
Functions
5.7 Closed-loop control
Frequency inverter
110
Operating Instructions, 08.10. 2008, t.b.d.
Additional information about this function is provided in the parameter list and in the function
diagrams 6100 and 6200 in the List Manual.
Note
Only increase the voltage boost in small steps until satisfactory motor behavior is reached.
Excessively high values in P1310 and P1311 can cause the motor to overhead and switch
off (trip) the frequency inverter due to overcurrent .
5.7.1.3
V/f control with parabolic characteristic
V/f control with a parabolic characteristic is used in applications in which
the motor torque increases with the motor speed. Examples of such
applications include pumps and fans.
V/f control with a parabolic characteristic reduces the losses in the motor
and inverter due to lower currents than when a linear characteristic is
used.
9
Q
I
Q
9
3
Note
V/f control with a parabolic characteristic must not be used in applications in which a high
torque is required at low speeds.
Table 5- 22 Setting the control type
Parameter Description
P0003 = 2
Extended access to the inverter functions
P1300 = 2
Control type: V/f control with parabolic characteristic