Recent developments in data packets based high speed digital communications have opened the door for new types of applications in power system protection and control. Intelligent Electronic Devices (IEDs) are equipped with various communication capabilities that make their functional integration a natural next step. Existing integration of substation equipment is not capable of clustering with the purpose of pooling hardware resources. <p> Presently, every electric device requiring protection has its dedicated hardware performing the predetermined set of protective functions. A new function-based protection and control philosophy is proposed, based on an open-system solution. In the proposed system, the resources of the protective and control hardware are pooled, and as a clustered system provide each protected unit (line, transformer, breaker, etc) with functions required for complete direct and backup protection. <p> The work presented in this thesis identifies the performance requirements of a digital relaying algorithm for processing samples that are sent across Ethernet-based communication channels. The work shows the shortcomings and unstable performance of widely used protective algorithms in accommodating data samples that are out of step from their proper position due to variable time delays of the communications media. A new digital relaying algorithm was developed that is able to extract the amplitude and phase angle of signals from data samples received across Ethernet networks with variable jitter. <p> The performance of the algorithm was tested by using the recovered phasor amplitude and phase angle information in protective solutions. The results show that there is significant flexibility in the algorithm that can be used to facilitate less performant communication channels, or, to take advantage of faster communications channels by reducing the response time of the protective function. <p> The results show that the algorithm works well with variable length data windows, and variable sampling frequencies. Higher sampling rates make communications problems more visible, but the presented algorithm is able to compensate for wide variations in network performance, effectively maintaining sampled signal phase and amplitude information during network performance fluctuations.

Recent developments in data packets based high speed digital communications have opened the door for new types of applications in power system protection and control. Intelligent Electronic Devices (IEDs) are equipped with various communication capabilities that make their functional integration a natural next step. Existing integration of substation equipment is not capable of clustering with the purpose of pooling hardware resources. <p> Presently, every electric device requiring protection has its dedicated hardware performing the predetermined set of protective functions. A new function-based protection and control philosophy is proposed, based on an open-system solution. In the proposed system, the resources of the protective and control hardware are pooled, and as a clustered system provide each protected unit (line, transformer, breaker, etc) with functions required for complete direct and backup protection. <p> The work presented in this thesis identifies the performance requirements of a digital relaying algorithm for processing samples that are sent across Ethernet-based communication channels. The work shows the shortcomings and unstable performance of widely used protective algorithms in accommodating data samples that are out of step from their proper position due to variable time delays of the communications media. A new digital relaying algorithm was developed that is able to extract the amplitude and phase angle of signals from data samples received across Ethernet networks with variable jitter. <p> The performance of the algorithm was tested by using the recovered phasor amplitude and phase angle information in protective solutions. The results show that there is significant flexibility in the algorithm that can be used to facilitate less performant communication channels, or, to take advantage of faster communications channels by reducing the response time of the protective function. <p> The results show that the algorithm works well with variable length data windows, and variable sampling frequencies. Higher sampling rates make communications problems more visible, but the presented algorithm is able to compensate for wide variations in network performance, effectively maintaining sampled signal phase and amplitude information during network performance fluctuations.

Studien syftar till att testa teorier om effekter av habitatstorlek, konnektivitet, områdesskydd, habitatmängd och fragmentering på enskilda arters förekomstmönster, samt undersöka existensen av fragmenteringströskel och utdöendetröskel. Förekomstdata för revlummer Lycopodium annotinum och mattlummer Lycopodium clavatum har insamlats i 61 skogsfragment utspridda i 10 kartrutor à 2,5×2,5 km i landskapet Södermanland. I vardera skogsfragment undersöktes en yta om 500m2. Revlummer förekom i 13 och mattlummer i 10 av de undersökta skogsfragmenten. I 7 kartrutor förekom revlummer i minst 1 skogsfragment, för mattlummer var motsvarande siffra 8 kartrutor. Resultaten visar att habitatstorlek har en signifikant positiv effekt på förekomst av revlummer och mattlummer samt att konnektivitet har en signifikant positiv effekt på förekomst av mattlummer. Områdesskydd, habitatmängd och fragmentering i landskapet har ingen påvisad effekt på förekomst av dessa arter och ingen fragmenteringströskel eller utdöendetröskel har hittats. Dessa resultat indikerar att ett bevarande av skogsfragment med stor storlek och hög konnektivitet är viktigt för de undersökta arternas fortsatta livskraft. / The aim of this study is to test theories of the effects of habitat size, connectivity, area protection, habitat amount and fragmentation on the occurrence of single species, plus examining the existence of a fragmentation threshold and an extinction threshold. Occurrence of stiff clubmoss Lycopodium annotinum and stag’s-horn clubmoss Lycopodium clavatum was examined in 61 forest fragments scattered over 10 large 2,5×2,5 km plots, located in the county of Stockholm in Sweden. In each forest an area covering 500m2 was searched for the two species. Lycopodium annotinum occured in 13 and L. clavatum in 10 of the investigated fragments. Lycopodium annotinum occurred in at least 1 fragment in 7 large plots, 8 large plots was the corresponding number for L. clavatum. The results showed a significant positive effect of habitat size on the occurrence of both species and a significant positive effect of connectivity on the occurrence of Lycopodium clavatum. Area protection, habitat amount and fragmentation had no observed effect on the occurrence of these species, and no fragmentation threshold or extinction threshold was found. These results indicate the importance of preserving large forest fragments with high connectivity, to assure continued viability of the examined species.

