Title :
Online calibration of high-frequency partial discharge signals in three-phase belted power cables
Author :
Wouters, P.A.A.F.
Author_Institution :
Fac. of Electr. Eng., Eindhoven Univ. of Technol., Netherlands
fDate :
3/4/2005 12:00:00 AM
Abstract :
Partial discharge (PD) magnitudes from classical detection techniques are expressed in terms of apparent charges. Signals from HF/VHF/UHF techniques on substation components are often hard to express in this quantity because of complex signal excitation and propagation channels. A method to calibrate PD signals obtained during online inductive detection in medium voltage belted cables is described. online inductive detection implies that the impedances of components present in substations essentially determine the detected PD signal magnitude. The use of belted cables means, that the coupling of a PD event to the conductors not only depends on the PD site within the cross-section of the cable or cable accessory, but also becomes dependent on the momentary phase angle. In addition, during signal propagation the signal magnitude may alter according to the propagation modes of a multi-conductor cable. These aspects are studied quantitatively by the use of theoretical modelling in addition to offline and online experiments. PD diagnostic equipment including pulse injection capability allows online calibration with sufficient accuracy, irrespective of the actual substation arrangement.
Keywords :
calibration; partial discharge measurement; partial discharges; power cables; substations; HF/VHF/UHF techniques; high-frequency partial discharge signals; medium voltage belted cables; multiconductor cable; online calibration; online inductive detection; propagation channel; signal excitation; signal propagation; substation components; three-phase belted power cables;
Journal_Title :
Science, Measurement and Technology, IEE Proceedings -
DOI :
10.1049/ip-smt:20051268