Two years of experience with a mobile resonant test system for testing of installed medium- and high voltage power cables

Since October 1996 one of the largest series resonant test systems with variable frequency has been in operation. More than 270 installed medium- and high voltage cables have been tested using this equipment in the Netherlands, Germany, Belgium and in the United Kingdom. The tested cable lines consist of either XLPE, oil-paper or a combination of both insulating materials. The principle of testing is briefly described and the results of these tests depending on the voltage level the age and construction of the cable are statistically evaluated. The experience in testing of power cables is summarized and testing trends and recommendations are discussed.