ABB RELION 670 Series Technical Manual page 1042

Section 16
Monitoring
Set value
for
parameter
"Mode"
8 B
9 C
* means complex conjugated value
It shall be noted that only in the first two operating modes that is, 1 & 2 the measurement function
calculates exact three-phase power. 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( )
EQUATION1403 V1 EN-US
=
Q Im( )
EQUATION1404 V1 EN-US
= =
S S
EQUATION1405 V1 EN-US
=
PF cos
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 current and voltage phasors. Binary
output signal ILAG is set to one when current phasor is lagging behind voltage phasor. Binary
output signal ILEAD is set to one when current phasor is leading the voltage phasor.
Each analog output has a corresponding supervision level output (X_RANGE). The output signal is
an integer in the interval 0-4, see section
1036
Formula used for complex,
three-phase power calculation
= × ×
*
S 3 V I
B B
(Equation 219)
EQUATION1575 V1 EN-US
= × ×
*
S 3 V I
C C
(Equation 221)
EQUATION1577 V1 EN-US
S
S
+
2 2
P Q
P
j
=
S
Formula used for voltage
and current magnitude
calculation
= ×
V 3 V
B
=
I I
B
(Equation 220)
EQUATION1576 V1 EN-US
= ×
V 3 V
C
=
I I
C
(Equation 222)
EQUATION1578 V1 EN-US
"Measurement supervision".
1MRK 502 066-UUS B
Comment
Used when only V phase-to-
B
ground voltage is available
Used when only V phase-to-
C
ground voltage is available
(Equation 223)
(Equation 224)
(Equation 225)
(Equation 226)
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