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 ime
Domain Reflectometry (TDR) has been used for localisation of transmission
line discontinuities in various applications. One of the challenges when
applying TDR is to obtain knowledge of the high frequency characteristics
of both the degraded and the undegraded sections of the cable. The wave
propagation characteristics of water-treed XLPE cables are investigated
in this study. The parameters are extracted from the cable S-parameters
measured with a Network Analyzer (NA) in the frequency range from 300 kHz
to 300 MHz. The cable samples are characterised at different temperatures
and with different water content of the water trees. The effect of the
application of nominal voltage for extended period on the cable wave
propagation characteristics is also shown. High voltage dielectric
spectroscopy is used as a reference method for estimation of the level of
water tree deterioration.
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