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This paper presents an adaptive protection scheme (APS) for solving the coordination problem that deals with coordination directional overcurrent relays (DOCRs) and distance relays second zone time, in relation to coordination with DOCRs. The coordination problem becomes more complex with the impact of renewable energy sources (RES) when added to the distribution grid. This leads to a change in the grid topology, caused by the on/off states of the distribution generators (DG). The frequency of topological changes in distribution grids poses a challenge to the power system’s protection components. The change in the state of DGs leads to malfunction in reliability and miscoordination between protection relays, since that causes a direct effect to the short circuit currents. This paper used the school-based optimization (SBO) algorithm, which simulates the educational process, in order to deal with coordination problems. That algorithm is modified (MSBO) by modified both learning and teaching processes. The IEEE 8-bus test system and IEEE 14-bus distribution network are used to validate the proposed coordination system’s effectiveness when dealing with the coordination process between distance and DOCRs, at both the near- and far-end in the typical topological grid and with DGs in working order.

Submitted by Biblioteca Central (biblioteca@unicap.br) on 2021-08-24T18:38:54Z No. of bitstreams: 2 Ok_ivan_xavier_lins.pdf: 1905284 bytes, checksum: f27f0a95dedc96277de69efd4e20b3f4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2021-08-24T18:38:54Z (GMT). No. of bitstreams: 2 Ok_ivan_xavier_lins.pdf: 1905284 bytes, checksum: f27f0a95dedc96277de69efd4e20b3f4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2021-03-10 The present work aims to propose a hydrodynamic study of a gas relay using the computational fluid dynamics tool, in order to predict the speed, temperature variation and oil pressure profiles, based on their physical properties, the expansion coefficient volume, and operating conditions, in order to obtain more accurate and reliable information regarding the volume of oil, inside the system. The proposed methodology will be based on three stages: preprocessing (development of a computational mesh, based on real three-dimensional geometry), processing (definition of boundary conditions and choice and resolution of hydrodynamic models in a FlowSimulation simulation environment) and post-processing (obtaining speed profiles, fin tilt, temperature and system pressure variation). The results show the upward flow, the fluid speed, there are significant temperature rises (above 60ºC and may be associated with transformer failures), including the behavior of the fluid dynamic flow and the pressure drop inside the system. Finally, an experimental study was carried out in order to validate the items simulated above. Through this study it was possible to observe the dynamic fluid behavior of the insulating oil in different failure situations, facilitating the understanding of the system. Being an important tool for the evaluation of the protection relay. O presente trabalho tem como objetivo propor um estudo hidrodinâmico de um relé de gás a partir da ferramenta fluidodinâmica computacional, a fim de prever os perfis de velocidade, variação de temperatura e pressão do óleo, a partir de suas propriedades físicas, do coeficiente de expansão volumétrica, e das condições operacionais, visando obter informações mais precisas e confiáveis a respeito do volume de óleo, no interior do sistema. A metodologia proposta será baseada em três etapas: pré-processamento (desenvolvimento de uma malha computacional, a partir da geometria tridimensional real), processamento (definição das condições de contorno e escolha e resolução modelos hidrodinâmicos em ambiente de simulação FlowSimulation) e pós-processamento (obtenção dos perfis de velocidade, inclinação da aleta, variação da temperatura e da pressão do sistema). Os resultados apresentam o escoamento ascendente, a velocidade do fluido, há elevações significativas de temperatura (acima de 60ºC podendo estar associadas a falhas no transformador), compreendendo o comportamento do escoamento fluidodinâmico e a perda de carga no interior do sistema. Por fim foi realizado um estudo experimental com a finalidade de validar os itens acima simulados. Através do presente estudo foi possível observar o comportamento fluido dinâmico do óleo isolante em diferentes situações de falhas, facilitando o entendimento do sistema. Sendo uma importante ferramenta para avaliação do relé de proteção.

The integration of load shedding schemes with mainstream protection in power system networks is vital. The traditional power system network incorporates different protection schemes to protect its components. Once the power network reaches its maximum limits, and the load demand continue to increase the whole system will experience power system instability. The system frequency usually drops due to the loss of substantial generation creating imbalance. The best method to recover the system from instability is by introducing an under-frequency load shedding (UFLS) scheme in parallel with the protection schemes. This paper proposed a new UFLS scheme used in power systems and industry to maintain stability. Three case studies were implemented in this paper. Multi-stage decision-making algorithms load shedding in the environment of the DIgSILENT power factory platform is developed. The proposed algorithm speeds-up the operation of the UFLS scheme. The load shedding algorithm of the proposed scheme is implemented as a systematic process to achieve stability of the power network which is exposed to different operating conditions. The flexibility of the proposed scheme is validated with the modified IEEE 39-bus New England model. The application of the proposed novel UFLS schemes will contribute further to the development of new types of engineers.

Energimarknadsinspektionen ställer krav på elnätsbolagen vad gäller elkvalitet. Varje år ska såväl aviserade som oaviserade avbrott rapporteras. Dessa avbrott anges med hjälp av avbrottsindikatorerna SAIDI (System Average Interruption Duration Index) och SAIFI (System Average Interruption Frequency Index), vilka skildrar medelavbrottstid per kund och medelavbrottsfrekvens per kund för ett aktuellt nätområde. Detta examensarbete genomfördes med Vattenfall Eldistribution AB som uppdragsgivare. Studiens syfte är för att undersöka hur oselektiva felbortkopplingar bidrar till att påverka det årliga SAIDI-resultatet. Då företaget strävar efter att uppnå sitt SAIDI-mål krävs en klarläggning över vilka faktorer som ger upphov till ett förhöjt SAIDI och undersöka om dessa kan reduceras. De felbortkopplingar som analyserats är sådana som orsakats av felaktig utlösning av brytorgan samt felbortkopplingar i samband med provningar, för avbrott som varat längre än tre minuter. De komponenter i elnätet som ansvarar för feldetektering och felbortkoppling är reläskydd, dessvärre känner de inte alltid av alla fel, ibland är de felkonfigurerade och felet kopplas inte bort av det avsedda reläskyddet, alltså felet kopplas bort oselektivt. Oselektiva felbortkopplingar kan också bero på att reläskyddet upptäckt felet och skickat en utlösningsimpuls, men någon annan komponent i kontrollanläggningen är trasig och felet kan därför inte kan kopplas bort med hjälp av det avsedda skyddet. Det resultat som framkommit är att oselektiva felbortkopplingar har en betydelsefull påverkan på det årliga totala SAIDI-resultatet som rapporteras in till Energimarknadsinspektionen. Felorsakerna som ligger till grund för de felbortkopplingar som kunnat analyseras är bland annat begränsningar i reläskydden. Utifrån studiens resultat kan slutsatserna dras att det kan vara lönsamt för Vattenfall Eldistribution AB att undersöka eventuella investeringar, för att minska SAIDI för oselektiva felbortkopplingar. Till exempel kan äldre komponenter som saknar möjlighet för omkalibrering bytas ut och befintliga som är möjliga att kalibrera kan kalibreras om för att erhålla förbättrad funktion. Swedish Energy Markets Inspectorate has requirements on the electrical distribution companies regarding power quality. Both power failure and planned interruptions in the distribution of electricity is to be reported annually. These interruptions are measured by SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index). These indexes narrate the average interruption duration or interruption frequency per electrical costumer per year, in a certain area. This thesis was made on the behalf of Vattenfall Eldistribution AB (VEAB). The purpose of this study was to analyze the annual effect on SAIDI by selectivity issues in power systems. If VEAB wants to reach the SAIDI-goal it is necessary for a study to be carried out. The study should investigate what factors that contributes to an increased SAIDI because of selectivity issues. The analyze involved interruptions that had been caused by an incorrect operation of the protection systems and interruptions due to testing of these systems. Only interruptions that lasted longer than three minutes was considered. There are components in power systems which are supposed to disconnect the faulty part, they are called protection relays. Unfortunately, they do not detect all faults that occur in the power system. For example, the protection systems can be wrongly configurated and the faulty part will not be disconnected in a properly way. The result of the study is that selectivity issues have a significant effect on the annual SAIDI that is reported to Swedish Energy Markets Inspectorate. One of the main reasons to selectivity issues are for example limitations in the protection relays. In conclusion, Vattenfall Eldistribution AB can profit from an investment to decrease SAIDI that is affected by selectivity issues. Older components that lacks the calibration feature could be replaced, and already existing ones that have such a calibration feature could be re-calibrated.

