Dissertations / Theses on the topic 'Overhead medium voltage line'

Overhead lines are using in the vast majority for distribution of electricity in medium voltage level in the Czech republic. This Master’s Thesis deals with theoretical and practical knowledges to design and construction of these lines. Particularly, the mechanical properties of overheads lines and solving their calculation in accordance with applicable standards. The main task is to acquaint potentional designers in this sphere with this issue, which is recently ignored. An important benefit is the practical calculation of the actual overhead 22kV.

The master´s thesis deals with the design of medium voltage power line protection and the calculation of reliability indicators. First, it deals with the possibilities of power system operation. Subsequently, it divides the networks according to the grounding of the transformer node and the switching elements and devices occurring in the MV distribution network are mentioned. It presents the basic classification of power line protection and its use, especially it focuses on overhead and cable MV power lines. It also discusses the reliability of the power supply and lists the basic reliability indicators and their possible calculation. The practical part describes the changes in the considered area of the distribution network, where the reconstruction of the power line VN872 and a new way of powering the village Drnholec will take place. The impact of this change on the reliability of the supplied energy is also calculated. Furthermore, the protection of the power line is designed and the correctness of its setting is then verified on the model in the PSS Sincal software.

This thesis is focused on assessing the impact of retrofitting dielectric All Dielectric Self-Supporting Cable (ADSS) to existing MV overhead line. This type of optical cable is a means of future strengthening of the communication infrastructure of the distribution network. However, its mechanical properties are significantly different from the properties ACSR cable, due to which its installation can be problematic in terms of meeting the requirements of the PNE 33 3301 standard. In practical part, this work deals with the design of the ADSS installation on the existing MV line and the determination of its impact based on the assessment of the results of this design.

Traditionally, the effectiveness of a phase overcurrent protection philosophy has been assessed by only considering a fault level versus protection operating time graph (only selectivity). In this research, an improved method was created to evaluate different phase overcurrent protection philosophies for medium-voltage feeders. A focus was placed on reliability, sensitivity, selectivity, speed of operation, performance and minimising risk. The hypothesis stated that it is possible to develop a method that allows for the evaluation of the effectiveness of phase overcurrent protection. To test this hypothesis, an application was created that allows for the analysis of an overcurrent protection philosophy. This application made provision for changes in source impedance, evaluation of protection backup contingencies, different conductor types, user-definable protection equipment, the placement of protection equipment, user-definable protection settings, primary plant equipment damage information, user-definable safety margins and source transformer protection information. The application provides graphs that allow the user to evaluate the protection philosophy in terms of the following criteria:  The protection operating time at specific positions in the network. The PU sensitivity of the feeder-installed protection equipment.  The PU sensitivity of the source transformer protection (backup function).  The let-through energy and associated equipment damage criteria.  The energy-area over the analysed path.  To classify the busbar voltage dip.  To determine the position of the fault on the analysed path for the associated busbar voltage dip.  To quantify the occurrence of a specific voltage dip category on the analysed path. The graphs that were generated by the application allowed for the analysis and optimisation of the applied protection settings. This optimisation includes determining operating time, operating curve selection and the number of auto-reclose attempts. It is possible to determine the preferred protection philosophy using the application. The application does not prescribe how settings are to be calculated, or the placement of the devices; it evaluates if the applied philosophy is protecting the feeder and how well it is protecting it.
Dissertation (MEng)--University of Pretoria, 2014.
tm2015
Electrical, Electronic and Computer Engineering
MEng
Unrestricted

This thesis concerns monitoring in Middle- and Low-Voltage distribution systems penetrated by distributed generation. Monitoring itself means measuring voltages and power flows and sending relevant data to the supervisory system. The first part of the thesis describes distribution systems with differences between individual voltage levels. The following chapter is focused on consequences of high share of renewable energy sources in distribution systems. Most of the problems are partially resolved by technical conditions for connection of the new power sources. However, difficulties with voltage regulation and uncontrolled power flows to higher voltage levels remain. These are the reasons for measuring voltages and currents in medium voltage networks. Second to last subhead of this chapter is dedicated to possible benefits of monitoring. The fourth part of the thesis deals with voltage and current sensors with their advantages and disadvantages. The best suitable devices are chosen in the end of the chapter. It is crucial to mention that sensors are only part of measuring system. Analog outputs from current or voltage transformers need to be converted to digital signal and further processed. After that required quantities are finally sent. Properties of these circuit cards are described in the sixth chapter. Following part aims to define a certain key that will determine the suitable locations for installation of the measurement. The final part of the thesis compares measured voltages and power flows from real 22 kV network with calculated values from computer program PAS DAISY Bizon.

