1.3 Characteristics
27
7SA522 Manual
C53000-G1176-C155-3
Transmission of In-
formation (only
with numerical pro-
tection data trans-
mission)
• Transmission of the measured values from all ends of the protected object
• Transmission of 4 commands to all ends
• Transmission of 24 additional binary signals to all ends
Tripping 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 avail-
able at one line end
• Phase segregated tripping and single-pole automatic reclosure (version with single-
pole tripping)
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 Overcurrent
Protection
• Selectable as emergency function in the case of measured voltage failure, or as
backup 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 stan-
dards is possible
• Blocking capability e.g. for reverse interlocking with any element
• Instantaneous tripping by any stage when switching onto a fault
• Stub fault protection: Additional stage for fast tripping of faults between the current
transformer and line isolator (when the isolator switching status feed back is avail-
able); particularly suited to substations with 1
1
/
2
circuit breaker arrangements.
Instantaneous
High-Current
Switch-onto-Fault
Protection
• Fast tripping for all faults on total line length
• Selectable for manual closure or following each closure of the circuit breaker
• With integrated line energization detection
Automatic Reclo-
sure Function (op-
tional)
• For reclosure after single-pole, three-pole or single-pole and three-pole tripping
• Single or multiple reclosure (up to 8 reclosure attempts)
• With separate action times for every reclosure attempt, optionally without action
times
• With separate dead times after single-pole and three-pole tripping, separate for the
first four reclosure attempts
• Controlled optionally by protection pickup with separate dead times after single,
two-pole and three-pole pickup
• Optionally with adaptive dead time, reduced dead time and dead line check.
Synchronism and
Voltage Check (op-
tional)
• Verification of the synchronous conditions before reclosing after three-pole tripping
• Fast measuring of voltage difference U
diff
of the phase angle difference Ï•
diff
and fre-
quency difference f
diff
;
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