U/F Control - Siemens SINAMICS G115D Operating Instructions Manual

6.18.1

U/f control

Overview
In the U/f control variant, "flux current control (FCC)," the converter controls the motor current
1)
(starting current) at low speeds
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
SINAMICS G115D distributed drive
Operating Instructions, 12/2020, FW V4.7 SP13, A5E48681219B-002
Advanced commissioning
6.18 Motor control
255