GE 350-A9

6–100 350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION CHAPTER 6: SETPOINTS
The element has an adjustable characteristic angle and minimum operating power as
shown in the Directional Power characteristic diagram. The element responds to the
following condition:
Where:
P and Q are active and reactive powers
angle theta is the element characteristic (RCA) angles
SMIN is the minimum operating power.
Figure 6-44: Sample applications of the directional power element
P
Q
OPERATE
RESTRAIN
RCA = 0
o
SMIN > 0
(d)
P
Q
OPERATE RESTRAIN
RCA = 180
o
SMIN > 0
(a)
P
Q
OPERATE
RESTRAIN
RCA = 0
o
SMIN < 0
(c)
P
Q
OPERATE
RESTRAIN
RCA = 180
o
SMIN < 0
(b)
P
Q
OPERATE
RESTRAIN
RCA = 90
o
SMIN > 0
(e)
P
Q
OPERATE
RESTRAIN
RCA = 270
o
SMIN < 0
(f)
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