Self-Contained Oil-Filled Cables for High Power Tranmission in the 750-1200 kV Range

Lanfranconi, G.M.; Maschio, G.; Occhini, E.

doi:10.1109/tpas.1974.293884

Cited by 11 publications

(1 citation statement)

References 3 publications

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“…IN many items of high voltage plant, a natural or synthetic oil is still used in conjunction with paper as the primary insulation system [1]. Since the early 1980s, high voltage cables in the UK have been impregnated with oil containing a mixture of alkylbenzenes having a molecular weight similar to that of dodecylbenzene (DDB) [2,3].…”

Section: Introductionmentioning

confidence: 99%

Chemical, physical and electrical properties of aged dodecylbenzene 2: thermal ageing of single isomers in air

Hosier

Vaughan

Sutton

et al. 2008

IEEE Trans. Dielect. Electr. Insul.

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The linear isomer of dodecylbenzene (DDB), 1-phenyldodecane, was aged at temperatures of 105 and 135 o C in air and the resultant products were analyzed using a range of analytical techniques. On ageing, the 1-phenyldodecane darkened, the acid number, dielectric loss and water content increased and significant oxidation peaks were detected in the infrared spectrum. When aged in the presence of copper, a characteristic peak at 680 nm was also detected by UV/visible spectroscopy but, compared with previous studies of a cable-grade DDB, the strength of this peak was much increased and no appreciable precipitate formation occurred. At the same time, very high values of dielectric loss were recorded. On ageing in the absence of copper, an unusually strong infrared carbonyl band was seen, which correlates well with the detection of dodecanophenone by gas chromatography / mass spectrometry and nuclear magnetic resonance spectroscopy. It was therefore concluded that the ageing process proceeds via the initial production of aromatic ketones, which may then be further oxidized to carboxylic acids. In the presence of copper, these oxidation products are present in lower quantities, most of these oxidation products being combined with the copper present in the oil to give copper carboxylates. The behavior is described in terms of a complex autoxidation mechanism, in which copper acts as both an oxidizing and a reducing agent, depending on its oxidation state and, in particular, promotes elimination via the oxidation of intermediate alkyl radical species to carbocations.

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Section: Introductionmentioning

confidence: 99%