Este trabalho tem o objetivo de apresentar o desenvolvimento de uma metodologia para a proteção de retaguarda de linhas de transmissão de grandes áreas, utilizando dados de um Sistema de Medição Fasorial Sincronizada. O estudo se justifica devido à contínua expansão dos Sistemas de Transmissão, tais como os que fazem parte do Sistema Interligado Nacional. Vale esclarecer que esta expansão pode vir a dificultar a operação e controle do mesmo, o que faz com que seja necessário, um sistema de proteção cada vez mais confiável, que diminua o impacto de eventos danosos de grande porte, e que atenda aos requisitos de um sistema de proteção de grandes áreas. Neste contexto, o modelo do sistema elétrico de potência em análise foi implementado computacionalmente a partir do RSCAD, ambiente computacional e interface gráfica do RTDS® (Real Time Digital Simulator). Como principal passo, o algoritmo desenvolvido verifica a variação da potência ativa em todos os barramentos monitorados do sistema de transmissão e, de acordo com tal variação, associada ao estado dos dois extremos da linha, detecta e aponta a localização de uma situação de falta. Pelos resultados obtidos, a metodologia se mostrou eficiente na detecção e localização da falta em linhas de transmissão para sistemas de grandes áreas. Toda a metodologia desenvolvida, considerações adotadas e os promissores resultados observados serão reportados neste documento. / This work aims to present the development of a methodology for wide area transmission line backup protection, using Synchronized Phasor Measurement Systems. This study is justified due to continuous expansion of Transmission Systems, such as those which are part of the National Interconnected System. It is worth clarifying that this expansion might difficult system operation and control, which makes necessary to have an increasingly reliable protection system, that minimizes the impact of large dangerous events, and, at the same time, supplies the requirements of a wide area protection system. Within this context, the electrical system model under analysis was implemented through RSCAD, which is a RTDS® (Real Time Digital Simulator) computing environment and graphical interface. As main step, the developed algorithm verifies the active power variation in all monitored buses of the transmission system and then, according to such variation, associated with the communication of the variation state of both line sides, detects and indicates the localization of a faulting condition. According to the results obtained, the methodology has shown its efficiency in transmission line faults detection and localization for wide areas of electrical power systems. The entire developed methodology, considerations adopted and promising outcomes will be reported along this document.

