Siemens siprotec 7SD5 User Manual page 30

1 Introduction
Transmission of In- • Transmission of the measured values from all ends of the protected object with the
formation
• Transmission of up to 4 fast commands to all remote ends (order option)
• Transmission of up to 24 additional binary signals to all remote ends (order option)
Time Overcurrent • Selectable as emergency function during a failure of the main protection function(s)
Protection
• Maximally two definite time stages (DT) and one inverse time stage (IDMT), each
• For inverse-time overcurrent protection a selection from various characteristics
• Blocking capability, e.g. for reverse interlocking with any element
• Instantaneous tripping by any stage when switching onto a fault
• Stub fault protection: fast tripping of faults between the current transformer and line
Instantaneous • Fast tripping for all faults on 100 % line length
High-Current
• Selectable for manual closure or following each closure of the circuit breaker
Switch-onto-Fault
Protection • With integrated line energization detection
Automatic Reclo- • For reclosure after single-pole, three-pole or single-pole and three-pole tripping
sure Function
• Single or multiple reclosure (up to 8 reclosure attempts)
(optional)
• With separate action times for every reclosure attempt, optionally without action
• With separate dead times after single-pole and three-pole tripping, separate for the
• With the option of an adaptive dead time: in this case only one device controls the
• Controlled optionally by protection pickup with separate dead times after single,
• Optionally with adaptive dead time, reduced dead time and dead line check
Synchronism and • Verification of the synchronous conditions before reclosing after three-pole tripping
Voltage Check (op-
• Fast measuring of voltage difference U
tional)
• Alternatively, check of the de-energized state before reclosing
• Closing at asynchronous system conditions with prediction of the synchronization
• Settable minimum and maximum voltage
30
amount and phase
due to a failure of the data communication and/or the measuring voltages, or as
backup function;
for phase currents and for earth currents
based on several standards is possible
isolator (when the isolator switching status feed back is available); particularly
suited to substations with 1
times
first four reclosure attempts
automatic reclosure cycles whilst at the other end(s) the automatic reclosure solely
depends on the one controlling device. The criteria used are voltage measurement
and/or the transmitted CLOSE command (Remote-CLOSE).
two-pole and three-pole pickup
quency difference f
Diff
time
1
/ circuit breaker arrangements
2
of the phase angle difference ϕ
Diff
and fre-
Diff
7SD5 Manual
C53000-G1176-C169-1