EnShuntReactor: Set Enabled or Disabled to enable the charging current to be involved in
the voltage compensation calculation.
Xsh: Per phase reactance of the line connected shunt reactor given in ohm.
16.8.5 Sudden change in current variation SCCVPTOC (51)
16.8.5.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Sudden change in current variation
SCCVPTOC - 51
16.8.5.2 Application
The Sudden change in current variation (SCCVPTOC, 51) function is fast way of finding
any abnormality in line currents. When there is a fault in the system then current changes
faster than the voltage. SCCVPTOC (51) finds abnormal condition based on phase-to-
phase current variation. The main application is as one of local criterion to increase
security when transfer trips are used.
16.8.5.3 Setting guidelines
GlobalBaseSel: Selects the global base value group used by the function to define IBase,
VBase and SBase as applicable.
IPickup: Level of fixed threshold given in % of IBase. This setting should be based on fault
calculations to find the current increase in case of a fault at the most remote point where
the direct trip scheme shall be active. The phase to phase current shall be calculated for
different types of faults (single phase to ground, phase to phase to ground, phase to phase
and three phase short circuits) at different switching states in the network. In case of
switching of large objects (shunt capacitor banks, transformers, etc.) large change in
current can occur. The IPickup setting should be larger than estimated switch in currents
measured by the protection.
tHold: Hold time (minimum signal duration). This time setting shall be long enough to
assure that the CR-signal is received. The default value 0.5 s is recommended.
tDelay: Trip time is set according to the individual application.
Section 16 1MRK 506 369-UUS -
Scheme communication
782 Line distance protection REL670 2.2 ANSI
Application manual
To Next Page
Loading...
