GE D90 Plus Instruction Manual page 204

GROUPED PROTECTION ELEMENTS
194
Quadrilateral Right Blinder
Range: 0.02 to 500.00 ohms in steps of 0.01
Default: 0.90 ohms
This setting specifies the right blinder position of the quadrilateral characteristic along
the resistive axis of the impedance plane. The angular position of the blinder is
adjustable with the use of the
applies only to the quadrilateral characteristic and should be set giving consideration to
the maximum load current and required resistive coverage.
Quadrilateral Right Blinder RCA
Range: 60 to 90° in steps of 1
Default: 85°
This setting specifies the angular position of the right blinder of the quadrilateral
characteristic.
Quadrilateral Left Blinder
Range: 0.02 to 500.00 ohms in steps of 0.01
Default: 0.85 ohms
This setting specifies the left blinder position of the quadrilateral characteristic along the
resistive axis of the impedance plane. The angular position of the blinder is adjustable
with the use of the
Quadrilateral Left Blinder RCA
quadrilateral characteristic and should be set with consideration to the maximum load
current.
Quad Left Blinder RCA
Range: 60 to 90° in steps of 1
Default: 85°
This setting specifies the angular position of the left blinder of the quadrilateral
characteristic.
Supervision
Range: 0.050 to 30.000 pu in steps of 0.001
Default: 0.200 pu
The phase distance elements are supervised by the magnitude of the line-to-line current
(fault loop current used for the distance calculations). For convenience, √3 is
accommodated by the pickup (that is, before being used, the entered value of the
threshold setting is multiplied by √3).
If the minimum fault current level is sufficient, the current supervision pickup should be
set above maximum full load current preventing maloperation under VT fuse fail
conditions. This requirement may be difficult to meet for remote faults at the end of
zones 2 through 5. If this is the case, the current supervision pickup would be set below
the full load current, but this may result in maloperation during fuse fail conditions.
Zone 1 is sealed-in with current supervision.
Voltage Level
Range: 0.000 to 5.000 pu in steps of 0.001
Default: 0.000 pu
This setting is relevant for applications on series-compensated lines, or in general, if
series capacitors are located between the relaying point and a point where the zone
shall not overreach. For plain (non-compensated) lines, set to zero. Otherwise, the setting
is entered in per unit of the phase VT bank configured in the distance
Effectively, this setting facilitates dynamic current-based reach reduction. In non-
directional applications (the
to the forward reach of the non-directional zone.
Quadrilateral Right Blinder RCA
setting. This setting applies only to the
is set to "Non-directional"), this setting applies only
Direction
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION
setting. This setting
setting.
Source