In this dissertation, the generalized averaging method models for inverters, reactive power control methods for photovoltaic inverters, and a noise immunity improvement for hybrid position observers for brushless dc motor drives are studied. Models of inverters and other converters based on averaging have been widely used in numerous simulation applications. Generalized averaging can be applied to model both average and switching behavior of converters while retaining the faster run times associated with average-value models. Herein, generalized average models for single- and three-phase pulse width modulation inverters are proposed. The modulation signal for the proposed model could be either a sinusoidal waveform without high order harmonics or a sinusoidal waveform with third-harmonic injection. And this generalized average models also can apply for modeling three-phase pulse width modulation inverters with varying modulation signal frequency in the reference frame. These models are based on a quasi-Fourier series representation of the switching functions that includes fundamental and switching frequency components as well as sideband components of the switching frequency. The proposed models are demonstrated both in simulation and experimentally and are found to accurately portray both the fundamental and the switching behavior of the inverter. In particular, the use of sideband components allows accurate representation of the variation in switching ripple magnitude that occurs in the steady state. The generalized average models are found to have simulation run times that are significantly faster than those associated with detailed models. Therefore, the proposed generalized average models are suitable for simulation applications in which both accuracy (including the switching behavior) and fast run times are required (e.g., long simulation times, systems with multiple converters, and repeated simulations). Variations in the output power of intermittent renewable sources can cause significant fluctuations of distribution system voltage magnitudes. Reactive power control methods that employ the reactive power capability of photovoltaic three-phase inverters to mitigate these fluctuations are proposed. These control methods cause the three-phase inverters to substitute reactive output power for real output power when fluctuations in the solar power are experienced, allowing the fluctuations to be controlled. Performance metrics for assessing the ability of these controllers to perform this mitigation are defined. The controllers are examined using the IEEE 123-bus feeder distribution system, and it is found that the controllers can effectively mitigate voltage magnitude fluctuations and that the appropriate choice of controller depends on the performance metrics of interest. Finally, a noise immunity improvement for hybrid position observers for brushless dc motor drives is proposed. A finite state machine is used to detect Hall-effect sensor transitions to determine if these transitions are true transitions or the result of momentary glitches. This filter causes a delay in the detection of the Hall-effect sensors that is compensated in the proposed observer. The proposed observer is compared in simulations with the original hybrid position observer under both non-noisy and noisy conditions for both constant and variable speed operation, and it has good performance even under high noise and variable speed conditions.

Orientadores: Ernesto Ruppert Filho, Marcelo Gradella Villalva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T10:01:12Z (GMT). No. of bitstreams: 1 Oliveira_LeonardoRuffeilde_M.pdf: 3470428 bytes, checksum: 7972e30772adc6b114e71c8f464265b8 (MD5) Previous issue date: 2013 / Resumo: O objetivo deste trabalho é a construção de um conversor eletrônico de potência monofá-sico completo para conexão à rede elétrica de distribuição de baixa tensão alimentado por painel fotovoltaico Painéis fotovoltaicos comerciais geram uma tensão contínua que varia entre 20 e 50V, dependendo do tipo de painel e da ocorrência ou não de conexão entre os mesmos; sendo necessário, portanto, a adequação dos níveis de tensão gerados pelo painel com o nível de tensão da rede elétrica de distribuição, na qual ele será conectado. O conversor eletrônico de potência utilizado neste trabalho é constituído de dois estágios sendo o primeiro CC ¿ CC e o segundo, um inversor, CC ¿ CA. Ele será controlado de duas maneiras: a primeira será responsável pelo con-trole da tensão de entrada do conversor CC - CC e pela injeção de potência no conversor CC - CA o qual, além de ser o responsável pela transformação da tensão contínua em alternada também é responsável pelo sincronismo do conversor CC - CA com a rede elétrica. São apresentados resultados de simulação