ABB 650 series, Техническое руководство

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Set value: Mode Formula used for complex power calculation
CA
* *
( )
CA C A
S V I I
= × -
EQUATION2060-ANSI V1 EN
(Equation 69)
A
*
3
A A
S V I
= × ×
EQUATION2061-ANSI V1 EN
(Equation 70)
B
*
3
B B
S V I
= × ×
EQUATION2062-ANSI V1 EN
(Equation 71)
C
*
3
C C
S V I
= × ×
EQUATION2063-ANSI V1 EN
(Equation 72)
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 Angle1(2) is calculated.
If this 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 Power1(2) . For
directional underpower protection, a pickup signal PICKUP1(2) is activated if the
calculated power component is smaller than the pick up value. For directional overpower
protection, a pickup signal PICKUP1(2) is activated if the calculated power component is
larger than the pick up value. After a set time delay
TripDelay1(2) a trip TRIP1(2) signal
is activated if the pickup signal is still 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 hysteresis in the power function. The absolute hysteresis for
stage 1(2) is 0.5 p.u. for Power1(2) ≥ 1.0 p.u., else the hysteresis is 0.5 Power1(2).
If the measured power drops under the (Power1(2) - hysteresis) value, the over-power
function will reset after 0.06 seconds. If the measured power comes over the (Power1(2)
+ hysteresis) value, the under-power function will reset after 0.06 seconds. The reset
means that the pickup signal will drop out and that the timer of the stage will reset.
8.7.4.1 Low pass filtering
In order to minimize the influence of the noise signal on the measurement it is possible to
introduce the recursive, low pass filtering of the measured values for S (P, Q). This will
Section 8
1MRK 502 048-UUS A
Current protection
260
Technical manual