# Using Prius Components to Build an EV?



## MrCrabs (Mar 7, 2008)

I can't answer your questions, but http://www.cleangreencar.co.nz/page/prius-transmission this page has a good overview of the Prius' drivetrain.


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## Mike D EV (Sep 11, 2007)

The prius has two brushless 3 phase motors, a pumped lube bearing system, has a 4:11 final drive ratio.
It electronically changes the drive ratios in the standard configuration, as explained on many websites.
The welding of the planet gears to the carrier, locks both motor generators and the power input/output shaft from the gas engine together so they all turn as a unit.
This pumps the oil lube, so it can be run this way indefinitely unlike the EV mode in the standard Prius, where the oil pump stops when the gas engine stops.
The two motors are powered by a dual power driver /inverter with boost capabilities so the motors can be run up to 8K or more rpm.
The inverters are also liquid cooled.
The position feedback from each motor feeds into the ECM which then based on some magic software, generates the two three phase drive waveforms and sends then to the Inverter to run each motor.
If the position feedback is used in a microcontroler based system that would generate the two three phase drive signals, and eliminate the ECM, and all of the rest of the car.
With this new controller set up as the inverter controller, any synergy drive could be turned into an electric car power plant.
There should be a law that makes them pull all synergy drives and inverters before they crush the car, and recycle them to EV converters.
I paid $500 for the drive, and $600 for the inverter.
The controller should be under $100?
Just need to get in a real prius with a scope, and get real clear as to how the drive signals work under different speed,regen conditions.
Too many projects not enough time or money.
Trying to finish an EV conversion of my old telephone truck.
http://www.99mpg.com/resources/articlesandblogs/pluggingintothesun/


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## MitchJi (Dec 14, 2007)

Mike D EV said:


> If the position feedback is used in a microcontroler based system that would generate the two three phase drive signals, and eliminate the ECM, and all of the rest of the car.
> 
> With this new controller set up as the inverter controller, any synergy drive could be turned into an electric car power plant.
> There should be a law that makes them pull all synergy drives and inverters before they crush the car, and recycle them to EV converters.
> ...


Hi Mike,

This sounds like a great idea! 

Someone with the proper knowledge could design and build a controller that could be built for about $100 for use with the Prius Motors, invertors and Drive Train. 

The advantage would be that if this is done properly it would be comparable to a much more expensive EV AC Motor and Inverter Combo because it would have regen.

The disadvantage would be you need to use the Prius Transmission which would make a conversion substantially more complex.

Thanks for the idea and posting the follow up information!

I hope someone who has the knowledge to pull it off does it and starts selling the controllers with DIY instructions.

Thanks Again!

Mitch


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## Mike D EV (Sep 11, 2007)

It may actually be easier as all of the battery disconnects/fusing, and other EV components are already there and connected.
I have this pretty high on my list of projects, so if no one else beats me to it, I hope o try this out this summer.


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## the slashmaster (Feb 24, 2008)

MitchJi said:


> Hi,
> 
> http://www.99mpg.com/ProjectCars/evinsight/
> Due to the terminology involved (what are MG1 and MG2 for example) and my own lack of knowledge I don't understand a lot of what he is saying/doing. But the possibility of getting a wrecked Prius and ending up with a EV Motor and Controller combo with regen that could be used to build a full EV sounds good.
> ...


Every time I go to a junkyard I always find it very difficult to find what I need because they always only have late model stuff. So I could probably easily find priuses. I was thinking if I could hook 3 or more prius motors together it would have the power I want but I'm sure I'd have to spend many hours figuring out a maze of wires and what each wire does.


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## the slashmaster (Feb 24, 2008)

Hey I found a pic in the wikipedia of the controller with the top off http://en.wikipedia.org/wiki/Image:ToyotaOpenHSD.jpg I'm guessing those 3 black capacitors are for the 3 phases in the motor but I don't have anything else figured out. Does anyone else have a clue? What fluid do you put under that black and yellow cap?


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## Mike D EV (Sep 11, 2007)

If you really want to get inside the inverter, my buddy Hobbit has dissected it here: http://www.techno-fandom.org/~hobbit/cars/ginv/
He has other interesting technical info there if you poke around.


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## the slashmaster (Feb 24, 2008)

Mike D EV said:


> If you really want to get inside the inverter, my buddy Hobbit has dissected it here: http://www.techno-fandom.org/~hobbit/cars/ginv/
> He has other interesting technical info there if you poke around.


Have not read the whole thing but looks good so far. Thanks!


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## Coley (Jul 26, 2007)

Quote:
"The welding of the planet gears to the carrier, locks both motor generators and the power input/output shaft from the gas engine together so they all turn as a unit."

This would make the trans useless!! All you end up with is 2 motor/generators ganged together, with the controller changing the vehicle speed.

What would be the point?

You would be right back with what most of us have now, only no shifting ratios!!

There must be something left out.....


