Tahle práce se zabývá monitorováním venkovních vysokonapěťových vedeních, což mohou být vedení od 70kV do 400kV. Senzory jsou umístěny na vodiči a hlavní myšlenkou je vyhodnotit mechanické chování vodičů, a to od nízkých frekvencí (zlomky Hz) až po vysoké frekvence (desítky Hz). Tahle práce se zabývala pohyby o nízkých frekvencích a vysokých amplitudách a popsala možnosti sestavení těchto pohybů na základě měření ze senzorů. Konkrétně se jedná o pohyby v případě silného větru, zkratu, opadávání ledu nebo dalších. Všechno tohle pomáhá operátorů dělat rozhodnutí ohledně provozování sítí. Vývoj zahrnuje přidání/kombinaci nových senzorů, popsání matematického algoritmu potřebného k sestavení pohybu na základě toho co bylo změřeno, ať už se jedná o hodnoty získané simulací, laboratorním testem nebo reálným měřením na vedení.

The thesis is dealing with data transmission over the electric network. It describes PLC technology, its properties, and elements used in this type of network. The important part of this thesis is discussion over the mathematical model of distribution network with two-port cascades. Transmission functions created according to mathematical model were compared with each other. Thesis was concluded with observation of the impact of interconnected parts on transmission function of designed branched conductor. Final results were processed by Matlab and compared with each other.

Att underhålla infrastruktur med hög standard är viktigt för alla länder, och att misslyckas med detta innebär allvarliga logistiska och ekonomiska konsekvenser. Kraftledningsinspektion är en betydelsefull del i detta. Denna uppsats har sökt svar på vad för- och nackdelarna är med att använda satellitövervakning av kraftledningar, samt svar på ifall teknik för satellitövervakning av kraftledningar också kan tillämpas på volymberäkningar av skog. Metoden har utgått från intervjuer med experter och relevanta företag samt litteratur som underlag. Att undersöka vilka för- och nackdelar som finns med satellitövervakning av kraftledningar var viktigt eftersom satellitövervakning är ett snabbt växande fält, men inte särskilt väl undersökt. Att undersöka huruvida teknik för kraftledningsövervakning med satelliter är tillräcklig för att estimera skogsvolym bedömdes vara värdefullt eftersom skogsvolym idag estimeras med luftburen LiDAR, medan luftburen LiDAR påstods vara signifikant mycket dyrare överlag än satellitmätningar. Det fanns alltså en eventuell ekonomisk fördel med att estimera skogsvolym med satelliter istället för dagens luftburna mätningar. Det förväntade resultatet var att tekniken för satellitövervakning av kraftledningar är tillräcklig för att estimera skogsvolym. De största nackdelarna med satellitövervakning av kraftledningar berör problemen med att nå tillräckligt hög noggrannhet i processerna för trädidentifiering, samt att utveckla effektiva tillvägagångssätt för att utvärdera detta då underlaget gällande föreslagna och utvärderade metoder är glest. En annan nackdel visade sig vara att satellitmetoderna är svåra att göra konkurrenskraftiga i jämförelse med de etablerade luftburna LiDAR-metoderna i fråga om kostnader. Anledningen är att de högupplösta satellitbilder som ofta krävts för att nå hög noggrannhet fortfarande är dyra, även om en fördel som också identifierades var att ny och billigare satellitteknik just nu utvecklas i hög takt. Gällande denna fråga visade sig den största fördelen vara den snabba utvecklingen av nya satelliter med högre upplösning, som öppnar upp möjligheten för att komma ikapp de konventionella metoderna. Det förväntade resultatet kring huruvida satellitövervakning har ekonomiska fördelar jämfört med luftburen övervakning motsägs alltså av resultatet i denna rapport, med avseende på kraftledningsövervakning. Däremot indikerar resultatet att tekniken för satellitövervakning av kraftledningar är tillräcklig för att estimera skogsvolym, vilket överensstämmer med det förväntade resultatet. / Maintaining infrastructure of high standard is important for all countries. Failing this means severe logistical and economic consequences. Power line inspection is an important part of this. This thesis has searched for an answer to what the advantages and disadvantages are of inspecting power lines by using satellites, as well as an answer to if the technology of satellite surveillance of power lines is sufficient to estimate forest volume. The methodology of the thesis has been to turn to companies and experts in the field and to use relevant literature. Examining what the advantages and disadvantages of satellite inspection of power lines are was important since satellite surveillance is a growing field, but not very well researched. To analyze whether technology of satellite surveillance of power lines is enough to estimate forest volume was thought to be valuable since forest volume today is estimated by airborne LiDAR, while airborne LiDAR was claimed to be significantly more expensive in general than 3 satellite measurements. Thus, there was a potential economic advantage to estimate forest volume with satellites instead of airborne measurements. The expected result was that the technology of satellite surveillance of power lines is sufficient to estimate forest volume. The biggest disadvantages of satellite surveillance of power lines involve the problems of achieving high enough accuracy in the processes of tree identification, as well as developing effective formulas to evaluate this when the research material of proposed methods is sparse. Another disadvantage turned out to be that the satellite methods are hard to compete with, in comparison to the established airborne LiDAR methods and in regard to cost. The reason is that the high-resolution satellite images that often are demanded still are expensive, even though an advantage that also was identified in this thesis is that new and cheaper satellite technology is being developed at a quick rate. The biggest advantage of satellite surveillance of power lines turned out to be the quick development of new satellites with higher resolution, which enables the possibility to catch up with the conventional methods. The expected result in regard to whether satellite surveillance has economic advantages compared to airborne surveillance is contradicted in the result of this thesis, in regard to power line inspection. However, the result indicates that the technology of satellite surveillance of power lines is sufficient to estimate forest volume, which concurs with the expected result.

