VAMP 259 - Power Calculation

4.8 Power calculation
4 Measurement functions
Technical description
192
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4.8. Power calculation
The equations used for power calculations are described in this
chapter.
Following equation is used for power calculation.
*
33
*
22
*
11 LLLLLL
IUIUIUS 
, where
S
=
Three phase power phasor
1L
U
=
Measured voltage phasor corresponding the
fundamental frequency voltage of phase
L1
.
*
1L
I
=
Complex conjugate of the measured phase
L1
fundamental frequency current phasor.
2L
U
=
Measured voltage phasor corresponding the
fundamental frequency voltage of phase
L2
.
*
2L
I
=
Complex conjugate of the measured phase
L2
fundamental frequency current phasor.
3L
U
=
Measured voltage phasor corresponding the
fundamental frequency voltage of phase
L3
.
*
3L
I
=
Complex conjugate of the measured phase
L3
fundamental frequency current phasor.
Apparent power, active power and reactive power are
calculated as follows
S
P
SimagQ
SrealP
SS




 cos
)(
)(