This thesis describes an investigation into the influences of arcing and conductor deflection due to magnetic forces on the accuracy of fault locator algorithms in electrical distribution networks. The work also explores the possibilities of using the properties of an arc to identify two specific types of faults that may occur on an overhead distribution line. A new technique using the convolution operator is introduced for deriving differential equation algorithms. The first algorithm was derived by estimating the voltage as an array of impulse functions while the second algorithm was derived using a piecewise linear voltage signal. These algorithms were tested on a simulated single-phase circuit using a PI-model line. It was shown that the second algorithm gave identical results as the existing dynamic integration operator type algorithm. The first algorithm used a transformation to a three-phase circuit that did not require any matrix calculations as an equivalent sequence component circuit is utilised for a single-phase to ground fault. A simulated arc was used to test the influence of the non-linearity of an arc on the accuracy of this algorithm. The simulations showed that the variation in the resistance due to arcing causes large oscillations of the algorithm output and a 40th order mean filter was used to increase the accuracy and stability of the algorithm. The same tests were performed on a previously developed fault locator algorithm that includes a square-wave power frequency proximation of the fault arc. This algorithm gave more accurate and stable results even with large arc length variations. During phase-to-phase fault conditions, two opposing magnetic fields force the conductors outwards away from each other and this movement causes a change in the total inductance of the line. A three dimensional finite element line model based on standard wave equations but incorporating magnetic forces was used to evaluate this phenomenon. The results show that appreciable errors in the distance estimations can be expected especially on poorly tensioned di stribution lines.New techniques were also explored that are based on identification of the fault arc. Two methods were successfully tested on simulated networks to identify a breakingconductor. The methods are based on the rate of increase in arc length during the breaking of the conductor. The first method uses arc voltage increase as the basis of the detection while the second method make use of the increase in the non-linearity of the network resistance to identify a breaking conductor. An unsuccessful attempt was made to identifying conductor clashing caused by high winds: it was found that too many parameters influence the separation speed of the two conductors. No unique characteristic could be found to identify the conductor clashing using the speed of conductor separation. The existing algorithm was also used to estimate the voltage in a distribution network during a fault for power quality monitoring purposes.

The optimal placement of reclosers on overhead lines in a medium voltage distribution network is known to improve the reliability of a power system. Traditionally, recloser placement studies have not considered the effect of greater numbers of reclosers on network damage during faults or the effect of positioning on protection settings. Recloser positions that enhance the reliability of the system may not necessarily improve other problematic operational aspects, such as the damage to equipment and the risk of incorrect tripping due to the sudden increase in loading. This research seeks to prove the hypothesis that: Recloser placement studies with the additional consideration of protection-related factors such as equipment damage and the risk of false tripping will result in different recloser positions compared to when the priority is only on improving reliability indices and cost. A tool is developed to assess the reliability indices, cost, damage and the risk of false tripping and it determines the best recloser positioning based on the priority given to each factor considered. Using this tool, observations are made on the effect of the added factors of damage and the risk of false tripping on recloser positioning. The addition of the protection-related factors to the objective function is unique in its ability to realise the value of recloser positions that cater for minimizing the damage factor and the possibility of tripping on load. In the absence of these factors, the value of certain recloser positions would not be identified as they would not improve reliability or cost factors. The importance of reliability and cost are not overruled by the addition of the protection-related factors. The consideration of protection-related factors in the planning process of optimising recloser placement ensures that the protection of the overhead line is optimal and is not compromised in any way. This would inherently have a positive effect on the lifespan of the equipment on the feeder and the reliability of the feeder in the long-term.
Dissertation (MEng)--University of Pretoria, 2014.
tm2015
Electrical, Electronic and Computer Engineering
MEng
Unrestricted

