On 2013.06.18 15:59, Peter C. Wallace wrote: > Maybe tha actual physical dead time is causing your torque ripple What do you mean by "actual physical dead time" - electric (which I described earlier) or physical some..?
> IGBTs have a large on voltage (maybe 2V or so) which will add to non > linearities. This and the larger dead time may be the cause of this. > It could also be a wiring error. Do you have 3 'flat spots' per electrical > phase rotation? (1/2 turn on a 4 pole motor) This may be a point! I need to try with 48V PSU. >> By the way, what max voltage I can go with this setup when I use phase >> current limiting? > 600V IRAMs? maybe 450V assuming your isolation, bypassing, and deadtime are > right. > I am asking about IRAM power voltage when driving these 48V motors. Would it be possible to drive them from 320V? As I understand it is a question of isolation and max current, which may be ok, or am I wrong? > > This is possibly a BLDC setup error. You do need to limit the applied voltage > in N mode via "initvalue" since current is only limited by winding resistance. I am testing various values (bldc.0.value in "n" mode and bldc.0.initvalue in "qi" mode) - from 0.1 to 0.6. > > No idea unless their motor outputs such a voltage. Spin your motor > and look at the generated voltage with a scope. Tried this - quite nice sine. ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
