Compensated Over And Undervoltage Protection Couvgapc - ABB REL670 2.2 IEC Applications Manual

Section 16
Scheme communication
16.8.4
16.8.4.1
16.8.4.2
730
LAP<: Level of low active power detection, given in % of SBase. This parameter
should be set as low as possible to avoid activation during low load conditions at
undisturbed network operation. The measurement is blocked for current levels
below 3 % of IBase and 30% of UBase. All outputs are blocked.
tOpLAP: Time delay for trip in case of low active power detection.
OperationLPF: Used to set the low power factor function On or Off.
LPF<: Level of low power factor detection. The setting should be set lower than
the lowest power factor at undisturbed network operation. A value lower than 0.4 is
normally sufficient.
tOpLPF: Time delay for trip in case of low power factor detection.
Compensated over and undervoltage protection
COUVGAPC
Identification
Function description
Compensated over and undervoltage
protection
Application
Compensated over and undervoltage protection (COUVGAPC) function calculates
the remote end voltage of the transmission line utilizing local measured voltage,
current and with the help of transmission line parameters, that is, line resistance,
reactance, capacitance and local shunt reactor.
For protection of long transmission line for in zone faults this function can be
incorporated with other local criteria checks within direct transfer trip logic to
ensure tripping of the line only under abnormal conditions and to avoid
unnecessary tripping during healthy operation of the line (for example, lightly
loaded or unloaded).
Long transmission line draws substantial quantity of charging current. If such a line
is open circuited or lightly loaded at the remote end, the voltage at remote end may
exceeds local end voltage. This is known as Ferranti effect and is due to the voltage
drop across the line inductance (due to charging current) being in phase with the
local end voltages. Both capacitance and inductance are responsible for this
phenomenon. The capacitance (and charging current) is negligible in short line but
significant in medium line and appreciable in long line. The percentage voltage rise
due to the Ferranti effect between local end and remote end voltage is proportional
IEC 61850 IEC 60617
identification identification
COUVGAPC
Line distance protection REL670 2.2 IEC
1MRK 506 369-UEN B
GUID-41C1AD2A-3E57-40A9-9039-F159A3CE3DF8 v1
GUID-F5F76C4D-DD25-4695-9FF1-6B45C696CC5E v1
ANSI/IEEE C37.2
device number
- 59_27
GUID-49CDDFEF-DB8F-4733-AD7C-0A87E0F6BAA1 v1
Application manual