ALL-Electric Prius

Unsprung weight is always a problem with hub motors. I don't really have the time now that is needed to mechanically do all that work but I think it is the best approach. I noticed that a few manufacturers are working on hub motor brake assemblies, so maybe someone will do the hard part for us!
And yes, I would do the servo analog, which for me is much easier then writing code!
I'm still toying with it, but I don't expect to do anything along those lines right away. Too many projects going on now.

 

Yeah, it's super complex as it is in a stock Prius, but if all you need is to drive MG2, then it's a doable. It would be basically a BLDC motor controller with a little additional stuff. In fact, for ease of implementation, it could be broken into 2 microcontrollers, one dedicated to generating the 6 waveforms that has the requisite hardware PWMs, and another to do the integration and car interface.

I wouldn't dare tackle trying to make a replacement for the HV ECU while keeping it basically a standard Prius! (And there is little point anyway!)

Yes, my "breadboard" battery ECU substitute is working. It's sending enough out to the CAN bus to make the Prius operate normally. I've still got software to write though to make it do everything I want.

 

we used an eLithion BMS to replace the stock prius battery ecu when working on the X-Prize. Davide from eLithion supplied his own code. It is my undertsanding that ( from memory) dcl, soc, and ccl are the only signals required from the ecu every 30ms.

if anybody cares, I will go check the Eaa-phev site for the required signals and timing.

or just buy it from elithion

 

Are you going to be using your own boost converter and motor controller? I'm just curious as to how much horsepower you'll end up with. If you can supply Mg2 with all of the juice it can handle, the car would probably perform decently well and I'd imagine you'd have about half to 2/3 of the power of a factory Prius. Which is plenty acceptable to me because it would be able to keep up with traffic in most situations, even on the highway, except those that would normally require "flooring it"

However, if you are using the stock inverter, I believe your power from the batteries is going to be limited to around 1/3 of the power of a stock Prius, maybe even closer to 1/4. It would still make a good around-town car, but highway usage would be questionable. I've seen those Prius with the PICC kit in going down the highway and they really struggle to keep up with traffic at 60mph.

And there's always that possibility of locking MG1 and MG2 together and driving them both. That would give the car some extra power.

 

Adric...Not offence intended but I'm sorry, you are thinking to much inside of your own box.
The "creator", without the intervention of any none else, had been only one, and far, far, far ago.
The key of the problem is diversification; what you can't handle, another bright brain could do and association is an smart move forward.
As a cheap example, open source developments is a great learning curve for everyone.

 

Who is this question for? (hint: use the built-in quote function.) If you read this entire thread fully, you will see plenty of information and discussion of the power capabilities and limitations of the Prius powertrain. MG2 by itself can sustain ~50kw, but you have to also look at the torque curves to get a feel for driveability.

The stock inverter's MG2 IGBT bridges can handle ~50kw. The boot converter (power from battery) is limited to around ~20kw however.

That's if you came up with your own inverter and HV ECU, and then you'd pretty much have to gut the rest of the Prius control systems, as without the CAN messages from the HV ECU, they would not work correctly.

If you kept the stock inverter you'd still be limited to ~20kw, as again, the boost converter is the limiting factor. If you built your own/augmented/bypassed the stock boost converter, you could get the full ~50kw out of MG2 alone using the Prius inverter. MG1 could then add ~30kw to the mix. The easiest way would be to simply install a 500v pack. In either case, you'd have to replace the HV ECU to bring the motors under control, as has been discussed. The inverter itself is a "dumb" device. It receives raw digital drive signals for the IGBT modules from the HV ECU.

 

I care! =)

I found in my 2008 If you want the car to work somewhat normally you need all of them. Otherwise the HV ECU freaks out and sets several codes, U0111 is one I remember. It will actually drive, but in a limp-home mode without using any battery. I think the frame you are referring to, (0x3CB) is only sent about every 100ms.

 

Nimblemotors and Vertex - I am rooting for both of you in a big way! Both are intriguing ideas.

In no time our Prius' will be worth far less, old and depreciated. Who knows, you could help create the next "Small Block Chevy" of EVs! EV kits for a VW or Porsche 914, small pickup trucks are plentiful. Yanking the engine and inserting an electric motor seems reasonable to me to try to figure out, and nonetheless will be fun, and you will learn a lot! Please keep us informed and incremental pictures are great.

 

Why not just get a Leaf?

 

Yeah I mentioned this early on in the thread. I'm enjoying this discourse though, as it's a great thought exercise!

I've learned there is much here on PriusChat that's not practical, or would survive any kind of cost-benefit analysis. We are enthusiasts, so investing hundreds of hours and even more dollars into this hobby has no business case, but it has a soul-case! =)

 

Not quite.

Here is the full list of CAN message that the Prius stock pack sends.

 

As always, Davide excels with the information he brings to the forum.

 

This especially applies to sheep.

Tom

 

Hi Davide,

Just curious, I saw some really sweet CAN logging tools on the EAA-PHEV site, and most likely, you had to do with that

Did you guys at hybrids-plus develop your own CAN logging tools(software), or did you use some stuff found on the market?

I've been working on attempting to make the 70 MPH "EV mode", but came just a bit short handed. I just need better logging tools.

Any suggestions?

 

Kiett, Come on over to Indiana.
You and I can put our talants together, PEEF, you should come as well.

anybody else seen Davide's book?

 

Kiett, the best all-around is probably Lawicel's CANUSB. Just fire up a terminal program and set the baud to 921,600 8N1, set local echo to on, and add CR to LF.

Then type V (uppercase) and hit enter. Should give you a V1011 as a response. Then issue a S6 command to set the bus speed to 500k, then O will open the stream.

This will keep up with the rate in the Prius with no problems.

I've been told that the Ewert's CANdapter will work as well, but I've never used it though, so I can't honestly say.

If you are going to mess with the CAN bus, it's probably a good idea to bite the bullet and find a microcontroller that is CAN capable and has a good IDE. I use the SiLabs C8051F5xx series to good effect. They have an excellent IDE and really good on-chip debug facilities that work in system. If you develop in C, it uses the Keil compiler which fully integrates with the IDE.

You can get started with the F502 Toolstick kit for under $30 bucks. It has all the CAN stuff right on the board, just strip the wires from the CAN bus and connect them. Here are the 2 parts you need:
1. The Base Adapter
2. The F502DC board

With only a little bit of coding, you can build your own CAN to PC interface using this kit. Plus, you can build a stand-alone module that will stay in the car and do logging, etc, no computer needed. It only needs +5v to run.

 

Kiett and I are in California, maybe you should come here? =)

Actually, there are more Prii per-capita in the Bay Area than any other place on the planet. Good place to be for Prius stuff!

But seriously, next time I have business out your way, I'll come see you for sure. If you end up needing to hire me for something, I'll come sooner! ;-)

 

to quote a famouse Pirate...
So,then we have established the principal is sound, now were haggling over price.

This is good.

and the above listed information is also very welcome, thanks.