DIY Electric Car Forums > EV Conversions and Builds > Controllers

Jozzer · #21 07-02-2012, 04:51 AM

Quote:

Originally Posted by Dennis

Regen braking is no where near as rough on a motor than plug braking is. Yet I see PM motors on equipment being routinely used in this fashion without damage. In robot competitions the motors are plugged brake to bring them to a complete stop before going the other way. The same is true for forklifts, yet I see no damage on the commutators or motors overheating. Forklifts have to run for 6 hours or more in a hot or cold warehouse environment, but I have not seen one failure of motors. Any decent motor for traction applications should have class H insulation anyways and any controller that has a reputation would gradually slow down the motor before changing direction or to bring to a stop. If a controller tries to slam the motor to a stop then of course there will be a problem. But that would be a cheap junk controller.

If you want regen then the best are Curtis or Sevcon Millipak for PM motors or SepEx motors.

Race track use is quite different from robot war. If you've got a motor that will take say 400A continuous, in a race setting that might mean you can have the throttle pegged at 600A for 50-60% of the race length. IF you start applying regen during the time when the throttle is off (braking), then you must reduce the amount of time the throttle is pegged when not braking.
I imagine a robot doesnt weight 300kg+ with rider and need to be slowed from 130mph in a hurry multiple times in an event..rather it would just be braking the motors inertia..

Of course, if you can fit a motor that can handle more power than you can throw at it on the track then you can regen brake - but you also have a heavier vehicle. THis also goes for the controller..

I can assure you that I HAVE seen motors damaged on the track for these very reasons..