ABB Relion 650 Series Technical Manual page 218

Section 6
Current protection
6.12.7 Operation principle
The sampled analog phase currents are pre-processed in a discrete Fourier filter (DFT) block. From
the fundamental frequency components of each phase current the RMS value of each phase
current is derived. These phase current values are fed to a comparator in the stub protection
function STBPTOC (50STB). In a comparator the RMS values are compared to the set operating
current value of the function
If a phase current is larger than the set operating current the signal from the comparator for this
phase is activated. If the fault current remains during the timer delay
activated. The function can be blocked by activation of the BLOCK input.
STUB PROTECTION FUNCTION
BLOCK
PU_A
PU_B
PU_C
ENABLE
ANSI05000731 V1 EN-US
Figure 111: Simplified logic diagram for Stub protection (50STB)
6.12.8 Technical data
Table 131: STBPTOC (50STB) technical data
Function
Operating current
Reset ratio
Operating time
Resetting time
Critical impulse time
Impulse margin time
6.13 Pole discrepancy protection CCRPLD (52PD)
212
IPickup .
OR
Range or value
(1-2500)% of
> 95%
20 ms typically at 0 to 2 x I
30 ms typically at 2 to 0 x I
10 ms typically at 0 to 2 x I
15 ms typically
© Copyright 2011 ABB Power Grids. All rights reserved
t , the TRIP output signal is
AND
en05000731_ansi.vsd
Accuracy
IBase
± 1.0% of I
± 1.0% of I at I > I
-
-
set
-
set
-
set
-
Line distance protection REL650
1MRK 506 326-UUS B
M12905-3 v4
TRIP
M12350-1 v7
at I £ I
n n
n
IP14516-1 v4
Technical manual