User’s Manual 7M
60
POWER
Active power by phases
N − a number of periods
n − index of sample in a period
f − phase designation
P
t
= P
1
+ P
2
+ P
3
Total active power
t − total power
1, 2, 3 − phase designation
SignQ6(φ)
φ
Э
[0° − 180°] –> SignQ*(φ) = +1
φ
Э
[180° − 360°] –> SignQ*(φ) = −1
Reactive power sign
Qf − reactive power (by phases)
− power angle
S = U
f
∙ I
f
Apparent power by phases
U
f
− phase voltage
I
f
− phase current
S
t
= S
1
+ S
2
+ S
3
Total apparent power
St − apparent power by phases
Reactive power by phases
S
f
− apparent power by phases
P
f
− active power by phases
Reactive power by phases (displacement method)
N − a number of samples in a period
n − sample number (0 ≤ n ≤ N)
f − phase designation
Q
t
= Q
1
+ Q
2
+ Q
3
Total reactive power
Q
t
− reactive power by phases
φ
s
= a tan2 (P
f
, Q
f
)
φ
s
= [–180°, 179,99°]
Total power angle
P
t
− total active power
Q
t
− total reactive power
Distortion power factor
P − active power
S −apparent power
THD
Current THD
I
1
− value of first harmonic
n − number of harmonic
Phase voltage THD
U
1
− value of first harmonic
n − number of harmonic
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