Over the last several decades, electricity consumption and generation have continually grown. Investment in the Transmission and Distribution (T&D) infrastructure has been minimal and it has become increasingly difficult and expensive to permit and build new power lines. At the same time, a growing increase in the penetration of renewable energy resources is causing an unprecedented level of dynamics on the grid. Consequently, the power grid is congested and under stress. To compound the situation, the utilities do not possess detailed information on the status and operating margins on their assets in order to use them optimally. The task of monitoring asset status and optimizing asset utilization for the electric power industry seems particularly challenging, given millions of assets and hundreds of thousands of miles of power lines distributed geographically over millions of square miles. The lack of situational awareness compromises system reliability, and raises the possibility of power outages and even cascading blackouts. To address this problem, a conceptual Power Line Sensor Network (PLSN) is proposed in this research. The main objective of this research is to develop a distributed PLSN to provide continuous on-line monitoring of the geographically dispersed power grid by using hundreds of thousands of low-cost, autonomous, smart, and communication-enabled Power Line Sensor (PLS) modules thus to improve the utilization and reliability of the existing power system. The proposed PLSN specifically targets the use of passive sensing techniques, focusing on monitoring the real-time dynamic capacity of a specific span of a power line under present weather conditions by using computational intelligence technologies. An ancillary function is to detect the presence of incipient failures along overhead power lines via monitoring and characterizing the electromagnetic fields around overhead conductors. This research integrates detailed modeling of the power lines and the physical manifestations of the parameters being sensed, with pattern recognition technologies. Key issues of this research also include design of a prototype PLS module with integrated sensing, power and communication functions, and validation of the Wireless Sensor Network (WSN) technology integrated to this proposed PLSN.

The aim of this work is the reconstruction and development of the distribution network of DS to ensure electricity supply in the required quality to existing customers and new customers connecting to the planned industrial zone Šlapanice. The first part deals with the inclusion of a distribution network in power system, its distribution and composition. Subsequently, the work deals with the description of the management of distribution networks, cable and outdoor leadership and their parameters. It also contains guidelines for the design of high voltage networks. The end of the first part is devoted to calculating the steady operation of the network. In the second part, the proposed project using the PAS DAISY Off-line v 4.00 Bizon. Based on the available evidence is developed steady state operation. We found that lines are overloaded and need to be strengthened with regard to the development of industrial zones and adjusting the network to ensure safe and reliable operation. The conclusion focuses on the economic evaluation of proposed alternatives.

