Siemens SINAMICS G120C Operating Instructions Manual page 355

Efficiency optimization, method 2
Generally, energy efficiency optimization method 2 achieves a better efficiency than
method 1.
We recommend that you set method 2.
Figure 8-76
Based on its thermal motor model, the converter continually determines - for the actual
operating point of the motor - the interdependency between efficiency and flux. The
converter then sets the flux to achieve the optimum efficiency.
Figure 8-77
Depending on the motor operating point, the converter either decreases or increases the flux
in partial load operation of the motor.
Efficiency optimization, method 1
Figure 8-78
SINAMICS G120C Converters
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK
Determining the optimum flux from the motor thermal model
Qualitative result of efficiency optimization, method 2
Reduce the flux setpoint in the partial load range of the motor
Advanced commissioning
8.31 Efficiency optimization
353