# Planning my first conversion: Renault R4



## Huub3 (Aug 16, 2009)

Johannes,

good luck with that conversion, I'll be watching closely, as my route is Industrial ACIM too (but rather with an industrial VFD).

Regards,


Huub


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## jhuebner (Apr 30, 2010)

I think this one is interesting for the industrial motor fans:

http://rc-autopilot.de/wiki/index.php/Opel_Corsa_Project

He hasn't even rewound the motor or added forced cooling. Also he just spins up to 3000rpm.

I'm thinking to increase my DC voltage even more with smaller batteries to be able to spin a bit higher than that at full torque.

/Johannes


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## jhuebner (Apr 30, 2010)

Besides planning and setting up my workshop I actually made some hardware progress:









This is the first out of 13 cell blocks. Each cell block will be monitored with an LTC6803 battery monitoring IC. It monitores 12 voltages and 2 temperatures.
The device communicates via SPI. So I will build a number of hubs, that will collect the data and provide it via RS485. Finally, the data will be evaluated by a standard PC software which can display bar graphs etc.
The LTC6803 also has shunt switches for each cell to allow passive balancing during charging.


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## jhuebner (Apr 30, 2010)

Now the remaining 144 TS cells have arrived.
When charging 12 of them they almost reached 100% simultaneously with very little need for balancing.

Also the motor has arrived. It is about the size of a 7,5kW motor and weighs 66kg. It is speced at 120Hz though, with a nominal output power of 18,5 kW at 3560 rpm.

My home-made inverter reved it up nicely but soon my tiny cables melted ;-)


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## jhuebner (Apr 30, 2010)

Meanwhile the car has arrived and we pulled motor and transmission from it.

We have made the drawings for the adapter plates and the shaft connector which will be fabricated this week.

Unfortunatly while pulling the motor I was so busy that I couldn't be bothered to take any pictures.

When the transmission and motor come back to my workshop I will take some pics.

One question arose: the motor has an IP55 rating. Is that ok for sitting in an engine bay?

I'm planning to put some of the TS batteries in the engine compartment as well, how much water-proofing will I have to do?

/Johannes


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## Woodsmith (Jun 5, 2008)

jhuebner said:


> One question arose: the motor has an IP55 rating. Is that ok for sitting in an engine bay?
> /Johannes


Here is the explanation for IP (Ingress Protection) http://www.protectingpeople.co.uk/fire_tech/ip_explained.htm
IP55 is protection from dust and protection from water from a nozzle. That is pretty tightly sealed, and a lot better sealed then a DC motor would be.

I think the average DC motor would be IP20 what with air vents over the fan and brush ring.


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## jhuebner (Apr 30, 2010)

Woodsmith said:


> Here is the explanation for IP (Ingress Protection) http://www.protectingpeople.co.uk/fire_tech/ip_explained.htm
> IP55 is protection from dust and protection from water from a nozzle. That is pretty tightly sealed, and a lot better sealed then a DC motor would be.
> 
> I think the average DC motor would be IP20 what with air vents over the fan and brush ring.


Yeah good point 
How do these motors cope with driving in heavy rain, possibly behind another car?


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## jhuebner (Apr 30, 2010)

We finally mated motor and transmission yesterday:









Shaft connector










We did a test run up to 3500 rpm and it all sounded pretty smooth. The transmission leaked some oil though.

Edit: Heres the video: http://www.youtube.com/watch?v=pMwnuqf-eFs

/Johannes


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## jhuebner (Apr 30, 2010)

We've gotten around to putting the motor in the car

Here it is supposed to be:










Here comes the motor+transmission:










And now it's all in:










Drive shafts are not mounted yet, had to solve some issues with the speed sensor first. That should happen next week. We will be able to do the first test-crawl with the 24-cell pack.

Unfortunatly we had to remove the motors fan because it wouldn't fit otherwise. I hope it won't overheat. Subject to test.


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## EVfun (Mar 14, 2010)

It looks like your cell connection straps are made from some clamps. It isn't a good idea to use some unknown zinc plated steel for electrical connections. It is quite possible to pick a metal with only 15% of the conductivity of the same size in copper.


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## jhuebner (Apr 30, 2010)

Thanks for pointing that out. Meanwhile I use copper straps on some cells and aluminum on others. The clamps had 10x higher resistance indeed.


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## jhuebner (Apr 30, 2010)

Some more progress made:










9 12-cell battery packs easily fit in the trunk. We will build a wooden box around it.

Also the final motor mounts have been welded together and are fixed to the motor with a total of 10 M10 screws. The motor sits on rubber brackets:









I have also replaced the three single wires to the motor with a single shielded cable. It's only 6mm² but according to DIN thats ok for 43A continous. Thanks to the high voltage thats the full load current. I've found some nice waterproof bushing that contacts the shield.

I've also added contactor control to my inverter as well as a precharge resistor. When the inverter is powered on, the precharge relais closes. When the voltage reaches a certain treshold, the main contactor is closed.


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## jhuebner (Apr 30, 2010)

*First test drive done!*

Hi everyone!

Last night we did the first test run with the Renault!
http://youtu.be/jCyK6MCE66o

It drove smoothly but the inverter shut down when accelerating a bit more.