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## Mike D EV (Sep 11, 2007)

The Prius EV mode uses the 33KW MG2 to drive the car, it is directly connected to the final drive at all times, and is the only driving source when in reverse, or the EV mode.
This site has a cool demo where you can play with the ratios.
http://eahart.com/prius/psd/

If you move the MG2 slider to 6500 RPM, you are looking at the RPM of the final drive input.The speedometer shows 110 MPH.
As you slide the MG2 slider,with the ICE off, and you will see that MG1 (18KW)reaches it's max -6500 RPM at 42 MPH
The 42 MPH max speed limit for the EV mode is not because the larger MG2 cannot go faster, it is because the smaller MG1 which spins 3 times faster in the standard configuration is at it's rpm limit. Once the ICE is moving, this speed limit is not a factor.
Welding the planets and removing the ICE eliminates this 3:1 ratio difference, and combines the torque and HP of both motors, and applies it directly to the final drive. 
MG2 alone outputs 258 lbfoot, with a 3.9:1 final drive ratio , for over 1000 lb foot output from the differential. That should push an Insight or other light car or pickup just fine without the need for a transmission, since like all electric motors, that torque is available through most to the rpm range. Add the 18KW from MG1, and we could have a tire burner.


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## MitchJi (Dec 14, 2007)

Mike D EV said:


> The prius has two brushless 3 phase motors, a pumped lube bearing system, has a 4:11 final drive ratio.
> It electronically changes the drive ratios in the standard configuration, as explained on many websites.
> The welding of the planet gears to the carrier, locks both motor generators and the power input/output shaft from the gas engine together so they all turn as a unit.
> This pumps the oil lube, so it can be run this way indefinitely unlike the EV mode in the standard Prius, where the oil pump stops when the gas engine stops.
> ...


Hi Mike,

So by welding the planet gears you end up with two different motors/invertors running at the same speed? If so would it be a lot easier to replace the MG1/Invertor with an MG2/Invertor? The advantage might be that it might be a lot easier to figure out how to simultaneously control two identical Motors/Invertors. It seems to me that this would be much less complex than simultaneously controlling two completely different Motors/Invertors. Another advantage would be more power.

The disadvantages would be the money and time required to replace an MG1 with an MG2.

The Siemens AC Motor Invertor combo sold by Metric Mind costs about $9k. The advantages over less expensive systems are an AC System with high quality user controllable regen using OEM quality components. The Prius parts combined with a high quality controller have the potential to be just as good or better. On the other hand if the controller is not done well it has the potential to not be a very good system. 

I really hope you or someone with the required knowledge can do a really good job with this and provide instructions and or parts. Please keep us posted with any progress!

Thanks!

Mitch


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## Mike D EV (Sep 11, 2007)

Actually the stock inverter is a dual inverter, so it will be pretty easy to just use both stock inverters. Regen with one or both of the motors is also easily possible once the system is fully hacked.
A single micro controller should easily take care of both.
Toyota designed this system for automotive use, and it is very robust and capable. I know a guy that had a Prius with 360K on it, with no battery or mechanical problems.


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## MitchJi (Dec 14, 2007)

Mike D EV said:


> Actually the stock inverter is a dual inverter, so it will be pretty easy to just use both stock inverters. Regen with one or both of the motors is also easily possible once the system is fully hacked.
> A single micro controller should easily take care of both.
> 
> Toyota designed this system for automotive use, and it is very robust and capable. I know a guy that had a Prius with 360K on it, with no battery or mechanical problems.


Hi Mike,

I'm glad to hear using the system with both stock motors/invertors will not be a problem.

My concerns about the quality is not about the Toyota components. The weak link IMO is using an additional controller with those components in an EV. It sounds like you believe its possible to design a controller that combined with the Toyota parts will be a very robust and high quality system and that you intend to do exactly that. That is great news, exactly what I was hoping to hear!

Thanks and Good Luck!

Mitch


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## inventorernie (8 mo ago)

Mike D EV said:


> The prius has two brushless 3 phase motors, a pumped lube bearing system, has a 4:11 final drive ratio.
> It electronically changes the drive ratios in the standard configuration, as explained on many websites.
> The welding of the planet gears to the carrier, locks both motor generators and the power input/output shaft from the gas engine together so they all turn as a unit.
> This pumps the oil lube, so it can be run this way indefinitely unlike the EV mode in the standard Prius, where the oil pump stops when the gas engine stops.
> ...


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## inventorernie (8 mo ago)

Did you ever complete this Prius project? We are working on a similar project, and would appreciate whatever help you can give us. We won't be putting it in a car. All we need to do is set the rpms of the motor at a fixed rate. Can you give us more information on the drive, inverter, nd controller that you bought? Thanks.


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## MattsAwesomeStuff (Aug 10, 2017)

inventorernie said:


> Did you ever complete this Prius project? We are working on a similar project, and would appreciate whatever help you can give us. We won't be putting it in a car. All we need to do is set the rpms of the motor at a fixed rate. Can you give us more information on the drive, inverter, nd controller that you bought? Thanks.


This thread is 14 years old.

There are other, modern Prius projects. No need to gravedig this one. You could even start your own project topic.

These guys were discussing a Gen 1 Prius, but, go pick up a Gen 2 and buy the controller from OpenInverter.org 's webstore, or the Gen 3 and buy the controller from EVBMW's webstore.


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