Previa madness vol.2, (i.e. oh no, celeron55 is messing around again!)

[celeron55]

1993 Toyota Previa, 8-seater
Q211 MGR
Leaf gen2 inverter with a custom openinverter board with lots of bodges
BMW X5 plug-in hybrid batteries

Yes, of course it has the full ICE system in and operational still. Just no propshaft...

Yes, the plastic spline adapters broke. But only after going back and forth at full throttle for more than 10 times.

Will order metal 3d printed ones.

There is no throttle pedal, charger, dc-dc, electric brake or steering assist yet. Only the MGR has bolts holding it down. Or more like up.

[Ev8]

Looks like a bit of fun, I’m a big fan of bmw phev modules

[johu]

Did you do all this in 5 days since you announced it on the FW thread? Wow...
Maybe I should keep my Diesel Sharan and do a quick and dirty conversion on it. Only it has front wheel drive, so motor would have to be removed.

[arber333]

Did you do all this in 5 days since you announced it on the FW thread? Wow...
Maybe I should keep my Diesel Sharan and do a quick and dirty conversion on it. Only it has front wheel drive, so motor would have to be removed.

Hah, maybe you should just replace rear axle and fit driven axle in the back. Then just add one Outlander rear motor or lexus MGR.
Also fit Model 3 cells in the back and make a false floor.
Keep the Diesel in for those really long hauls .

And i also found a good spring enhancement system with TUV to fight the increased rear weight. You put spring into spring and you can haul extra 90kg. I think i will buy one set for my Pug too keep it from taking off.
https://mad-suspensionsystems.com/en/

[celeron55]

Did you do all this in 5 days since you announced it on the FW thread? Wow...
Maybe I should keep my Diesel Sharan and do a quick and dirty conversion on it. Only it has front wheel drive, so motor would have to be removed.

I had the battery, inverter and motor already wired up and configured since I did the torque tests in January. What I did in 5 days was remove the diff, mount the MGR and modify one driveshaft that was from a non-hybrid Lexus RX. And then jacked the battery inside and pulled the wires through the motor cover under the driver's seat.

I have to say, "removing the diff" sounds easy, until you realize the diff and the surrounding components, mounts and also the driveshafts last literally forever, i.e. they have been never touched since it left the factory almost 30 years ago. Took some elbow grease.

I do think quick and dirty conversions have a place in this world. Some cars aren't driven enough to warrant the nicest, most powerful and longest range conversion, but can be in reasonable condition and still very useful when you need them. Or just have them as test beds for EV parts.

[celeron55]

Something seems off

[Ev8]

Oops, shaft to short?

[celeron55]

A multitude of problems, including my temporary MGR mount breaking almost immediately, causing it to move downwards and to the right, and the position of the MGR being too low (due to space constraints below the floor), causing suspension geometry to pull the shaft out too much. A slightly longer shaft could have helped but not fixed this.

I need to figure out how much I need to cut into the structural "beam" under the floor in order to get the MGR to a higher position, or whether I can move it forwards and then upwards to gain better suspension/shaft geometry.

[celeron55]

Welded a better mount for this. Now I need to source some aluminium and try to mill bit of a spacer on the side that popped off last time.

[celeron55]

Well, it's a spacer. With a bit of luck this should last for a long time. I'm currently 3D printing a centering back piece that uses the existing hole in this piece of aluminium. I need all the height I can get from this piece, and milling aluminium is very annoying with my mini CNC.

[MattsAwesomeStuff]

I have been eyeing up my Caravan with the angle grinder for a while now. This is more tempting than it should be, considering how many projects on-the-go I already have to deal with...

[celeron55]

Got the axles installed once again, will start testing soon.

I ended up pressing in steel nuts into the aluminium spacer, as I measured and calculated the aluminium threads wouldn't be able to provide enough clamping force to hold the axle in place when the motor produces its maximum torque. The aluminium threads I originally made stripped at 15Nm, which wasn't enough.

I torqued these M8 bolts to about 28Nm, which should provide about 75kN total clamping force for the 4 bolts combined, which at 50mm radius and let's say 0.4 coefficient of friction will hold 1500Nm of torque from the axle. That's enough for the MGR's 650Nm per axle. I also used Nord Lock washers so that if there is movement, coming apart will take a long time.

I also took one axle off and calculated the allowable length movement and compared to what the range caused by suspension travel was. It barely does it now, having about 10mm of range left in each direction before destruction. Adding 5mm more spacers to both sides would be a good idea, but I'll skip that for now.

Then I painted the mount yellow. In the most obnoxious way.

[celeron55]

First test drive done, mostly just to see if it can handle some driving without exploding. It didn't explode, which is good. Now to check the log whether everything looks ok there also.

I don't think I'll find anything enlightening here, but if I do I'll probably post in the MGR FW mystery thread instead: viewtopic.php?f=7&t=1683

The tire circumference is about 2075mm and the graph shows fstat peaked at about 175Hz. This means my speed peaked at 47km/h. (4 polepairs, 6.9:1 gearing)

Well, it does look like ud is maxing out so it's running out of voltage, which is to be expected.

