ABB ETL600, Instruction Manual

Page: 156 / 382

ABB Switzerland Ltd
1KHW001489-EN ETL600
Note:
The programmed alarm pick up times of the ETL600
must be equal or higher than the programmed Tx trip
duration time of the external teleprotection device.
5.2.15.3. Persistent command transmission with external NSD570/NSD70C
If persistent commands shall be transmitted with the external
teleprotection devices NSD570/NSD70C, the boost criterion may not
be applied to the external boost input of the respective O4LE board.
Note:
The internal boosting facility of the NSD570/NSD70C
may be enabled for this purpose, but consequently
the weight of the tripping signal has to be considered
when configuring the teleoperation port (by means of
the HMI600, refer to Section 5.3.4.5).
5.2.16. Signal boosting for teleprotection devices
“Boosting” means “Increasing the power of a TPE signal” (TPE =
T
ele
P
rotection
E
quipment) relative to the level of the guard signal
during the transmission of a tripping signal. This can be done only if
some other signals are switched off. Otherwise clipping of the PLC
signal would occur.
Loop test commands of NSD600 are boosted to a system level of
0dBm0 except if the level of the guard signal is higher than this: In this
case, the NSD600 loop test commands are transmitted with the guard
signal level, i.e. they are not boosted.
A correction term w
corr
is included in the calculation of the S-value in
case the sum of the weights of the configured speech channels is too
low for transmitting the NSD600 loop test command.
Internal TPE – i.e. TPE integrated in ETL600 – are NSD600 devices.
In case of two internal TPE, each of these gets half of the available
output power for boosting.
External TPE such as ABB’s NSD570, NSD70C, NSD 70 or
teleprotection equipment from other manufacturers are standalone
analog TPE connected to one of ETL600s external teleprotection
ports. For each APLC channel, up to one external TPE is supported.
5.2.16.1. Disconnectable and non-disconnectable ports or signals
The amount of boosting depends on how many of the signals to be
transmitted by the PLC link may be disconnected during the
transmission of the tripping signals. Each of the teleoperation ports of
the ETL600 can either be set to disconnectable or to non-
disconnectable mode:
•
The input signal path of a
disconnectable port
is disabled during
the transmission of tripping signals, thereby suppressing all signals
entering the PLC terminal via this port for the duration of the
teleprotection command. The signals suppressed like that are
called
disconnectable signals
. The power of disconnectable
signals is automatically given to the teleprotection tripping signal by
5-12 November 2005 Configuration and Set-up