Razvojem računalne tehnologije učestala je pojava numeričkih uređaja relejne zaštite u transformatorskim stanicama koji programiranom automatikom upravljaju distribucijskom električnom mrežom. Rad prikazuje princip rada admitantne zaštite te izračun i preporuku podešenja admitantne zaštite za 20 kV vodna polja u sustavima sa malo omskim uzemljenjem i djelomičnom kompenzacijom. Admitantna zaštita korištena je za osjetljivu detekciju jednopolnog kratkog spoja odnosno zemljospoja te prema ispunjenim uvjetima zaštita isključuje prekidač vodnog polja. Navedena zaštita je složenija od tradicionalno korištenih zaštita od zemljospoja koje koriste uvjet rezidualne struje i pojavu rezidualnog napona. Za korištenje admitantne zaštite potrebno je proračunati vrijednosti nulte admitancije što je elaborirano u radu. Aktiviranje admitantne relejne zaštite moguće je kod novih serija numeričkih releja kao što su uređaji serije Relion 600 i serije Siprotec 5 proizvođača ABB odnosno Siemens., With the development of computer technology, the occurrence of numerical relay devices for protection in substations has become more common which are then programmed to control the electrical distribution network. The paper present operation principle of admittance protection, calculation and recommendation for activating admittance protection for 20 kV feeders in system with low-ohmic and parallel compensation grounding. Admittance relay protection is used for detection of sensitive earth faults which operates a trip signal for opening feeder's circuit breaker. Admittance protection is more complex than traditionally used earth fault protections which are using residual current and voltage conditions. For a proper protection use, it is necessary to calculate the value of zero admittance, which is elaborated in this paper. Activation of admittance relay protection is possible with a new series of numerical relays such as Relion 600 series and Siprotec 5 series from ABB and SIEMENS respectively.

Resumen del proyecto: La generación basada en energía renovable, como parques eólicos o solares presentan una respuesta ante cortocircuito diferente a los generadores síncronos convencionales debido a su acoplamiento a la red mediante inversores basados en electrónica de potencia. Estas llamadas fuentes de generación basados en inversores (IBR) se comportan como fuentes de intensidad, no como fuentes de tensión y su intensidad de cortocircuito está determinada en gran medida por su sistema de control. Esta intensidad está generalmente limitada alrededor de 1.2 p.u. y está caracterizada por una falta de componente de secuencia inversa (I2) debido a que la mayoría de filosofías de control actuales toman en cuenta solo la secuencia positiva aún en presencia de faltas desbalanceadas. Debido a esto se prevé que funciones de protección que están basadas en I2 para reconocer faltas como Sobre-Intensidad Direccional de Secuencia o Selectores de Fase en Falta (FID) sufran la falta de este componente que se esperaría de generadores convencionales. Los códigos de red modernos requieren una capacidad para soportar huecos de tensión que incluyen control de I2. Además de utilizar componentes de secuencia, los selectores de fase en falta hacen uso del concepto de cantidades incrementales para operar. La teoría de cantidades incrementales está basada en el principio de superposición, que también se espera que sea impactado en presencia de IBRs. El objetivo del presente trabajo es proveer una descripción del impacto de las IBRs en la ingeniería de protecciones y poner a prueba diferentes funciones de protección en presencia de IBRs. Abstract: Renewable energy-based generation like wind and solar farms present a different response to short circuit than conventional synchronous generators due to their coupling trough power electronics based inverters. Those so called Inverted Based Resources (IBR) behave like current sources as opposed to voltage sources and their short circuit current is highly determined by their control system. This fault current is generally limited to around 1.2 p.u. and is characterized by the lack of an expected negative sequence current (I2) due to most current control philosophies only taking in account positive sequence even in the presence of unbalanced faults. Protection Units that are based on I2 for fault recognition like Directional Sequence Overcurrent or Faulted Phase Selectors (FID) are foreseen to particularly suffer the lack of I2 expected from traditional Synchronous Generation. Modern Grid Codes specify advanced Low Voltage Ride Through (LVRT) requirements, including I2 control. Besides sequence components, Faulted Phase Selector algorithms makes use of incremental quantities concept to successfully identify faulted phase. Incremental quantities theory is based on the superposition principle, which is also expected to suffer in presence of IBRs. Present work goal is to provide a good understanding of the IBR phenomena that impacts protection engineering and to put to test different protection functions under IBR presence.

This paper presents novel zero sequence current filter and earth fault protection relay, which utilize cable screens earthing current in protection algorithm. Different problems connected with state of the art of zero sequence current filters and protection relays are presented and compared with the proposed solution. The presented concept is verified in PowerFactory simulation software, experiment concerning modeling the earth fault current flow in medium voltage (MV) cable supplied from the low voltage (LV) network and measurements in the MV network in the Polish distribution system. The proposed solution is characterized by higher sensitivity and reduced number of erroneous trips. The presented solution is suitable for any MV cable lines. Biggest advantages are observed in power output lines from renewable energy sources, which are often operated under no-load conditions.

