Prius Gen 3 Inverter Logic Board Support Thread

[Ctwidle]

Back in April jeffb reported he was getting a PRECHARGE error when attempting a first motor spin. I have a Yaris inverter with a full size Prius V1c board from mid 2020 (I let the smoke out of the Yaris board) running, correction - hoping to run, an Outlander rear motor. I have tried 4.96 and 5.2 sine and 5.2 foc with 36v manually precharged through a bulb. Uploading different firmware seems to work as expected and I was able to observe PWM.
All that happens, apart from the error, is that the motor is slightly more reluctant to turn manually when the inverter is started. The error message is present even after a clear and restart without turning the inverter on.
I tried to follow the thread from jeffb but didn’t see that it was resolved and attempts to follow suggestions led to programming rabbit holes that I am too big (and old) to go down.
Any suggestions gratefully recieved.
Is there any way that I can check that I actually have a functional inverter?

[m.art.y]

All that happens, apart from the error, is that the motor is slightly more reluctant to turn manually when the inverter is started. The error message is present even after a clear and restart without turning the inverter on.
Any suggestions gratefully recieved.
Is there any way that I can check that I actually have a functional inverter?

Hi, which error message that is, could you perhaps take a picture of your settings or upload your parameter list?
I would suggest you upload the sine software version and do a sensorless spin attempt. 36V is a bit low so that might be your problem, would be good if you had at least double that. Also what is your udcsw value set to?

[Bigpie]

Is your udc reporting the correct voltage? If not what's your params? Check the little white connector for a dey joint.


Does swapping 2 of the phase cables spin the motor? Is this open loop mode you're trying?

[Ctwidle]

Thanks for the tips guys,
Error message is STOP - PRECHARGE
Params are as per Gen 3 tuning manual with encmode AB and pinswap 8 when I tried foc firmware
udscw changed to 30v,
Got some more batteries on charge for another try tomorrow afternoon (downunder time)
Tried all 6 phase wire combinations!
Will check voltage reporting next time.
How far is it safe to raise testing parameters?

[m.art.y]

Thanks for the tips guys,
Error message is STOP - PRECHARGE
Params are as per Gen 3 tuning manual with encmode AB and pinswap 8 when I tried foc firmware
udscw changed to 30v,
Got some more batteries on charge for another try tomorrow afternoon (downunder time)
Tried all 6 phase wire combinations!
Will check voltage reporting next time.
How far is it safe to raise testing parameters?

Hi,

Set udcsw to 0, make sure your 12v power supply is good (doesn't drop below 12v), select a direction (by connecting a forward or reverse wire to 12v). That's all that is needed to test spin with sine firmware. Then you select manual run and start entering values as per wiki. Please let us know how it goes and if you still have trouble. Precharge error can be due to a bad 12v power to the inverter if I remember correctly, also you have to have your inverter case grounded to 12v ground.

If precharge error still there, can you wire precharge line to negative of your precharge contactor? +12V has to be permanently connected to contactor. And main contactor line connect to your main contactor.

[Ctwidle]

Didnt get much time today but Still no spin and still got the precharge error. 12v supply is reliable as is the earth to box connection. Still need to try the precharge to groundconnection.
I’m guessing that battery v should equal udc? If so I’m way off. With an applied 36v udc was 2.18v and with 72v it was 2.49. Will go looking for dry joints tomorrow and see if I can find any obvious errors. Ive been working on the basic vehicle work since I bought the inverter a couple of years ago and I did attempt to uphrade the capacitors and the voltage dividing resistors so I will have a good look around there.

[Ctwidle]

Doh! It was the two capacitor/connections on the end opposite the ampseal! (Or rather the lack thereof). Feeling rather foolish but strangely happy as well. Thanks for the moral support now the real fun begins.

[m.art.y]

Doh! It was the two capacitor/connections on the end opposite the ampseal! (Or rather the lack thereof). Feeling rather foolish but strangely happy as well. Thanks for the moral support now the real fun begins.

Hi, ok that might explain the Precharge error then . Let us know if you finally have a spin.

[Ctwidle]

Yes thanks. Feel a bit of a prat though as I was aware that better brains than mine had confessed to having forgotten to reconnect the mg2 bolts and I was determined not to make the same mistake, so I made a similar one. A flying instructor once told me “learn from other peoples mistakes in case you don’t live long enough to make them all yourself”!
Time to re-digest some tuning videos but more importantly I had decided that I would not start any other part of the project till
I was confident that I could at least spin a motor so now its time to start raiding the piggy bank.

[FFMan]

So i've got the working V1C board back thanks to some nice folks on here

I fired it up standalone, led flashing, OTA working.

When I install it in my gen3 inverter and plug in all the connections (no HV attached), using my current limited supply, the 12v drops to 8 and the draw is by the psu to 1.2amp. If I unplug the jst connector this drain goes away.

Of course the inverter was bought as working but i see normal drain is 600-800ma so what might be the issue ? Have I been sold a duff one ?

TIA

[Pete9008]

First, bear in mind that I haven't powered up an inverter myself yet!

If you have the PSU current limit set at 1.2A then that sounds like its just the switch mode power supplies in the inverter doing their thing. If you have set the current limit on the power supply a little too low it can get into a mode where the voltage drops during the power on surge (while charging the caps). The switch mode supply tries to pull the normal power (12v x 0.8A = 9.6W) but since the volts are low pulls a bit more current (9.6 / 8V = ~1.2A) and holds the PSU in current limit. Try increasing the current limit on the PSU just a little bit to see if the problem disappears.

