Quote:
Originally Posted by Pdelcast
You know, I've been thinking about this --
It wouldn't be too hard to do a 400V MOSFET based 3 phase controller for an EV. And it wouldn't be hard to do a PM motor for it either (expensive magnets though...) Both ST and Infineon have some nice 500V MOSFETs now (that don't have 1000nC charges.)
Need to sleep now, but I'm thinking about it.  |
Too bad we are far from each other,
I am less concern about cooling, can fix that.
If you can get me some ESC's already pre-fabbed with caps and tvs, I would like to share with you one more aspect of this tuning. I am sure you aware of that, but still. Pushing 30V fet's towards 6S is not great and we have seen more than one catastrophic fet's failure. What I was trying to add to MM, but didn't find a good place, is tvs per phase, not across H-bridge. 3 TVS total, no TVS across power leads required if caps are good and leads are short.
Concern - V=L*di/dt
With higher Kv motors, motors inductance and fast high current switching can exceed fet rating pretty quick. It would be the best to place clamp that would be before fet's diodes.
If you have any catastrophic fet's failures (I had one unit from DickyT) than it might be related to that.
Neu 1515 1.5D has about 2.3uH @ 50Amps and 1us it can hit 115V, your are not clamping phase - but just a thought.
Need to go, see you next weekend,