Challenges facing power system protection in a wide-area system are latency and full coverage of a wide-area disturbance. The complexity of large-scale power system configurations has led to challenges in the design of coordination and operating systems for protection relays. Local measurements used for primary and backup protection cannot consider wide system disturbances. A new wide-area-monitoring-system-based primary protection is presented for a complex power system involving double and single lines. It is based on describing the non-linear dynamic operation of the transmission lines during a fault in the form of a set of differential equations that are solved through paths movements in a phase diagram. The fault on the lines can be precisely recognised. The speed of the traditional communication media limits wide-area monitoring as backup protection. This study presents the primary protection scheme for double and single circuits in a wide area for the first time based on fourth-generation technology with low latency. The justification for applying the proposed scheme as primary protection in a wide-area-monitoring system is discussed. The number of relays on the studied configuration is reduced from 18 local relays to only 5 phasor measurement units for protecting the lines in the area.

Orientador: Prof. Dr. Ricardo Caneloi dos Santos Coorientador: Prof. Dr. Edmarcio Antônio Belati Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Elétrica, Santo André, 2019. Os sistemas elétricos de potência (SEP) têm como função fornecer energia elétrica de forma segura e confiável aos consumidores. Na ocorrência de contingências cabe ao sistema de proteção atuar para minimizar os danos causados aos consumidores finais e ao próprio SEP. Um dos equipamentos mais importantes presentes no sistema de proteção é o transformador de corrente (TC), cuja principal tarefa é fornecer ao relé de proteção uma réplica, em escala reduzida, da corrente primária do SEP. No entanto, os TCs possuem características físicas que os tornam susceptíveis à saturação, resultando na distorção da sua forma de onda secundária. Diante desta distorção o relé de proteção pode falhar, visto que sua decisão depende da integridade do sinal proveniente do TC. Tal falha pode resultar em severos danos aos equipamentos do SEP com perdas financeiras significativas, sem mencionar o risco a vidas humanas. Para evitar uma tomada de decisão incorreta do relé, vários algoritmos para a detecção e reconstrução de formas de onda distorcidas provenientes de TCs são propostos na literatura. Uma parte significativa destes algoritmos baseia-se em técnicas de aproximação de funções e uso de inteligência artificial. Neste sentido, este trabalho propõe o uso de redes neurais artificiais (RNAs) para corrigir a forma de onda secundária distorcida proveniente de TCs. As RNAs utilizadas para corrigir a forma de onda secundária são do tipo MLP, especificadas por meio de um processo de treinamento supervisionado. Várias taxas de amostragem e tamanho de janelas de dados foram avaliadas, visando a especificação de uma RNA capaz de oferecer alto desempenho ao algoritmo proposto. Ainda, para fins de comparação de desempenho, dois diferentes ambientes computacionais foram utilizados para modelar as RNAs: MATLAB e Keras. Os sinais utilizados no processo de treinamento e testes das RNAs são provenientes de duas fontes de dados distintas, sendo a primeira baseada na modelagem clássica de TCs, amplamente utilizada pela comunidade científica (IEEE), enquanto a segunda é baseada no modelo de TC no Simulink. Os resultados mostram claramente que uma forma de onda altamente distorcida pode ser totalmente reconstruída pela RNA, fornecendo aos relés de proteção um sinal confiável para a correta tomada de decisão. Electrical power systems (EPS) are responsible for providing electrical power in a safe and reliable manner to the final consumers. On the occurrence of contingencies it is the role of the protection system (PS) to act in favor of minimizing the damages caused to the final consumers and to the EPS equipments. One of the most important components used in PS is the current transformer (CT), whose main task is to provide to the protection relay a copy, in smaller scale, of the primary current. However, the CTs have physical characteristics that makes them susceptible to saturation, causing the secondary current¿s waveform to be distorted. Due to that distortion the relay may fail, as its decision relies on the CT secondary waveform. Such fail may result in severe damages to the electrical equipments and also financial losses. Moreover, this situation can result in problems regarding the safety of human beings. In order to avoid the incorrect relay operation, several algorithms for detecting and reconstructing distorted waveforms have been proposed in the literature. Most of them are based on artificial intelligence techniques. Therefore, this work proposes the use of Artificial Neural Networks (ANNs) to reconstruct distorted secondary current¿s waveform provided by saturated CTs. The ANNs used to perform the mentioned reconstruction are Multilayer Perceptron Networks (MLPs), specified by a supervised learning method. Different sampling rates and size of moving data window were evaluated in an attempt to find the best ANN, able for providing a high performance to the proposed algorithm. In addition, for comparison purposes, two different computational environments were used to model the proposed ANNs, i.e., MATLAB and Keras. All signals used for training and testing purposes were originated from two sources: a classic CT model, widely used by the scientific community (IEEE), and a CT model available in Simulink. The results clearly show that a highly distorted current waveform can be fully reconstructed by the specified ANN, providing a reliable CT secondary waveform to the protection relay.

Elektrik enerjisinin sürekli, güvenilir ve kaliteli bir şekilde iletilmesini sağlamak, elektrik güç sistem işletmeciliğinin amacıdır. Bunu sağlamak için sistemde meydana gelen kısa devre arızalarının koruma röleleri tarafından tespit edilip arızalı bölgenin sistemden en hızlı şekilde izole edilmesi gerekmektedir. Bu çalışmanın temel amacı, gerçek sistem verilerini kullanarak güç sistemi benzetim programı ile bölgesel çapta hat koruma analizi yapmaktır. Bu çalışmada; DIgSILENT güç sistemi analiz program ile iletim sisteminin bir parçası olan 400 kV'luk sistemde Ankara Bölgesinde yer alan iletim hatları modellenip koruma analizi gerçekleştirilmiştir. Bir kısa devre arızasında mesafe koruma rölelerinin arızayı tespit edememesi, çalışmaması ve kesicinin açmaması gibi durumlarda arızanın sistemden nasıl temizlendiği ve bunun sisteme olan etkileri incelenmiştir. Diğer analiz çalışmalarından farklı olarak gerçek zamanlı yük akış verileri ve bara düzenleri kullanılarak sistem modeli oluşturulmuştur. Mesafe koruma rölesi ayarları, iletim sistemi operatörü tarafından belirlenen koruma prensiplerine göre ayarlanarak benzetim modelinde yer alan mesafe koruma rölelerine yüklenmiştir. Yapılan analizlerde çeşitli senaryolar oluşturularak sistem arızalarında meydana gelen kısa devre akımları, koruma rölelerinin çalışma davranışları, servis harici olan enerji iletim hatları gözlemlenerek sonuçlar çıkarılmış ve öneriler sunulmuştur. Providing transmission of energy continuously, reliably and high in quality is aim of transmission system operator. In order to achieve this short circuit faults in the power system, it should be detected by protection relays then faulty parts should be isolated immediately. Main purpose of this study is performing line protection analysis on simulation program in a regional base utilising real system parameters. In this study, 400 kV transmission lines in Ankara have been modelled and simulated in DIgSILENT power system analysis program and protection analysis is performed. It is investigated how a fault is cleared from the power system in cases the relay could not detect the fault or not operate, mulfunctioning of circuit breaker. Also, the effect of this situation on power system is inspected. Unlike other studies, real time load flow data and real bus systems are used for modelling. Settings of distance relays which are used in simulations are based on setting principles determined by transmission system operator. In simulations, different cases are investigated in terms of fault currents, behaviours of relays, lines became out of service. Results and suggestions are also presented. 94

