ABB RELION 670 Series Product Manual page 28

Bay control REC670 2.1 IEC
• Distance protection function.
• Undervoltage function.
• Energisation function and voltage check for the weak
infeed logic.
These functions can operate unintentionally, if a fault
occurs in the secondary circuits between voltage
instrument transformers and the IED. These
unintentional operations can be prevented by VDSPVC.
VDSPVC is designed to detect fuse failures or faults in
voltage measurement circuit, based on phase wise
comparison of voltages of main and pilot fused circuits.
VDSPVC blocking output can be configured to block
functions that need to be blocked in case of faults in the
voltage circuit.
Multipurpose filter SMAIHPAC
The multi-purpose filter function block, SMAIHPAC, is
arranged as a three-phase filter. It has very much the
same user interface (e.g. inputs and outputs) as the
standard pre-processing function block SMAI. However
the main difference is that it can be used to extract any
frequency component from the input signal. Thus it can,
for example, be used to build sub-synchronous
resonance protection for synchronous generator.
10. Scheme communication
Scheme communication logic with delta based
blocking scheme signal transmit ZCPSCH
To achieve instantaneous fault clearance for all line
faults, scheme communication logic is provided. All
types of communication schemes for permissive
underreaching, permissive overreaching, blocking, delta
based blocking, unblocking and intertrip are available.
The built-in communication module (LDCM) can be used
for scheme communication signaling when included.
Current reversal and weak-end infeed logic for
distance protection ZCRWPSCH
The ZCRWPSCH function provides the current reversal
and weak end infeed logic functions that supplement
the standard scheme communication logic. It is not
suitable for standalone use as it requires inputs from
the distance protection functions and the scheme
communications function included within the terminal.
On detection of a current reversal, the current reversal
logic provides an output to block the sending of the
teleprotection signal to the remote end, and to block
the permissive tripping at the local end. This blocking
condition is maintained long enough to ensure that no
unwanted operation will occur as a result of the current
reversal.
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GUID-EB0B11C3-FF79-4B8D-A335-649623E832F9 v2
M13860-3 v11
M13896-3 v14
On verification of a weak end infeed condition, the weak
end infeed logic provides an output for sending the
received teleprotection signal back to the remote
sending end and other output(s) for local tripping. For
terminals equipped for single- and two-pole tripping,
outputs for the faulted phase(s) are provided.
Undervoltage detectors are used to detect the faulted
phase(s).
Local acceleration logic ZCLCPSCH
To achieve fast clearing of faults on the whole line, when
no communication channel is available, local
acceleration logic ZCLCPSCH can be used. This logic
enables fast fault clearing and re-closing during certain
conditions, but naturally, it can not fully replace a
communication channel.
The logic can be controlled either by the autorecloser
(zone extension) or by the loss-of-load current (loss-of-
load acceleration).
Scheme communication logic for residual
overcurrent protection ECPSCH
To achieve fast fault clearance of earth faults on the
part of the line not covered by the instantaneous step of
the residual overcurrent protection, the directional
residual overcurrent protection can be supported with a
logic that uses communication channels.
In the directional scheme, information of the fault
current direction must be transmitted to the other line
end. With directional comparison, a short operate time
of the protection including a channel transmission time,
can be achieved. This short operate time enables rapid
autoreclosing function after the fault clearance.
The communication logic module for directional residual
current protection enables blocking as well as
permissive under/overreaching, and unblocking
schemes. The logic can also be supported by additional
logic for weak-end infeed and current reversal, included
in Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH function.
Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH
The Current reversal and weak-end infeed logic for
residual overcurrent protection ECRWPSCH is a
supplement to Scheme communication logic for residual
overcurrent protection ECPSCH.
To achieve fast fault clearing for all earth faults on the
line, the directional earth fault protection function can
be supported with logic that uses tele-protection
channels.
This is why the IEDs have available additions to the
scheme communication logic.
1MRK 511 361-BEN D
M13823-3 v6
M13918-4 v10
M13928-3 v7
ABB