do funcionamento do conversor para geração fotovoltaica de energia elétrica, sua malha de controle e o funcionamento do sistema elétrico completo. O projeto com-pleto dos conversores e dos circuitos auxiliares bem como os resultados experimentais obtidos em laboratório são apresentados / Abstract: The objective of this work is the construction of a complete single-phase power electronic converter for grid connection of low voltage distribution powered by photovoltaic panels. Photo-voltaic panels generates a DC voltage that varies between 20 and 50V, depending on the type of panel and presence or absence of connection between them, it is necessary, therefore, the ade-quacy of voltage levels generated by the panel with the voltage level of the electrical distribution network, in which it is connected. The power electronic converter used in this study consists of two stages with the first is a dc ¿ dc converter and the second is a dc-ac converter, frequency inverter. It will be controlled in two ways: the first is responsible for controlling the input voltage of the dc-dc converter and the power injection in the ac-dc converter which, besides being res-ponsible for the transformation into alternating voltage is also responsible by the synchronism of the converter dc-ac with the utility grid. Simulation results of the converter operation connected to the utility grid are presented, its network control and operation of the complete electrical sys-tem. The complete design of converters and auxiliary circuits and the experimental results obtai-ned in the laboratory are presented / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Satellite power systems can be understood as islanded dc microgrids supplied by specialized and coordinated solar cell arrays augmented by electrochemical battery systems to handle high-power loads and periods of eclipse. The periodic availability of power, the limited capacity of batteries, and the dependence of all mission service on power consumption create a unique situation in which temporal power and energy scarcity exist. A multi-period model of an orbital satellite power system’s performance over a mission’s duration can be constructed. A modular power system architecture is used to characterize the system’s constraints. Using mathematical programming, an optimization problem can be posed such that the optimal power and energy ratings for the power system are determined for any load schedule imposed by a given mission’s requirements. The optimal energy trajectory of the electrical power system over a mission’s duration is also determined when the mathematical programming problem is solved. A generic set of mission requirements is identified to test this approach, but the objective function of the resulting optimization problem can be modified to return different results. These results can provide a clear illustration of the trade-offs that designers of such power systems consider in the design process.

A new Markov chain based energy storage model to evaluate the power supply availability of microgrids with renewable energy generation for critical loads is proposed. Since critical loads require above-average availability to ensure reliable operation during extreme events, e.g., natural disasters, using renewable energy generation has been considered to diversify sources. However, the low availability and high variability of renewable energy sources bring a challenge in achieving the required availability for critical loads. Hence, adding energy storage systems to renewable energy generation becomes vital for ensuring the generation of enough power during natural disasters. Although adding energy storage systems would instantaneously increase power supply availability, there is another critical aspect that should be carefully considered; energy storage sizing to meet certain availability must be taken into account in order to avoid oversizing or undersizing capacity, which are two undesirable conditions leading to inadequate availability or increased system cost, respectively. This dissertation proposes to develop a power supply availability framework for renewable energy generation in a given location and to suggest the optimal size of energy storage for the required availability to power critical loads. In particular, a new Markov chain based energy storage model is presented in order to model energy states in energy storage system, which provides an understanding of the nature of charge and discharge rates for energy storage that affect the system's power output. Practical applications of the model are exemplified using electrical vehicles with photovoltaic roofs. Moreover, the minimal cut sets method is used to analyze the effects of microgrid architectures on availability characteristics of the microgrid power supply in the presence of renewable energy sources and energy storage. In addition, design considerations for energy storage power electronics interfaces and a comparison of various energy storage methods are also presented. / text