Selective, fast and reliable protection measures are essential for the electric power system, particularly for the transmission network operating at high power levels. Due to the dependence of the society on electric power, the protection systems are critical in minimizing the risks of personal injuries, economical losses and interruptions in the supply of electricity. For the same reason, the power quality is another important issue in the modern transmission systems. To compensate reactive power and reduce the harmonic content in the grid, power electronic solutions such as static synchronous compensators (STATCOMs) and static VAr compensators (SVCs) have been developed. The complex control systems of these compensators require an efficient design method, and simulations with Matlab and Simulink are used widely for this purpose. However, the protection system is still often designed conventionally by verifying the setting calculations with intensive stability tests in laboratory. Moreover, the effect of the trips on the control system must be analysed manually. In this thesis, Simulink models for overcurrent and differential protection functions were implemented to reduce the need for testing. Two different commercial protection relay models were analysed for both functions with the results compared to each other and the standards defining the functions. For the overcurrent protection, a simplified simulation model was also created according to the standard. Particularly, operating characteristics of the functions as well as the differences between the relay models were examined by visualising them with the Simulink modelling. In the comparison of the performance of the relays, the focus was on the operating speed. The models were verified first with idealized unit test schemes and finally with a control system model from an actual STATCOM project. In the tests performed, the simulation models succeeded in detecting the simulated problems and tripping the circuit accordingly to the specifications from manuals and standards. The harmonic blocking of differential protection, the reset process of the timers, as well as the sampling were identified as the main differences between the relay models. However, limited information is often available on these features. Therefore, the further development of them will require more detailed modelling of their structures and applications. Another challenge related to the stability simulations was found to be the large computational capacity required by the control system model. Based on the successful results from this thesis, the simulation models will be developed further with the stability simulations in future commercial projects. In addition, new models will be developed to cover more typical functions found in STATCOM and SVC applications, as well as to include the setting calculations.

Ground faults in electrical power systems represent more than 90% of total faults. Their detection, location, and elimination are essential and must be carried out in a precise way to allow multiterminal high-voltage direct current (HVDC) cable networks to operate in stable conditions by removing only the faulty cable from service. This paper presents a new differential protection method based on the measurement of currents at both ends of the shields of power cables. This new method is cheaper and easier to set in operation compared to other protection methods that measure currents circulating in the active conductors. The values of such intensities and their polarities were evaluated to know which cable had a ground fault in a multiterminal HVDC cable network. The method was successfully validated by computer simulations, and experimental results were successfully obtained.

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır. Yenilenebilir enerji sektöründeki son gelişmeler, dağıtım şebekesinde dağıtık üretim sistemleri olarak rüzgar türbininin yeni bir enerji kaynağı olarak popülaritesini arttırdığını göstermektedir. Geleneksel şebeke ile ilişkili önemli faktörlerden biri, dağıtık üretim sistemlerinin koruma ve kontrol gereksinimleri iletim şebekesinden farklı olduğu için, dağıtık üretim sistemi şebekeye bağlandığında koruma ve ayar şemasının yetersiz olmasıdır. Böylece, birbirine bağlı bu sisteme sürekli olarak güç sistemi kararlılığında yeni zorluklar yüklenmektedir. Bu zorlukları giderebilmek veya en azından hafifletmek için, söz konusu dağıtık üretim sistemlerinin şebekeye etkileri ve boyutları uygun olmalıdır. Bu tezde, dağıtık üretim sistemlerinin arıza koşulları esnasında dağıtım şebekesi üzerindeki etkisi incelenmektedir. Arıza koşulları kısa devre arızalarını, geçici olayları ve kısa süreli gerilim sarkmalarını içermektedir. Bu koşullara karşı koruma sistemi olarak kesiciler sağlam, etkin ve hızlı anahtarlama görevi yapmaktadır. Kesicilerin etkin, hızlı anahtarlama yapması için ters zamanlı aşırı akım rölesi kullanılmaktadır. Ayrıca bu tez, fotovoltaik gibi kaynaklar için de uygulanabilir ve geçerlidir ancak sadece rüzgar türbinleri örnek olarak seçilmiştir. IEEE'nin 30 baralı dağıtım sistemi, değişik arıza senaryoları için PSCAD/EMTDC programı ile analiz edilmiştir. Bu dağıtım sisteminde, arıza analizi için ve rüzgar türbininin bağlanacağı bazı baralar belirlenmiştir. Rüzgar türbininin gücü, bağlandığı baradan sonraki yüklerin tamamını karşılayacak şekilde seçilmiştir. Rüzgar türbini için bu yüklerle belirlenen gücün 1,5 katı seçilerek de analizler yapılmıştır. Rüzgar türbininin bulunup bulunmadığı her iki durum için baralardaki arıza öncesi akım ve gerilim değerleri elde edilmiştir. Ardından, bu baralarda sırayla faz-toprak ve üç faz-toprak arızaları yapılmıştır ve koruma sisteminin yapılan arızaları önlemesi sağlanmıştır. Son olarak, baralardaki arıza esnası akım ve gerilim değerleri elde edilip, baralara ait akım ve gerilim grafikleri çizdirilmiştir. Recent developments in the renewable energy sector show that wind turbine as distributed generation systems in the distribution network increases their popularity as a new energy source. One of the important factors associated with the traditional network is the inadequacy of the protection and setting scheme when the distributed generation system is connected to the network due to the protection and control requirements of the distributed generation systems that are different from the transmission network. Thus, the interconnected system constantly faces new challenges in therms of power system stability. To overcome the challenges or at least alleviate the effect of the challenges, the dimensions of distributed generation systems must be appropriate distribution system. In this thesis, the effects of distributed generation systems on the distribution network during the fault conditions are examined. Fault conditions include shortcircuit faults, transient events and voltage sags. As a protection system against these conditions, the breakers should be performing robust, efficient and fast switching tasks. Also, an inverse time overcurrent relay is used for the breakers to make effective, fast switching to eliminate the faults. This thesis can be also examined for other sources such as photovoltaics, but only wind turbines have been discussed in this thesis. The IEEE 30-bus distribution system has been analyzed by the PSCAD/EMTDC program for different fault scenarios. Particular busses in this distribution system are selected for fault analysis and the installation of wind turbines. The power of wind turbine is determined by the total of the loads after the bus connected to wind turbine. The analysis is also done with the wind turbine which has a power capacity 50% more than obtained before. The pre-fault current and voltage values of busses are obtained with and without wind turbine before the faults. Then, phase to ground and three-phase to ground faults are occured in these buses and the protection system is provided to clear the faults. Finally, the current and voltage values during faults are obtained in the buses. Also, the current and voltage graphs of the buses are plotted.

