AC Induction (or other) Motor for EV Race Car

Mainly the vehicle needs to be able to put out 400-500 HP total.

I think you need to have a look at actual electric vehicles that have been built over the last 5 years along with the electric motors they used (both AC and DC). You will find that the motor sizes are rather smaller, and for good reason. 500HP=373kW, so as a rough figure you are looking at a portable power supply capable of say ~1617A@230V AC or say 8857A@42V DC (ignoring conversion losses), which is awfully high. A Google search of 400HP electric motors and inverters will give you a better idea of just how physically large, heavy and expensive these things are, along with the battery packs necessary to provide this much power.

ROFLOL.

The British EV land speed record was set using twin 40kW motors and the Tesla Roadster uses a single 185kW (250HP) motor.

Exactly what sort of racing (as this will determine what the best motor selection and compromise between weight, power, endurance, acceleration, cost, practicality, etc)

Is it

- Drag, long distance endurance, cross country, flat racing, racing over hills, various terrain types, etc

- Novice, university racing team, professional, etc

- Low budget, high budget, corporate funding, etc

- Building car from scratch, modifying existing car.

- Building the car for - specific race event, university race team, racing around parents farm, concept car, etc

- Vehicle type - go-cart, pod racer, standard 2-door car, modified Humvee, old school bus, etc

- No idea about EV (thought it would be cool), some idea of electronics and power, at least one professional electrical engineer + mechanic on the team who know what they are doing, whole team of people from various relevant backgrounds, etc

More info is necessary as there is no single right answer, and many of the solutions will involve very dangerous and potentially lethal levels of voltage and current that the average 'Joe' should NOT be playing around with without help from the professionals.

Let me see if I can fill in some of the details;

This is a fairly well funded project with people from the racing industry. Some of the people were former race drivers in IMSA http://en.wikipedia.org/wiki/Grand_Touring_Over. They have extensive experience in endurance racing and car building in general.

The goal is to create a car that can competitively race in a similar series. It will need roughly 400HP and be able to drive for 1.5 hours between battery swaps (pit stops). We are expecting to completely swap out the batteries each pit stop based on a cartridge system.

We have been looking at the battery issues also. The power densities are getting high enough to actually support this concept assuming that the new technologies do actually come to fruition. You actually hit it on the head, the power storage system is the core piece of technology to make the vehicle work, but at this point I am looking at the motors.

AC Propulsion has a pretty impressive AC motor that is being used in the Tesla Roadster. Other vehicles have other motors. I am really fishing for companies that I haven't seen so far that I should be looking at.

Thanks,

Doug

Most of my experience is with the small scale vehicles back in 2005-2006 (Also see my previous CR4 posts) so the motors I was looking at were less than 100HP. Now days DC-AC inverters are great and readily available as a cheap mass produced item (I have had a lot of experience with AC-Tech in America), so I never really found a DC motor that could match the AC motor (certainly not above 50HP).

Some links that may help.

500HP AC Induction motor F1 Racer - (I forgot about this one) http://www.rasertech.com/media/pdfs/Raser_Edge_Slick_05-web.pdf

I don't know what the endurance of this racer is but just off the top of my head 400HP, 1.5 hours of racing, say averaging 200HP=150x1.5=225kW hours minimum. Your Li Ion (or similar) batteries are going to be in the order of 200WH/kg (or more), meaning you would need atleast roughly 1125Kg = 2480 pounds.

We are expecting to completely swap out the batteries each pit stop based on a cartridge system.

Really the only quick way.

Are you aiming for a horsepower class or could you use a smaller motor and knock the motor, battery and overall vehicle weight down, increasing the range and speed. A smaller, lighter electric vehicle can outperform a larger electric vehicle (especially when only small hills are involved), the trick is to find the ideal compromise between weight and power. This is especially the case for electric vehicles as the 'fuel' weighs a hell of a lot more than the equivalent gasoline vehicles and it doesn't get any lighter as the 'tank' emptys.

It may look like a gasoline car from the outside but it is quite different in many ways and will require some different ways of thinking.