The inspection of power lines is an important process to maintain a stable electrical infrastructure. Simultaneously it is very time consuming task considering there are 164 000 km of power lines in Sweden alone. A cheaper and more sustainable approach is an automatic inspection with drones. But for a successful inspection with drones, exact power line coordinates is needed, which is not always available. To identify power lines in satellite images a machine learning approach was implemented. In machine learning, semantic segmentation is the process of pixel-wise classification of an image. Where you not only label the entire image, but every pixel individually. This way not only the existence of a power line will be identified, but their position inside the image. This thesis aims to investigate if semantic segmentation is an effective approach to locate power lines in satellite images. And what methods can be used on the segmented output data to extract linestring coordinates representing the power line. Linear regression and a polygon centerline extraction method was implemented on the segmented output data to define a line that represents the true location of the power line. The semantic segmentation model could find power lines where they were clearly visible, but struggled where they were not very visible. From good output data from the segmentation model, the linear regression and the polygon centerline extraction methods could successfully extract linestring coordinates that represented the true location of the power line. In the best case around 67% of power lines was correctly identified. But still, with good output data from the model, complex shapes such as intersections might still get bad results. Even if the approach needs further work, and cannot reliably identify all power lines in the current state, it has proven that this could be a promising method to identify power lines in satellite images.

The stiffness and frequency properties of tensegrity structures are functions of the pre-stress, topology, configuration, and axial stiffness of the elements. The tensegrity structures considered are tensegrity booms, tensegrity grids, and tensegrity power lines. A study has been carried out on the pre-stress design. It includes (i) finding the most flexible directions for different pre-stress levels, (ii) finding the pre-stress pattern which maximizes the first natural frequency. To find the optimum cross-section areas of the elements for triangular prism and Snelson tensegrity booms, an optimization approach is utilized. A constant mass criterion is considered and the genetic algorithm (GA) is used as the optimization method. The stiffness of the triangular prism and Snelson tensegrity booms are modified by introducing actuators. An optimization approach by means of a GA is employed to find the placement of the actuators and their minimum length variations. The results show that the bending stiffness improves significantly, but still an active tensegrity boom is less stiff than a passive truss boom. The GA shows high accuracy in searching the non-structural space. The tensegrity concept is employed to design a novel transmission power line .A tensegrity prism module is selected as the building block. A complete parametric study is performed to investigate the influence of several parameters such as number of modules and their dimensions on the stiffness and frequency of the structure. A general approach is suggested to design the structure considering wind and ice loads. The designed structure has more than 50 times reduction of the electromagnetic field and acceptable deflections under several loading combinations. A study on the first natural frequencies of Snelson, prisms, Micheletti, Marcus and X-frame based tensegrity booms has been carried out. The result shows that the differences in the first natural frequencies of the truss and tensegrity booms are significant and not due to the number of mechanisms or pre-stress levels. The tensegritybooms of the type Snelson with 2 bars and prism with 3 bars have higher frequencies among tensegrity booms. / <p>QC 20120904</p>