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-25T13:55:05Z No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-10-01T18:11:02Z (GMT) No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Made available in DSpace on 2018-10-01T18:11:02Z (GMT). No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) Previous issue date: 2018-08-29 / O mundo está tentando mudar para um ambiente de energia mais limpa, especialmente no setor de geração de eletricidade, que é responsável por uma grande parcela das emissões de CO2. No Brasil, fontes renováveis são responsáveis por grande parte da geração de eletricidade, mas mudanças atuais no clima brasileiro trouxeram uma necessidade de diversificação na matriz energética. Logo, a geração distribuída é uma boa maneira de diversificar a matriz energética brasileira. Considerando que os sistemas de cogeração se enquadram na geração distribuída, e que os prédios brasileiros necessitam de resfriamento, devido ao clima quente, o uso de cogeração adicionado à um chiler de absorção ou absorção pode ser muito útil. O sistema de trigeração é um processo altamente eficiente, que pode produzir eletricidade, aquecimento e resfriamento a partir da mesma fonte de energia primária. No entanto, existem poucas pesquisas sobre os sistemas de trigeração no Brasil, especialmente em pequena e micro escala. Assim, esta dissertação fará uma avaliação técnica e econômica de sistemas de micro e trigeração para diferentes edifícios sob políticas tarifárias distintas no Brasil. Para tanto, este trabalho otimizará o dimensionamento e o cronograma de despacho mensal dos sistemas de trigeração para cada um dos quatro estudos de caso. Em seguida, avaliará o valor presente líquido máximo (VPL) considerando a variação da taxa de desconto e da taxa de conversão do dólar norte-americano. Na sequência, o índice de dependência da rede (GDI), o payback descontado, o custo nivelado da energia (LCOE) e a razão da energia primária (PER) para os melhores VPLs serão apresentados e analisados. Como resultado, esta dissertação mostrará que as plantas de trigeração podem ser lucrativas e certamente ser uma maneira eficiente de utilização de uma geração distribuída confiável e controlável. Além disso, provará que é possível encontrar situações em que a planta de trigeração possa oferecer uma alta taxa de energia primária (PER), um adequado custo de energia nivelado (LCOE) e, ao mesmo tempo, pode proporcionar economia financeira com tempo de retorno razoável em edifícios brasileiros. / The world is trying to move to a cleaner energy environment, especially on the electricity generation sector, which is responsible for a large share of CO2 emissions. In Brazil,crenewable energy sources are responsible for a great part of the electricity generation, but current changes in the Brazilian climate brought a necessity of diversification on the energy matrix. Then, distributed generation is a good way to diversify the Brazilian power matrix. Considering that cogeneration systems are distributed generation, and Brazilian buildings have need of cooling, due to the warm weather, the use of cogeneration equipped with an absorption or adsorption chiller could be beneficial. The trigeneration system is a highly efficient process, which can produce electricity, heating and cooling from the same primary energy source. However, there are really few researches concerning trigeneration systems in Brazil, especially on small and micro plants. Thus, this thesis will make and provide a technical and economical evaluation of small and micro trigeneration systems to different buildings under distinct tariff policies in Brazil. To do so, this work will optimize the sizing and monthly schedule the dispatch of the trigeneration systems to each one of the four study cases. Then, it will evaluate the maximum net present value (NPV) considering the variation of discount rate and US Dollar conversion rate. In the sequence, the grid dependence index (GDI), the discounted payback, the levelized cost of energy (LCOE) and the primary energy ratio (PER) to the best NPVs will be presented and analysed. As a result, this thesis will show that trigeneration plants can be profitable and can be certainly an efficient way to adopt a reliable and controllable distributed generation. Also, it will prove that it is possible to find situations in which the trigeneration plant can offer a high primary energy ratio, a fair levelized cost of energy, and in the meantime, it can provide financial savings with fair payback time in Brazilian buildings.

