Parker 590+ 4Q 110A - problem with the table feed during processing

I have a problem with the table feed while machining. Speed ​​feedback is taken from armature voltage measure. Settings: Nom motor volts, armature current and field current are written from the engine and are set to - 220V , 46A and 3.1A . Main curr . limit at 120%. The drive has been calibrated and carried autotune . If there is no load table goes well over the entire length , but when there is resistance of the machined detail, then at some point table stops. while it stops, there is no alarm on the drive, in diagnostic- > current fbk, the value is 25A , diagnostic- > speed feedback - 6%.

The same drive we have used on another machine , where the feedback is also armature voltage and there is no problem as above. The question is - should we use tachometer , or is there any parameter in the drive , which will help us to solve the problem?

When diagnostic->speed feedback is 6%, what does it say the reference is?
If the reference is also 6%, then yes, you need feedback.
Toss an encoder on the thing and try it.

The reference is 6% aswell. I'll try tacho as soon as my company buy additional board to attach it to the drive(it's not shipped with that sadly).
Atm we machine details at higher speed - it's 7-8% and table doesn't stop. The problem appears only at lower speed rates. I'll get tacho board in like 2 weeks, so I wonder if there are some settings i could try to make armature voltage feedback works at lower speed... What about setup parameters::speed loop::spd.prop.gain and spd.int.time? I forgot to mention, that the table weight is like 5ton and detail itself weight the same.

Struggling to remember. Isn't there some kind of compensation for the armature resistance? Maybe called IR Comp? This should compensate for the volt drop across the armature under load.

Nick

From the manual:

IR COMPENSATION SETUP
Properly setting the PARAMETERS::CALIBRATION::IR COMPENSATION parameter, or motor loss compensation, improves the speed accuracy when running in armature voltage feedback.
• Run the motor without a load. Monitor the actual speed with a hand tachometer.
• With the same speed setpoint, run the motor at full load and monitor the actual speed again with a hand tachometer.
• Adjust IR COMPENSATION until the full load speed is the same as the no load speed.
NOTE Too much IR COMPENSATION causes instability.

Nick

Yeah, there is a parameter called IR compensation. I'll try to play around with it. It's set to 0% by default. The speed under load drops by like 7%(from 56 to 52 mm/min), but I guess it increase with the increase of demanded speed. Should I go with IR comp parameter set to 7, or some higher value? I don't want to destroy the drive so better ask in advance...
Edit: I was replying with the manual and calculator opened, so I didn't notice you replied. Thanks for thathpope it will help!

pareto said:

I'll try to play around with it. !

Click to expand...

DC Drive not for play

You're right osmanmom. I'll start with lower IR compensation value and see if it helps. I'm going to work tomorrow, so I wanted to get as many hints as possible. I'll post results as soon as I check it. Wish me luck

Hello again, I'm 1 day late, cause we needed to do some testings. IR compensation worked surprisingly well so it was that simple... Unfortunately that wasn't even mention in polish language manual, so it seems for the future I have to read english manuals. Anyway, thanks for help!