Functional Description; General - ABB ETL600 Instruction Manual

ABB Switzerland Ltd
Dual-tone tripping signals also give added security against speech and
interference, e.g. an audio frequency generator.
An automatic or manually initiated loop testing routine checks the
teleprotection channel. The test signal, which is transmitted in the
same way as a genuine tripping signal, is recognized by the receiver
and "echoed" back to the transmitter.
By making use of the carrier pilot for monitoring the quiescent state of
the tripping channel and the speech band for transmitting the tripping
signals, the NSD600 does not require any PLC bandwidth of its own.
Signals are processed completely digitally by a signal-processor, i.e.
signal generation at the transmitting end and filtering and evaluation of
the guard and tripping signals at the receiving end. The only A/D and
D/A converters are at the RF section of the PLC equipment. Digital
processing eliminates calibrating, as well as the influences of ageing
and temperature fluctuations.
Adaptive algorithms especially developed for PLC channels adjust
themselves continuously to the prevailing PLC channel conditions and
achieve even under worst-case conditions the high degree of security
against loss of genuine, respectively acceptance of false tripping
commands, which is essential for protection signals.
3.6.8.

Functional description

3.6.8.1.

General

The NSD600 can be operated in one or two 4 kHz APLC channels of
the ETL600 as well as in the first channel of the "three APLC in 8 kHz"
mode. In case of a dual-channel ETL600 with one APLC and one
DPLC, an NSD600 can also be operated in the DPLC. This also
applies for the "DPLC only" mode of the ETL600.
Each TPE operates in one of the channels APLC1, APLC2, DPLC.
The association TPE x to the channels is fixed:
Available Channels
APLC1
DPLC
APLC1, DPLC
APLC1, APLC2,
DPLC
APLC1, APLC2,
APLC3, DPLC
APLC1, APLC2,
APLC3 (in 8 kHz)
APLC1, APLC2,
APLC3 (in 12 kHz)
Table 3-4
3-72
1KHW001489-EN
Channel of TPE1
APLC1,
300 ... 2000 Hz
DPLC
APLC1,
300 ... 2000 Hz
APLC1,
300 ... 2000 Hz
APLC1,
300 ... 2000 Hz
APLC1,
300 ... 2000 Hz
APLC1,
300 ... 2000 Hz
Channel association for TPE1 and TPE2
November 2005
ETL600
Channel of TPE2
n.a.
n.a.
DPLC (own guard)
APLC2,
300 ... 2000 Hz
APLC2,
300 ... 2000 Hz
n.a.
APLC2,
300 ... 2000 Hz
Structure and Function