Keep us informed as there are a lot of knowledgeable EV engineers here and I am certainly interested along with keeping up to date on any new EV battery and motor developments you may find. Heck, we may even be able to give your team the edge.

I assume you've considered PML Flightlink wheel motors. They are a little more efficient than the AC Propulsion motor, and with four, you'd have 640 hp. 1.5 hours at racing speed would be difficult, but probably not impossible, with Altair Nano batteries. You'd need to be racing on fairly smooth tracks to make wheel motors viable, I'd think, although lots of battery weight would help the unsprung/sprung ratio.

A Tesla with an extra motor would work, and even with stock batteries it could go for 1.5 hours, but of course you'd be trading speed for range, and could rarely use all 500 hp. If you averaged 100 hp (75 kW or so) then 1.5 hours would require 112 kWh in batteries, which would be about 3500 lb of Altair Nano batteries, retailing for about $200,000. (A stock Tesla, operating at an average 100 hp would have an endurance of about 45 minutes.)

If you find out anything conclusive re EEstor, we'd all like to know. If the EEstor pans out, then your battery issues are pretty well solved.

Wish I could help. Sounds like great fun!

Yeah, the EEStor question is the big mystery right now. I would really like to know where they stand. If I find out anything and I am not locked down by an NDA I will let you know.

The PML Flight link wheel motors aren't really ready for production at this point. We spoke with them and there is a LOT of waffling from the sales engineers. At this point they are also only willing to work with the BIG car companies like Volvo, who have a partnership with them on this.

AC Propulsion seems to have the only in production model ready for off the shelf use. We have considered using two of the 248HP models that are used in the Tesla. Part of this exercise is looking for alternatives to that plan.

Does anyone out there have any experience with PM motors for this type of use? We know that there are electric drag racing vehicles that use PM motors but at this point I don't have any suppliers or specific information about the motors.

-Doug

Yeah, the EEStor question is the big mystery right now. I would really like to know where they stand.

Yes well if you do don't forget to let the rest of us know as well. If it wasn't for the high profile companies showing real continued interest I would start to think that EEStor's miracle product is all a scam. Even the serious EV engineers here have had trouble trying to get samples or place orders.

Oh why do you tempt us so only to continue to dangle that carrot in front of us.

<end of rant>

With regard to motors, ABB motors were used in the E=motion dragster, Emerson Motors motors were used in the E-Blue F1 car. Other electric race cars I know of just mention 3ph ac induction motors but no manufacturing company is given.

I just ran across this on the net the other day. Be happy I printed the page.

www.adaptivematerials.com

They have pictures of a solid oxide fuel cell, propane, 20 watts and 50 watts, the one being held in the picture about the size of a lunch box.

What struck me were the efficiency claims which of course is the issue that goes toward weight.

The data suggests you could build a battery pack with these devices and fuel them with propane bottles for quick change.

I queried them as to availability. They were not helpful although it is clear they have produced and can produce them, although still mainly interested in development.

Perhaps, having a race car project dangled in front of their face, and the publicity that might generate, they would be interested.

j.

Ahh, I have come across products like these before. For the 20W unit, 20W continuous output, 1.5kg module weight (excluding propane), 2kg total weight (including propane).

20W is not really suitable for powering a large load like a vehicle. I am not sure how their marketing team came up with the energy density figures but they are misleading at best, and key data is missing from their data sheet.

You could connect 100 of these up (200kg total) and then you could possibly get 2000W continuous, but that is still not very helpful, especially when you consider the weight and physical volume this would take up (even if the modules were cheap).

Better just to have a propane gas-driven engine if you are trying to scale up power to decent levels (better power to weight ratio). These fuel cell devices are only really useful for light-duty portable power supplies where access to the power grid is not possible.

What was the end result of this vehicle??? I found this thread doing research on Snowhite. Did this project grow into Cleanspeed??? Cleanspeed [or greenspeed] seemed to apply several of Showhite design concepts and did quite well at Re-fuel last year, or was it another vehicle and did the project get completed?