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır. Yenilenebilir enerji kaynaklarına olan talebin artmasıyla birlikte elektrik şebekelerine çok sayıda dağıtık enerji üretim kaynağı (DEÜK) bağlanmaya başlamıştır. DEÜK'lerin kullanımının artması, klasik elektrik şebekelerinde sorunlara neden olduğundan mikro şebekeler tercih edilmektedir. Mikro şebekeler, DEÜK'leri ve yükleri koordine ederek şebekenin daha etkili çalışmasını sağlamaktadır. Mikro şebekelerde kullanılan DEÜK'lerle, klasik şebekelerde kullanılan üreteçler arasında ciddi farklılıklar bulunmaktadır. DEÜK'ler çoğunlukla invertör tabanlıdır ve şebekede bir arıza meydana gelmesi durumunda genellikle yüksek miktarda arıza akımı üretememektedir. Ayrıca enerji üretme kapasiteleri düşük olduğundan şebekedeki arz talep dengesinde yaşanan değişimlerden daha çok etkilenmektedir. Klasik şebekelerde kullanılan arıza akımına dayalı koruma fonksiyonları mikro şebekelerde etkisiz kalabildiğinden mikro şebekeler için farklı koruma fonksiyonları geliştirilmiştir. Bu çalışmada, ring şebeke yapısına sahip mikro şebekelerde yürüyen dalga tabanlı arıza yeri tespit yöntemi geliştirilmiştir. Yürüyen dalga tabanlı arıza yeri tespitinde hattın bir veya iki ucundan alınan ölçümler kullanılmaktadır. Ring şebeke yapılarında kullanılan hatların ise bir başı veya sonu bulunmamaktadır. Yürüyen dalga tabanlı korumanın ring şebekelerde kullanılabilmesi için şebeke üç bölgeye ayrılmıştır. Ayrılan her bölgeye ayrı ayrı D tipi arıza yeri tespit algoritması uygulanmıştır ve bu algoritmaların kendi aralarında uyumlu çalışması sağlanarak ring şebeke yapısına sahip mikro şebekelerde arıza yeri tespiti sağlanmıştır. Arıza yeri tespit edildikten sonra koruma algoritması arızayı izole edecek şekilde ilgili şalterlere açma komutu göndererek arızayı enerjisiz bırakmaktadır. Geliştirilen koruma fonksiyonu Matlab/Simulink ortamında test edilmiştir. Yapılan testlerde arıza yerinin 46,39 metrelik bir hata payı ile tespit edilebildiği saptanmıştır. Arıza yeri tespit edildikten sonra ilgili şalterlere açma komutu gönderilerek arızanın enerjisiz bırakılması sağlanmıştır. With the increase in demand for renewable energy sources, a large number of distributed generators (DG) have been connected to electrical grids. Since the increase in the use of DGs causes problems in traditional electrical grids, microgrids are preferred. Microgrids help the grids work more efficiently by coordinating DGs and loads. There are critical differences between the DGs that are used in microgrids, and the generators that are used in traditional grids. Generally, DGs are inverter based and unable to produce vast amounts of fault current when a fault occurs in the grid. In addition, due to their relatively low energy generating capacities, they are more affected by the changes that occur regarding the supply and demand balance in the grid. Since current-based protection functions which are used in traditional grids may remain ineffective in microgrids, different protection functions are developed for microgrids. In this study, a traveling wave-based fault location detection system for looped microgrids was developed. In traveling wave-based fault location detection, measurements that are taken from one or both ends of the line are used. However, there is no beginning or end of the lines in looped grids. To allow the use of traveling wave-based protection in loop distribution systems, the system is separated into three zones. To each three separate zone a type D fault locator method was applied, and by ensuring that these algorithms worked in accordance, fault location detection was carried out in a looped microgrid. After the detection of fault location, the protection algorithm isolates the fault and sends a "power on" command to related switches and thus leaves the fault without energy. The developed protection function is tested in Matlab/Simulink setting. In the performed tests it was determined that the fault location could be detected with an error rate of 46.39 meters. After the fault location was detected, a "power on" command was sent to the related switches to ensure that the fault was left without energy.

У статті розглянуті проблемні питання, які стосуються технічної експлуатації сучасних автоматичних пристроїв релейного захисту силових трансформаторів та автотрансформаторів, а зокрема проаналізовані випадки їх неправильної дії в об’єднаній електроенергетичній системі України, на підставі чого встановлені причини виникнення цих випадків та виявлені недоліки релейного захисту, що призвели до їх виникнення. Встановлено, що найбільш поширеними причинами хибної та надлишкової дії захисту є поява кидку струму намагнічування при увімкненні під напругу силового трансформатору, порушення цілісності струмових кіл захисту та помилки, допущені обслуговуючим персоналом при налаштуванні захисту та в процесі його експлуатації. На підставі статистичних даних щодо роботи релейного захисту трансформаторів протягом останніх 10 років розраховані показники надійності його дії (надійності спрацювання, надійності неспрацювання та загальної надійності), зокрема встановлено, що загальна надійність пристроїв диференційного струмового захисту трансформаторів становить 88,5%, та запропоновані заходи, що спрямовані на підвищення цих показників. The article deals with the issues related to operation of modern transformer protection relays, especially, the cases of their false tripping in the electric power system of Ukraine. Cases of false tripping were analyzed to explore disadvantages of transformer protection relays. It was identified that the most common causes of false tripping of protection relays are: magnetizing inrush current, damage of secondary current circuits and errors committed by the maintenance personnel during setting and operation. Based on the statistical data of the protection relays operation over the past 10 years, the reliability of it work was calculated. The overall reliability of transformer differential protection relays is 88.5% In this work the actions aimed to improve these indicators are advised. В статье рассмотрены проблемные вопросы, касающиеся технической эксплуатации современных автоматических устройств релейной защиты силовых трансформаторов и автотрансформаторов, а в частности проанализированы случаи их неправильного действия в объединенной электроэнергетической системе Украины, на основании чего установлены причины возникновения этих случаев и выявлены недостатки релейной защиты, которые привели к их возникновению. Установлено, что наиболее распространенными причинами ложной и излишней работы защиты является появление броска тока намагничивания при включении под напряжение силового трансформатора, нарушение целостности токовых цепей защиты и ошибки, допущенные обслуживающим персоналом при настройке защиты и в процессе ее эксплуатации. На основании статистических данных о работе релейной защиты трансформаторов на протяжении последних 10 лет рассчитаны показатели надежности ее действия (надежность срабатывания, надежность несрабатывания и общая надежность), в частности установлено, что общая надежность устройств дифференциальной токовой защиты трансформаторов составляет 88,5%, и предложены мероприятия, направленные на повышение этих показателей.

