ABB Relion 670 series - Page 1042

Set value
for
parameter
“Mode”
Formula used for complex,
three-phase power calculation
Formula used for voltage
and current magnitude
calculation
Comment
8 B
*
3
B B
S V I= × ×
EQUATION1575 V1 EN-US (Equation 219)
3
B
B
V V
I I
= ×
=
EQUATION1576 V1 EN-US (Equation 220)
Used when only V
B
phase-to-
ground voltage is available
9 C
*
3
C C
S V I= × ×
EQUATION1577 V1 EN-US (Equation 221)
3
C
C
V V
I I
= ×
=
EQUATION1578 V1 EN-US (Equation 222)
Used when only V
C
phase-to-
ground voltage is available
* 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:
Re( )=P S
EQUATION1403 V1 EN-US (Equation 223)
Im( )=Q S
EQUATION1404 V1 EN-US (Equation 224)
2 2
= = +S S P Q
EQUATION1405 V1 EN-US (Equation 225)
cos
P
PF
S
j = =
EQUATION1406 V1 EN-US (Equation 226)
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
"Measurement supervision".
Section 16 1MRK 502 066-UUS B
Monitoring
1036
Technical manual