Quote:
Originally Posted by P-hack
Interesting re: dual motors. To me the simplest is to just one set of igbts and one controller in slip mode and two motors in parallel. Read both motor speed signals and take the max speed for determining slip (prevents wheelspin runaway and encourages the slower one to speed up). Set 0% throttle to not regen and coast around the corners when you can. The latter fits well with "good" driving, traction pie habits anyway, you *shouldn't* be braking or accelerating much while turning and saving your traction for changing direction.
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Interesting .. running AC motors in parallel while in FOC.
Extending that to 4 AC motors for AWD ... 4 speed sensors.
I'm not sure about using the maximum motor speed, though. If you use the maximum speed, you're going to have rated slip on the fastest motor, higher than rated slip on the slower turning motors. I think that gives the slowest turning motor the highest torque. So it will speed up, and the highest speed motor will also speed up? Not sure, just thinking out loud.
I think selecting the lowest motor speed for the slip is the way to go. It would effectively give you 1 wheel drive (on the slowest rotating wheel) during normal driving of the car, and if the slowest motor begins to lose traction, the other motors will begin to exert torque as the vehicle slows down just a bit. Or maybe I'm way off base?