[cajunfj40]

oil pan 4:

The industrial VFD I work with use up to 700vdc but that voltage is contained within the drive it's self and then only produces 480 volt 3 phase out to the motor.

I think the one the Red Suzi uses is similar - it can't rev very high due to not being able to get enough voltage to match an increase in frequency. They described in the thread I linked that they later had the motor rewound and rewired to give them a lower design voltage. I don't understand it all, but it influenced how fast the motor could rev with a given DC bus voltage and had other beneficial effects on torque as well.

thingstodo:

I would expect this to be quite reliable - using off-the-shelf parts, staying within the design window for the individual parts.

It may be a bit heavier than it needs to be, so it may take a bit more power to move it. But if you are building a daily drive that you need to be reliable .. over-built with much room for error is GREAT!

Apparently the unit ran great, and wasn't terribly heavy - ~2500lbs, IIRC? It is in the thread somewhere. The motor itself wasn't very big or heavy - nominal 11kw at 415V/50hz. A lot of the motivation was "proof of concept" and getting real-world data to go with a *ton* of theoretical work that had been done in other threads on that forum. Further steps, most likely in other threads, were to go with a more powerful drive (higher current capability) and LiFePO4 type batteries, in a more aerodynamic chassis, though I think they ended up buying an iMiev instead and tweaked the Red Suzi more. The thread I linked was from 2008.

[QUOTE]13 contactors is a lot of contactors for the series string. Does that mean 24 contactors to put the packs in parallel? WOW.[\QUOTE]

Maybe? Not sure - posted total drop through all the contactors, cables, etc. in series was only ~2V tops. Peak current to the motor was 97A, so they are not large contactors.

I think the DC bus is a set of terminals on the Variable Frequency Drive.

Later in the thread - which I read after I posted - it was mentioned that this drive was meant to run off a common DC bus, so no hacking needed.

I would expect so - seems reasonable to me

I'd prefer not to push lots of excess current through the motor. I'll need to figure out some way to monitor rotor as well as stator and water jacket temperature to avoid cooking the rotor magnets and/or windings if I run a modified/aftermarket inverter that can really whack the power into it. One of the major reasons I am looking exclusively at brushless designs is to get the ability for near-continuous locked or really slow rotor torque without the fear of burning up the commutator. It won't be as high as 1000A into an 11" brushed DC motor would give, but the wider total speed range means the lower gear needed to multiply out that torque will go faster, likely meaning only a single gear reduction setup would be needed for good street performance, rather than having to shift. Low range is still available for off-road - either using the 2 speeds already present in the transfercase with a gear reduction box in front of it, or using a 2-speed transmission ahead of a transfercase modified to have a 3:1 or 4:1 or so low range gearset that is locked in - and better bearings to handle the continuous high-speed usage.