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2019-03-18T18:15:52Z No. of bitstreams: 1 Renard Lopes Villas Boas do Lago.pdf: 4581569 bytes, checksum: 9c4647056794f2f9266e721e689971ee (MD5) / Made available in DSpace on 2019-03-18T18:15:52Z (GMT). No. of bitstreams: 1 Renard Lopes Villas Boas do Lago.pdf: 4581569 bytes, checksum: 9c4647056794f2f9266e721e689971ee (MD5) Previous issue date: 2019-02-08 / In seeking the construction of an intelligent city there is a need to identify the processes that may or may not contribute to its construction and which challenges to overcome, taking into account the aspects of urban life, such as mobility, security, communication systems, sanitation and also for the electrical system. This research is a case study with the purpose of transforming Búzios into an intelligent city, as it is published by the municipal administration. The study aimed to verify if all the projects presented were executed and if the concepts of sustainability, rationality and loss control are being applied. The approach defined for research was qualitative, verifying the facts and seeking to clarify the dynamics of social relations, through a descriptive and exploratory research. During the visit to the city information was collected through interviews and direct observations, among the interviews were qualified 20 residents and collected 202 photographs. Among the projects implemented and in operation are three generators of photovoltaic energy, as for the projects implemented and that presented discontinuity and failures in its operation are the intelligent LED lighting system, the free internet system project, the projects with the systems of generation of aerogenerator energy, power network automation projects and installation projects of smart meters. During the technical visit, it was not possible to identify characteristics or contributions that define the city of Búzios-RJ, as the first intelligent city in Latin America, as little as an intelligent city, once the projects executed show flaws, a small part of the city was contemplated, the population does not have knowledge about the project, lack of continuity and governance. Although the projects listed make sense as components of an intelligent city with an intelligent electric grid, it was not possible to characterize the city as "intelligent" since the projects did not show, in their majority, effectiveness and scope enough to do so. The city can, however, become intelligent by expanding the reach and effectiveness of the projects. / Ao almejar a construção de uma cidade inteligente existe a necessidade de identificar os processos que podem ou não contribuir para sua construção e quais os desafios a serem superados, levando-se em conta os aspectos da vida urbana, como mobilidade, segurança, sistemas de comunicação, saneamento e também para o sistema elétrico. A presente pesquisa é um estudo de caso tendo como objeto a transformação de Búzios em cidade inteligente, conforme é divulgado pela administração municipal. O estudo teve como objetivo verificar se todos os projetos apresentados foram executados e se os conceitos de sustentabilidade, racionalidade e controle de perdas estão sendo aplicados. A abordagem definida para pesquisa foi qualitativa, verificando os fatos e buscando esclarecer a dinâmica das relações sociais, por meio de uma pesquisa descritiva e exploratória. Durante a visita a cidade foram coletadas informações por meio de entrevistas e observações diretas, dentre as entrevistas foram qualificados 20 moradores e coletadas 202 fotografias. Dentre os projetos implementados e em funcionamento estão três geradores de energia fotovoltaica, quanto aos projetos implementados e que apresentaram descontinuidade e falhas no seu funcionamento estão o sistema de iluminação a LED inteligente, o projeto de sistema de internet gratuita, os projetos com os sistemas de geração de energia aerogerador, os projetos de automação da rede de energia e os projetos da instalação dos medidores inteligentes. Durante a visita técnica não foi possível identificar características ou contribuições que definam a cidade de Búzios-RJ, como a primeira cidade inteligente da América Latina, tão pouco como cidade inteligente, uma vez que os projetos executados apresentaram falhas, uma pequena parte da cidade foi contemplada, a população não possui conhecimento sobre o projeto, falta de continuidade e de governança. Embora os projetos elencados façam sentido como componentes de uma cidade inteligente, com rede elétrica inteligente, não foi possível caracterizar a cidade como "inteligente" dado que os projetos não apresentaram, em sua maioria, efetividade e alcance suficiente para isso. A cidade pode, no entanto, tornar-se inteligente ao ampliar o alcance e a efetividade dos projetos.

