Tension and Draw Control on Paper Machine

It is very much possible to implement controls as desired by you. It is called cascade control. Analogue out put (or Pulse RTrain Output) from the master VFD can be given as speed reference analogue input to the slave VFDs such that if the master speeds up the slaves too will and when the master slows down the slaves too would.

Agree and you can also add a little droop on the slaves to the main speed command from the 'master' to give a little tolerance in operation.

The 'master' naturally needs to have a slower response to speed command changes than the 'slaves'.

In such situations it is recommended to have a possibility to compensate for the differences in time constant of the different inertia. Usually it is a loop which can eithe accumulate or deliver a limited quantity during the short periods of time when synchronisation is not perfect.

please check eurotherm (now parker) drives. they have many models with built in algorithms for tension control and winding built up calculations. but you will have to have a plc connecting all the drives in a network which will pass on the parameters to the drives after doing all the calculations. drive setup software also is free on the net.