Siemens Sinamics CU240D-2 DP Operating Instructions Manual page 242

Advanced commissioning
6.22 Efficiency optimization
The inverter has two different methods of optimizing the efficiency.
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 6-57
Based on its thermal motor model, the inverter continually determines - for the actual
operating point of the motor - the interdependency between efficiency and flux. The inverter
then sets the flux to achieve the optimum efficiency.
Figure 6-58
Depending on the motor operating point, the inverter either decreases or increases the flux
in partial load operation of the motor.
240
Determining the optimum flux from the motor thermal model
Qualitative result of efficiency optimization, method 2
Converter with the control units CU240D-2
Operating Instructions, 04/2018, FW V4.9 SP10, A5E34262100B AF