El món de les comunicacions per la xarxa elèctrica (CXE) pot ser dividit en tres grans tipus: CXE en baix voltatge (CXE-BV), en mig voltatge (CXE-MV) i en alt voltatge (CXE-AV). En aquests últims anys, les CXE-BV han atret una gran expectació, ja que les seves capacitats han fet d'aquesta tecnologia una bona opció com alternativa pel bucle local d'accés i pel desplegament de xarxes d'àrea local, focalitzades aquestes últimes en l'entorn domèstic. A més, les CXE-BV inclouen un conjunt d'aplicacions de baixa velocitat orientades a l'operador, com la lectura automàtica de comptadors (LAC), distribució de càrrega, facturació dinàmica, etc. Per altra banda, les CXE-MV i CXE-AV, històricament lligades a tasques de telecontrol i teleprotecció, s'estan començant a considerar com un canal de comunicacions eficient i fiable. El desenvolupament de sistemes digitals i els esforços d'estandardització estan fent d'aquests canals un medi atractiu per a que els operadors elèctrics ofereixin serveis de comunicacions, ja que no necessiten invertir en infraestructura perquè la xarxa elèctrica ja està desplegada.
En aquesta Tesi s'introduiran i es comentaran les particularitats de les tres xarxes elèctriques, després, es mostraran al lector les solucions tecnològiques existents pels canals de BV basats en la norma Europea CENELEC així com pels canals d'AV, mostrant que els sistemes actuals de LAC ofereixen una diversitat freqüencial molt baixa i que els mòdems CXE-AV estan ancorats en estendards antiquats.
Aquest treball es mou per les tres topologies de la xarxa, particularment, en aplicacions orientades a la banda CENELEC, en mesura i modelat de canal, i en mesura i disseny del nivell físic per sistemes CXE-BV, CXE-MV i CXE-AV respectivament. Els sistemes actuals que exploten la banda CENELEC ofereixen mecanismes d'explotació de la diversitat freqüencial del canal molt limitats o nuls, donant lloc a una baixa robustesa en front a interferències i soroll de fons acolorit. Aquest treball proposa un esquema de modulació multiportadora que, mantenint una complexitat baixa, ofereix unes altes prestacions permetent un bon nivell d'explotació de la selectivitat freqüencial. Per al que a CXE-MV respecta, aquesta Tesi desenvolupa un model de canal determinístic-estadístic pels anells urbans de distribució de potència i, finalment, en sistemes CXE-AV, aquest treball proposa, basat en mesures de canal i proves de camp, un nivell físic de banda ampla capaç de incrementar la velocitat de comunicació mentre manté una baixa densitat espectral de potència limitant així la interferència a altres sistemes.
PARAULES CLAU: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
El mundo de las comunicaciones por la red eléctrica (CRE) puede ser dividido en tres grandes tipos: CRE en bajo voltaje (CRE-BV), en medio voltaje (CRE-MV) y en alto voltaje (CRE-AV). En estos últimos años, las CRE-BV han atraído una gran expectación, ya que sus capacidades han hecho de esta tecnología una buena opción como alternativa para el bucle local de acceso y para el despliegue de redes de área local, focalizadas estas últimas en el entorno doméstico. Además, las CRE-BV incluyen un conjunto de aplicaciones de baja velocidad orientadas al operador como la lectura automática de contadores (LAC), distribución de carga, facturación dinámica, etc. Por otro lado, las CRE-MV y CRE-AV, históricamente ligadas a tareas de telecontrol y teleprotección, se están empezando a considerar como un canal de comunicaciones eficiente y fiable. El desarrollo de sistemas digitales y los esfuerzos de estandarización están haciendo de estos canales un medio atractivo para que los operadores eléctricos ofrezcan servicios de comunicaciones, ya que no necesitan invertir en infraestructura porque la red eléctrica ya está desplegada.
En esta Tesis se introducirán y se comentarán las particularidades de las tres redes eléctricas, luego, se mostrarán al lector las soluciones tecnológicas existentes para los canales de BV basados en la norma Europea CENELEC así como para los canales de AV, mostrando que los sistemas actuales de LAC ofrecen una diversidad frecuencial muy baja y que los módems CRE-AV están anclados en estándares anticuados.
Este trabajo se mueve por las tres topologías de red, particularmente, en aplicaciones orientadas a la banda CENELEC, en medida y modelado de canal, y en medida y diseño del nivel físico para sistemas CRE-BV, CRE-MV y CRE-AV respectivamente. Los sistemas actuales que explotan la banda CENELEC ofrecen mecanismos de explotación de la diversidad frecuencial del canal muy limitados o nulos, dando lugar a una escasa robustez frente a interferencias y ruido de fondo coloreado. Este trabajo propone un esquema de modulación multiportadora que, manteniendo una complejidad baja, ofrece unas altas prestaciones permitiendo un buen nivel de explotación de la selectividad frecuencial. Por lo que a CRE-MV respecta, esta Tesis desarrolla un modelo de canal determinístico-estadístico para los anillos urbanos de distribución de potencia y, finalmente, en sistemas de CRE-AV, este trabajo propone, basado en medidas de canal y pruebas de campo, un nivel físico de banda ancha capaz de incrementar la velocidad de comunicación mientras mantiene una baja densidad espectral de potencia limitando así la interferencia a otros sistemas.
PALABRAS CLAVE: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.
The world of Power line communications (PLC) can be divided into three main types: low voltage PLC (LV-PLC), medium voltage PLC (MV-PLC) and high voltage PLC (HV-PLC). These last years, LV-PLC has attracted a great expectation since its wideband capabilities has made this technology a suitable choice for last-mile access and in-home communications. Moreover, LV-PLC also includes a utility oriented low frequency and low speed applications, such as automatic meter reading (AMR), load distribution, dynamic billing and so on. On the other hand, MV-PLC and HV-PLC, historically oriented to teleprotection and telecontrol tasks, are being considered as a reliable communication channel. The development of digital equipment and the standardization efforts are making those channels an attractive medium for electrical utilities telecommunications services, since the network, as well as in LV-PLC, is already deployed.
In this PhD dissertation, the three different PLC topologies are reviewed and the different communications techniques in such channels exposed. Then, a deep technological review of existing AMR solutions for the European CENELEC band, as well as HV-PLC systems is given, showing that existing AMR systems deliver low frequency diversity and HV-PLC systems are anchored in old fashioned standards.
This work walks around the three topologies, specifically, CENELEC band utility oriented applications, channel measurement and modeling and channel measurement and physical layer design, regarding LV-PLC, MV-PLC and HV-PLC respectively. Existing CENELEC compliant systems deliver low or none frequency diversity mechanisms, yielding in a low robustness against colored noise and interference. This work propose a multicarrier based physical layer approach that, while keeping the complexity low, delivers high performance allowing a great level of frequency diversity. Focusing on MV-PLC, a hybrid deterministic-statistical channel model for urban underground rings is developed and, finally, in HV-PLC systems, this work proposes, based on measurements and field tests, a wideband physical layer in order to increase data rate while keeping low both the power spectral density and possible interference to other systems.
KEYWORDS: Power line communications (PLC), low voltage (LV), medium voltage (MV), high voltage (HV), automatic meter reading (AMR), orthogonal frequency division multiplexing (OFDM), multicarrier spread spectrum (MC-SS), communication system design, channel measurements, channel modeling, scattering parameters.