Yes / This work presents the development of a new approach of modelling the source excitation and the penetration of structures by continuous propagating electromagnetic (EM) plane waves. The technique incorporates the solution of time-dependent Maxwell's equations and the initial value problem as the structures are illuminated by the plane waves. The propagation of waves from source excitation is simulated by solving a finite-difference Maxwell's equation in the time domain. Subgridding method is used to condense the lattice at the point of interest locally for observing field distribution in high resolution. The computational burden due to huge number of time steps has been eased by employing quasi-static approach. An example of induced EM fields near an underground pipeline runs parallel to a 132 kV overhead power transmission line (OHTL) has been presented which paves the way in the development of new approach of EM fields interaction modelling. / MSCRC

With a projected increase in electricity demand and low-carbon energy generation in the UK, expansion of the existing transmission grid network is required. In going beyond the NIMBY concept, Devine-Wright (2009) posited a place-based approach that highlights the roles of place attachment and place-related symbolic meanings for understanding public responses to energy infrastructure proposals. This PhD research investigated two overarching and interrelated research aims. The first sought to enlarge our understandings of the processes of attachment and detachment to the residence place by investigating the dynamics of varieties of people-place relations across the life course (people's 'life-place trajectories'), thus addressing the limitation of studies adopting a 'structural' approach to the study of people-place relations. This research, in a second instance, sought to better understand the role of people's life-place trajectories and a range of project-based factors (i.e. procedural and distributive justice) in shaping people's responses to a power line proposal. This research focussed on the Hinckley Point C (HPC) transmission line proposal and residents of the town of Nailsea, South-West England. A social representations theory framework was usefully applied to this research by acknowledging that people's personal place relations and their beliefs about proposed place change, are situated and embedded within wider social representations of place and project. A mixed methods approach was employed comprising three empirical studies. The first consisted of twenty-five narrative interviews, the second a set of five focus group interviews, and the third a questionnaire survey study (n=264) amongst a representative sample of Nailsea residents. Triangulating findings across the three studies produced a novel set of key findings. By elaborating five novel 'life-place trajectories', this PhD research moved beyond structural approaches to the study of people-place relations and made a novel contribution to our understandings of the processes and dynamics of attachment and detachment to the residence place across the life course. This research further confirmed the existing typology of people-place relations and revealed a novel variety termed 'Traditional-active attachment'. Life-place trajectories were instrumental in informing divergent representations of the nearby countryside which were more or less congruent with objectified representations of the HPC project. Future studies investigating place and project meanings should be sensitive to these trajectories. Interestingly, place as a 'centre of meaning' rather than a 'locus of attachment' (or non-attachment) emerged as particularly salient for understanding responses to the project. Project-based factors were salient in informing participants' responses toward the project. A perceived imbalance between high local costs and an absence of local benefits was seen to result in distributive injustice and opposition toward the project. However, improved perceived procedural justice following National Grid's announcement of siting concessions in the spring of 2013, was seen to ameliorate local trust in the developer and project acceptance.