DC urban light railway systems are used as public transportation systems in many towns worldwide. In these systems, short circuit currents are often similar, both in steady state magnitude and in rate-of-rise, to normal operation currents. In order to properly set the protection relays, to obtain short circuit discrimination and to avoid nuisance trippings, it is important to analyse short circuit and normal operation current patterns. This paper presents the results of measurement campaigns performed for this purpose on the tram network of Turin, in Northern Italy.

Bu çalışmada, enerji iletim hatlarının korunmasında kullanılan mesafe rölelerinin güç salınımlarında yanlış kesici anahtarlaması yaptırmalarının önlenmesi üzerinde durulmaktadır. Böylesi yanlış anahtarlamalar enerji sürekliliğini aksatabileceği ve sistemi kararsızlığa götürebileceği için rölelerin kısa devre arızası ve güç salınımı durumlarını birbirinden yüksek doğrula ayırt etmesi gerekmektedir. Bunun için rölede güç salınımı perdeleme ve güç salınımı geri perdeleme fonksiyonları kullanılmaktadır. Literatürde söz edilen klasik ve güncel bazı yöntemlerin bu fonksiyonları iyileştirmede bazı eksik ve yetersiz kalan noktaları bulunduğu görülmektedir. Bu tez çalışmasında, bazı mevcut yöntemlerin başarısız olduğu durumlar olduğu gösterilmiş ve Taylor serisi açılımına ve tahmin hatasını izlemeye dayanan yeni bir yöntem geliştirilmiştir. Yöntemlerin başarımını değerlendirmek için PSCAD'te çeşitli analizler gerçekleştirilmiş; tek makina sonsuz güçlü bara test sistemi ve 68 baralı New England test sistemi – New York güç sisteminde farklı kısa devre arızası, güç salınımı ve güç salınımı esnasında kısa devre arızası senaryoları oluşturulmuştur. MATLAB'te gerçekleştirilen analizler, tezde önerilen yöntemin yüksek başarım gösterdiğine işaret etmektedir. Yapılan analizlere göre, yöntemin doğru anahtarlama cevabı vermeyi sağladığı, algoritma ve işlemci temelinde cevap verme hızının yüksek olduğu ve parametre çıkışının kısa devre arızası ve güç salınımı durumlarının ayrımı yapmayı kolaylaştıracak yapıda olduğu görülmektedir. Ayrıca, yöntemin akım ölçü transformatörlerinin doyması durumundaki tepkisi de incelenmekte ve başarımının yine yüksek düzeylerde olduğu görülmektedir. Sonuç olarak, tezde önerilen yöntem basit ve uygulanabilir bir yapıdadır ve sistemin güvenilirliğini arttırmaktadır. Yapılan çalışma ile mesafe rölesinin güç salınımı perdeleme ve güç salınımı geri perdeleme fonksiyonları iyileştirilmektedir. In this study, prevention of wrong breaker action of distance relays during power swing is focused on. Because such wrong actions may disturb continuity of power supply and lead to system instability, it is necessary for relays to distinguish power swing and short circuit fault cases with high accuracy. Power swing blocking and power swing deblocking functions are employed in the relay for that purpose. There seems some missing and insufficient points of conventional and some latest methods mentioned in literature for enhancing these functions. In this thesis study, it is shown that there are cases in which some current methods are unsuccessful and a novel method is developed which is based on Taylor series expansion and tracking of estimation error. Various analyses are carried out in PSCAD for evaluating performances of methods; different short circuit fault, power swing and short circuit fault during power swing scenarios are constituted in single machine infinite bus test system and 68-bus New England test system – New York power system. Analyses carried out in MATLAB points out that the proposed method has high performance. According to the analyses, it is shown that the method ensures correct breaker action, speed of it is high when algorithm and processor execution times are considered and structure of its parameter output makes discrimination of short circuit fault and power swing cases easier. Moreover, reaction of the method in current transformer saturation case is also examined and it is shown that performance of it is in high level again. As a conclusion, structure of the proposed method is simple and applicable and it improves system reliability. Power swing blocking and power swing deblocking functions are improved as a result of this work. 112