This thesis deals with the modelling and simulation of MV network overcurrent protection using EMTP. Transmission lines 25 Km in length for both radial and loop network with constant parameters operates at 50 Hz and 66 kV line to line voltages are simulated using EMTP. The first part of the thesis discusses the simulation of Radial network with unearthed neutral for analysing the behaviour of the fault current making the comparison with healthy feeder. Second part is to use a Radial network with compensated neutral, Petersen Coil (PC) is used for compensation of the short circuit current making the similar comparison. Third step is to design a 67N directional replay protection in EMTP to trip the circuit breaker in the fault situation. Then using both Radial and Loop network, a comparison and response of the 67N protection in both situations is analysed. Several simulations of Single Line to Ground Faults (SLGF) with different fault locations were carried out to verify the correct operation of the relay based on the developed protection scheme. The results of the simulation the operation of the relay based on its protection scheme and its response time based on the fault location. Finally, delay between the blocking signals are inserted to see the behaviour of the protection system under loop network configuration.

This diploma thesis is concerned with reconstruction of distribution network in Hruba Vrbka. The diploma thesis is divided in two parts. For better understanding to this issue, the first theoretical part is shortly dedicated to the history of electrical power system, to the several types of distribution network of low voltage and high voltage and their utilization in the area, considering the reliability and the quality of delivery of the electric energy. In this thesis there is mentioned division of distribution grids according to placing of cable lines, according to voltage and according to type of grid connection. Next part of this work is dedicated to the description of overhead lines and cable lines and their characteristics. For the proper concept of the grid we should know some characteristics of the electric line’s proposal: mechanical strength, warming, voltage drop, efficiency, degree of safety and provision of delivery. In the end of the theoretical part there are described methods for calculation of grid’s steady state as a linear task and also non-linear task, elimination of the balancing node, the iterative method, the reduction of external power take-off nodes and the solution of the steady state of the network through the direct current model. The second part of the diploma thesis is concerned with the calculation of the steady state in the village Hruba Vrbka. In this part is also described the KASI program which was used for the calculation of the grid’s steady state. Firstly low voltage grid’s balance in Hruba Vrbka was found out and evaluated and then there were proposed some solutions of the reconstruction for the grid improving. The suggested options of the reconstruction are considered from technical and economical point of view and the best solution is chosen. For this solution there is suggested the protection through program SICHR 9. In the end of this diploma thesis there is checked the load of the high voltage line.

