ABB Relion 650 Series Technical Manual page 352

Section 11
Scheme communication
IREV
IFWD
ANSI10000259 V2 EN-US
Figure 183: Current reversal logic
The preventing of sending the send signal CS and activating of the TRIP is carried out by
connecting the IRVL signal to the inputs BLKTR and BLKCS in ZCPSCH (85).
The function has an internal 10 ms drop-off timer which secure that the current reversal logic will
be activated for short input signals even if the pick-up timer is set to zero.
11.2.6.2 Weak-end infeed logic
The weak-end infeed logic (WEI) function trip and sends back (echoes) the received signal under
the condition that no fault has been detected on the weak-end by different fault detection
elements (distance protection in forward and reverse direction).
The WEI function returns the received signal, see figure 184, when:
• No active signal present on the input BLOCK.
• The functional input CRL is active. This input is usually connected to the CRL output on the
scheme communication logic ZCPSCH.
• The WEI function is not blocked by the active signal connected to the WEIBLK1 functional
input or to the BLKZ functional input. The later is usually configured to the BLOCK functional
output of the fuse-failure function.
• No active signal has been present for at least 200 ms on the WEIBLK2 functional input. An OR
combination of all fault detection functions (not undervoltage) as present within the IED is
usually used for this purpose.
BLKZ
BLOCK
CRL
WEIBLK1
WEIBLK2
ANSI10000260 V1 EN-US
Figure 184: Echo of a received signal by the WEI function
When an echo function is used in both IEDs (should generally be avoided), a spurious signal can be
looped round by the echo logics. To avoid a continuous lock-up of the system, the duration of the
echoed signal is limited to 200 ms.
346
0 0
0-tPickUpRev
0-tPickUpRev 10ms
OR
-
0 tWEI
AND
0
50ms
0
200ms
© Copyright 2011 ABB Power Grids. All rights reserved
0
AND
0-tDelayRev
0 200ms
0
AND
1MRK 506 326-UUS B
IRVL
0
ANSI05000122-2-en.vsd
GUID-E46D1AD7-A4FF-4DE1-83B1-735E96010928 v1
ECHO - cont.
ECHO
ANSI10000260-1-en.vsd
Line distance protection REL650
Technical manual