Este trabalho tem o objetivo de apresentar o desenvolvimento de uma metodologia para a proteção de retaguarda de linhas de transmissão de grandes áreas, utilizando dados de um Sistema de Medição Fasorial Sincronizada. O estudo se justifica devido à contínua expansão dos Sistemas de Transmissão, tais como os que fazem parte do Sistema Interligado Nacional. Vale esclarecer que esta expansão pode vir a dificultar a operação e controle do mesmo, o que faz com que seja necessário, um sistema de proteção cada vez mais confiável, que diminua o impacto de eventos danosos de grande porte, e que atenda aos requisitos de um sistema de proteção de grandes áreas. Neste contexto, o modelo do sistema elétrico de potência em análise foi implementado computacionalmente a partir do RSCAD, ambiente computacional e interface gráfica do RTDS® (Real Time Digital Simulator). Como principal passo, o algoritmo desenvolvido verifica a variação da potência ativa em todos os barramentos monitorados do sistema de transmissão e, de acordo com tal variação, associada ao estado dos dois extremos da linha, detecta e aponta a localização de uma situação de falta. Pelos resultados obtidos, a metodologia se mostrou eficiente na detecção e localização da falta em linhas de transmissão para sistemas de grandes áreas. Toda a metodologia desenvolvida, considerações adotadas e os promissores resultados observados serão reportados neste documento. / This work aims to present the development of a methodology for wide area transmission line backup protection, using Synchronized Phasor Measurement Systems. This study is justified due to continuous expansion of Transmission Systems, such as those which are part of the National Interconnected System. It is worth clarifying that this expansion might difficult system operation and control, which makes necessary to have an increasingly reliable protection system, that minimizes the impact of large dangerous events, and, at the same time, supplies the requirements of a wide area protection system. Within this context, the electrical system model under analysis was implemented through RSCAD, which is a RTDS® (Real Time Digital Simulator) computing environment and graphical interface. As main step, the developed algorithm verifies the active power variation in all monitored buses of the transmission system and then, according to such variation, associated with the communication of the variation state of both line sides, detects and indicates the localization of a faulting condition. According to the results obtained, the methodology has shown its efficiency in transmission line faults detection and localization for wide areas of electrical power systems. The entire developed methodology, considerations adopted and promising outcomes will be reported along this document.

Made available in DSpace on 2014-12-17T15:03:19Z (GMT). No. of bitstreams: 1 JoelsonKFB_Da_capa_ate_pag_29.pdf: 1955626 bytes, checksum: 9b00453786a4db0410b45c73118b2694 (MD5) Previous issue date: 2006-11-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Due to the increasing activities and its disordered occupation, the catchment of the Pitimbu river is reason of concern for the population, since the river empties in the lagoon of the Jiqui where 30% of the water of this lagoon are caught for the supplying the city of Natal, playing an important fuction in the supply of water superficial for the capital of the Rio Grande do Norte. The superior stretch of the hydrography catchment of the Pitimbu river - Maca?ba/RN, object of this study, is denoted by the eminently agricultural occupation with the use of the irrigated agriculture in the many properties that compose this stretch. Because of this becomes necessary to analyze the availability of the water resources in the catchment of the Pitimbu river, in the superior stretch, collating with the use and occupation of the existing terrain. The stretch in study was divided in eight points which had been performed tests throughout the water and analyzed the parameters physicist-chemistries and heavy metals that are praised by resolution CONAMA n? 357 e, visits in field with photographic survey for characterization of this verifying the situation where if it finds the river. The stretch presented some divergence in the parameters of pH and iron, however the results denote a characteristic of the region. The great amount of slide barrages throughout the river and the wet street was observed, had also verified near the edges the launching of garbage and, the great amount of aquatic vegetation. With this it is concluded that the water of the river can be used for human supplying, therefore inside presents a quality of drinking waters of the standards demanded for resolution CONAMA n? 357, in this way, the stretch in study could be adopted as an Envoiremental Area Protection (APA), to preserve and to guarantee, at least in this stretch, that its condition remains unchanged and continues to supply of permanent form a water of excellent quality / Devido ?s atividades crescentes e sua ocupa??o desordenada, a bacia do rio Pitimbu ? motivo de preocupa??o para a popula??o, visto que o rio des?gua na lagoa do Jiqui onde 30% da ?gua desta lagoa ? captada para o abastecimento da cidade de Natal, desempenhando um papel importante na disponibiliza??o de ?gua doce superficial para a capital do estado do Rio Grande do Norte. O trecho superior da bacia hidrogr?fica do rio Pitimbu Maca?ba/RN, objeto deste estudo, ? denotado pela ocupa??o eminentemente rural com a utiliza??o da agricultura irrigada nas diversas propriedades que comp?em este trecho. Diante disto faz-se necess?rio analisar a disponibilidade dos recursos h?dricos na bacia do rio Pitimbu, no trecho superior, frente ao uso e ocupa??o do solo existente. O trecho em estudo foi dividido em oito pontos aos quais foram realizadas coletas de ?gua e analisado os par?metros f?sico-qu?micos e metais pesados que s?o preconizados pela resolu??o CONAMA n? 357 e, visitas em campo com levantamento fotogr?fico para caracteriza??o deste verificando a situa??o em que se encontra o rio. O trecho apresentou alguma diverg?ncia nos par?metros de pH e ferro, por?m os resultados denotam uma caracter?stica da regi?o. Foi observada a grande quantidade de barramentos ao longo do rio e as passagens molhadas, tamb?m se verificaram o lan?amento de lixo pr?ximo ?s margens e, a grande quantidade de vegeta??o aqu?tica. Com isso conclui-se que a ?gua do rio pode ser utilizada para abastecimento humano, pois apresenta uma qualidade de ?gua pot?vel dentro dos padr?es exigidos pela resolu??o CONAMA n? 357, desta forma, o trecho em estudo poderia vir a ser adotado como uma ?rea de Prote??o Ambiental (APA), para preservar e garantir, pelo menos neste trecho, que sua condi??o permane?a inalterada e continue a fornecer de forma permanente uma ?gua de excelente qualidade