Power losses are always a cause of worry for any power grid. In India, the situation is even worse. Though recent reports by Ministry of Power shows that Aggregate Technical and Commercial losses (AT &C losses) have come down from 36.64% in 2002-03 to 27% in 2011-12, yet they are much higher than the losses seen in many of the developed nations. The reduction shown in power loss is because of the Electricity Act, 2003 and the amendments made to it in 2007 which controlled the commercial losses rather than the technical losses. According to Ministry of Power, technical losses (Transmission & Distribution losses or T&D losses) in India are reported to be 23.65% in 2011-12. However, according to the study done by EPRI, for systems deployed in developed countries, these losses are estimated to be in the range of 7-15.5%. T & D losses occur in four system components namely step-up transformers and high voltage transmission (0.5-1%), step down to in intermediate voltage, transmission and step down to sub transmission voltage level (1.5-3%), sub-transmission system and step down to low voltage for distribution (2-4.5%), and distribution lines (3-7%). 1% of power loss is approximately equivalent to annual loss of Rs 600 million for a single state. Hence, in a year, loss in distribution line alone causes approximate loss of Rs 1.8-4.2 billion per state. Understanding and reducing power losses in distribution lines which contribute nearly 50% of the total T&D losses assume significance and has formed the motivation for the work reported in the thesis. In recent years, the trend has been to encourage users to generate solar power predominantly at residential complexes and captive power plants at industrial complexes. It has been suggested in the literature that Distributed Generation (DG) can not only reduce the load demanded from the power grid but also the power loss. In this thesis, it has been shown that by the choice of proper size and location of DG, the power loss can be reduced substantially as compared to unplanned deployment of DGs. The objective of the thesis is to design strategy for location of distributed user generated power to maximize the reduction in power loss. The thesis begins with a study of distributed generation in primary distribution networks and proceeds to problem formulation, with the aim being to develop an algorithm that can find out the optimal locations for DG allocation in a network. A greedy approximation algorithm, named OPLODER (i.e. Optimal Locations for Distributed Energy Resources), is proposed for the same and its performance on a benchmark data set is observed, which is found to be satisfactory. The thesis then moves on to describe the actual data of 101,881 commercial, residential and industrial consumers of Bangalore metropolitan area. A loss model is discussed and is used to calculate the line losses in LV part of the grid and loss is estimated for the said actual data. The detailed analysis of the losses in the distribution network shows that in most cases the losses are correlated with the sanctioned load. However there are also some outliers indicating otherwise. The analysis concludes that the distributed generated sources need to be optimally located in order to benefit fully. Also presented thereafter is a study about the impact of electrical properties and the structure of the network on power loss. In the second part of the thesis, OPLODER was again used to process the BESCOM data of 101,881 consumers by modeling them to be connected in three topologies namely Bus (i.e. linear structure), Star (i.e. directly connected) and Hybrid (i.e. tree structure). In case of Bus topology, when DG capacity available is 5% of the demand in substation, OPLODER reduced the loss from 14.65% to 10.75%, from 11.63% to 7.71% and from 13.33% to 9.24% for IISc, Brindavan, and Gokula substations respectively. Similarly, for the same amount of DG in case of star topology, OPLODER reduced loss from 1.75% to 1.26%, from 3.39% to 2.59% and from 2.96% to 1.99% for IISc, Brindavan, and Gokula substations respectively. Thereafter, the available real world data is re-modeled as a tree-type structure which is closer to the real world distribution network and OPLODER is run on it. The results obtained are similar to those presented above and are highly encouraging. When applied to the three substations viz. IISc, Brindavan and Gokula, the power loss dips from 9.95% to 7.42%, from 6.01% to 4.44% and from 8.07% to 5.95%, in case of DG used is 5% of the demand in substation. For the optimal strategies worked out in the thesis, additional overheads will be present. These overheads are studied and it has been found that the present infrastructure and technologies will be sufficient to handle the smart distribution network and the optimal strategy for distributed sources.

