ABB RELION 670 Series Technical Manual page 561

1MRK 502 066-UUS B
Table 290: Complex power calculation
Set value:
A,B,C
Arone
PosSeq
A,B
B,C
C,A
A
B
C
The active and reactive power is available from the function and can be used for monitoring and
fault recording.
The component of the complex power S = P + jQ in the direction
angle is 0° the active power component P is calculated. If this angle is 90° the reactive power
component Q is calculated.
The calculated power component is compared to the power pick up setting
signal PICKUP1(2) is activated if the calculated power component is larger than the pick up value.
After a set time delay
active. At activation of any of the two stages a common signal PICKUP will be activated. At trip
from any of the two stages also a common signal TRIP will be activated.
To avoid instability there is a settable hysteresis in the power function. The absolute hysteresis of
the stage1(2) is
protection the power setting is very low, normally down to 0.02 p.u. of rated generator power. The
Technical manual
Mode
TripDelay1(2) a trip TRIP1(2) signal is activated if the pickup signal is still
Hysteresis1(2) = abs (Power1(2) – drop-power1(2)). For generator reverse power
Formula used for complex power calculation
* *
= × + ×
S V I V I
A A B B
EQUATION2038 V1 EN-US
*
-
= × ×
S V I V
AB A BC
EQUATION2039 V1 EN-US
*
= × ×
S 3 V I
PosSeq
PosSeq
EQUATION2040 V1 EN-US
*
*
-
= × )
S V (I I
AB A B
EQUATION2041 V1 EN-US
*
*
-
= × )
S V (I I
B C
BC
EQUATION2042 V1 EN-US
*
*
-
= × )
S V (I I
CA C A
EQUATION2043 V1 EN-US
*
= × ×
S 3 V I
A A
EQUATION2044 V1 EN-US
*
= × ×
S 3 V I
B B
EQUATION2045 V1 EN-US
*
= × ×
S 3 V I
C C
EQUATION2046 V1 EN-US
Angle1(2) is calculated. If this
Current protection
*
+ ×
V I
C C
(Equation 152)
*
I
C
(Equation 153)
(Equation 154)
(Equation 155)
(Equation 156)
(Equation 157)
(Equation 158)
(Equation 159)
(Equation 160)
Power1(2) . A pickup
Section 8
555