The dissertation describes several types of low and high voltage distribution networks including their implementation in specified location with regards to the reliability and quality of electric power supply. The distributions networks are classified according to ways of cable routing, distribution line voltage levels as well as according to types of network interconnections. The high and low voltage distribution networks are further categorized based on used cable types, where, more attention is paid to insulated lines used in the Czech Republic, low voltage lines called „AES“ and „PAS“ high voltage lines used more and more during the distribution network reconstruction. Attention is also given to the description of used methodology for the calculation of network performance stability. An individual part of the dissertation is devoted to a low voltage distribution network proposal in the village of Kovalovice. Based on performed analysis of distribution network conditions, several reconstruction versions were proposed with the help of „KASI“ software, the description of which is also included. The proposed versions are further analysed for both, technical and economical aspects and is selected most suitable version of the distribution network.

The aim of this Master’s thesis is the design and reconstruction of the high voltage distribution network for the company E. ON with focus on calculation of the stabilized operation and on the planning of new cable taps from the transformer substation Moravany u Brna. The first part of the theoretical analysis of the work deals with the inclusion of the distribution network into the power system and with principles of development and construction of high voltage networks. The second part includes a general calculation of stabilized operation of the power distribution network and a familiarization with the program PAS Off - Line Bison 4.0. The practical part of the thesis is focused on the calculation of the stabilized operation at the current state of transformer substation Moravany u Brna using the PAS Off - Line Bizon 4.0 V programme. This part also contains the design of six new cable lines which are needed to strengthen the power distribution in the southern part of the city Brno. The closing part of this chapter constitutes of a outdoor and indoor cable line renovation. These cables are connected to the transformer substation Moravany u Brna and a calculation of stabilized operation is also included in this part.

The diploma thesis deals with the issue of the reconstruction of outdoor cables of low voltage distribution network in exchange for the cable line. It analyzes the important factors which are necessary for the preparation of the project documentation for the issue of the territorial consent. The thesis is divided into 4 main chapters. After the first chapter there is introduced chapter 2, which shows the differences between cable and outdoor cables with their advantages and disadvantages. Chapter 3 deals with the guiding principles for low-voltage cable design and the types of equipment needed for the proper operation of a particular distribution network while respecting the requirements of valid PNEs and ČSNs. Chapter 4 explains the chronology of the process leading to the formulation of a basic technical proposal, which is further addressed in Chapter 5, which deals with the complete formulation of the project documentation for the issue of territorial consent.

Etude de l'aspect statique du contournement, on montre experimentalement que les criteres de wilkins et hampton ne s'appliquent qu'au modele d'obenaus. Mise en evidence de l'importance du champs electrique au voisinage de la decharge. Etude detaillee de la conduction electrolytique et de son evolution pendant le contournement

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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

碩士
元智大學
電機工程學系
106
In this paper, the radio transmission multiplexing technology is applied to online monitoring system to achieve the synchronous reverse transmission of radio and signal. It provides a new way for wireless sensor data transmission, and has important application value for medium voltage electrical equipment online monitoring system. First of all, a radio transmission multiplexing technology based on load modulation technology is proposed to transmit the state data of the electrical equipment on the high voltage side to the low voltage side, and then transmit the data received by the low-voltage side to the monitoring center through the power line carrier technology. Then, the modeling and analysis of the magnetic coupled resonant radio transmission system is carried out. Aiming at the maximum output power and transmission efficiency of the system, it is often impossible to have both. The maximum efficiency product is used as the objective function of the transmission coil of the optimization system. In addition, an equivalent model of E class HF power amplifier and magnetic coupling structure is established, and the effect of different.load modulation on the circuit performance is theoretically analyzed and verified by simulation. The influence of the surrounding metal on the system is also analyzed. Secondly, in order to give better consideration to output power and transmission efficiency, the maximum efficiency product is taken as the objective function, and the PCB coil is optimized under limited size space. According to the requirements of the switch cabinet's internal structure, high and low voltage insulation distance, sensor power consumption, data transmission rate and other requirements, the key indicators of the prototype were established. Combined with theoretical analysis and simulation results, the hardware circuit parameters of the system were designed. Finally, based on the above design method, we made an experimental prototype, verified the relevant theory, and tested the prototype system. The test results show that the online monitoring system is stable and reliable. The on-line monitoring system of medium voltage electrical equipment based on radio transmission and multiplexing technology has good application value.

