1. SINAMICS drive Commissioning Workshop
‘Closed loop’ Bode Analysis
Current Controller Tuning
Speed Controller Tuning
Position Controller Tuning
Engineering-Software SIMOTION SCOUT

2. Set the Speed controller gain to 0. 1(P1460) and int
Set the Speed controller gain to 0.1(P1460) and int. time to 100msec (P1462). Now select measuring Function 1 from the drop Down Choice
Start with the first Measuring function from the drop down list. This function is used to locate the frequency of the Current set point bandwidth filter.
The axis will travel in the positive direction with readings started after the offset. Reduce the travel with a lower Measuring periods.

3. Start the axis and then Run Trace and use X Cursor to find Frequency
of 1st Pole

4. Record Frequency for use in next section

5. Open Current Setpoint Filter and use Previous value for Notch Frequency.

6. Use this Measuring Function Choice for Next Step
Select the last Measuring function from the drop down list. This function is used to optimize the Current Controller P Gain (p1715) and reset (p1717) parameters.

7. Start the axis and Measuring function again . Now adjust the
Current controller gain and Int. times to achieve the desired response
P1715 = gain P1717 = int. time.

8. Note the default value for the gain and integration time

9. Adjust Kp and Tn from the default values

10. Notice the Overshoot in the Current Actual

11. Adjust current curve to desired value

12. Curve example on DEMO drive

13. Values used in Last Example Curves - optimized Current Controller settings

14. Note Default Value of n (speed) Controller and set Tn to 100ms
Expand the Open-loop /closed-loop control below the drive. Double click the Speed controller.

15. Closed Speed Controller Measuring Function – Time Domain
Select the fifth Measuring function from the drop down list. This function is used to optimize the Speed Controller parameters

16. Observe Curves for Overshoot or Delay
Starting values for this example:
P gain p1460[0] = Nms/rad
Reset time p1462[0] = 100 ms

17. Ensure Torque Limits are not exceeded during speed step
response

18. Adjust Kp and Tn to desired value

19. Adjust Kp and Tn for Desired Results
Speed Controller settings this example:
P gain p1460[0] = Nms/rad
Reset time p1462[0] = 50 ms
Speed controller optimized, and torque limit not exceeded

20. Closed Speed Controller Measuring Function – Frequency Domain
This is an optional step to ensure the Kp value derived above does not produce a bode diagram that raises above the 0db line.
Select the first Measuring function from the drop down list. This function is used to optimize the Speed Controller parameters in the Frequency Domain.

21. Only P- controlled Kp = p1460[0] Nms/rad
Measurement of Closed Speed Controller – Bode Diagram – Frequency Domain
Only P- controlled Kp = p1460[0] Nms/rad
Kp=0.04 Nms/rad, Kp=0.1 Nms/rad, Kp=0.2 Nms/rad, Tn =1000 ms
Red: Peak above 0 dB  Controller can start oscillating!
Higher Kp gain increases the band width of the controller

22. Comparison of Time Domain and Frequency Domain
Kp=0.04 Nms/rad, Kp=0.1 Nms/rad, Kp=0.2 Nms/rad, Tn =1000 ms
Higher Kp gain increases the band width of the controller  shorter rise time (see step response)

23. The Reference model can be used to dampen the initial overshoot with an aggressive Kp setting.
Red: Kp = 0.15 Nms/rad, Tn 6 ms, fref = 250 Hz, D = 0.707
Green: Kp = 0.15 Nms/rad, Tn 6 ms ,fref = 60 Hz, D = 0.707
Blue: Kp = 0.15 Nms/rad, Tn 6 ms, fref = 130 Hz, D = 0.707
Reference model too small fref = 60 Hz

24. Closed Position Controller - Axis Position Tuning
Step 1: Switch on the speed additional set-point from the axis System variable
Axis.servosettings.additionalcommandvalueswitch = YES
CAUTION: Remember to deactivate this setting upon completion of the position tuning.
Step 2: Setup a temporary program to enable the axis to allow the function generator to enable movement of the axis.

25. Step 3: Open the expert list and initialize the PV_Controller variables shown below.
Open the Expert list of the Axis for balanceFilterMode, kpc, and preCon
TypeOfAxis.NumberOfDataSets.ControllerStruct.PV_Controller.balanceFilterMode 1
Select the entries as shown above in the Next value column.
Switch the expert list to the “System variables” tab.
Select the restartactivation entry as “activate_restart”. Click back on the “Configuration data” tab to have the entries accepted into the Current value. See the next slide for the result. 2 3

26. Step 3: The values from previous slide are now in the current value column
Step 4: Initialize DynamicData with zero values for positionTimeConstant, torqueTimeConstant, and velocityTimeConstant.

27. Step 5: Configure the function generator to the Signal Name: Triangular with a carefully selected Amplitude and Period
Adjust the Amplitude to limit the travel of the oscillating axis.

28. Adjust the Positioning window and the Standstill window to prevent function from
Generating a Standstill error. Rotary axis will be in degrees.

29. Step 6: Configure a trace with the axis data as shown below.

30. Step 6: Run the initial trace and note the Following error readings.
Kpc = 0.0 %
Kv = 10, Following error 0.4

31. Step 7: Optimize the performance by setting Kpc Weighting factor of the precontrol to 100%
Kv = 10, Following error 0.016

32. Step 8: Continue to optimize the performance with adjustments to the Kv value.
Kpc = %
Kv = 40, Following error 0.016

33. Kpc = %
Kv = 80, Following error 0.016

34. Kpc = %
Kv = 200, Following error Axis movement may be to stiff for mechanical connections with this Kv

35. This trace shows the same Position tuning values with the period decreased to 800 ms. The overall spike in the following error can be reduced with adjustments to Kpc, though; this introduces a greater average following error.
Kpc = %
Kv = 200, Following error Axis movement may be to stiff for mechanical connections with this Kv

36. Important parameters for the tuning in Simotion
• Cycle time DP-, Servo- and IPO-cycle time
• DSC needed Telegram 105
• Kv position controller-amplification
• Kpc Pre-control
• FIPO Fine interpolation type
• VelocityTimeConstant (vTc) Symmetry filter time constant (PT1-Glied)
• PositionTimeConstant (pTc) Position extrapolation time