Siemens SINAMICS G120 Operating Instructions Manual page 301

When the speed setpoint is increased, the speed controller responds with a higher setpoint
for current component I
setpoint 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 keep the motor flux constant using the output voltage, and adjust the matching
d
current component I
The complete function diagrams 6020 ff. for vector control are provided in the List Manual.
Settings that are required
Select the vector control during to quick commissioning.
In order to achieve a satisfactory control response, as a minimum you must set the partial
functions – shown with gray background in the diagram above – to match your particular
application:
● Motor and current model: In the quick commissioning, correctly set the motor data on the
rating plate corresponding to the connection type (Y/Δ), and carry out the motor data
identification routine at standstill.
● Speed limits and torque limits: In the quick commissioning, set the maximum speed (p1082)
and current limit (p0640) to match your particular application. When exiting quick
commissioning, the inverter calculates the torque and power limits corresponding to the
current limit. The actual torque limits are obtained from the converted current and power
limits and the set torque limits.
● Speed controller: Start the rotating measurement of the motor data identification. You must
manually optimize the controller if the rotating measurement is not possible.
The load falls due to incorrect closed-loop control settings
For encoderless vector control, the inverter calculates the actual speed based on an electric
motor model. In applications with pulling loads - e.g. hoisting gear, lifting tables or vertical
conveyors - an incorrectly set motor model or other incorrect settings can mean that the load
falls. A falling load can result in death or serious injury.
● Correctly set the motor data during the quick commissioning.
● Carry out the motor data identification.
● Correctly set the "Motor holding brake" function.
● For pulling loads, carefully comply with the recommended settings for vector control.
Converter with the CU250S-2 Control Units
Operating Instructions, 04/2018, FW V4.7 SP10, A5E31759476B AG
(torque setpoint). The closed-loop control responds to a higher torque
q
in the motor.
q
Quick commissioning with a PC (Page 134)
WARNING
Motor holding brake (Page 220)
Advanced settings (Page 303)
Advanced commissioning
6.21 Motor control
and
q
299