In recent years, the electric power industry around the world is changing continuously due to transformation from regulated market structure to deregulated market structure. The main aim of the transformation of electric supply industry under open access environment is to overcome the some of the limitations faced by the vertically integrated system. It is believed that this transformation will bring in new technologies, integration of other sources of energy such as wind, solar, fuel cells, bio-gas, etc., which are self sustainable and competitive, and better choice for the consumers and so on. As a result, several new issues and challenges have emerged. One of the main issues in power systems is to support reactive power for maintaining the system voltage profile with an acceptable margin of security and reliability required for system operation. In this context, the thesis addresses some of the problems related to planning and operation of reactive power in power systems. Studies are mainly focused on steady state operation of grid systems, grid connected wind farms and distribution systems as well. The reactive power support and loss allocation using Y-bus approach is proposed. It computes the reactive power contribution from various reactive sources to meet the reactive load demand and losses. Further, the allocation of reactive power loss to load or sink buses is also computed. Detailed case studies are carried out on 11-bus equivalent system of Indian southern region power grid under different loading conditions and also tested on 259-bus equivalent system of Indian western region power grid. A comparative analysis is also carried out with the proportional sharing principle and one of the circuit based approach in the literature to highlight the features of the proposed approach. A new reactive power loss index is proposed for identification of weak buses in the system. The new index is computed from the proposed Y-bus approach for the system under intact condition as well as some severe contingencies cases. Fuzzy logic approach is used to select the important and severe line contingencies from the contingency list. The validation of weak load buses identification from the proposed reactive power loss index with that from other well known existing methods in the literature such as Q-V sensitivity based modal analysis and continuation power flow method is carried out to demonstrate the effectiveness of the proposed index. Then, a short-term reactive power procurement/optimal reactive power dispatch analysis is also carried out to determine the optimum size of the reactive compensation devices to be placed at the weak buses for reactive compensation performance analysis in the system. The proposed approach is illustrated on a sample 5-bus system, and tested on sample 10-bus equivalent system and 72-bus equivalent system of Indian southern region power grid. A comprehensive power flow analysis of PQ type models for wind turbine generating units is presented. The different PQ type models of fixed/semi-variable speed wind turbine generating units are considered for the studies. In addition, the variable speed wind turbine generating units are considered in fixed power factor mode of operation. Based on these models, a comparative analysis is carried out to assess the impact of wind generation on distribution and transmission systems. 27-bus equivalent distribution test system, 93-bus equivalent test system and SR 297-bus equivalent grid connected wind system are considered for the studies. Lastly, reactive power coordination for voltage stability improvement in grid connected wind farms with different types of wind turbine generating units based on fuzzy logic approach is presented. In the proposed approach, the load bus voltage deviation is minimized by changing the reactive power controllers according to their sensitivity using fuzzy set theory. The fixed/semi-variable speed wind turbine generating units are also considered in the studies because of its impact on overall system voltage performance even though they do not support the system for voltage unlike variable speed wind generators. 297-bus equivalent and 417-bus equivalent grid connected wind systems are considered to present the simulation results. A comparative analysis is also carried out with the conventional linear programming based reactive power optimization technique to highlight the features of the proposed approach.

