Peter C. Wallace wrote: > One of our customers would like to use our small LV 3 phase HBridge (7I39) to > drive a motor using EMC. I currently dont have a HostMot2 configuration that > would support this (its normally used with SoftDMC), but the hardware part is > pretty trivial, just a pinout change. (unless I wanted make a special 3 phase > PWMGEN with 3 x 10 bit PWM gens at a single write location - thats a driver > change) > > The 7I39 is very simple, its just a 3 phase bridge with current limit so > the interface requirements are just 3 PWM generators. What I'm wondering is > if anyone has done simple sine wave PWM 3 phase drive via HAL and > suitable COMPs alone?
A while back I wrote HAL components for the clarke and inverse clarke transforms (three phase to DQ vector and back again). See http://www.linuxcnc.org/docview/html//man/man9/clarke2.9.html http://www.linuxcnc.org/docview/html//man/man9/clarkeinv.9.html I intended to write a vector rotate component as well, but never got around to it. But you could send the sine and cosine outputs of the siggen component into "clarkeinv" to generate three phase sinewaves. > At a 4 KHz or so update rate , waveform quality would be pretty good up to > normal servo speeds > Is this for a permanent magnet AC servomotor, or just an induction motor? It seems like for a servomotor you'd need a current loop, which implies current feedback, which implies A/D converters. Or is it possible to get decent performance from such a motor with an open-loop drive? I'm interested in doing the same thing, but it is one of many projects and I haven't found that round-tuit yet. Regards, John Kasunich ------------------------------------------------------------------------------ Check out the new SourceForge.net Marketplace. It is the best place to buy or sell services for just about anything Open Source. http://p.sf.net/sfu/Xq1LFB _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