Freileitungsmaste aus herkömmlichen Beton werden bereits heute in großer Zahl in Mittelspan-nungsnetzen eingesetzt. Im Bereich der Hochspannungsfreileitungen existieren bisher international nur wenige erste Freileitungen mit Masten aus herkömmlichen Beton. Um zukünftig Elektroenergie über große Entfernungen über Trassen mit geringen Flächenbedarf transportieren zu können, sind neue Hochspannungsfreileitungen in kompakter Bauweise notwendig. Um dieses Ziel zu erfüllen, sollen die Kompaktmaste aus ultra-hochfestem Beton (UHPC) hergestellt werden. Dafür ist eine neue Sorte von UHPC mit hoher Festigkeitsklasse zu entwickeln. Die mechanischen, elektrischen und thermischen Eigenschaften des neuen Betonmaterials waren zunächst unbekannt. Bisher gab es kaum Kenntnisse über die elektrischen und thermischen Belas-tungen, die auf die Betonmaste einer Freileitung in kompakter Bauweise einwirken. Ein Teilthema im interdisziplinären Forschungsprojekt „KoHöMaT“ (gefördert durch das Bundesmi-nisterium für Wirtschaft und Energie) war es, gemeinsam mit Forschungsinstituten (IMB, Fichtner, Lapp, Europoles, KIT, iBMB) die Materialparameter des neuen UHPC zu bestimmen. Den Einfluss der elektromagnetischen Belastungen auf die Lebensdauer und die Festigkeit des Ver-bundes aus Stahl und Beton habe ich untersucht. Aufgabe meiner Arbeit ist es auch, die elektrischen und thermischen Eigenschaften, wie die elektrische Leitfähigkeit, die elektrische Festigkeit, die Per-mittivität, den Verlustfaktor und die Wärmeleitfähigkeit experimentell zu bestimmen. Anhand der experimentellen Untersuchungen wurde der Versagensmechanismus des UHPC-Betons bei Span-nungsbelastung identifiziert. Die am Betonmast auftretenden elektrischen und thermischen Belas-tungen wurden mit Hilfe von verschiedenen FEM-Modellen berechnet und den gemessenen Fes-tigkeiten gegenübergestellt. Es wurde der Einfluss permanenter elektrischer Felder auf die mechanischen Eigenschaften des UHPC bestimmt. Hierfür wurde die Druckfestigkeit des Betons vor und nach Dauerversuchen bei verschiedenen Spannungsbelastung gemessen. Der Verbund zwischen Stahl und Beton wurde in Lastwechselversuchen thermisch hoch beansprucht und dessen mechanische Festigkeit vor und nach der thermischen Belastung bei Auszugsversuchen gemessen. Aufgrund der befürchtenden gesundheitlichen Risiken für Menschen und Tiere, sowie der gegen-seitigen Beeinflussung benachbarter elektronischer Systeme (EMV) dürfen die elektromagnetischen Felder von Freileitungen die jeweiligen maximal zulässigen Grenzwerte nicht überschreiten. Ich habe die Berechnungen der elektrischen und magnetischen Feldverteilung für die im Verbundvorhaben entwickelten Mastdesigns durchgeführt. Gemeinsam mit den Forschungsinstituten (Europoles, Fichtner, Lapp) wurden die Mastdesigns hinsichtlich der Feldverteilung optimiert.
The Overhead line towers made of conventional concrete are already used in large numbers in the medium voltage nowadays. So far, only a few towers of overhead transmission line made of con-ventional concrete which exists internationally in the area of high voltage. In order to be able to transmit electrical energy over long distances by routes of less floor space requirements, new high voltage overhead lines in compact construction are necessary. To achieve this goal, the compact towers have to be made of ultra-high-performance concrete (UHPC). Therefore, a new kind of UHPC with a high strength class has to be developed. For this kind of new concrete, the mechanical, electrical and thermal characteristics were unknown till now either, there was rare knowledge about the electric and thermal loads which have an effect on the concrete towers of an overhead line in compact construction method. The main purpose part of this interdisciplinary research project 'KoHöMaT “, which funded by the Federal Ministry for Economic Affairs and Energy), was to identify the material parameters of the new UHPC together with the following research institutes (IMB, Fichtner, Lapp, Europoles, KIT, iBMB). It was examined the influence of electromagnetic loads on the lifetime and its’ strength bond be-tween both of composite steel and concrete, also as my major involve was to determine the elec-trical and thermal properties experimentally, such as electrical conductivity, electrical strength, per-mittivity, dissipation factor and finally thermal conductivity. As a result, the failure mechanism of the UHPC under the electrical stresses has been identified then,the electrical and thermal loads on the concrete towers were calculated by using various FEM models accordingly, the measured values were used in the determination of electrical strength. All mentioned theoretical calculated parameters were compared with the real measured parameters. The influence of permanent electric fields on mechanical properties of the UHPC was determined as well. Mainly, the compressive strength of the concrete was measured before and after durability tests at different voltage loads. In addition, the composite (interface) between steel and concrete was thermal extremely loaded by alternating load tests. Its mechanical strength has been measured by pull-out tests before and after this thermal loads. Due to the fear of health risks for both humans and animals, as well as the mutual influence of neighboring electronic systems (EMV), the electromagnetic fields of open lines must not exceed the respective maximum permissible limit values. The calculations of the electrical and magnetic field distribution were carried out for the mast design developed in the composite project. Together with the other research institute (Europoles, Fichtner, Lapp). the tower designs were optimized with re-gard to the field distribution.