The modern power system is aiming to progress away from conventional synchronous machine  based power generation towards converter dominated system that leads to extensively high penetration of renewable energy such as wind and PV. This transition of modern power system toward converter based renewable energy comes with new challenges as the conventional synchronous generation is being replaced by converter based power system (CBPS). The converter is commonly interfaced to the power system with Phase Locked Loop (PLL) technique to synchronize the converter with the grid voltage angle and inject the current at the right angle. Therefore, this approach is called grid- ­following converter; this type of configuration of converters may lead to some power system instabilities (e.g., voltage instability, frequency instability, synchronous and sub­synchronous instabilities). In order to overcome the limitation of the grid-­following converters, another converter control concept become present in the literature as a grid-­forming converter where the synchronizing method to the grid eliminates the need for PLL .In this thesis, a grid- ­forming controlled power converter is implemented with an energy storage system to emulate the inertia of the synchronous generator through the VSM control concept. An electromagnetic transient (EMT) simulation has been modeled in the PSCAD simulation environment. The model is the well­known four-­machine two-­area power system. The model has been tested by incrementally replacing the synchronous machines with wind farms connected through power converters; this weakens the grid and may lead to frequency instability during a disturbing event. An Energy Storage System (ESS) has been implemented and added to the system to mitigate the loss of the kinetic energy of the rotating masses of the synchronous generators. The ESS is integrated with a grid-­forming converter that is controlled to mimic the dynamic behavior of a synchronous generator. Thus, the ESS is synchronized to the system based on the swing equation of the synchronous generator. The results show significant improvements in the frequency stability of the system under study. / Det moderna energisystemet har som mål att bortgå från den konventionella synkronmaskinbaserade energiförsörjning mot ett konverteringsdominerat system som leder till  en mycket hög penetration av förnybar energi, som tillexempel vind och solenergi. Den här övergången av modernt energisystem mot konverteringsbaserad förnybar energi medför nya utmaningar i och med att konventionell synkrongenerering byts ut mot konverterarbaserat energisystem (Converter Based Power System, CBPS) . Konverteraren är ofta integrerad i energisystemet via Phase Locked Loop ­teknik (PLL) för att synkronisera konverteraren med kraftnätets spänningsvinkel och injicera strömmen i rätt vinkel. Det här tillvägagångssättet kallas därför för nätföljande konvertering; denna typ av konfiguration av konverterare kan leda till instabilitet i energisystemet (t.ex. instabil elektrisk spänning, frekvensinstabilitet, synkron och sub- ­synkron instabilitet). För att hantera begränsningarna som nätföljande konverterare träder ett koncept om ytterligare en konverteringskontroll fram i litteratur, i form av en nätformande konverterare där synkroniseringsmetoden i nätet eliminerar behovet av PLL.I denna avhandling implementeras en nätformande konverterare med ett energiförvaringssystem för att emulera trögheten i synkrongeneratorn genom VSM-­styrkonceptet. En elektromagnetisk transientsimulering (EMT) har modellerats i simuleringsmiljön PSCAD. Modellen är det välkända energisystemet med fyra maskiner och två områden. Modellen har testats genom att stegvis byta ut synkronmaskinerna med vindkraftverk anslutna genom energikonverterare; detta gör nätet svagare och kan leda till frekvensinstabilitet vid en störande händelse. Ett energiförvaringssystem (Energy Storage System, ESS) har implementerats och kopplats till systemet för att mildra förlusten av kinetisk energi i de roterande massorna hos synkrongeneratorerna. Energiförvaringssystemet ESS är integrerat med en nätformande konverterare som styrs för att härma det dynamiska uppförandet av en synkrongenerator. Således är ESS synkroniserat med systemet baserat påsynkrongeneratorns svängekvation. Resultaten visar betydelsefulla förbättringar av frekvensstabiliteten i systemet under studien.

The thesis is focused on the information and communication technologies used in the energetic. Problematic areas in energetic which are regulation, metering, control of waste minimalizations, expense and maximalization of earnings. These aspects lead to implementing expert systems, which have to process this bulk of information necessary for increasing efficiency and economization of single processes. Systems used in practice have their own hierarchical structure, where every application requires specific access of selection of used components that suit to the application. First of all it is about acceptable device selection in single level of the system: metering and regulation, data acquisition out of the process and informative layer. Suitable choice flowing from previous, already settled up application is possible to reach maximum efficiency of the whole system. In the thesis there are introduced systems used in practice and possibilities of increase the effectiveness of generation, transmission and distribution with ICT usage in distributed power generation. We are mainly talking about upgrade processes joined with power generation of energy, diagnostics, isolation states on the power line and usage of expert systems for distribution.