We have two motors connected to gearbox which is again connected to a common speed synchronisation shaft. we are finding a lag of 200 ms between the start of both the motors ( speed feedback)  duing the shaft decoupled condition. The speed of both the systems matches after that. The normal operation of both the motors are within 200 rpm.

Is that OK. Will it create any problem while coupling the shaft. Should we redo the tuning once again to reduce the lag time. 

Dear RMTB,

It is not OK. After you coupled the shaft because you have two separate loop of control, one of them goes to saturation. Maybe you damage mechanical or electrical part.

In this case you should use master salve configuration. there are some solution for performance master slave .

I have experienced with two of them. best one is you choose one drive for master and send speed reference to it .after you should used  current feedback of master as current limit of the slave. point that you should put the speed loop of the slave to saturation by lead reference (means for example " the slave reference = master reference + 10 %" )

Best regards

www.sinamic.ir

Hi RMTB,

I  found 2 descriptions on SIOS.

Here some load sharing application specially for SINAMICS DCM:

https://support.industry.siemens.com/cs/ww/en/view/47216918

And here some DCC application for SINAMICS S (which describes the operation as master / slave):

https://support.industry.siemens.com/cs/ww/en/view/38470057