ABB RELION REX640 Technical Manual page 1081

1MRS759142 F
-P
Figure 607: Power factor quadrant
If the polarity of the voltage signal is opposite to the normal polarity, the correction
can be done by setting
vector by 180 degrees.
If the magnitude of all three phase currents or voltages are respectively less than
Current block value and Voltage block value settings, the power factor is set as unity
that is 1.00 and the function is disabled internally.
The DISABLE input can be used to coordinate the correct operation during the
startup situation. By activating the DISABLE signal, the power factor calculation is
blocked. Once the DISABLE signal is deactivated, the function remains blocked for
additional time duration as set through the setting
Level detector 1
The Level detector 1 compares the calculated power factor to the set
the power factor value goes below the set
Dir start value , the Level detector sends an enabling signal to the Timer 1 module.
Level detector 2
The Level detector 2 compares the calculated power factor to the set
the power factor value goes below the set
Dir alarm value , the Level detector sends an enabling signal to the Timer 2 module.
Timer 1
Once activated, the Timer 1 activates the START output. The timer characteristic is
according to DT. When the operate timer has reached the value set by
time in the DT mode, the OPERATE output is activated. If a drop-off situation occurs,
that is, a power factor improves and exceeds the
as defined by
REX640
Technical Manual
Generator convention
Forward reactive power
+Q
Synchronous
Generator
motor
PF<0 (lead) PF>0 (lag)
Q2 Q1
(PF = -1.0)
Q3 Q4
PF<0 (lag)
PF>0 (lead)
Induction Induction
motor generator
-Q
Reverse reactive power
I
E V
Voltage reversal to "Yes", which rotates the power factor
Dir start reset value before the operate delay is exceeded or either
(PF = -1.0)
(PF = 1.0)
+P -P
Start value in the direction as defined by
Alarm value in the direction as defined by
Start reset value in the direction
Protection functions
Motor convention
Forward reactive power
+Q
Induction Induction
generator motor
PF<0 (lead) PF>0 (lag)
Q2 Q1
Q3 Q4
PF<0 (lag)
PF>0 (lead)
Synchronous
Generator
motor
-Q
Reverse reactive power
I
E V
Disable time .
Start value . If
Alarm value . If
Start delay
(PF = 1.0)
+P
1081