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would suffer from chemical sweat-out.
Shelf life makes storing premix compounds
a concern.
Online
dosing
removes
some
of
these restrictions and gives the cable
manufacturer awider selection of peroxides
and antioxidants.
Online dosing offers a significantly longer
shelf life, and using alternative peroxides
can even result in increased extruder
outputs and longer production runs.
Maillefer’s Smart Dosing is a system for
both antioxidant and peroxide dosing,
consisting of two separate feeders with
gravimetric loss in weight measurement
for accurate dosing, that also ensures that
cable insulation cleanliness will not be
compromised.
Smart Dosing has no impact on extruder
stability, but is said to guarantee thorough
distribution of injected ingredients and
ensure high product quality.
During development, model cables
produced with online dosing of XLPE have
shown good geometrical properties as
well as excellent peroxide and antioxidant
homogeneity in the insulation material.
Underground record
cable
A record 640kV extruded DC cable system
has been successfully tested and qualified
by NKT Cables.
The commercialization of the first 640kV
extruded DC underground system will
increase the maximum power transmission
of cable systems by 20 percent, and allow
better integration of distant renewable
energy sources into global energy systems
with minimum energy loss. A single pair of
640kVDCcablescan transmit enoughgreen
energy to supply three million households.
Michael Hedegaard Lyng, president and
CEO of NKT Cables, commented: “The
development of interconnector grids
globally represents some of the biggest
infrastructure projects of our time, and
we are proud to pioneer the associated
technology. The interconnector market
is expected to grow significantly and with
this 640kV cable system we are underlining
our leading position within this promising
market.”
The new system will reach a transmission
capacity of over 3GW, 20 percent higher
than the existing top solution based on
525kV technology.
The new system is technically and
commercially qualified according to the
international recommendation Cigré TB
496.
The cables use the same design and utilize
the same DC XLPE insulation material as the
company’s 525kV cable system, and the
accessories for the 640kV cable system are
the same as for the 525kV system.
S
S
The 640kV extruded DC cable tested by NKT Cables
wiredInUSA - May 2017
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