Temperature monitoring of XLPE-insulated power cables by means of optical fibres

The authors report on the design principle involved in integrating optical fibres in the copper wire screens of XLPE-insulated power cables and on the tests carried out. Contrary to the usual application, the transmission of information, the authors point out the sensory properties of optical fibres. These allow the temperature of the power cable to be determined, e.g. the influence of additional power cables and other heat sources (hot spots), on the permissible cable load, can be considered. The measuring principle, its accuracy and limits are described. The tests were first of all carried out on medium voltage cable. Because the cable voltage does not materially affect the results of the tests, the pilot installation, in 110 kV XLPE-insulated cable in commercial operation, is presented. The first results of the measurements are shown and analysed