Modern power networks incorporate communications and information technology infrastructure into the electrical power system to create a smart grid in terms of control and operation. The smart grid enables real-time communication and control between consumers and utility companies allowing suppliers to optimize energy usage based on price preference and system technical issues. The smart grid design aims to provide overall power system monitoring, create protection and control strategies to maintain system performance, stability and security. This dissertation contributed to the development of a unique and novel smart grid test-bed laboratory with integrated monitoring, protection and control systems. This test-bed was used as a platform to test the smart grid operational ideas developed here. The implementation of this system in the real-time software creates an environment for studying, implementing and verifying novel control and protection schemes developed in this dissertation. Phasor measurement techniques were developed using the available Data Acquisition (DAQ) devices in order to monitor all points in the power system in real time. This provides a practical view of system parameter changes, system abnormal conditions and its stability and security information system. These developments provide valuable measurements for technical power system operators in the energy control centers. Phasor Measurement technology is an excellent solution for improving system planning, operation and energy trading in addition to enabling advanced applications in Wide Area Monitoring, Protection and Control (WAMPAC). Moreover, a virtual protection system was developed and implemented in the smart grid laboratory with integrated functionality for wide area applications. Experiments and procedures were developed in the system in order to detect the system abnormal conditions and apply proper remedies to heal the system. A design for DC microgrid was developed to integrate it to the AC system with appropriate control capability. This system represents realistic hybrid AC/DC microgrids connectivity to the AC side to study the use of such architecture in system operation to help remedy system abnormal conditions. In addition, this dissertation explored the challenges and feasibility of the implementation of real-time system analysis features in order to monitor the system security and stability measures. These indices are measured experimentally during the operation of the developed hybrid AC/DC microgrids. Furthermore, a real-time optimal power flow system was implemented to optimally manage the power sharing between AC generators and DC side resources. A study relating to real-time energy management algorithm in hybrid microgrids was performed to evaluate the effects of using energy storage resources and their use in mitigating heavy load impacts on system stability and operational security.

Recent major electrical disturbances highlight the extent to which modern societies depend on a reliable power infrastructure and the impact of these undesirable events on the economy and society. Numerous blackout models have been developed in the last decades that capture effectively the cascade mechanism leading to a partial or complete blackout. These models usually consider only the state of the electrical part of the system and investigate how failures or limitations in this system affect the probability and severity of a blackout.However, an analysis of the major disturbances that occurred during the last decade, such as the North America blackout of 2003 and the UCTE system disturbance of 2006, shows that failures or inadequacies in the Information and Communication Technology (ICT) infrastructure and also human errors had a significant impact on most of these blackouts.The aim of this thesis is to evaluate the contribution of these non-electrical events to the risk of power system blackouts. As the nature of these events is probabilistic and not deterministic, different probabilistic techniques have been developed to evaluate their impact on power systems reliability and operation.In particular, a method based on Monte Carlo simulation is proposed to assess the impact of an ICT failure on the operators’ situation awareness and consequently on their performance during an emergency. This thesis also describes a generic framework using Markov modeling for quantifying the impact of insufficient situation awareness on the probability of cascading electrical outages leading to a blackout. A procedure based on Markov modeling and fault tree analysis is also proposed for assessing the impact of ICT failures and human errors on the reliable operation of fast automatic protection actions, which are used to provide protection against fast-spreading electrical incidents. The impact of undesirable interactions and the uncoordinated operation of these protection schemes on power system reliability is also assessed in this thesis.The simulation results of these probabilistic methods show that a deterioration in the state of the ICT infrastructure and human errors affect significantly the probability and severity of power system blackouts. The conclusion of the work undertaken in this research is that failures in all the components of the power system, and not just the “heavy electrical” ones, must be considered when assessing the reliability of the electrical supply.

