ABB RES670 Technical Manual page 262

Section 8
Current protection
256
Chosen current
phasors
Complex
power
Chosen voltage
calculation
phasors
ANSI06000438 V2 EN-US
Figure 81: Simplified logic diagram of the power protection function
The function will use voltage and current phasors calculated in the pre-processing
blocks. The apparent complex power is calculated according to chosen formula as
shown in table 138.
Table 138: Complex power calculation
Set value: Mode
A, B, C
Arone
PosSeq
AB
BC
Table continues on next page
P
Derivation of
S( angle)
S( composant)
in Char angle
Q
Formula used for complex power calculation
= ×
S V I
A
EQUATION2055-ANSI V1 EN-US
=
S V
AB
EQUATION2056-ANSI V1 EN-US
= ×
S 3 V
PosSeq
EQUATION2057-ANSI V1 EN-US
= ×
S V
AB
EQUATION2058-ANSI V1 EN-US
= ×
S V
BC
EQUATION2059-ANSI V1 EN-US
Phasor measurement unit RES670 2.2 ANSI
1MRK 511 408-UUS A
S( angle ) < t TRIP 1
Power1
0
PICKUP1
S( angle ) < t TRIP2
Power2
0
PICKUP2
P = POWRE
Q = POWIM
ANSI06000438-2-en.vsd
* * *
+ × + ×
V I V I
A B B C C
(Equation 28)
* *
× - ×
I V I
A BC C
(Equation 29)
*
×
I
PosSeq
(Equation 30)
* *
-
( I I )
A B
(Equation 31)
* *
-
( I I )
B C
(Equation 32)
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