Functions
5.7 Closed-loop control
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.
111
5.7.1.4 Additional characteristics for the V/f control
In addition to linear and square-law characteristics, there are the following additional variants
of the V/f control that are suitable for special applications.
Table 5- 23 Further V/f control methods (P1300)
Parameter
value
Application
P1300 = 1 Linear V/f characteristic with Flux Current Control (FCC)
Voltage losses across the stator resistance are automatically compensated. This is
particularly useful for small motors since they have a relatively high stator
resistance. The prerequisite is that the value of the stator resistance in P350 is
parameterized as accurately as possible.
P1300 = 3 Freely adjustable V/f characteristic,
which supports the torque behavior of
synchronous motors (SIEMOSYN
motors)
Q
9
3
I
3
I
PD[
3
9
PD[
U
9
3
3
3
I
+]
I
3
I
3
I
Q
3
I
3
3
P1300 = 5
P1300 = 6
Linear V/f characteristic for textile applications where it is important that the motor
speed is kept constant under all circumstances. This setting has the following
effects:
1. When the maximum current limit is reached, the stator voltage is reduced but
not the speed.
2. Slip compensation is inhibited.
P1300 = 19 V/f control without characteristic. The interrelationship between the frequency and
voltage is not calculated in the frequency inverter, but is specified by the user. With
BICO technology, P1330 defines the interface via which the voltage setpoint is
entered (e.g. analog input → P1330 = 755).
For more information about this function, see function diagrams 6100 and 6200 in the List
Manual.
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