Sel 411L - Figure 9.15 Complex Power (P;Q) Plane; Table 9.14 Instantaneous Metering Quantities-Powers

P.9.28
SEL-411L Relay Protection Manual Date Code 20151029
Monitoring and Metering
Metering
Figure 9.15 Complex Power (P/Q) Plane
High-Accuracy Instantaneous Metering
The relay is a high-accuracy metering instrument. Table 9.15 and Table 9.16
show the metering accuracy for the relay instantaneous metering quantities at
nominal power system frequency and at 20C. Use a method similar to that in
Example 9.11 to compute exact error coefficients.
Table 9.14 Instantaneous Metering Quantities—Powers
Metered Quantity Symbol
Fundamental
(50 Hz/
60 Hz Only)
RMS
(Harmonics
Included)
Per-phase fundamental real power P
1
X
Per-phase true real power P
rms
X
Per-phase reactive power Q
1
XX
Per-phase fundamental apparent power S
1
X
Per-phase true apparent power U
rms
X
Three-phase fundamental real power 3P
1
X
Three-phase true real power 3P
rms
X
Three-phase reactive power 3Q
1
XX
Three-phase fundamental apparent power 3S
1
X
Three-phase true apparent power 3U
rms
X
Per-phase displacement power factor PF
1
X
Per-phase true power factor PF

X
Three-phase displacement power factor 3PF
1
X
Three-phase true power factor 3PF X
Q
P
+P
+Q
C
o
mpl
e
x
P
o
wer
S
1
C
om
p
l
e
x
P
o
we
r
S
2
pf = Lead
pf = Lag
—P
+Q
+P
—Q
—P
—Q
Export power and
export reactive power
(inductive load)
Export power and
import reactive power
(capacitive load)