Jon Elson wrote: > > Also, a good brushless servo motor has minimal torque or velocity > ripple, even down to > extremely slow speeds. Certainly, a car alternator is not optimized for > smoothness at > low speeds.
I get some used PMSM from auctions. Replacing the bearings gives them a second life. Keep the angle position of the resolver on the rotor! So you can test it with an old (with analog velocity input) 3 phase power supply. Usually this motors run very smooth if the stator pack is twisted giving nearly no torque ripple (assuming rotating magnets). Motors with torque ripple maybe used as a drive if the control can do a predistortion to the current to compensate for the ripple. But I have not seen this until now with my eyes. Three phase ac motors (no magnets, cheap) do not have this torque ripple. But the torque is a function of difference in frequency of rotating magneting field and the rotor. A different control strategy is required. Joachim ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
