Characteristics Of V/F Control - Siemens Sinamics G120P Operating Instructions Manual

7.5.3.1

Characteristics of V/f control

The inverter has several V/f characteristics. Based on the characteristic, as the frequency
increases, the inverter increases the voltage at the motor.
①
The voltage boost of the characteristic improves motor behavior at low speeds. The voltage boost is effective for fre-
quencies < rated frequency
Figure 7-16 V/f characteristics of the inverter
The inverter increases its output voltage – also above the motor rated speed up to the
maximum output voltage. The higher the line voltage, the higher the maximum inverter
output voltage.
If the inverter has reached its maximum output voltage, then it can only increase its output
frequency. From this point onwards, the motor is operated in field weakening; this means
that the available torque linearly decreases with increasing speed.
Inverter cabinet units
Operating Instructions, 12/2014, A5E32923362A
Functions
7.5 Motor control
361