Description of Operation
GARD 8000 Distance Relay
RFL Electronics Inc.
The operating characteristic that consists of a straight line is shown. The operation zone is an area +/-
90 degrees from the set maximum torque angle. The angle is generally set to the complement of line’s
positive sequence angle as shown in the example in the next section.
Blocking zone
Operating zone
Characteristic angle
Maximum torque
Operating phasor
Polarizing phasor
Figure 9-50. Vector diagram for the phase directional unit
The operating criterion is shown in the following table. ANG_67 is the set 67P characteristic angle
Table 9-14. Phase Directional Element
Phase Directional Element
Phase
Operating
quantity
Polarizing quantity
Criteria
A I
A
V
BC
= V
B
- V
B
C
B I
B
B
V
CA
= V
C
- V
A
C I
C
V
AB
= V
A
- V
B
B
-(90
°
-ANG_67)
≤
[arg(OP)-arg(POL)]
≤
(90
°
+ANG_67)
August 1, 2009
9-56
973.334.3100