In the recent years, there has been a trend to run metallic pipelines carrying petroleum products and high voltage AC power lines parallel to each other in a relatively narrow strip of land. The case of electromagnetic interference between high voltage transmission lines and metallic pipelines has been a topic of major concern since the early 60’s. The main reasons for that are: • The ever increasing cost of right-of-ways, suitable for power lines and pipelines, along with recent environmental regulations, aiming to protect nature and wildlife, has forced various utilities to share common corridors for both high voltage power lines and pipelines. Therefore, situations where a pipeline is laid at close distance from a transmission line for several kilometers have become very frequent. • The rapid increase in energy consumption, which has led to the adoption of higher load and short circuit current levels, thus making the problem more acute. Due to this sharing of the right-of-way, overhead AC power line field may induce voltages on the metallic pipelines running in close vicinity leading to serious adverse effects. This electromagnetic interference is present both during normal operating conditions as well as during faults. The coupling of the field with the pipeline takes place either through the capacitive path or through the inductive or conductive paths. In the present work, the induced voltages due to capacitive and inductive coupling on metallic pipelines running in close vicinity of high voltage power transmission lines have been computed.The conductor surface field gradients calculated for the various phaseconfigurations have been presented in the thesis. Also the electric fields under transmission lines, for both single circuit and double circuit (various phase arrangements) have been analysed. Based on the above results, an optimum configuration giving the lowest field under the power line as well as the lowest conductor surface gradient has been arrived at and for this configuration induced voltage on the pipeline has been computed using the Charge Simulation Method (CSM). For comparison, induced voltages on the pipeline have been computed for the various other phase configurations also. A very interesting result is that the induced voltage on the pipeline becomes almost negligible at a critical lateral distance from the center of the powerline and beyond which the induced voltage again increases.This critical distance depends on the conductor configuration. Hence it is suggested that the pipeline be located close to the critical distance so that the induced voltage would be close to zero. For calculating the induced voltage due to the inductive coupling, electromotive force (EMF),induced along the pipeline due to the magnetic field created by the transmission line has been calculated. The potential difference between the pipeline and the earth, due to the above induced EMFs, is then calculated. As the zones of influence are generally formed by parallelism, approaches, crossings as well as removals, the computation involves subdividing the zone into several sections corresponding to these zones. The calculation of voltages is carried out at both the ends of the sections. Each section is represented by an equivalent π electrical network, which is influenced by the induced EMF. The induced EMF is calculated during faulted conditions as well as during steady state conditions. Inductive coupling calculations have been carried out for the following cases: •Perfect parallelism between powerline and pipeline. •zone of influences formed by parallelism, approaches, crossings and removals. It has been observed that when the pipeline is approaching the HV transmission line at an angle, then running parallel for certain distance and finally deviating away, the induced voltage is maximum at the point of approach or removal of the pipeline from the transmission line corridor.The induced voltage is almost negligible near to the midpoint of the zone of influence. The profile of the induced voltage also depend on whether the pipeline is grounded or left open circuited at the extremities of the zone of influence. Effect of earth resistivity and anti-corrosive coatings on induced voltage has also been studied. For mitigating the induced voltage on the pipeline,numerous low resistive earthings have been suggested. Results show that significant reduction in induced voltage can be achieved as the number of earth points is increased.

Ubiquitous computing application developers have limited options for a practical activity and location sensing technology that is easy-to-deploy and cost-effective. In this dissertation, I have developed a class of activity monitoring systems called infrastructure mediated sensing (IMS), which provides a whole-house solution for sensing activity and the location of people and objects. Infrastructure mediated sensing leverages existing home infrastructure (e.g, electrical systems, air conditioning systems, etc.) to mediate the transduction of events. In these systems, infrastructure activity is used as a proxy for a human activity involving the infrastructure. A primary goal of this type of system is to reduce economic, aesthetic, installation, and maintenance barriers to adoption by reducing the cost and complexity of deploying and maintaining the activity sensing hardware. I discuss the design, development, and applications of various IMS-based activity and location sensing technologies that leverage the following existing infrastructures: wireless Bluetooth signals, power lines, and central heating, ventilation, and air conditioning (HVAC) systems. In addition, I show how these technologies facilitate automatic and unobtrusive sensing and data collection for researchers or application developers interested in conducting large-scale in-situ location-based studies in the home.

