Just for the record, the Dodge TEVan is separately excited. Current limit is 300Amps and system voltage is 180Vdc (typically 205Vdc open circuit and fully charged). The biggest problem that I have noticed is arcing during regen. The brushes are advanced for motoring operation, so in regen it is not operating at it's optimum brush location. The highest current that I have experienced in regen is 65 Amps at 210Vdc.
I plan on replacing the IGBT's in the controller with higher rated devices that have lower Vsat and switching losses. I should be able to bump up current limit to 350-400amps. The only problem with this is the motor will overheat in the summer on hilly terrain if driven more than 15-20 miles. Rod Thomas Shay wrote: > Do seperately-excited (sepex) motors and controllers > suitable for highway capable EVs exist? They are becoming > common in golfcarts, NEVs, lift trucks, pallet trucks, etc. > These motor-controller systems are too small for EVs and I'm > not aware of any sepex system the right size for an EV. > > Consider a typical modern golf cart. Its motor and > controller provides regenerative braking and reversing > without using contactors. Its controller automatically > applies regen braking to limit speeds going down hill. > > I'd really like a sepex motor and controller in my next EV. > Is that possible or am I just dreaming? Hi Tom, The biggest sep-ex system I've seen in use is from Canadian EV: http://www.islandnet.com/~canev/Commercial/FMI/FMI.html and http://www.islandnet.com/~canev/Commercial/CEV/MightTruck/MightTruck.htm l. These are industrial trucks with 25-35 mph speed capability. They use 96 V, 500 A controllers. (Zapi controller, Kostov motor, I think.) Is it fair to assume a 96V sep-ex road EV would have similar performance to a 96V series setup? I've read about the advantages of sep-ex and don't really understand why higher voltage systems aren't available. Would it be possible to have Warfield or NetGain rewind a series motor for high voltage sep-ex? Wouldn't building a high voltage sep-ex controller from scratch be much easier than a similar voltage series controller? Chris
