PowerFlex DC Drive

[GTaylor 0]

I have a PowerFlex DC drive that is causing me some issues.  I will preface this by saying I am not a drives guy.  Our problem is we ask it to reach a certain speed and it will overshoot for just a bit before normalizing.  This causes issues with other components of our line (speed too fast so it shuts down).  I have attached my CCW project file.  The trends in CCW follow pretty closely, reference speed, amps, and encoder feedback all track together pretty well.  Just the initial reference request will over shoot and then settle down.  Is there a group of parameters I could change to eliminate this?

1000 ton press as left_Copy_1.ccwsln

[VFD Guy 13]

This file cannot be opened by itself. You’ll need to attach a ccwarc file or the entire folder zipped. This is likely a tuning issue. Have you followed the DC user manual?

[GTaylor 0]

Sorry I have reattached a zipped folder.  Yes we went through the manual step by step and even had a rockwell engineer out though his specialty was AC.  He mad a couple of changes:  Speed RI - parameter 88, and Speed BW - parameter 434.  We saw improvements at the low end of the speed reference but that isn't really an issue.  Only when we speed the drive up to our max for the machine, which we do all the time, does this become an issue.

1000 Ton CCW Archive.zip

[ElectronGuru 81]

Have you auto-tuned the drive? If not, try doing a speed tune (parameter 1027) and see if that helps.

I have seen loose motor or encoder wires, damaged or misaligned encoder couplings, etc. cause issues with responses to changes in speed reference. Also, incorrect values on encoder and motor nameplate parameters can cause speed control problems.

Do you get the problem on decel commands, as well? You have relatively long accel/decel times (50/45 secs) but your S-curves are on the default settings. If you're driving a high-inertia load, overshooting the commanded speed reference might be expected without some S-curve added.

[GTaylor 0]

Thank you.  Sorry been doing a controls upgrade and haven't had a chance to get back to this.  I will add some S-Curve and shorten the accel/decel times.   Next week and see what we get.  I appreciate your time.