Η BPL τεχνολογία είναι μια υποσχόμενη τεχνολογία η οποία προσφέρει τηλεπικοινωνιακές υπηρεσίες μέσω των γραμμών ηλεκτρικής ενέργειας και η οποία τα τελευταία χρόνια γνωρίζει ραγδαία ανάπτυξη. Σκοπός της παρούσας διπλωματικής εργασίας είναι η παρουσίαση της BPL τεχνολογίας και η υλοποίηση της με τρεις διαφορετικούς τρόπους σε συγκεκριμένο ηλεκτρικό δίκτυο. Στο πρώτο κεφάλαιο γίνεται μια γενική αναφορά στην BPL τεχνολογία. Παρουσιάζονται τα επίπεδα του δικτύου ηλεκτρικής ενέργειας τα οποία συμμετέχουν σε ένα BPL δίκτυο, τα διάφορα δίκτυα πρόσβασης, οι αρχιτεκτονικές και ο εξοπλισμός τους, καθώς και διάφορα προβλήματα που αντιμετωπίζει η συγκεκριμένη τεχνολογία. Στο δεύτερο κεφάλαιο περιγράφονται τα επίπεδα του BPL δικτύου. Αναλύονται οι διάφορες τεχνικές διαμόρφωσης όπως η OFDM (ορθογώνια μέθοδος διαμόρφωσης με διαίρεση συχνότητας) και η διαμόρφωση απλωμένου φάσματος. Επίσης γίνεται αναφορά στη διαχείρηση σφαλμάτων, στο BPL MAC στρώμα καθώς και στα πρωτόκολλα 802.11. Στο τρίτο κεφάλαιο αναφέρονται οι διάφορες τηλεπικοινωνιακές υπηρεσίες που προσφέρονται από την BPL τεχνολογία καθώς και οι εφαρμογές του έξυπνου δικτύου (Smart Grid) και του έξυπνου σπιτιού (Smart Home) που υλοποιούνται με τη συγκεκριμένη τεχνολογία. Στο τέταρτο κεφάλαιο γίνεται μια σύντομη αναφορά στην τεχνολογία των οπτικών ινών και στο τρόπο με τον οποίο η τεχνολογία αυτή θα χρησιμοποιηθεί ως δίκτυο κορμού το οποίο θα φτάνει μέχρι και τους μετασχηματιστές μέσης/χαμηλής τάσης. Επίσης παρουσιάζεται και η PON-BPL τεχνολογία. Στο πέμπτο και τελευταίο κεφάλαιο πραγματοποιείται η σχεδίαση του BPL δικτύου πρόσβασης με τρεις διαφορετικές αρχιτεκτονικές σε περιοχή της Λακωνίας της οποίας το ηλεκτρικό δίκτυο ψηφιοποιήθηκε με τη χρήση ενός προγράμματος GIS (Γεωγραφικά Συστήματα Πληροφοριών) και συγκεκριμένα του Mapinfo. Στη συνέχεια γίνεται σύγκριση των αρχιτεκτονικών ως προς το κόστος και την ταχύτητα. / BPL technology is a promising technology that offers telecommunications services through power lines, which in the recent years is facing a rapid development. The object of this specific project is the presentation of BPL technology and its realization in three different ways on a specific power grid. In the first chapter there is a general reference to BPL technology. Also it includes a presentation of the levels of the power grid which participate in a specific BPL network. Furthermore there is a presentation of the various access network, their architectures, equipment and various problems faced by this technology. The second chapter contains the description of the levels of BPL network. Also various modulation techniques like OFDM (Orthogonal Frequency Division Multiplexing) and spread-spectrum configuration are analyzed. Finally there is a reference to the management of errors, BPL MAC layer and to the protocols 802.11 as well. In the third chapter there is a reference about the various telecommunication services which are provided via BPL technology as well a reference for the implementations of the Smart Grid and Smart House which are realized with the specific technology. At chapter four a brief reference is conducted about the optical fiber technology and about the manner in which this technology will be used as a backbone which reaches up the medium/low voltage transformers. Also PON-BPL technology is presented. Finally in the fifth and last chapter takes place the design of BPL access network with three different architectures in an area of Laconia whose power grid digitized by using a GIS program (Geographic Information Systems), namely the Mapinfo. Eventually there is a comparison between architectures as concern the cost and the speed of realization needed.