Sammendrag
This paper presents an evaluation and results from a
water aging test performed at 10 kV/mm - 500 Hz of a
HV 52 kV XLPE core. Water permeation tests and
associated modelling have been performed on power
cores with a PE-sheath only and a non-impervious water
barrier to evaluate the effect of the “semi-wet” barrier. The
cable is installed as part of an HV dynamic power
umbilical in Åsgard Subsea Compression Project in
Norwegian Sea. The estimated lifetime of high voltage
(HV) XLPE cables having such a “semi-wet” design is
discussed on basis of test results and diffusion models. It
is shown that for example swelling tapes, overlapping Cutapes
and PE-sheath in combination may increase the
time to reach critical relative humidity levels significantly in
cable insulation. Water treeing does occur but will
terminate at a level which could be acceptable at voltage
levels higher than traditionally limited to medium voltage
(MV). HV cables for oil/gas industry, HV dynamic cables,
HV array cables for wind farms, may be applications of
interest for this design. However, even if results seem to
be safe for many types of applications, caution has to be
taken to the conditions needed to such a market
introduction; i.e. good and robust material selection,
material cleanliness and process technologies are vital
water aging test performed at 10 kV/mm - 500 Hz of a
HV 52 kV XLPE core. Water permeation tests and
associated modelling have been performed on power
cores with a PE-sheath only and a non-impervious water
barrier to evaluate the effect of the “semi-wet” barrier. The
cable is installed as part of an HV dynamic power
umbilical in Åsgard Subsea Compression Project in
Norwegian Sea. The estimated lifetime of high voltage
(HV) XLPE cables having such a “semi-wet” design is
discussed on basis of test results and diffusion models. It
is shown that for example swelling tapes, overlapping Cutapes
and PE-sheath in combination may increase the
time to reach critical relative humidity levels significantly in
cable insulation. Water treeing does occur but will
terminate at a level which could be acceptable at voltage
levels higher than traditionally limited to medium voltage
(MV). HV cables for oil/gas industry, HV dynamic cables,
HV array cables for wind farms, may be applications of
interest for this design. However, even if results seem to
be safe for many types of applications, caution has to be
taken to the conditions needed to such a market
introduction; i.e. good and robust material selection,
material cleanliness and process technologies are vital