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Old 12-08-2016, 05:05 PM   #2914 (permalink)
MPaulHolmes
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Location: Maricopa, AZ (sort of. Actually outside of town)
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Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
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The encoder signal breaking is pretty catastrophic. So maybe if that happens, the controller could go into a coast mode where all IGBTs go off. Then whether it's permanent magnet or induction, it would just be like you lost power in a normal car, and are coasting. Maybe then you could assume the motor is about the same RPM as it was before "broken encoder" happened. Then you could set the frequency/voltage to match what the frequency was before, and officially be in V/Hz mode for the purpose of limping home. Or if it's a Leaf sort of motor, just coast to a halt with all igbts off. One reason I like the Leaf resolver is it's very reliable and is largely immune to noise/dirt. It would have to be a cut wire to cause a problem.

The newest board has a variable brake input. Just like a throttle. I'm not sure how useful it is. Tesla, for example, uses normal brakes, and has the throttle in a wig wag, with programmable max regen, but just stops the regen once the car has stopped. I don't know if everybody does that or what. Arber, do you have reverse from the transmission? I wonder how standard it would be for people driving a car with no reverse except for a button on their dashboard.
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