Motor on PF755 vibrates at standstill

[taylor1982]

Hi all,

I have a 100hp torque motor running on a Powerflex 755 drive. The motor is coupled to a drum which is accellerated and decellerated.

The problem now is, that the drum start to vibrate when the drive is enabled and get set speed = 0. This happens not every time and when you turn the drum manually just a bit then the vibrate is gone.

Has anybody hints what could avoid this vibrations? I did the Autotune with the drive an all other functions are fine.

Thank you
Steve

 

[raffles]

Did you do a static or rotating tune?

What is the control mode?

 

[taylor1982]

Did you do a static or rotating tune?

What is the control mode?

I did static and rotating tune. Control mode is FV flux vector. I use the drive in speed mode only.

 

[cjd1965]

Do you still have run 'run' high when command is 0 ?

 

[taylor1982]

Do you still have run 'run' high when command is 0 ?

Yes, actually the run is always high and i just manipulate the reference speed. Of course a FALSE on run would help but are there any solutions that would avoid the vibrations even when drive is in control mode?

 

[cjd1965]

Is the control 4 to 20 mA or 0 to 10V etc ?


There maybe tiny variation in plc signal or noise like emc causing the drive to pick up a speed reference. Does the vibration go away if you disconnect the speed reference

 

[BITS N BYTES]

Been a while since I worked with this drive. If I recall correctly you could use the Sleep/Wake parameters [351-355] to limit movement until a minimum reference level [Volts or Current] is reached.

 

[taylor1982]

Is the control 4 to 20 mA or 0 to 10V etc ?


There maybe tiny variation in plc signal or noise like emc causing the drive to pick up a speed reference. Does the vibration go away if you disconnect the speed reference

I completely control the drive with Ethernet/IP. I think it has something to do with the drive‘s internal management when in control mode and Target speed 0.
Maybe it toggles between encoder increments and that causes this vibration around standstill speed. The motor has an 2048 increment encoder.

 

[taylor1982]

Been a while since I worked with this drive. If I recall correctly you could use the Sleep/Wake parameters [351-355] to limit movement until a minimum reference level [Volts or Current] is reached.

Thanks for that hint! I will have a detailed view on that parameters the next days and will give feedback.