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Old 03-24-2011, 11:57 AM   #4545 (permalink)
DJBecker
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Quote:
Originally Posted by isaac_alaska View Post
i'm fairly certain that the motor voltage limit is only because of the rpm limit of the motor (higher voltage=higher rpm.)
You can over-rev a typical EV motor with modest voltage. Perhaps with 24V if there is no load. Certainly with 48V.

The motor voltage limit is a combination of insulation breakdown, especially over time+heat+voltage, and commutator/brush arcing.

Quote:
Originally Posted by isaac_alaska View Post
If the voltage pulses are a problem i could probably come up with a low pass filter circuit that would average the voltage...essentially the same thing that happens in a rectifier. i'm not sure how pre-charge would be taken care of though.
There isn't a reasonable way to do a low pass filter. The currents are too large, and the load varies too much. You would end up with something that is inefficient or huge, likely both.

In particular, think about current multiplication and what happens with the freewheel current.
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