GEK-106310AB F650 Digital Bay Controller 5-81
5 SETTINGS 5.4 PROTECTION ELEMENTS
5
5.4.9.3 WATTMETRIC GROUND FAULT (32N)
a) WATTMETRIC ZERO-SEQUENCE DIRECTIONAL HIGH AND LOW LEVEL (32NH, 32NL). ELEMENT DESCRIPTION
This document specifies wattmetric zero-sequence directional function, which can be used on solidly grounded, low-
resistance grounded, isolated or resonant (Petersen coil) grounded systems. The function determines presence and
direction of ground faults by measuring value and direction of zero-sequence power.
The element responds to power derived from zero-sequence voltage and current in a direction specified by the element
characteristic angle. The angle can be set within all four quadrants, the power can be selected to be either active or
reactive. Therefore, the element may be used to sense either forward or reverse ground faults in either inductive, capacitive
or resistive networks. Inverse time characteristic allows time coordination of the elements across the network.
Typical applications include ground fault protection in solidly grounded transmission networks, grounded/ungrounded/
resistor-grounded/resonant-grounded distribution networks, or for directionalizing other non-directional ground elements.
b) ELEMENT SETTINGS
wattmetric ground fault settings are:
Function: Enables or disables the directional element.
Voltage Pickup Level: The element uses neutral, i.e. 3 times zero-sequence, voltage. This setting specifies the
minimum neutral voltage supervising the directional power measurement. This threshold
should be higher than possible unbalance during normal operation of the system.
Current selection: The element responds to the neutral (3 times zero-sequence) current, either calculated
internally (IN) from the phase currents, or supplied externally (IG) via the ground CT input.
This setting allows selecting the source of the operating current.
OC Pickup Level: This setting specifies the current supervision level for the measurement of the zero-sequence
power.
OC Pickup Delay: This setting specifies delay for the overcurrent portion of this element. The delay applies to
the 32N1(2 3) HIGH(LOW) OC PKP operand driven from the overcurrent condition.
Power Pickup: This setting specifies the operating point of the element.
SETPOINT > PROTECTION ELEMENTS > POWER >
WATT GND FLT HIGH 1> WATT GND FLT HIGH 2 > WATT GND FLT HIGH 3
WATT GND FLT LOW 1> WATT GND FLT LOW 2 > WATT GND FLT LOW 3
SETTING DESCRIPTION NAME DEFAULT VALUE STEP RANGE
Function permission Function DISABLED N/A [DISABLED-ENABLED]
Supervision minimun voltage Voltage Pickup Level 2.00 0.01 V [2.00 : 70.00]
Source of operating current. Current selection IN N/A [IN-IG]
Pickup Level for Overcurrent OC Pickup Level 0.005 0.001A [0.005 : 0.400]
Pickup Delay for Overcurrent OC Pickup Delay 0.20 0.01 s [0.00 : 600.00]
Pickup Level for operating Power Power Pickup 0.01 0.01 W [0.01 : 4.50]
Max torque angle MTA 0 1 Deg [0 : 360]
Pickup Delay for Operating Power Power Pickup Delay 0.20 0.01 s [0.00 : 600.00]
Curve shape Curve DEFINITE TIME N/A [DEFINITE TIME - INVERSE TIME -
USER CURVE A - USER CURVE B -
USER CURVE C - USER CURVE D]
Multiplier Multiplier 1.00 0.01 s [0.02 : 2.00]
Snapshot event generation Snapshot Event DISABLED N/A [DISABLED-ENABLED]
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