VFD switched frequency

[gaux]

I have a problem with a VFD and a syncronous motor permanet magnets (10 kw 100 hz 400 V), i had asked before some tips, now i could start up without flashing... with a 10khz,the motor have electrical arc between rotor and stator.... and then, i reduce to 3 khz the electrical arc dissaperar, but the people from the VFD said that it´s better for the motor to work on 10 khZ and with a ground between rotor and stator....

what do you think? what would be the best switching frequency for this motor? I think it´ll have a high L that will filter the 2 Khz sgnal?

 

[Skogsgurra]

If you have a "flash" at 10 kHz and not at 3 or 2 kHz, then the low frequency is obviously better for the motor. The whining sound may be unpleasant but the smooth running at 2 or 3 kHz is good enough. Not much extra heating either at those frequencies.

What kind of "flash" is it you are seeing? Is it EDM in the bearings? Or an actual arc from rotor to stator?

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...