On-site testing and diagnosis up to 200kV of
transmission (E)HV power cables with DAC
technology.
After-laying testing and diagnosis of newly installed,
repaired or service-aged (E)HV cable systems with
reliable results and an appropriate assessment of the
condition of the cable insulation as well as of the
accessories is the key to successful operation of the
transmission networks.
Cable diagnosis by partial discharges and
dissipation factor (tan δ): DAC voltage test
and diagnostic measurements (PD and tan δ) provide for
reliable detection of poor installation, failures due
to inappropriate laying, failures in accessories or
deterioration in cable insulation due to aging. It
allows much more than a simple “go or no-go”
decision. DAC testing is an advanced maintenance tool
which supports asset management and grid operation as
well.
The PD Measurement gives users the
certainty to see nearly all PD inceptions during test
voltage application. As a result, it allows to turn-off
the test if PD appears and to avoid a breakdown during
the test if not appropriate (cable under specific
surveillance will be exchanged or repaired soon).
Additionally, localization and identification of PD
patterns (e.g. joints) is possible. All PD measurements
are according to IEC standard(s) and have been proven
by experience over the last 14 years.
The Dissipation Factor (tan δ)
estimation is based on the determination of the damping
factor of the DAC voltage itself. This measurement
gives a reliable indication of the integral
deterioration of the cable insulation. Especially
service aged oil-impregnated transmission power cables
aged for more than 40 years can be differentiated into
groups of highly and acceptably aged ones. In case of
investments for exchange programs this method supports
the decision which cable has to be exchanged first on
the best available bases.
DAC HV technology for all types of transmission
(E)HV cables with lengths of up to > 100 km!
Download HV300 datasheet
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How to apply DAC on (E)HV cable systems:
This method provides system operators with a
lightweight, small and easy to apply technology. All
parts of the DAC HV300 test equipment can easily be
covered with flight cases and fit into a truck with a
cargo load below 1.300kg. The application takes approx
6 to 8 hours:
1. |
DAC HV300 system assembly on site
(1 hour) |
2. |
Connection of all parts and checking of
system (0,5 hours) |
3. |
Testing and measurement of all three phases
of a system (3 hours) |
4. |
Analysis of the measuring results -
disconnection and packing of test system into
boxes (1 hour) |
Main advantages:
|
Low energy consumption on site – small
footprint for test equipment |
|
Only two engineers are needed to execute the
full test |
|
Cable system shut-down time will be minimized
to 4 to 5 hours |
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Voltage withstand test automatically
monitored by partial discharges |
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Results of non-destructive and sensitive PD
measurement and tan δ are available on the
same day |
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This approved testing methodology is in
accordance with relevant international
standards and recommendations (IEEE, IEC,
CIGRE) |
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