ABB REX 521 - Page 216

216
1MRS751802-MUM
Protection Relay
Technical Reference Manual, Standard Configurations
REX 521
The network is either compensated or isolated. Three-phase current measurement is
established with a set of current transformers. The neutral current I
0b
is measured
with a cable current transformer and the neutral current I
0
is measured with the sum
connection of the phase current transformers. The residual voltage is measured with
a set of voltage transformers in an open-delta connection. Phase-to-phase voltage
measurements are established with voltage transformers.
Fig. 11.4.1.-1 REX 521 H04 used for protection, measuring and supervision on
an outgoing feeder in a single busbar system. The supplying
network is either compensated or isolated.
REX 521 H04
Application Example 11
UserOutgH04
49F
3
I >
46
0
I
79
3I >
50/51
I >
0
50N/51N
f
P
3U
3I
I
0
Q
E
pf
TCS
CBCM
0
I
MCS
3I~harm
000
R
3U~harm
CBFP
*/62
I >
0
67N
U
0