SINAMICS drive Commissioning Workshop

Automation and Drives

SINAMICS_S120

SINAMICS drive Commissioning Workshop

•‘Closed loop’ Bode Analysis

•Current Controller Tuning

•Speed Controller Tuning

•Position Controller Tuning

Engineering-Software SIMOTION SCOUT


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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

The axis will travel in the positive direction with readings started after the offset. Reduce the travel with a lower Measuring periods.

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.


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


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Record Frequency for use in next section


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


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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.


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Start the axis and Measuring function again . Now adjust the Current controller gain and Int. times to achieve the desired responseP1715 = gain P1717 = int. time.


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Note the default value for the gain and integration time


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Adjust Kp and Tn from the default values


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Notice the Overshoot in the Current Actual


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Adjust current curve to desired value


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Curve example on DEMO drive


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Values used in Last Example Curves - optimized Current Controller settings


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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.


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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


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Observe Curves for Overshoot or Delay

Starting values for this example: P gain p1460[0] = 0.100 Nms/radReset time p1462[0] = 100 ms


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Ensure Torque Limits are not exceeded during speed step response


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Adjust Kp and Tn to desired value


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Adjust Kp and Tn for Desired Results

Speed Controller settings this example: P gain p1460[0] = 0.200 Nms/radReset time p1462[0] = 50 ms

Speed controller optimized, and torque limit not exceeded


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Closed Speed Controller Measuring Function – Frequency Domain

Select the first Measuring function from the drop down list. This function is used to optimize the Speed Controller parameters in the 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.


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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

Higher Kp gain increases the band width of the controller

Red: Peak above 0 dB Controller can start oscillating!


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• 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)


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• Reference Model– 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

The Reference model can be used to dampen the initial overshoot with an aggressive Kp setting.


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Step 1: Switch on the speed additional set-point from the axis System variableAxis.servosettings.additionalcommandvalueswitch = YES

CAUTION: Remember to deactivate this setting upon completion of the position tuning.

Closed Position Controller - Axis Position Tuning

Step 2: Setup a temporary program to enable the axis to allow the function generator to enable movement of the axis.


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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.

2. Switch the expert list to the “System variables” tab.

3. 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.

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Step 3: Open the expert list and initialize the PV_Controller variables shown below.


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Step 4: Initialize DynamicData with zero values for positionTimeConstant, torqueTimeConstant, and velocityTimeConstant.

Step 3: The values from previous slide are now in the current value column


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Adjust the Amplitude to limit the travel of the oscillating axis.

Step 5: Configure the function generator to the Signal Name: Triangular with a carefully selected Amplitude and Period


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


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


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Kpc = 0.0 %Kv = 10, Following error 0.4

Step 6: Run the initial trace and note the Following error readings.


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Step 7: Optimize the performance by setting Kpc Weighting factor of the precontrol to 100%


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Step 8: Continue to optimize the performance with adjustments to the Kv value.



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


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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


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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

Documents

SINAMICS drive Commissioning Workshop