Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

MPaulHolmes · 12-03-2009, 08:13 PM

EDIT: THANKS JACK!

Also, you can run a motor at any voltage, but it just won't have the same top end RPM. It can have the same low RPM torque though, which is just related to the current. That's what Fran was telling me. I've never experimented with 3 phase motors before.

I have mostly been busy with work this week, but have also been reading about how to generate the pwm signals that will give the rotating magnetic field. It's not bad at all. It all comes down to projecting the 3 phase currents onto the complex plane, and finding their vector sum, and projecting that sum onto the real and complex axes. It sounds sort of confusing, but it's not bad, I promise!

I'm going to try programming the pwm for a basic rotation in the next few days and control it with a V/freq = const and then make the step to FOC. Its a big change from lighting leds though

12-03-2009, 08:13 PM	#128 (permalink)
MPaulHolmes PaulH Join Date: Feb 2008 Location: Maricopa, AZ (sort of. Actually outside of town) Posts: 3,832 Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000 Thanks: 1,368 Thanked 1,202 Times in 765 Posts	EDIT: THANKS JACK! Also, you can run a motor at any voltage, but it just won't have the same top end RPM. It can have the same low RPM torque though, which is just related to the current. That's what Fran was telling me. I've never experimented with 3 phase motors before. I have mostly been busy with work this week, but have also been reading about how to generate the pwm signals that will give the rotating magnetic field. It's not bad at all. It all comes down to projecting the 3 phase currents onto the complex plane, and finding their vector sum, and projecting that sum onto the real and complex axes. It sounds sort of confusing, but it's not bad, I promise! I'm going to try programming the pwm for a basic rotation in the next few days and control it with a V/freq = const and then make the step to FOC. Its a big change from lighting leds though __________________ kits and boards Last edited by MPaulHolmes; 12-03-2009 at 08:45 PM..