Anyway, the home-build, home-programmed inverter moved the car. I'm really quite happy about it and will go bug-hunting now.

Cheers,
Johannes

_Getting ready to test-drive. The laptop is only there to modify parameters and restart on fault:_









_Made it out of the garage








_


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## Woodsmith (Jun 5, 2008)

Good to see it running.

That shelf looks like it should stay there, with the laptop screen poking out of the bonnet/hood.


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## jhuebner (Apr 30, 2010)

Yeah, how about it 

There will be some kind of shelf for the remaining batteries.

Today I did another test run in V/f mode. I.e. theres no more slip control, the pot plainly controls the inverter frequency. That way I could accelerate up to 30 km/h and might have illegaly taken it on the road.
I learned a lesson how sensitive the motor reacts to wrong V/f settings. I found that above 1 Hz I don't need any boost voltage. Must be down to the low ohmic resistance of the stator.

I didn't succeed in testing with 4,4 kHz because the scaling factors are all set up for 8,8 kHz and thus my V/f parameters were off again.

Finally a cable of my usb-uart converter came off and I decided to quit the experiment for today.

Oh and I definitly need to route the reverse/forward switch into the cockpit. Getting under the bonnet every time I want to change direction really is disturbing


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## Mesuge (Mar 6, 2008)

Johannes> so you are basically transplanting that kiwi software on completely different driving board and different igbt/mosfet power stage which is designed by yourself (as followed in you homebrew AC controller thread)? That's some advantureous approach indeed.

You might consider ditching the stock ACIM cooling fan completely for ever and just add low voltage PC/electronics or automotive fan over there. It's more efficient and less noisy, the aussie guys are doing it for some time with ok results.


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## jhuebner (Apr 30, 2010)

Mesuge said:


> Johannes> so you are basically transplanting that kiwi software on completely different driving board and different igbt/mosfet power stage which is designed by yourself (as followed in you homebrew AC controller thread)? That's some advantureous approach indeed.


Well basically it was me who contributed the first V/f software to the project. So it's not a black box to me. Running it on a different controller board is no rocket science either, just need to change some gpios.
I guess my self-designed power stage is the biggest adventure. I'm rather into computer science and the strange paths of current in power electronics offend me very much 
Right now I'm running the software on an Olimex board which will replace my box of many wires which you can see to the left of the power stage.



Mesuge said:


> You might consider ditching the stock ACIM cooling fan completely for ever and just add low voltage PC/electronics or automotive fan over there. It's more efficient and less noisy, the aussie guys are doing it for some time with ok results.


Yes, I guess that cooling method is more reliable on low motor revs anyway. I'll read out the temp sensor within the motor and until it doesn't show alarming values I won't add any cooling at all. The motor runs at 1% slip nominal, so it is on the efficient side.


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## Mesuge (Mar 6, 2008)

Thanks for the prompt reply.

I'm wondering what is your strategy then for making it street legal especiallly in TUV-Germany, lolz? I gather It's either individual electromagnetic compliance test for the entire vehicle, which runs into thousands of EUR or producing papers for each individual component as been certified by its manufacturer/dealer in Europe. That latter "easy" option would also incl. your new controller..


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## jhuebner (Apr 30, 2010)

Mesuge said:


> Thanks for the prompt reply.
> 
> I'm wondering what is your strategy then for making it street legal especiallly in TUV-Germany, lolz? I gather It's either individual electromagnetic compliance test for the entire vehicle, which runs into thousands of EUR or producing papers for each individual component as been certified by its manufacturer/dealer in Europe. That latter "easy" option would also incl. your new controller..


Don't remind me... We'll take it to the TÜV as soon as we have things cleaned up and ask them about things to change. I will have to go though a compliance test, maybe working at an inverter company helps...

I did another test run today with a frequency ramp behind the slip control. This prevents spikes to cause frequency jumps which result in instant over-current. It runs smoothly now above 10km/h, below that it still tends to oscillate and sometimes trip from over-current.


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## jhuebner (Apr 30, 2010)

Good news!

http://youtu.be/xkuDTby8pQw

I refined the control algorithms a bit and took the car for a spin. Accelerates very smooth now but has a mind of its own. Coming to a stop again is difficult, i.e. the throttle response is so slow, that you need to know well in advance when you want to stop. It even pushes against the brakes if you try to stop that way.
But thats nothing that can't be fixed, I'm happy for now.


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## somanywelps (Jan 25, 2012)

Is it just the camera's mic, or is that ungodly loud?


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## jhuebner (Apr 30, 2010)

It is running in 1st gear -> high revs. Plus the inverter runs at 4,4 kHz which is very audible.


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## jhuebner (Apr 30, 2010)

We've found the final location for the controller and put in the front batteries to see if they fit:










What are the ideas for protecting the battery poles/the BMS from spray water and from being touched. My first idea was to build a wooden box. But is that stury enough? Will it hold back the batteries when the car crashes into something?


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## jhuebner (Apr 30, 2010)

I've cancelled this project and transferred the hardware to a Polo. New build thread here> http://www.diyelectriccar.com/forums/showthread.php/vw-polo-86c-1991-ac-conversion-88106.html


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