A presente dissertação de mestrado tem como principal objetivo, o desenvolvimento de um projeto de uma linha aérea de alta tensão 60 kV, efetuando-se o estudo das metodologias, cálculos e dimensionamentos de acordo com as diretrizes da EDP-Distribuição, do regulamento de segurança de linhas elétricas de alta tensão (RSLEAT) e utilizando critérios de projetista. Foi ainda desenvolvida uma aplicação implementada em ambiente de simulação Matlab, com o intuito de sistematizar o cálculo e projetos futuros. Esta aplicação permite também efetuar o estudo do comportamento das flechas das catenárias em função da variação da temperatura ambiente e do respetivo comprimento de vão. Estes modelos foram sustentados com base num projeto real, o qual consiste numa linha aérea de transporte de energia elétrica com um comprimento de 16.1 km, uma potência de transporte de 38 MVA e com uma tensão de transporte de 60 kV. Este projeto foi estabelecido tendo por base no regulamento de segurança de linhas elétricas de alta tensão, cumprindo todos os requisitos técnicos relativamente às localizações dos apoios, distâncias mínimas exigidas para as estruturas e para o meio envolvente.
The main objective of this master's thesis is the development of a high-voltage 60 kV overhead power line project, carrying out its study of methodologies, calculations and performing dimensioning according to EDP-Distribuição guidelines, high-voltage power line safety regulation (RSLEAT) and using designer criteria. An application was also developed and implemented in Matlab simulation environment, with the purpose of systematizing the calculation and future projects. This application allows the study of the behaviour of overhead catenaries sags, according to the variation of the ambient temperature and the respective span length. These models were supported based on a real project, which consists of an overhead power line with a length of 16.1 km, a transport power of 38 MVA and a transport voltage of 60 kV, this project was established based on the safety regulations for high voltage power lines, fulfilling all the technical requirements regarding the locations of the supports, minimum distances required for the structures and the surrounding environment.