Structure Of Nsd600 - ABB ETL600 Instruction Manual

ETL600
In conjunction with one APLC channel, the DPLC channel requires its
own guard signal for the NSD600 (which is not necessary without TPE
in the DPLC).
NSD600 is excellent for transmitting direct transfer tripping, permissive
tripping, or blocking signals via a PLC communications channel
between the ends of power transmission lines. It is not suitable for
steady-state signals, because it normally uses the speech band of the
APLC channel or partly uses the band of the DPLC channel and
speech as well as data communication is thus interrupted whilst
tripping signals are being transferred.
The programmable external teleprotection equipment type NSD570
which operates at higher frequencies than the speech band is
recommended for steady-state signals of any duration or if more than
four protection commands have to be transmitted in the same APLC
channel. NSD570 should be used with single tone command signals
for transmission over power line carriers, i.e. for obtaining best
practical signal-to-noise ratio.
NSD600 can transmit up to four independent commands, simulta-
neously in any possible combination. Depending on the application
requirements, they can be individually configured for direct transfer
tripping, permissive tripping or blocking schemes. Four commands
permit, for example, the protection of dual-circuit lines and direct
tripping for reactor or breaker failure protection.
An unblocking (deblocking) output used in protection schemes with
overreaching first zones can be configured on one of the various
outputs. Should the PLC channel break down, i.e. neither guard nor
active tripping signals are being received, the unblocking contacts
close for a preset period (e.g. 200 ms).
Application details are to be found in section 3.6.5.
All local and remote equipment features and parameters are selected
and programmed by means of the user interface type HMI600. All
status-, configuration- und alarm-messages are also accessible from
remote.
An integrated event recorder and trip counters are provided (command
start/stop events, alarm events and manipulation events are recorded
and stored with time stamp in a non-volatile memory).
3.6.3.

Structure of NSD600

The NSD600 signals are processed completely digitally by a DSP
(Digital Signal Processor) on the RF-Converter type P4LT of the basic
ETL600 equipment and by a DSP on the Teleprotection Interface type
G4AI, so the firmware for the NSD600 resides on both modules.
The NSD600 comprises at least one teleprotection interface type
G4AI. As contact multipliers or to exploit all possible NSD600
functions, additional interface modules can be directly plugged into
reserved slots of the PLC equipment. However the user will not be
allowed to select the position of the modules. He must only select the
Structure and Function
1KHW001489-EN
November 2005
ABB Switzerland Ltd
3-55