ABB RELION REX640 Technical Manual page 1300

Section 8
Measurement functions
1294
Power and energy calculation
The three-phase power is calculated from the selected voltage and current
measurements as described in
which voltage and current measurements are used.
It is also possible to use positive-sequence components for calculating the apparent
power, which makes the determination of power insensitive to any asymmetry in
currents or voltages.
Table 1212: Measured apparent power
Measurement mode setting values
PhsA, PhsB, PhsC
Arone
Pos Seq
PhsAB
PhsBC
PhsCA
PhsA
PhsB
PhsC
Depending upon the set Measurement mode, the Power and energy calculation
module calculates active power, reactive power and apparent power values from the
available set of measurements.
= Re( )
P S
GUID-92B45FA5-0B6B-47DC-9ADB-69E7EB30D53A V3 EN
= Im( )
Q S
GUID-CA5C1D5D-3AD9-468C-86A1-835525F8BE27 V2 EN
Table 1212. The setting Measurement mode determines
Power calculation
*
S U I
A A
= ⋅
GUID-0E4C3325-1A8B-4DFA-8A70-CBB508838B60 V2 EN
S U I
AB A
= ⋅
GUID-8A07ECC3-F782-48AF-9401-E709F69BF0CD V2 EN
S 3 U I
1
= ⋅ ⋅
GUID-C55D5498-6C37-4B07-B758-B8A3674DEC79 V1 EN
S U I
(
= AB ⋅
GUID-F67848F8-BB18-445B-B52F-46C6CBB5986C V2 EN
S U
(
= BC ⋅
GUID-BCA2A686-B97C-4905-93C6-7AD6A65D5692 V2 EN
S U
(
CA
= ⋅
GUID-7003D94A-A22D-41AF-A749-37B0F29C0852 V2 EN
S U I
3
= ⋅ A ⋅
GUID-E5B78E29-83FD-4CD1-AC06-7F0C9454EA09 V2 EN
S U I
3
= ⋅ B ⋅
GUID-64E089D0-5EA1-447B-ADD5-A50D647F460A V2 EN
S U I
3
= ⋅ C
GUID-48147482-88A8-4004-B3FE-078F438050E3 V2 EN
1MRS759142 C
* *
U I U I
B B C C
+ ⋅ + ⋅
(Equation 304)
* *
U I
BC C
− ⋅
(Equation 305)
*
1
(Equation 306)
* *
I
)
A − B
(Equation 307)
* *
I I
)
B − C
(Equation 308)
* *
I I
)
C A
−
(Equation 309)
*
A
(Equation 310)
*
B
(Equation 311)
*
⋅ C
(Equation 312)
(Equation 313)
(Equation 314)
Technical Manual
REX640