Rewinder Regen Drive

I'm specing out a regen drive for our rewinder system for our papermill.

We have a double drum rewinder (40hp motors) that currently uses a pneumatic brake to create roll tension. The drums are powered by PF700 drives using load share. The brake is regulated via the PLC using the 'master' drive torque (i.e. Setpoint of 80%. Master torque = 80%, current = 90%. Slave torque = 88%, current = 98% (110%load share)).

The idea is to couple a 100hp motor onto the brake shaft and use this as a regen drive instead of the brake pads.

The winder will run for approx 15mins continuously every 30mins at close to full load.

The two 50hp winder drives PF700's are connected to our DC bus (660V). We use a regen bridge to convert this back to AC when the other DC bus drives cannot use it.

Can I use a vanilla 100hp PF700 drive as the regen drive or is there a better alternative?
Parameters to set
88 = Speed regulation - The PLC would vary the regen drives speed to vary the torque on the winder master drive
153 = -800
161 = dynamic brake
361 = precharge enabled
No encoders are to be used.

speed regulation is not the case better is torque.
and the torque varies a lot.
i would also leave the brake in place and have the drive take over the torque.

Cheers for the reply. I don't fully understand what you are saying. To try to clarify.

Exisiting setup. Winder master torque is regulated using a PIDE which outputs to a 4-20mA I/P which output to a brake.

The plan is, instead of going to the 4-20mA output, to regulate the speed of the unwind drive (coupled to the brake shaft, but the brakes will not be active) i.e. Need more torque, slow the brake down, etc.

some thoughts..

I beleive the PF700 is a good choice, but you really need to ask an AB drive guy to be certain. I know that some drives are not ideal for torque control (pf40's for instance) because they use "current control" which is not the same as torque control.

If you hang the new drive on your DC bus, the unwind regen should be used by the rewind drives.

Is this a single 2-roll surface winder with a drive on each roll? If so, you might be able to do tension control between the two drives by overspeeding the second drive but torque limiting it for tension control...might be able to run the unwind brake at minimum braking.

The nice thing about the PF700 is that we can test the system using one of our spares (if needed we go back to the winder brake instead).

The regen power should be used by the winder. We have the regen bridge attached to the dryer sections as well as the winder which is only really used when an E-Stop is pressed (i suppose you would actually call it fast stop then E-Stop).

Yes, Its a 2 roll center shaft surface winder. We have played with varying the load share between the 2 surface drums, but when the 2nd gets over 15% it has a tendency to slip.

I'll contact AB about this. I was hoping someone had already done something similar so I could avoid any pitfalls that they discovered.