Open topic with navigation

V/f mode

In V/f mode in the Closed-loop control subject area it is possible to run a simple test indicating to the user whether a motor is connected correctly and moving in the right direction (linear drive: right/left running). If the direction has been reversed, the motor is stopped or executing uncontrollable movements, the termination and the motor data must be checked.
As a test mode, a voltage/frequency control system is implemented in such a way that the closed-loop speed control circuit is replaced by open-loop control. So the reference in this case is also the speed reference; the actual speed is set equal to the reference. A linear characteristic with two interpolation points is implemented, with a fixed boost voltage setting P 0313 CON_VFC_VBoost at 0 Hertz. As from the rated frequency P 0314 CON_VFC_FNom the output voltage remains constant. An asynchronous machine is thus automatically driven into field-weakening as the frequency rises.

Bild: V/f mode dialog box