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

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.

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

Record Frequency for use in next section

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

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.

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.

Note the default value for the gain and integration time

Adjust Kp and Tn from the default values

Notice the Overshoot in the Current Actual

Adjust current curve to desired value

Curve example on DEMO drive

Values used in Last Example Curves - optimized Current Controller settings

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.

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

Observe Curves for Overshoot or Delay Starting values for this example: P gain p1460[0] = 0.100 Nms/rad Reset time p1462[0] = 100 ms

Ensure Torque Limits are not exceeded during speed step response

Adjust Kp and Tn to desired value

Adjust Kp and Tn for Desired Results Speed Controller settings this example: P gain p1460[0] = 0.200 Nms/rad Reset time p1462[0] = 50 ms Speed controller optimized, and torque limit not exceeded

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.

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

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)

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

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.

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

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.

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.

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

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

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

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

Step 8: Continue to optimize the performance with adjustments to the Kv value. Kpc = 100.0 % Kv = 40, Following error 0.016

Kpc = 100.0 % Kv = 80, Following error 0.016

Kpc = 100.0 % Kv = 200, Following error 0.012 Axis movement may be to stiff for mechanical connections with this Kv

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 = 100.0 % Kv = 200, Following error 0.2 Axis movement may be to stiff for mechanical connections with this Kv

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