MI 2883 Energy Master
Theory and internal operation
129
fundP
fundP
fundP
I
U
S
[VA],
p: 1,2,3
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)
Positive sequence apparent power:
I
U
S
tot
3
[VA],
(23)
Positive sequence power factor:
tot
tot
tot
S
P
DPF
.
(24)
U
+
, U
-
, U
0
and
+
are obtained from unbalance calculus. See section 5.1.10 for details.
Nonfundamental phase power measurements
Standard compliance:
IEEE STD 1459-2010
Nonfundamental power measurements are measured according to following equations:
Phase nonfundamental apparent power:
2
2
2
Hp
Vp
Ip
Np
S
D
D
S
[VA],
p: 1,2,3
(25)
Phase current distortion power
Ip
fundP
Ip
THD
S
D
[VA],
p: 1,2,3
(26)
Phase voltage distortion power:
(27)
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
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