Operating And Inhibit Conditions - ABB Relion Technical Manual

Section 7
Impedance protection
7.1.6.5
158
ZOUT_A
ZOUT_B
ZOUT_C
I0CHECK
BLK_I0
BLK_SS
BLOCK
DET 1of3 - int
DET 2of3 - int
EXT_PSD
ANSI09000223 V3 EN
Figure 64: Simplified block diagram for ZMRPSB (68) function

Operating and inhibit conditions

Figure 64 presents a simplified logic diagram for the Power swing detection function
ZMRPSB (68).
The load encroachment characteristic can be switched off by setting the parameter
OperationLdCh = Disabled, but notice that the DFw and DRv will still be calculated from
RLdOutFw and RLdOutRv. The characteristic will in this case be only quadrilateral.
There are three different ways to form the internal INHIBIT signal:
• Logical 1 on functional input BLOCK inhibits the output PICKUP signal
instantaneously.
• The INHIBIT internal signal is activated, if the power swing has been detected and
the measured impedance remains within its operate characteristic for the time, which
OR
ZIN_A
ZIN_B
AND
ZIN_C
AND
10 ms
AND
t
OR
tR1
AND
t
-loop
0-tR2
AND
0
-loop
0
OR
0-tH
1MRK 502 048-UUS A
ZOUT
OR
INHIBIT
OR
OR
PICKUP
AND
ANSI09000223-3-en.vsd
Technical manual
ZIN