a wind turbine. The third chapter presents the components, the kinds of control and the categories of wind turbines that are in use in industry nowadays. The fourth chapter presents the technical requirements for the wind farms in the Greek System of Electrical Energy. In the fifth chapter we use the program Matlab - Simulink in order to simulate a non-linear direct power control of DFIG wind turbines for Virtual Power Plant (V.P.P.) integration.

With increasing intermittency from renewable energy production, such as solar and wind power, the need of increased flexibility is quickly arising. The Åland Islands have an energy transition agenda to reach the goal of having a 100 % renewable energy system. Since there is no possibility of hydro power acting as regulatory power on Åland, reaching the goal is a challenging task. Increasing flexibility can be achieved by either implementing energy storage in the system or by matching the demand with the production.  Therefore the purpose of this study was to estimate and evaluate the technical potential of demand response (DR) on Åland, both for 2019 and for a scenario in 2030 where the domestic production of wind and solar have increased. Six areas of interests were identified; electric heating, refrigeration processes, lighting, ventilation and air conditioning, electric vehicles and industries. The import from Sweden to Åland was examined since high import coincides with either low domestic renewable production or high consumption and therefore indicates when flexibility is most required. The results show that the technical potential of DR on Åland can lower the maximum electricity import from Sweden by 18 % in 2019. 4.3 % of the total import can be moved to times when there is less stress on the grid. Electric heating is the biggest contributor, and can by itself lower the import with three fourths of the total reduction. The domestic renewable production in 2019 is too low for DR to have an effect on self-sufficiency. For 2030 the self-sufficiency and utilization of domestic renewable production could be increased with 4.2-9.9 % and 5.4-12 % respectively when using DR, depending on if vehicle-to-grid is implemented on a large scale or not. The cost of DR is still unclear, and it varies between the different resources. However, electric heating seems to be a less expensive alternative to batteries, while providing a similar service.