Load Reactor - dV/dt Filters

[Jieve]

Possibly a silly question, but when installing load reactors or dV/dt filters on the VFD output, I'm guessing the auto-tune should be completed WITH the reactor/filter installed, and not without it, correct? Just want to verify that this is indeed the case.

 

[WhinnieThePooh]

Yes, I would definitely do an autotune with the load reactors installed.

This thread may be of use. See post #4
https://www.plctalk.net/qanda/showthread.php?t=116283

 

[Jieve]

Thanks for that reply.


I see others recommending to run auto-tune with the reactor/filter as well in that thread.


In contrast, while not the drive I'm using, this app note from Toshiba on auto-tuning drives for induction motors says the following: "The auto-tune will not work if there are other devices installed between the S15 and the motor like a load reactor, long lead filter, or sinewave filter. A manual tune is required, and is not covered here."


https://www.toshiba.com/tic/datafiles/app_notes/S15_App_Note_2.8.0_Motor_Auto_tuning.pdf


I'd assume from this that there is probably a preferred method regardless of drive used ...

 

[strantor]

Thanks for that reply.


I see others recommending to run auto-tune with the reactor/filter as well in that thread.


In contrast, while not the drive I'm using, this app note from Toshiba on auto-tuning drives for induction motors says the following: "The auto-tune will not work if there are other devices installed between the S15 and the motor like a load reactor, long lead filter, or sinewave filter. A manual tune is required, and is not covered here."


https://www.toshiba.com/tic/datafiles/app_notes/S15_App_Note_2.8.0_Motor_Auto_tuning.pdf


I'd assume from this that there is probably a preferred method regardless of drive used ...

Interesting. The autotune measures the LCR + BEMF of the motor and measured response for a given output, and stores that data to use in the future for predicting the correct output to hit a given target. Anything between the VFD and the motor is part of what it's measuring, part of what it's adjusting for, and needs to be part of the equation. I have never seen another app note making such claims as the Toshiba one you linked. I have commissioned Toshiba VFDs including autotune with output reactors and had no issues, but they were not S15.

If it were me, I would disregard what that app note says, and do the autotune with reactor installed. Only if there is bad speed regulation would I try taking the reactor out of the circuit and retuning.

 

[Jieve]

Ok, I will tune with the filter and report back if I have any issues. Thanks!