Curious about the best option out there for EV motors.

[PantheonEngineering]

I'm undertaking a personal project working on putting together and EV, and i'm buidling a team here locally. I'm looking for an EV motor platform to conform to. I've heard things such as the AC-75 motor from AC propulsion. I haven't gotten my electrical engineer yet so i can't ask these questions to him.
It says it has a Power of 75 kW(100 hp) max, and 27 kW(36 hp) Continuous.
How would i interpret this information?
It has a Voltage of 247 VAC nominal (line-line rms)<- Also don't know what this means.
Current of 250A rms max, 80A continuous <- Not too sure about this also.

http://www.acpropulsion.com/datasheet/ac75.pdf

Thats the information i'm looking at.

Insight would be great until i can get an electrical engineer going on specifics.

The way i'm understanding it would be that to get to running spead it would require at max 75 kW and 247VAC with a current of 250A, but at running speed it would be significantly Less.
It has a base speed of 6,000 RPM and a max at 13,000 RPM.

Would it be bad if i wanted to run this at a regular of 2500-3500rpm as a constant running speed, and generally not going over that?

Thanks in advance everybody.

 

[GregLocock]

No, that is a pretty terrible interpretation of what a motor does in an EV.

The spec means that you will be able to use anything you like up to 75 kW briefly, but should not use more than 27 kW for sustained operation (but it is more complex than that).

If you are using a gearbox those are sensible numbers for a small vehicle (say up to 800 kg), for a larger one you'll need roughly twice as much (or more). Without a gearbox then /by eye/ you will run into problems with inclines and initial acceleration, I suspect, depending on your desired top speed.

The motor will, absent anything really odd, run OK at any speed from 0 rpm to 13000, at 1/3 of the torque shown on that graph (which is the maximum it can deliver), all day.

Yes, you need someone who understands cars and electric motors. An EE may struggle with generating a performance profile for a given vehicle.

That motor may or may not be the 'best' for your application, it seems odd to start with the motor- more usually you start with the vehicle and then generate vehicle level targets before cascading them down to subsystem requirements.

Incidentally you may get some static on your choice of company(?) name, engineering is a restricted term in your neck of the woods.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[PantheonEngineering]

Greg, thank you for a little clearing there. I myself am not a PE, but that is the company reference i use is my screen name. I'm a mechanical designer, and i realize that i am essentially doing it backwards. My intentions for the project are a little more individual than it would seem, but the goal is the same. I'm trying to find an efficient way to have a motor and setup that i can design around. Once i know my given parameters for the drivetrain, then it would be much easier for me to design mechanically within the constrains of that box. I.e. knowing my max weight to power ratio, as well as the type of transmission i will use with that. Also when i start looking at necessary power needs to be able to compensate with batteries and other methods of powering it. I realize that this is very broad, its just i'm in a new territory of engineering that i am vaguely used to. I was assuming that an Electrical Engineer would be the best background for the kind of information that i am looking for.
Again, thank you for your input, and i'm still open to further information should anyone have, or opinions.

 

[itsmoked]

There are many EV enthusiast websites. Thru those a lot of rule-of-thumb standards have evolved. They include overall vehicle cost aim-point, performance, vehicle weight classes, ultimate usage range, and battery weight/type/capacity,

All this is gone over continuously in the various EV forums. It would greatly help you in your endeavor if you'd dive into those forums and read about various 'builds' as often people will completely document their entire builds illuminating common problems and their solutions.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

You may want to look in at this thread in the Hobbies Forum. moltenmetal has been sharing his successes with us over the last 15 months as he built an electric powered car.
Electric Car Conversion
thread1528-364721

Bill
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"Why not the best?"
Jimmy Carter