This master thesis aims to investigate whether an installation of a High Temperature Low Sag-conductor (HTLS-conductor) could be beneficial for a 130 kV-transmission line owned by the Swedish company Vattenfall. The HTLS-conductors investigated in this thesis were ACCC-conductors and three different models were included: Warsaw, Dublin and Stockholm 3L ACCC-conductors. The aim of an installation was to roughly double the thermal line rating without needing to replace any supporting towers in the line section that was studied.    Simulations were conducted using MATLAB and PLS-CADD Ultralite and included calculations of the thermal line rating as well as conductor sag and tension in the supporting towers. The results showed that all three ACCC-conductors fulfilled Vattenfall’s requirements for increased thermal line rating. However, conductor sag was a problem which required an increase in tension. This increase in tension was only possible for Warsaw and Stockholm 3L ACCC-conductors. The Dublin ACCC-conductor proved too heavy and would have required a replacement of supporting towers if installed in this line section.    Finally, the thesis recommends further studies of the effects of an installation of Warsaw and Stockholm 3L ACCC-conductors and also suggests investigations concerning economic profitability, environmental sustainability and suitability of other types of HTLS-conductors.

The diploma thesis deals with the comparison of the conduction with the classic "AlFe" ropes (ACSR technology - aluminium conductor steel reinforced) and the line with the ACCC technology (aluminum core composite core). The first part describes the development of the transmission and distribution network in the Czech Republic. Subsequently types of conductors are described, its construction and main characteristics. The theoretical part also consists of theoretical knowledge about compared types of conductors and knowledge from the field of external lines. During the creation of the theoretical part of the thesis, we gained experience in the advanced functions of Excel, which are later used in practical part. The practical part of the thesis consists of creation of the calculation program itself, instructions and calculation methodology. Included is also an example of use of the program that compars two types of conductors of the same diameter, the same transmitted current and the same weight per unit length.

Wireline telecommunications infrastructure in the customer access network or CAN is undergoing a veritable technological and commercial revolution. The paired-copper CAN is being modernised with optical fibre deployed ever closer to customers, culminating soon with fibre-to-the-home networks or some variant thereof. Although bandwidth ceases to be a scarce commodity, the underlying natural monopoly will most likely be strengthened. National competition policy desires open access to multiple service providers yet commercial pressure calls for closure. This has been the recent experience with the hybrid fibre coaxial networks delivering pay television and Internet access. This research asks the question: What are the factors that prevent open access to the broadband services of next generation wireline infrastructure? How can these obstacles be overcome? A particular focus is given to non-price considerations which come to the fore due to the unique strategic and technological characteristics of optical fibre in the access network. The methodological approach involves data gathering via three case studies - that of the Telstra/Foxtel pay television network, the TransACT broadband network and fibre-to-the-home networks in general. Although the ultimate focus is on the research question above, these cases are discussed in a holistic way with consideration of a number of contextual factors. The research also examines the relationship between the concepts of 'open access' and 'network neutrality', visiting the concept of 'common carriage' in doing so. Several findings are reached that illuminate the field of telecommunications access regulation as applied to infrastructure capable of delivering truly next generation broadband services. Since 1993, our politicians have only paid lip service to the importance of competition and have deferred to the demands of the dominant builder of telecommunications infrastructure. From the viewpoints of end-users and access seekers, the access regime is found to be incapable of dealing with the technical and commercial bottlenecks arising from optical fibre in the CAN. It is concluded that communication between users should be recognised as the prime purpose of telecommunications and that the regulatory regime should not reward discriminatory practices detracting from the development of a networked information economy. It is also concluded that dominant players should never be rewarded with access holidays which could otherwise entrench market dominance through the creation of new bottlenecks. Access regulation is ill-equipped to cope with optical fibre in the CAN until it also recognizes the strategic potential of such infrastructure.

abstract: The future grid will face challenges to meet an increased power demand by the consumers. Various solutions were studied to address this issue. One alternative to realize increased power flow in the grid is to use High Temperature Low Sag (HTLS) since it fulfills essential criteria of less sag and good material performance with temperature. HTLS conductors like Aluminum Conductor Composite Reinforced (ACCR) and Aluminum Conductor Carbon Composite (ACCC) are expected to face high operating temperatures of 150-200 degree Celsius in order to achieve the desired increased power flow. Therefore, it is imperative to characterize the material performance of these conductors with temperature. The work presented in this thesis addresses the characterization of carbon composite core based and metal matrix core based HTLS conductors. The thesis focuses on the study of variation of tensile strength of the carbon composite core with temperature and the level of temperature rise of the HTLS conductors due to fault currents cleared by backup protection. In this thesis, Dynamic Mechanical Analysis (DMA) was used to quantify the loss in storage modulus of carbon composite cores with temperature. It has been previously shown in literature that storage modulus is correlated to the tensile strength of the composite. Current temperature relationships of HTLS conductors were determined using the IEEE 738-2006 standard. Temperature rise of these conductors due to fault currents were also simulated. All simulations were performed using Microsoft Visual C++ suite. Tensile testing of metal matrix core was also performed. Results of DMA on carbon composite cores show that the storage modulus, hence tensile strength, decreases rapidly in the temperature range of intended use. DMA on composite cores subjected to heat treatment were conducted to investigate any changes in the variation of storage modulus curves. The experiments also indicates that carbon composites cores subjected to temperatures at or above 250 degree Celsius can cause permanent loss of mechanical properties including tensile strength. The fault current temperature analysis of carbon composite based conductors reveal that fault currents eventually cleared by backup protection in the event of primary protection failure can cause damage to fiber matrix interface. / Dissertation/Thesis / Fault current temperature relationship program in C / Current temperature relationship program in C / M.S. Electrical Engineering 2014