ABB Relion REG670, Applications Manual

Page: 483 / 780

14.3.2 Application
Some protection functions operate on the basis of measured voltage at the relay point.
Examples of such protection functions are distance protection function, undervoltage
function and energisation-check function. These functions might mal-operate if there
is an incorrect measured voltage due to fuse failure or other kind of faults in voltage
measurement circuit.
VDSPVC is designed to detect fuse failures or faults in voltage measurement circuit
based on comparison of the voltages of the main and pilot fused circuits phase wise.
VDSPVC output can be configured to block voltage dependent protection functions
such as high-speed distance protection, undervoltage relays, underimpedance relays
and so on.
FuseFailSupvn
IED
L1 L2 L3
U
2
L1
U
2
L2
U
2
L3
U
1
L
1
U
1
L
2
U
1
L
3
IEC12000143-1-en.vsd
Main Vt circuit
P
ilo
t
V
T
c
ir
cu
it
IEC12000143 V1 EN
Figure 222: Application of VDSPVC
1MRK 502 071-UEN -
Section 14
Secondary system supervision
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 477
Application manual