Project RX8 , Prius gen2, Lexus transaxle to rwd

Tell us about the project you do with the open inverter
Richerson
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Richerson »

Great solution, and less noise.
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

I had some doubts about how well it would work, but testing showered me with high pressure atf so seems up to the job
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

At last i can no longer put off the control electronics!

Will the lack of availability of Modice enclosures and the fact I want to drive both mg1 and mg2 in this inverter I have squeezed 2 gen2 Prius boards into and old vw ecu housing
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

I have also found resolver pin outs for the rx400 transaxle so that should help take the guesswork out of resolver wiring
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Well a little testing with bits of inverter and motor on the smallest table possible has confirmed resolver wiring is good
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

https://youtu.be/7AnE_7L9ZMk

I’ve had time to do most of the car wiring, up to a point where I could test/tune mg2, foc tuning with 2 motors on the same shaft seem more difficult, mg1 is currently disconnected at the phase wires but when performing foc tuning the area range of values between reserve rotation and forward is a lot I get from reverse rotation at 10a at 7000 and forward direction 10a at 14500 everything in between is no movement with 100a so I’ve set it to 10500 and it seems to behave well enough for some low speed testing, a little juddering when first setting off, I will tune further when I have a working cooling loop and power steering, please excuse the Rusty brakes and flat tyres the car has been neglected
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

A couple of other random pictures of recent things
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Vacuum pump control circuit squeezed into the vcu case
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Prius power switch for start signal and manual regen pot
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

A quick question for anyone interested, currently UDC is measured by mg2 vcu and this controls the contactors, mg2 vcu also takes the analog pot feeds which are mapped across can to mg1 vcu, this works fine however if I try to map across udc via can I get nothing.
I was reluctant to connect the vh pin on the inverter to both vcu as it might require some adjustment to the udc gain? But it not possible via can this is the way to go.
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Ok interestingly with udc mapped over can from mg2 I can see if I plot udc on mg1 that the data is getting across because at random intervals the plot jumps to battery voltage, instead of the adc -84v the floating pin gives. I wonder if tieing that pin to ground would make a difference?
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

A little forum digging found the udc answer
https://openinverter.org/forum/viewtopic.php?t=1428
Useful info for anyone else wishing to run 2 boards/motors
I will connect the inverter vh pin to the mg1 vcu as well and report back if I need to rescale anything.
RetroZero
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Hmmm, so if there's no CAN and run the 2vcu's in parralel, there could be gain issues? Will await your findings.. I was thinking of putting diodes to all inputs running in parallel, with 'dummy relays' for precharge and dcsw on 2nd vcu.
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Currently my set up is mg2 vcu does contactor control, takes analog pot inputs shares pots over can to mg1 vcu, all +12v logic inputs from the car ie, brake,start,forward,reverse are connected to both vcu, although have since discovered I could have shared this via can also.
I think I’m happy for mg1 vcu to have no influence over the contactors, if there’s an mg1 inverter fault condition it’ll shut down the igbts anyway it’ll be down to me to restart both vcu to reset. But I will let you know how that goes, gen2 inverters are cheap!
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Also interesting side note syncof or rx400h mg2 also appears to be 10200 much like oth have found on the Prius
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

[media] [/media]

Mg2 only still but progress 3rd gear, conservative parameters, fmax300, throtcur3, throtramp10,

Needs further tuning on ramps as I get a lot of driveline clatter at slow speed when transitioning between throttle and regen,
RetroZero
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Nice going. Bravo to get the wheels turning!
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johu
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by johu »

Nice! much of vibration was fixed in later firmwares, which one are you running?
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

I just updated to the 5.17 before this test yesterday, I think the issue is with physical slack in the driveline and to aggressive ramps currently, I exprerienced similar harsh chatter before with my dc motor before I got that dialed in better with software
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

So I’ve had a bit of time to tune mg2, and it’s getting close to drivable, I unfortunately have had one or 2 instances of unwanted regen and accelation, which have mostly been solved with tweaking syncofset (I had a 1000point wide deadband when foc tuning)

I’ve also run into what others have experienced with Prius motors and mgr’s in that torque falls flat past around 2500rpm, no amount of field weakening makes any difference, so I look forward to helping test alternative field weakening strategy
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Ev8
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by Ev8 »

Side note for retro zero I have no issues paralleling the inverter vh pin into both vcu boards, no need to change scaling
RetroZero
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Re: Project RX8 , Prius gen2, Lexus transaxle to rwd

Post by RetroZero »

Thanks for that 👌
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