1,720,996 research outputs found

    Towards Recyclable Insulation Materials for High Voltage Cables

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    The preferred material for modern extruded high voltage transmission cables is cross-linked polyethylene (XLPE). This material has excellent thermo-mechanical and dielectric properties, however it is not easily recycled at end of use, raising questions as to its long term sustainability [1]. Therefore research work at Southampton has sought to identify suitable recyclable alternatives to XLPE. Such candidate materials need to have low temperature flexibility and high temperature mechanical stability combined with a sufficiently high electrical breakdown strength

    Raman Microprobe Analysis of Electrical Treeing in Silicone Rubber

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    Previous papers have identified Raman microprobe analysis as a useful tool in the chemical analysis of electrical trees and have successfully applied the technique to trees grown in polyethylene. This paper comprises a detailed spectroscopic study of electrical trees grown in silicone rubber. A selection of trees of varying fractal dimensions were exposed using cryogenic microtomy and then the individual tree channels were subjected to surface specific Raman microprobe analysis. It was found that although some trees show that few chemical changes have occurred, some trees (including some where complete breakdown has occurred) show evidence of the presence of silica and carbon, the latter possibly originating from the side groups of the polymer chain. After this, some of the samples were then analyzed using scanning electron microscopy (SEM) to provide an alternative method of analysis and to reinforce the conclusions made. Results are discussed in comparison to previously published results from a similar analysis on trees in polyethylene

    Propylene based systems for high voltage cable insulation applications

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    Crosslinked polyethylene (XLPE) remains the material of choice for extruded high voltage cables, possessing excellent thermo-mechanical and electrical properties. However, it is not easily recyclable posing questions as to its long term sustainability. Whilst both polyethylene and polypropylene are widely recycled and provide excellent dielectric properties, polypropylene has significantly better mechanical integrity at high temperatures than polyethylene. However, while isotactic polypropylene is too stiff at room temperature for incorporation into a cable system, previous studies by the authors have indicated that this limitation can be overcome by using a propylene-ethylene copolymer. Whilst these previous studies considered unrelated systems, the current study aims to quantify the usefulness of a series of related random propylene-ethylene co-polymers and assesses their potential for replacing XLP
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