U/F Control - Siemens SINAMICS G120C Operating Instructions Manual

Advanced commissioning
8.20 Motor control
Parameter
Number
p0010
p0230
p0235
p0350[M]
p0352[M]
For further information on parameters, please refer to the parameter list.
8.20.2

U/f control

8.20.2.1 U/f control
Overview
1)
Figure 8-46
The U/f control is a speed feedforward control with the following properties:
• The converter sets the output voltage on the basis of the U/f characteristic.
• The output frequency is essentially calculated from the speed setpoint and the number of
pole pairs of the motor.
• The slip compensation corrects the output frequency depending on the load and thus
increases the speed accuracy.
• The omission of a control loop means that the U/f control is stable in all cases.
• In applications with higher speed accuracy requirements, a load-dependent voltage boost
can be selected (flux current control, FCC)
For operation of the motor with U/f control, you must set at least the following subfunctions
appropriate for your application:
• U/f characteristic
• Voltage boost
300
Name
Drive commissioning parameter filter
Drive filter type, motor side
Number of motor reactors in series
Motor stator resistance, cold
Cable resistance
In the "Flux Current Control (FCC)" U/f version, the converter controls the motor current (starting
current) at low speeds.
Simplified function diagram of the U/f control
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK
Factory setting
1
0
1
0 Ω
0 Ω
SINAMICS G120C Converters