Superconducting fault current limiters (SFCL) are a promising technology for power systems, i.e. they provide efficient current limitation from the very beginning of the fault without requiring any control system. In fact, the current limiting characteristics are directly connected to the physical properties of superconducting materials. There is a need for accurate models to help designing resistive-type SFCLs (rSFCL) and planning their integration into electrical networks. Such models have to take into account the physics involved for simulating (as accurately as possible) the electrical and thermal behaviours for a wide range of fault conditions, i.e. high and low short-circuit currents that can be of various durations. It is difficult to see how the planning and integration of SFCLs can be realized without using numerical tools, especially tools that allow realizing power system transient simulations, such as EMTP-RV. In fact, such software packages support engineers in predicting the behaviour of SFCLs in realistic network conditions, which may comprise a wide variety of overcurrent or fault situations. However, rSFCLs exhibit highly non-linear behaviours with a strong coupling between thermal and electrical phenomena. The implementation of such a model in power systems simulation tools is therefore challenging. Although some models have been already developed over the years, improvements are needed to take into account i) all the phenomena linked to the current limitation (electrical and thermal), ii) geometric properties of superconducting tapes that are used in rSFCLs, and iii) the possibility to perform simulations at the system level, and iv) the influence of the tape architecture in relationship to local phenomena (hot spots). This thesis hence focuses on the development of a models for resistive-type SFCLs based on second generation high temperature superconducting coated conductors (2G HTS CCs), i.e. (RE)BCO tapes. The models are implemented in EMTP-RV, a tool that is used by many utilities around the world. However, the modeling technique can be adapted to other simulation tools as well. The model proposed in this thesis is based on an electro-thermal analogy, which allows modeling thermal effects with non-linear electrical circuit elements such as resistors and capacitors. The model has been developed with the aim of providing flexibility. Hence, it can be used with an AC or DC excitation, and can also take into account non-uniformity in critical critical current density typically observed along length of the conductors (i.e. tapes). It also allows modeling virtually any tape architecture using modular and flexible electrical and thermal basic building blocks that can be different in size. This in turn also allows modeling SFCLs with different level of discretization, i.e. from hot spot modeling with local heat transfer to several meters of (RE)BCO tape. It therefore becomes possible to analyze in the same simulation phenomena happening at the sub-millimetric scale, such as hot-spot phenomena, and at the system-scale, such as the impact on the network of several hundred meters of superconducting tape. In order to validate the EMTP-RV circuit model, comparisons with results obtained with finite elements have been carried out. A similar behavior could be observed, as long as the discretization size of the electro-thermal elements were appropriate. The EMTP-RV circuit model allows performing optimizations of the tape architecture for various thicknesses of stabilizer, in presence or not of an interfacial resistance layer, e.g. between the superconductor and the substrate. While the circuit model was developed to allow representing heat transfer and current distribution in 3D, simulations are still limited to 2D cases because the size of the nodal matrix is otherwise exceeded in EMTP-RV. Simulation results also show that neglecting heat transfer along the thickness of the tape can be risky, [...], Les limiteurs de courants de court-circuit supraconducteurs sont des appareillages à fort potentiel pour les réseaux électriques. En effet, ils offrent une limitation efficace dès les premiers instants du court-circuit. On peut qualifier la limitation de "naturelle", c’est-à-dire qu’elle est intrinsèquement liée aux caractéristiques du matériau et ne nécessite pas de commande particulière. Afin de faciliter la conception et l’intégration des limiteurs de courant de court-circuit supraconducteurs résistifs (rSFCL) destinés aux réseaux électriques, il est nécessaire de disposer de modèles de simulation précis. Ces derniers doivent prendre en compte et simuler correctement (et le plus précisément possible) les phénomènes électriques et thermiques du rSFCL en présence de surintensités de courant, qu’il s’agisse d’un court-circuit franc ou d’un phénomène temporaire de plus faible amplitude. Il est difficile d’envisager la planification de l’intégration d’un rSFCL sans passer par des outils numériques qui permettent la simulation d’un tel dispositif dans un réseau électrique en régime transitoire. Il est alors plus facile d’appréhender et de prédire le comportement transitoire du limiteur dans des conditions de stress réalistes, qui peuvent comprendre une grande variété de surintensités, tant en durée qu’en amplitude. Néanmoins, les rSFCL sont des dispositifs fortement non-linéaires caractérisés par un couplage électrique et thermique très fort. L’implémentation d’un tel modèle dans un logiciel de simulation de type “circuits électriques” en régime transitoire présente un certain défi. Bien que des modèles de rSFCL existent déjà, des améliorations doivent être apportées pour prendre en compte i) l’ensemble des phénomènes physiques liés à la limitation (thermiques et électriques), ii) les propriétés géométriques des rubans supraconducteurs utilisés et iii) la possibilité de réaliser des études globales (impact du limiteur sur le réseau) et iv) l’influence de l’architecture du ruban en présence de phénomènes locaux (points chauds). Cette thèse se concentre donc sur le développement d’un modèle de rSFCL basé sur des rubans supraconducteurs de deuxième génération. Ce modèle est développé dans le logiciel EMTP-RV, qui est un outil utilisé par un grand nombre de compagnies d’électricité dans le monde. Le modèle proposé dans cette thèse repose sur une analogie qui fait le lien entre les phénomènes électriques et thermiques, et qui permet une modélisation entièrement basée sur des éléments de circuits électriques. Le modèle permet de prendre également en compte les propriétés non linéaires des matériaux, tant au niveau électrique qu’au niveau thermique, avec l’utilisation de dipôles non-linéaires. Le modèle a été développé pour offrir un niveau de généricité intéressant pour la modélisation des rubans supraconducteurs. Il permet un fonctionnement avec une excitation AC ou DC en tension ou en courant et tient compte de la non-uniformité de courant critique, qui est typiquement observée dans la longueur des rubans disponibles commercialement. Il est également possible de représenter des variantes d’architectures (géométries et matériaux), avec une souplesse de modélisation qui est basée sur un assemblage de blocs “élémentaires” dont les dimensions peuvent être différentes. Cela permet alors d’évaluer, dans une même simulation, l’architecture du limiteur à une échelle submillimétrique (points chauds) et à une échelle “systémique”, tel que le comportement de plusieurs centaines de mètres de ruban. Des comparaisons ont permis de vérifier que le modèle circuit avait un comportement similaire à son équivalent en éléments finis, seulement si la taille des éléments électrothermiques de base (dans EMTP-RV) est adéquate. Le modèle équivalent circuit permet de réaliser des simulations de différentes architectures de rubans supraconducteurs, avec ou sans résistance d’interface, entre les couches tampons et la couche de (RE)BCO par exemple [...]

Yüksek gerilim enerji iletim sistemleri, günümüzde artan enerji talepleriyle birlikte sürekli büyüme göstermektedir. Üretim santrallerinin, tüketimin yapıldığı merkezlere uzak olması ve sayılarının her geçen gün artması iletim sisteminin büyümesinde önemli rol oynamaktadır. Ayrıca, radyal şebeke yapısının yerine enterkonnekte şebeke yapısının kullanılması iletim sistemini daha karmaşık bir hale getirmektedir. Tüm bu sebepler, iletim sistemlerinin güvenilir bir şekilde işletilmesini güçleştirmektedir.Bu çalışmada geliştirilen algoritmalarla, iletim sisteminde farklı arıza analizleri yapılmış ve aşırı akım rölelerinin ayar değerleri uygun olarak yeniden hesaplanmıştır. İletim sistemi modeli olarak Türkiye iletim sisteminden 48 baralı örnek bir bölge seçilmiştir. Bu örnek, model güç sistemi analiz programı DigSilent PowerFactory yazılımına aktarılmıştır. DPL (DigSilent Programlama Dili) programlama diliyle geliştirilen algoritmalar, gerçekleştirilen analizler ile doğrulanmıştır.İletim sisteminde meydana gelen değişikliklere bağlı olarak koruma rölelerinin ayarlarının tekrar yapılması gerekmektedir. Günümüzde, üretilen koruma rölelerinin iletişim özellikleri uzaktan ayar okuma ve yazma imkânı sağlamaktadır. Haberleşme sistemleri ile koruma rölelerinin ayarlarının izlenmesi ve geliştirilen algoritmanın iletim sistemindeki değişiklikleri de göz önünde bulundurarak röle ayarlarını yeniden hesaplanması ve değiştirmesi daha güvenilir bir işletme sunacaktır.Aşırı akım koruma röleleri, iletim hatlarında ana ve yedek koruma işlevini yerine getirmek için kullanılmaktadır. Türkiye iletim sisteminin koruma pratiği referans alınarak aşırı akım röle ayarları hesaplanmıştır. Sonrasında ise, geliştirilen algoritma ile tekrar hesaplamalar yapılmıştır. Her iki metoda göre set edilen aşırı akım rölelerinin arıza tepkileri karşılaştırmalı olarak sunulmuştur. High voltage energy transmission systems are showing continuous growth with increasing energy demands today. The fact that production plants are far from the centers where consumption is made and its numbers are increasing every day play an important role in the growth of the transmission system. In addition, the use of interconnect network structure instead of radial network structure makes the transmission system more complex. For all these reasons, it is difficult to reliably operate the transmission system.With the algorithms developed in this study, different fault analyzes were made and the setting values of the overcurrent relays were recalculated accordingly. As a transmission system model, a sample region with 48 buses was chosen from Turkey transmission system. This sample model has been transferred to the power system analysis program DigSilent PowerFactory software. The algorithms developed with the DPL (DigSilent programming language) have been verified with the analysis performed.Depending on the changes in the transmission system, the settings of the protection relays need to be reset. Nowadays, the communication features of the produced protection relays provide remote setting read and write. Monitoring of the settings of the protection relays with the communication systems, setting exchange and re-calculation of the relay settings taking into account the changes in the transmission system of the developed algorithm will provide a more reliable operation.Overcurrent protection relays are used to perform for main and backup protection functions on transmission lines. Overcurrent relay settings were calculated with reference to the protection practice of the Turkish transmission system. Subsequently, the overcurrent relays were calculated again with the developed algorithm. The fault responses of the overcurrent relay is setting according to both methods are given comparatively. 106

