Characteristics Of U/F Control - Siemens SINAMICS G120D Series Operating Instructions Manual

7.5.1.1

Characteristics of U/f control

The inverter has different V/f characteristics.
①
②
Figure 7-20
The inverter increases its output voltage to the maximum possible output voltage. The
maximum possible output voltage of the inverter depends on the line voltage.
When the maximum output voltage is reached, the inverter only increases the output
frequency. At this point, the motor enters the field weakening range: At constant torque, the
slip decreases quadratically as the speed increases.
Converter with control units CU240D-2
Operating Instructions, 04/2015, FW V4.7.3, A5E34262100B AB
The voltage boost of the characteristic optimizes the speed control at low speeds
With the flux current control (FCC), the inverter compensates for the voltage drop in the stator
resistor of the motor
Characteristics of U/f control
Advanced commissioning
7.5 Motor control
147