EDIT: I'll have to figure out battery management and charging somehow. I guess I'll port the SimpBMS BMW code to some board I have lying around and then try to cobble up a working PDM out of the PDM parts I have, and try to control that via CAN.

[celeron55]

I'm gonna swiftly rip off Damien's work to get this PDM working under CANbus control. It has been cobbled together from a broken 6.6kW one I bought on Ebay years ago (no cables or anything, I'll cobble up those too from some Toyota junk or something), and some boards I got from johu from the 3.3kW unit starring his teardown video. I think mine had the charger main transistor board broken so this will be downgraded to 3.3kW. I'm also using the brain board and the charger control board from johu so that it all matches.

I was thinking of using the ZombieVerter to control this, but the GD32 chip isn't co-operating with me, so I'll grab a trusty Arduino Nano and solder up an MCP2515 module and some transistors, and try to write some tight code to make it all fit and perform. There are quite a lot of 10ms messages that need to happen.

I'll also be connecting the BMW PHEV modules to the Nano in order to request BMS info from them, and if it turns out it's necessary, I'll try to connect the BMW PHEV S-Box on yet the same CANbus in order to measure pack current and system voltage. It will be necessary if the PDM doesn't want to charge without matching voltage and/or current info that would have came from the BMS originally on the Leaf.

Well, I guess just wish me some luck and I'll be golden.

[paaa]

I have the can logs Damien used if thats any help to you. If you want them let me know.

[celeron55]

Holy shit, it was ready to kill me right away:

Now we know it's capable of 558 volts, eh?

This is as barebones as it gets: 9 wires coming out of the case: L, N, PE, CP, PP, CAN H, CAN L, permanent 12V, switched 12V, and the 10th wire is the grounding of the case:

Then just send the boatloads of CANbus messages Damien has jotted down in his latest ZombieVerter commits: https://github.com/damienmaguire/Stm32- ... eafinv.cpp

It doesn't even need a HV battery, it'll go ahead and charge anyway. There's a dual safety interlock in the case, but that doesn't matter either, I guess it just sends its status over CAN to the VCU which decides what to do with it. There's no voltage limit, I guess the BMS or VCU is supposed to deal with that.

[Bratitude]

oh I’m am kicking my self for ditching my pmd now seeing it can produce higher than 400v
This is great news

[celeron55]

The DC-DC is hardware limited to something like 185V if anyone's wondering what the practical lower limit is. I know this from my previous conversion where I force-enabled it with hardware mods. (similar to the inverter with OEM control)

[Jack Bauer]

Glad to be able to pay it back around.

[celeron55]

Here's the absolutely unholiest combination of things:

A do-it-yourself type1 connector,
attached to a Lexus battery cable, with +/-/shield/signal1(?)/signal2(?) mapped as L/N/PE/CP/PP,
connected to the EVSE input of a stock Nissan Leaf PDM,
charging a BMW PHEV battery in its original casing,
the PDM being bolted on a Nissan Leaf inverter which has a replacement openinverter logic board,
driving a Lexus Q211 MGR.

Ok the integration work is still on the way, but I felt like writing a poem.

[MattsAwesomeStuff]

A manual? You don't have a manual?

Celeron built this IN A VAN... with a BUNCH OF SCRAPS!

Yeah, well, we're not Celeron.

[celeron55]

Just managed to connect the wires and program the arduino to read the module voltages and very crudely command the PDM. I'm still controlling the contactors by starting the inverter. In a couple of hours I should have a fully charged battery ready for testing. If I forget to unplug it, there's only a 10% chance it explodes.

[celeron55]

So let's make an EV conversion!

The throttle pedal...

The gear shift...

The VCU...

The 12V power distribution...

The wiring harness...

The mod board...

The cooling system...

The power electronics...

The motor...

The EV grin...

[celeron55]

Flooring the throttle for a total of 4.6km, 2.3 km back and forth, brings the motor and inverter temperatures warm to the touch. The outside temperature is about 12°C.

The top speed during that run is about 85km/h, which is pretty good for the Q211 MGR, with a hacky tune, moving a minivan. I'm using syncadv=30 and a special firmware version with configurable throtiq and throtid, which both are set to 2.0. Moving away from these parameters worsens the performance. EDIT: Altough the 2.0/2.0 split is similar enough to the official MTPA formula that it's worth checking at some point whether the performance is the same with that one.

When charging the battery from halfway to full at 2kW, the charger gets so hot the crud on the aluminium starts smelling funny.

(I should warn you shouldn't do this with almost any other inverter or charger - the Leaf stuff is special in that entire the aluminium casting works as the heatsink for the high power components. Coolant is (well, should be) circulated on the other side of the casting, but the casting itself is so large and heavy that it barely needs any coolant for driving or charging, given you have a light foot and small battery.)

[bexander]

Very interesting!
How much power are you getting from the MGR? Specially at higher speeds, >40km/h?
Does this mean you are running 50/50 id/iq distribution all the time and still get FW?