Voltage and frequency dependence of the dielectric loss factor measurement on XLPE-insulated medium voltage cables

Summary

The integral state of cable systems can be determined by the loss factor measurement. Changing in the loss factor value is mainly caused by the global aging of the cable. In order to obtain meaningful and comprehensive information by such meas-urement, the measurement results should firstly be reproducible and secondly should in-dicate a temporal trend with the operational aging of the cable. In this paper, the investi-gations of the dielectric loss factor tan d in XLPE-insulated medium voltage cables are presented, which are based on different established measuring principles for measuring the dielectric loss factor. The voltage and frequency dependence of dielectric loss factor has been considered. The main question is raised whether the measuring voltage up to 2U0 has an influence on the dielectric loss factor in XLPE-insulated medium voltage ca-bles. In addition, the measurement disturbances such as relative humidity and stray ca-pacitance have been investigated. Finally, the main issue arises; how can the obtained condition assessment findings of XLPE-insulated medium voltage cables be used?

Additional informations

Keywords

Dielectric loss factor, XLPE, FDS measurement, Vectorial impedance measurement, Diagnostic