zeva wrote: Well I think everyone agrees that commutated motors have a limited lifespan and will only be around while they offer a significant cost and/or simplicity advantage.
Ok, but I think that DC will be around for a while yet.
So I guess those of us involved with EV R&D should be doing our best to bring the price of induction and PMSM/BLDC technologies down.
I've never understood why separately excited DC isn't more popular. Is it that the motors are less common? A quick look through the EV Album
indicates that they are mostly European conversions. Kelly make controllers for them, so it can't be a lack of controllers.
It seems to me that separately excited motors offer the economy of DC, yet with reasonably easy regen. Is it the arcing at the commutators? Maybe that you need to tell the controller about the field characteristics... but surely that's a bit of research and/or experimentation, and plugging in a few numbers into the controller somehow?
Plenty of cheap industrial AC induction motors around, though they're usually too big & heavy to fit in compact FWD engine bays.
I don't know about that. There are plenty of circa 7.5 kW 132 frame motors around, I think. But we need the technology for rewiring for lower voltage, so we can take advantage of the low voltage controllers out there: Kelly, and hopefully soon Tritium. The controllers are where the AC bottleneck is, I feel. Over AU$10K for a 100 kW controller isn't going to attract too many conversions. Even the 50 kW controllers are expensive, or difficult to scrounge.
Maybe we could contract a manufacturer to build something more appropriate for EVs (e.g more compact, lighter housing, higher RPM rating, possibly water cooled?).
I don't think we need water cooled. Lower voltage windings and balanced for 6000 RPM are all we really need, unless we want permanent magnets. I suspect that local manufacturers might not be set up for PM. PM seems to offer two main advantages: higher efficiency and less torque (hence power) drop off at higher speed.
Nissan Leaf 2012 with new battery May 2019.
5650 W solar, 2xPIP-4048MS inverters, 16 kWh battery.
1.4 kW solar with 1.2 kW Latronics inverter and FIT.
160 W solar, 2.5 kWh 24 V battery for lights.
Patching PIP-4048/5048 inverter-chargers.