frako PQC - Page 51

Description of the menu | 51
FRAKO | Operating Manual | Power Quality Controller – PQC
Control characteristic at
cosφ
target
=0.92 ind
Limitation = OFF
Parallel shift = –1.0 (capacitive)
Here the set cosφ
target
constitutes
the lower (more inductive) limit of
the control band. When regenera-
tion occurs, the lower (more induc-
tive) limit constitutes a cos φ
target
of 1. This means that no inductive
reactive power can result during
feed-in operation.
Limitation
This setting gives new possibilities that could not be attained previously due to con-
flicting requirements.
The range of values for limitation are -2 to +2 in increments of 0.5, plus the setting
OFF. Setting the limitation at 1 and cosφ
target
at 1.00 has exactly the same effect as the
parallel shift described above. If cosφ
target
is not set at 1, a kink results in the control
curve, as shown in the following example. The limitation forms an absolute boundary
beyond which the reactive power may not go.
Control characteristic at
cosφ
soll
=0.92 ind
Limitation=+1.0
Parallel shift= 0.0
This setting has the following
effects:
– The set cosφ
target
is attained,
on average, in the upper power
range.
– Overcorrection (capacitive,
usually disruptive) is avoided in
the low load range.
Reactive power
ind
4
3
cap
Regeneration
Switch in
Switch out
One division =
0.65 × smallest cap.
stage
-2
-1
Active power
Reactive power
ind
2
1
cap
Regeneration
Switch in
Switch out
One division =
0.65 × smallest cap.
stage
-3
Active power
Reactive power
ind
4
3
cap
Regeneration
Switch in
Switch out
One division =
0.65 × smallest cap.
stage
-2
-1
Active power
Reactive power
ind
2
1
cap
Regeneration
Switch in
Switch out
One division =
0.65 × smallest cap.
stage
-3
Active power