MI 2893 / MI 2892 / MI 2885
Measurement methods
184
Fundamental phase power measurements
Standard compliance: IEEE STD 1459-2010
All fundamental power measurements are calculated from fundamental voltages and currents obtained
from harmonic analysis (see section 5.1.8 for details).
Fundamental phase active power:
p
p
I
U
fundP
fundP
fundP
I
U
P
cos
[W], p: 1,2,3
(17)
Fundamental apparent and reactive power and power factor are calculated according to the following
equations:
Fundamental phase apparent power:
fundP
fundP
fundP
I
U
S
[VA], p: 1,2,3
(18)
Fundamental phase reactive power:
p
p
I
U
fundP
fundP
fundP
I
U
Q
sin
[var], p: 1,2,3
(19)
Phase displacement power factor:
p
p
p
p
S
P
DPF
cos
, p: 1,2,3
(20)
Positive sequence (total) fundamental power measurements
Standard compliance: IEEE STD 1459-2010
According to the IEEE STD 1459, positive sequence power (P
+
, Q
+
, S
+
) are recognised as very important
intrinsic power measurements. They are calculated according to the following equation:
Positive sequence active power:
cos
3
I
U
P
tot
[W],
(21)
Positive sequence reactive power:
sin
3
I
U
Q
tot
[var],
(22)
270
0
+DPF
ind
Le
ad
L
a
g
+DPF
cap
-DPF
cap
-DPF
ind
180
0
90
0
0
0
+P
-P
-Q
+Q
I
II
III
IV
