Adjust Speed Loop - Parker 590+ DRV Product Manual

Adjust Speed Loop

For most applications, the default values for speed loop parameters SPD.PROP.GAIN and SPD. INT. TIME provide stable performance. In a few
cases, you may need to tune the speed loop for optimum speed response. The following procedures explain how to tune the speed loop.
For this procedure, monitor the speed feedback with an oscilloscope between terminals A7 (SPEED FEEDBACK) and A0 (0V).
NOTE
Adjust the speed loop only after tuning the current loop with AUTOTUNE. Make certain the motor is connected to the load it will normally
be running.
•
SPD.PROP.GAIN scales the output based upon the input speed error.
Increasing SPD.PROP.GAIN improves response time but also increases overshoot.
•
SPD.INT.TIME eliminates steady-state error. Reducing SPD.INT.TIME improves response, but will cause instability if set too short.
1. Connect terminal B3 (+10 VDC) through a switch to terminal A3. This will provide the step change input for verifying speed loop performance.
2. Calibrate terminal A3 for 10% output by setting SETUP PARAMETERS::SPEED LOOP::SETPOINTS::RATIO 2 (A3) to 0.1000.
3. Set SETUP PARAMETERS::SPEED LOOP::INT. DEFEAT to ON. This disables the integral gain.
4. Run the motor at a typical operating speed through the speed ramp input, terminal A4. Do not set the speed above 50 percent.
5. Check the speed loop performance by making step changes using the switch at terminal A3. Increase SETUP PARAMETERS::SPEED LOOP::
PROP. GAIN until the response is critically damped, generally no more than 4% overshoot, as illustrated (refer to Chapter 5).
6. Once stable, proportional control is attained, set SETUP PARAMETERS::SPEED LOOP::INT. DEFEAT to OFF.
7. Check the speed loop performance by making step changes using the switch at terminal A3. Reduce SETUP PARAMETERS::SPEED
LOOP::SPD.INT.TIME until the response is critically damped.
Note:
8. Stop the drive and remove the switched signal from terminal A3.
9. Set SETUP PARAMETERS::SPEED LOOP::SETPOINTS::RATIO 2 (A3) back to 1.0000, then run normally.
10. SAVE PARAMETERS prior to disconnecting power.
DC590+ DRV Series DC Digital Drive
The default value for SPD.INT.TIME is 0.5 seconds. That value may be too small for large inertia loads and cause the system to
be unstable from the start.
Calibration and Start-Up
4-15