Vector Control With Speed Controller - Siemens sinamics G120 Operating Instructions Manual

6.5.2

Vector control with speed controller

Overview
The vector control comprises current control and a higher-level speed control.
for induction motors
1)
Image 6-38 Simplified function diagram for vector control with speed controller
The complete function diagrams 6020 ff. for vector control are provided in the List Manual.
Using the motor model, the inverter calculates the following closed-loop control signals from
the measured phase currents and the output voltage:
● Current component I
● Current component I
The setpoint of the current component I
speeds above the rated speed, the inverter reduces the flux setpoint along the field
weakening characteristic.
When the speed setpoint is increased, the speed controller responds with a higher setpoint
for current component I
by adding a higher slip frequency to the output frequency. The higher output frequency also
results in a higher motor slip, which is proportional to the accelerating torque. I
I controllers maintain the motor flux constant using the output voltage, and set the matching
d
current component I
Converter with CU250S-2 Control Unit
Operating Instructions, 01/2016, FW V4.7 SP6, A5E31759476B AE
q
q
(flux setpoint) is obtained from the motor data. For
d
(torque setpoint). The control responds to the higher torque setpoint
q
in the motor.
q
Advanced commissioning
6.5 Motor control
and
q
233