Bevarandet av natur och miljö är en viktig del av Sveriges markanvändningsplanering. Ett sätt att bevara dessa rika områden på lång sikt är genom inrättandet av naturreservat. Naturreservat upprättas oftast av Länsstyrelsen för just detta syfte vilket i vissa fall kan stå i kontrast till kommunens önskan om att använda marken för andra intressen och ändamål. Ett sådant exempel utgör Naturreservatet Häcksören som upprättades i december 2021 av Länsstyrelsen i Uppsala och inom vilket Älvkarleby kommuns avloppsreningsverk är beläget. Reningsverket och naturreservatet representerar båda allmänna intressen som i den avvägning som gjorts strider mot varandra. Syftet med arbetet är att se hur utvecklingsambitionerna hos Älvkarleby kommun påverkas av den avvägning som är gjord mellan det allmänna intresset för reningsverket och det allmänna intresset för naturreservatet. Förhoppningen är att studien är till nytta för andra kommuner i fall där avvägningar görs mellan liknande motstridande allmänna intressen och där dess konsekvenser beaktas.  Studien är baserad på kvalitativa metoder som har genomförts via en kombination av litteraturstudie, semi-strukturerade intervjuer och studier i lagrum och domar för att på bästa sätt besvara arbetets frågeställningar. Sju intervjuer har genomförts med sakkunniga personer inom ämnet som representerar de olika myndigheterna samt en utomstående juridiskt sakkunnig. Resultatet av fallstudien visar att det finns olika syn mellan Älvkarleby kommun och Länsstyrelsen när det gäller den avvägningen som gjorts. Framför allt är detta förknippat med att de båda parterna ser fallet utifrån olika tidsperspektiv. Kommunen är angelägen om att ett eventuell nödvändigt framtida utökat ianspråktagande av mark för reningsverket säkerställs och således inte påverkar kommunens långsiktiga utvecklingsvisioner. Länsstyrelsens beslut grundar sig i situationen såsom den är idag. De förnekar inte att en utbyggnad av reningsverket kan bli aktuell men eftersom detta är oförutsägbart i tid och rum anses det inte relevant att ta detta i beaktande vid tillfället då reservatet inrättas. Studien avslutar med att diskutera huruvida kommunens argumentation ska tas i större beaktande vid liknande framtida fall. / Preserving nature and the environment is essential for Sweden's land use planning. One way to preserve these rich areas for the future is by setting up nature reserves. The County Administrative Board usually establishes nature reserves for this very objective, which in some cases may contrast with the municipality's desire to use the land for other interests and purposes. One such example is the Häcksören Nature Reserve, established in December 2021 by the County Administrative Board in Uppsala and within which Älvkarleby municipality's sewage treatment plant is located. The treatment plant and the nature reserve represent public interests that conflict with each other in the balance that has been struck. The purpose of the study is to see how the development ambitions of Älvkarleby municipality are affected by the balance that has been made between the general interest in the treatment plant and the public interest in the nature reserve. The hope is that the study will be helpful for other municipalities in cases where balances are made between similar conflicting public interests and where its consequences are considered. The study is based on qualitative methods carried out through a combination of literature study, semi-structured interviews, and studies in law and judgments to best answer the work's questions. Seven interviews were conducted with experts in the subject representing the various authorities and an outside legal expert. The case study results show that there are different views between Älvkarleby municipality and the County Administrative Board regarding the balance that has been made. Above all, this is associated with the two parties seeing the case from different time perspectives. The municipality is concerned that any necessary future increased use of land for the treatment plant is ensured and thus does not affect the municipality's long-term development visions. The County Administrative Board's decision is based on the situation today. They do not deny that an expansion of the treatment plant may be relevant, but since this is unpredictable in time and space, it is not considered pertinent to take this into account when the reserve is established. The study concludes by discussing whether the municipality's argumentation should be taken into more significant consideration in similar future cases.