ABB Relion 650 Series Technical Manual page 386

Section 10
Monitoring
380
Set value for Formula used for complex, three-
parameter phase power calculation
"Mode"
8 L2
= ×
S 3
EQUATION1399 V1 EN-US
9 L3
= ×
S 3
EQUATION1401 V1 EN-US
* means complex conjugated value
It shall be noted that only in the first two operating modes that is, 1 & 2 the
measurement function calculates the three-phase power accurately. In other
operating modes that is, from 3 to 9 it calculates the three-phase power under
assumption that the power system is fully symmetrical. Once the complex apparent
power is calculated then the P, Q, S, & PF are calculated in accordance with the
following formulas:
=
P Re( ) S
EQUATION1403 V1 EN-US
=
Q Im( ) S
EQUATION1404 V1 EN-US
= = 2 + 2
S S P Q
EQUATION1405 V1 EN-US
P
j
= =
PF cos
S
EQUATION1406 V1 EN-US
Additionally to the power factor value, the two binary output signals from the
function are provided which indicates the angular relationship between the current
and voltage phasors. Binary output signal ILAG is set TRUE when current phasor
is lagging behind voltage phasor. Binary output signal ILEAD is set TRUE when
current phasor is leading the voltage phasor.
Each analogue output has a corresponding supervision level output (X_RANGE).
The output signal is an integer in the interval 0-4, see section
supervision".
Formula used for voltage and
current magnitude calculation
× * U
U I
L 2 L 2
(Equation 15)
I
EQUATION1400 V1 EN-US
×
* U
U I
L 3 L 3
(Equation 17)
I
EQUATION1402 V1 EN-US
1MRK 511 424-UEN B
Comment
Used when
= ×
3 U
only U
L 2
phase-to-
earth voltage
=
I
is available
L 2
(Equation 16)
Used when
= ×
3 U
only U
L 3
phase-to-
earth voltage
=
I
is available
L 3
(Equation 18)
"Measurement
Bay control REC650 2.2 IEC
Technical manual
L2
L3
(Equation 19)
(Equation 20)
(Equation 21)
(Equation 22)