Asynchronous motors in U/f control mode

The U/f control mode is intended for easy open-loop operation of asynchronous motors without encoder feedback. The procedure operates an asynchronous machine on a parameterizable voltage/frequency characteristic.

To keep the magnetizing current on a constant level, the voltage (V) is adjusted in proportion to the frequency (f). The actual slip is estimated and can be compensated.

Control mode is suitable for applications with a limited speed setting range, where no dynamic step changes in load occur and where there are small requirements regarding the control characteristics.

Control mode is suitable for multi-motor drives.

Slip compensation may only be activated with rigidly coupled drives.