Yenilenebilir enerji kaynaklarını da içeren dağıtık enerji sistemlerinden oluşan yeni nesil şebeke sistemleri, günümüzde akıllı şebekeler kapsamında yüksek verimlilik, güvenilirlik ve sürdürebilirlik hususlarında önemli gelişmeler sağlamıştır. Bunun yanı sıra düşük elektriksel kayıplar ve çevre kirliliği sunması sayesinde de geleneksel merkezi elektrik enerjisi yapısına alternatif olarak ortaya çıkmaktadır. Akıllı şebekeler kavramı dikkate alındığında çözülmesi gereken en önemli hususlardan birisi evirici arayüzlü dağıtık üreteçlerden oluşan bu tarz şebekelerin özellikle de ada modundayken değişken ve belirsiz hata karakteristikleri göstermeleri nedeniyle mevcut geleneksel koruma sistemlerinin yetersiz kalmasıdır. Bu husus için literatürde çeşitli çözüm önerileri mevcuttur. Ancak mevcut çalışmalar incelendiğinde henüz dağıtık üretim tesisleri (distributed generation-DG) içeren şebekeler için güvenilir, genel kabul görmüş ve standart bir koruma tekniğinin bulunmadığı gözlenmiştir.Bu tez üç ortaklı (TÜBİTAK ve YTÜ-Türkiye, Aalborg Üniversitesi-Danimarka, SIMULA-Norveç) bir `SmartGrids ERA-NET` konsorsiyumu projesi (Avrupa Birliği Projesi) tarafından desteklenmekte olup tezin amacı yenilenebilir enerji kaynaklarından oluşan dağıtım şebekeleri için etkin ve adaptif bir koruma tekniği geliştirmektir. Bu açıdan tez kapsamında geliştirilen adaptif koruma stratejisi ile farklı yük ve dağıtık üretim tesislerini de içeren bir akıllı şebeke sistemindeki koruma ve röle koordinasyonu uygulaması, verimli ve etkin bir şekilde gerçekleştirilmiştir. Birden çok kaynağın bağlı olduğu yeni nesil şebeke sistemlerinde güç akışının yönlü olması nedeniyle koruma sistemi röle tercihi önemli bir husus haline gelmektedir. Bu amaçla tez çalışmasında, konvansiyonel şebekelerde de sıklıkla kullanılan yönlü aşırı akım rölesine ait işletim karakteristiklerindeki ayar değerleri, sistemdeki bütün koruma cihazlarının izlenmesi ve haberleşmeleri vasıtası ile değişken yük taleplerine hızlı bir şekilde cevap verecek şekilde adaptif olarak belirlenmiştir. Bu sayede sistem kararlılığı, sürekliliği ve güvenilirliğinin arttırılması hedeflenmiştir.Yukarıda bahsi geçen kontrol yaklaşımının etkin bir biçimde oluşturulması için öncelikle benzetim ortamında yenilenebilir enerji bazlı dağıtık üretim tesislerini de içeren akıllı bir şebeke için örnek bir güç sistem modeli oluşturulmuştur. Burada sisteme ait bütün bileşenler için detaylı benzetim modelleri oluşturularak modeller üzerinde en iyileştirme çalışmaları gerçekleştirilmiştir. Oluşturulan komple model üzerinde önerilen kontrol yapısının etkinliği değerlendirilerek kontrol algoritmasında gerekli değişiklikler yapılmış ve etkinliği farklı dağıtım şebekeleri referans alınarak benzetim (simulasyon) ortamında test edilmiştir. Nowadays, microgrids composed of distributed generators including renewable energy sources have appeared as alternative to conventional electrical energy structure in terms of higher efficiency, reliability, sustainability, lower electrical losses and environmental pollution. However, one of the most significant obstacles that prevents the widespread application of microgrids is the insufficiency of conventional protection systems due to their variable and indefinite fault characteristics especially in islanding mode of operation. In the literature, there exist several solution proposals for this issue. However, when investigated; it is observed that there is a lack of a reliable, widely accepted and standard protection technique in the literature.This thesis is a SmartGrids ERA-NET Consortium project of three partners (TUBITAK and YTU-Turkey, Aalborg University-Denmark, SIMULA-Norway) with the purpose of development of an effective protection technique for microgrids composed of renewable energy sources. In this concept, the protection and control issues in a smart grid system including different loads and several sources with distributed generation units have efficiently been realized in this thesis by employing smart controller. The set points of the widely utilized protection devices such as over-current relays in conventional power systems have adaptively and dynamically been determined considering the observation and communication of all protection devices in the system in order to provide fast responses to varying load demands. Thus, the system stability, durability and reliability could be enhanced.In order to provide the above mentioned control approach efficiently, a power system model of smart grid including renewable energy based distributed generation plants have been realized in simulation environment. The detailed simulation models of each component of the system have been provided and the necessary revisions on developed models have been realized. The efficiency of the control approach has been analyzed utilizing the mentioned overall system model. 139