Elcontrol Microvip 3 plus, User Manual

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39
1
31 23
2
31
2
23 12
V V V V V
•
− + =
8. 6 FORMULAE
8.6.1 SINGLE PHASE FORMULAE
True rms voltage
V
1
N
= ∑ ( v
1
N
)
²
Active power
W
1
= ∑ (v
1
N
) . (a
1
)
Power factor
P. F. = W
1
/ VA
1
True rms current
A
1
=
∑
(a
1
)
²
Apparent power
VA
1
= V
1
N
. A
1
Reactive power
VAr =
where
(v
1
N
)
i
(a
1
)
i
:
samples of voltage and current
j : number of samples corresponding to 90° electrical degrees
8.6.2 THREE PHASE FORMULAE
Equivalent three phase voltage
V
∑
= (V
1N
+ V
2N
+ V
3N
) /
V
∑
= (V
12
+ V
23
+ V
31
) / 3
where
V
∑
= (V
1N
+ V
2N
)
Three phase reactive power
VAr
∑
= (VAr
1
+ VAr
2
+ VAr
3
)
Equivalent three phase current
A
∑
= (VA
∑
)/( 3 . V
∑
)
A
∑
= VA
∑
/ V
∑
Three phase active power
W
∑
= W
1
+ W
2
+ W
3
i
i
n
1
n
i
( )
.
( )
j i
1
a
i
n
1
n 1
n
1
v
+
∑
(Two-phase)
(Star)
(Delta)
(Star)
(Delta)
(Two-Phase)
(Star)
(Delta)
n
1
n
1
1
i
n
n
1
( )
2 1
VAr VAr VAr
+ =
∑
( )
2 1
W W W
+ =
∑
3