Dielectric response measurements in time and frequency domain of different stressed low pressure oil-filled cables

Power transmission has become commercially relevant to an increasing degree. Therefore it is necessary to find out strategies for an assessment of the reliability of cable systems, especially after many years under operating conditions which have changed the ageing state of the insulation owing to electrical, thermal, environmental or mechanical influences. With the aim of gaining a better understanding of these problems from a technical point of view, the dielectric properties of low pressure oil-filled cable cores, which have been equally produced but differently used, are investigated. Results are presented and discussed in this paper and should lead to some new experiences of diagnostic tools for ageing mechanisms in oil-paper insulation.