Introduction
1-8
7SA522 Manual
C53000-G1176-C119-2
•
Blocking;
•
All teleprotection schemes are applicable to 2- and 3- terminal lines;
•
Transfer of phase-segregated transmission signals possible;
•
User specific applications can be implemented by way of the integrated CFC-Logic.
Earth Fault
Protection
•
Earth fault overcurrent protection, with a maximum of three definite time stages
(DT) and one inverse time stage (IDMT) for high resistance earth faults in earthed
systems;
•
for the IDMT protection a selection of various characteristics based on several
standards is possible;
•
high sensitivity (depending on the version from 3 mA is possible);
•
phase current stabilization against error currents during current transformer satura-
tion;
•
inrush stabilization with second harmonic;
•
each stage can be set to be non-directional or directional in the forward or reverse
direction;
•
direction determination with zero sequence system quantities (I
0
, U
0
), with zero se-
quence current and transformer star-point current (I
0
, I
Y
). or with negative sequence
system quantities (I
2
, U
2
);
•
one or more stages may function in conjunction with a signal transmission supple-
ment;
•
non-delayed tripping after switch on to fault with any stage is possible.
Tripping/Echo at
Line Ends with No
or Weak Infeed
•
possible in conjunction with teleprotection schemes;
•
allows fast tripping at both line ends, even if there is no or only weak infeed available
at one line end;
•
phase segregated tripping is possible.
External Direct and
Remote Tripping
•
tripping at the local line end from an external device via a binary input;
•
tripping of the remote line end by internal protection functions or an external device
via a binary input (with teleprotection);
Time Delayed Over-
current Protection
•
selectable as emergency function in the case of measured voltage failure, or as
back up function independent of the measured voltage;
•
maximally two definite time stages (DT) and one inverse time stage (IDMT), each
for phase currents and earth current;
•
for IDMT protection a selection from various characteristics based on several stand-
ards is possible;
•
blocking options e.g. for reverse interlocking with any stage;
•
non-delayed tripping in the case of switching onto a fault with any stage is possible;
•
stub protection: additional stage for fast tripping of faults between the current trans-
former and circuit breaker (when the isolator switching status feed back is avail-
able); particularly suited to sub-stations with 1
1
/
2
circuit breaker arrangements.
Summary of Contents for siprotec 7SA522
Page 20: ...7SA522 Manual C53000 G1176 C119 2 ...
Page 64: ...7SA522 Manual C53000 G1176 C119 2 ...
Page 89: ...SIPROTEC 4 Devices 4 25 7SA522 Manual C53000 G1176 C119 2 Figure 4 20 CFC Logic example ...
Page 408: ...7SA522 Manual C53000 G1176 C119 2 ...
Page 456: ...7SA522 Manual C53000 G1176 C119 2 ...
Page 516: ...7SA522 Manual C53000 G1176 C119 2 ...
Page 620: ...Appendix B 48 ...
