MI 2892 Power Master
Theory and internal operation
153
2
2
)
(
p
p
p
p
P
S
Q
Sign
N
[var], p: 1,2,3
Phase power factor:
p
p
p
S
P
PF
, p: 1,2,3
(10)
Total combined power measurements
Standard compliance: IEEE STD 1459-2010
Total combined (funda nonfundamental) active, nonactive and apparent power and total power
factor are calculated according to the following equation:
Total active power:
3
2
1
P
P
P
P
tot
[W],
(11)
Total nonactive power:
3
2
1
N
N
N
N
tot
[var],
(12)
Total apparent power (effective):
Ie
Ue
Se
tot
3
[VA],
(13)
Total power factor (effective):
tot
tot
tot
Se
P
PFe
.
(14)
In this formula U
e
and I
e
are calculated differently for three phase four wire (4W) and three phase three
wire (3W) systems.
Effective voltage Ue and current Ie in 4W systems:
3
2
2
3
2
2
2
1
N
I
I
I
I
Ie
18
)
(
3
2
31
2
23
2
12
2
3
2
2
2
1
U
U
U
U
U
U
Ue
(15)
Effective voltage U
e
and current I
e
in 3W systems:
3
2
3
2
2
2
1
I
I
I
Ie
9
2
31
2
23
2
12
U
U
U
Ue
(16)
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)
