# looking for an electric motor(300kW)



## droopdog (Oct 27, 2008)

hey,

I'm working on my thesis and i need to build an heavy duty hybrid car. For this I need an electric motor that has 300kW. the torque at the wheels of the vehicle is 40.000Nm so I need alot of torque because it would be much cheaper to only use the differential en not a reductor.

But i can't find any motor with 300kW and i'm not sure if I need to use an AC or DC motor.

I hope someone can help me further.
Thanks in advance.

Droopdog


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## major (Apr 4, 2008)

droopdog said:


> hey,
> But i can't find any motor with 300kW and i'm not sure if I need to use an AC or DC motor.
> 
> I hope someone can help me further.
> ...


Hey Droopdog,

I'd check over your requirements. But there are lots of 300 kW motors. Baldor makes a 44404T-4 model. It weighs 2300 pounds and list for $48709.

You want something that might actually fit into a car, go with two systems from ACPropulsion. Those are 150 kW peak each. Still would cost about the same.

Regards,

major


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## droopdog (Oct 27, 2008)

thnx for the information!

can you explain me why a 150kW electric motor (from siemens for example) weighs only 90 kg and a 300kW electric motor suddenly weighs 2000 kg ??

DD


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## major (Apr 4, 2008)

droopdog said:


> thnx for the information!
> 
> can you explain me why a 150kW electric motor (from siemens for example) weighs only 90 kg and a 300kW electric motor suddenly weighs 2000 kg ??
> 
> DD


Hey DD,

Lot of things enter into the ratings. Duty cycle. One may be a peak, one may be a continuous rating. Insulation class or the running temperature for the motor. The cooling method of the motor, totally enclosed non ventilated (TENV) vs liquid cooled. The design of the motor, namely the rated speed. Typically higher speed motors can be rated higher in power output. The durability and life requirements for the motor. Some are automotive quality intended for like 5 to 7 years. Others may be designed to run 30 years continuously. Then you have the construction of the motor. Cast iron housings vs aluminum. Lots of reasons.

And I'm not sure your example power vs weight figures are correct.

Regards,

major


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## samborambo (Aug 27, 2008)

DD,

Electric motors normally have a size and weight proportional to their torque. Torque (Nm) multiplied by rotational speed (rads/s) produces Power (Watts). Conversely, torque is proportional to electrical current and speed is proportional to voltage. The proportional relationship between these figures is governed largely by the windings and the number of magnetic poles.

This is why you find RC aero modellers who build 15kW motors that weigh under 2kg. For a given torque rating, a motor is only limited to what maximum speed it can sustain safely. The problem comes when you need that power in a "useful" manner via a gearbox or reduction drive. These solutions will add extra weight and a drop in efficiency. Ultimately, your design will be a compromise of these factors.

So, if you're looking for a versatile motor with lots of torque, have a look at Etel's torque motor series.

Good luck,

Sam.


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## ElectriCar (Jun 15, 2008)

You're not trying to replace a petrol based motor with an electric of the same HP rating are you?

I've read that electric motor HP is 8-10x the power of a gas engine, FWIW. My Advanced motor is 28HP or so but is supposed to have more torque than the V6 gasser...

Then again you may know of this difference.


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## jaimeson55 (Mar 12, 2011)

ElectriCar said:


> You're not trying to replace a petrol based motor with an electric of the same HP rating are you?
> 
> I've read that electric motor HP is 8-10x the power of a gas engine, FWIW. My Advanced motor is 28HP or so but is supposed to have more torque than the V6 gasser...
> 
> Then again you may know of this difference.


I am also looking for a 300kw motor, I am putting it in a heavy jeep with very large tires that will be also running a gas generator for off road trips.

Check out the jeep here, it run stock tires and has a 200kw motor
http://www.jpmagazine.com/featuredvehicles/154_0901_jeep_wrangler_ev/index.html


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## major (Apr 4, 2008)

jaimeson55 said:


> Check out the jeep here, it run stock tires and has a 200kw motor
> http://www.jpmagazine.com/featuredvehicles/154_0901_jeep_wrangler_ev/index.html


Looks like the UQM motor. $34,000 if you can convince them to sell you one. You can get powerful electric motors and drives. All it takes is money


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## jaimeson55 (Mar 12, 2011)

Wow those uqm motors look like the way to go but $34,000? Who is there target market?

I love how uqm combines the motor and controller, any other companies like them out there that are not targetting concept cars?


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## jeremyjs (Sep 22, 2010)

jaimeson55 said:


> Wow those uqm motors look like the way to go but $34,000? Who is there target market?
> 
> I love how uqm combines the motor and controller, any other companies like them out there that are not targetting concept cars?


I bet if you're a ev manufacturer you can get those motors and their controllers for a very reasonable price. If you're joe down the street they charge you a fortune to get you to go away.


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## CroDriver (Jan 8, 2009)

jeremyjs said:


> I bet if you're a ev manufacturer you can get those motors and their controllers for a very reasonable price.


The price for 100 units is still pretty high. 

I think that DIY-ers will stick to DC for many more years.


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## Bowser330 (Jun 15, 2008)

CroDriver said:


> The price for 100 units is still pretty high.
> 
> I think that DIY-ers will stick to DC for many more years.


I agree... 

300kw peak can be obtained by using the following...

(1) Netgain Warp11HV Motor ~ 3500$
(2) Netgain controller 360V 1400A ~4300$
(3) 1000 cells of Headway 8A (100S 10P) ~19000$


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