[FFMan]

First, bear in mind that I haven't powered up an inverter myself yet!

If you have the PSU current limit set at 1.2A then that sounds like its just the switch mode power supplies in the inverter doing their thing. If you have set the current limit on the power supply a little too low it can get into a mode where the voltage drops during the power on surge (while charging the caps). The switch mode supply tries to pull the normal power (12v x 0.8A = 9.6W) but since the volts are low pulls a bit more current (9.6 / 8V = ~1.2A) and holds the PSU in current limit. Try increasing the current limit on the PSU just a little bit to see if the problem disappears.

yep that did it - thanks. I was being a bit cautious, but i turned the limit up to 2amps and it's settled at 12v @ 800ma when idle.

[Pete9008]

yep that did it - thanks. I was being a bit cautious, but i turned the limit up to 2amps and it's settled at 12v @ 800ma when idle.

Been there a few times when testing new boards - you feel the need to be cautios but with switch mode supplies it can catch you out. Glad it looks OK

[4markowen]

On a scale of 1-10 how much have I cocked up after getting over enthusiastic taking the case off?

It was £18, and 'not working' so can live with it if I've completed borked it.

Not sure if you can see the full damage, will that glue back on? Should I not attempt it?

[4markowen]

One further question. The MG1 and MG2 current sense connectors. I've soldered them 'notches out' as per silk screen and wiki, but on the Toyota board they're notches in. So I have to turn the cables around to attach it?

There's also a gap in the wiki about updating/instructions for the Atmega328p firmware. Does anyone have any information about that? A thread here, or video I can point to?

I'm presuming its using the FTDI interface? Is there a pin out diagram for the board? Does is directly match an FTDI USB to Serial converter pin out? Voltage (5v).

Beyond that I presume it's just uploading a sketch from the Arduino IDE or Platformio as you would a USB connected development board but via serial and a converter?

[m.art.y]

One further question. The MG1 and MG2 current sense connectors. I've soldered them 'notches out' as per silk screen and wiki, but on the Toyota board they're notches in. So I have to turn the cables around to attach it?

There's also a gap in the wiki about updating/instructions for the Atmega328p firmware. Does anyone have any information about that? A thread here, or video I can point to?

If you're using v1c then current sense connectors need to be soldered opposite to how they are in toyota oem board. You just twist the cables a bit when connecting, no problem there.
Do you mean code to Atmega328p as for charger and boost converter? There have been at least couple made I remember one by damien, the other one by celeron55. There might be others. There are threads about that you'll need to search, haven't been any update on those for a while though.

If you're not going to use the inverter as charger or reduce battery voltage for dcdc (there is a resistor mod that you can do instead) with internal boost converter you don't even need to use the atmega328p.

[4markowen]

Yeah atmega328p on the board, Charger and boost converter. I’ve been having a read of the code for it, just trying familiarise myself with the hardware. Looking to try and make that ‘do it all solution’ before I probably also abandon it for a separate charger

Got an(other) Audi A2 to convert along with the others on here. Outlander rear, this gen 3 and a bmw hybrid pack. So it’s that light weight minimalist vibe to match the car.

Did manage to connect the cables, but just wanted to check. Cheers.

[4markowen]

hmm, suspect the 'cheap for a reason' inverter I've got is because it is actually dead.

I've connected the board up in the inverter and just checking different connectors after no leds come on. The 50way, when connected, neither board turns on. When disconnected the OI board does, but manillas the remaining connectors are just listening as such.

The installed board settles on drawing 3-ish volts and has 5 amps available to it. No leds or activity though.

I'm confident the connector is soldered on correctly, aside from a slight burn to the plastic case I'm quite proud of it. Other connectors on the board less so, but working.

But is there any means of testing the remaining Toyota board?

Would testing the continuity between pads and pins in the 50 way rule that out to confirm I haven't shorted pins on that?

[Bigpie]

Yeah atmega328p on the board, Charger and boost converter. I’ve been having a read of the code for it, just trying familiarise myself with the hardware. Looking to try and make that ‘do it all solution’ before I probably also abandon it for a separate charger

Got an(other) Audi A2 to convert along with the others on here. Outlander rear, this gen 3 and a bmw hybrid pack. So it’s that light weight minimalist vibe to match the car.

Did manage to connect the cables, but just wanted to check. Cheers.

A problem with using prius buck/boost for charging is that it only works when bucking down voltage (current code) (it can only buck in one direction and boost in the other). When single phase is rectified it is about 310v, so if you've got 96s and discharge to 3.2v per cell you'll need to be able to cover ~307v to ~398v, so you'd need externally increase the voltage input, or alternatively many be some contactors to switch the battery from the bucking side to the boosting side mid charge and amend the code accordingly. There's also no PCF.

[4markowen]

Like I said, probably abandon for a separate charger for ease, but there's just that compactness that is attractive.

Was looking at the mini countryman hybrid packs with 10kwh, 5 modules, and a voltage range of roughly 224v to 336v for the pack - quick bit of maths for a 6 module 330e pack dropping a module, but keeping the pack as a whole and the OEM BMS intact.

So probably unlikely, I'm more at the 'getting the inverter to spin the motor' stage of things at present, working board, but with a potentially non-working inverter to get a PWM from.

PCF? Power correction factor / Power factor correction? asking so I can add it to the reading list

[johu]

PFC - power factor correction. Aims to draw a sinusoidal current from a sinusoidal voltage source. The quick current loop on the openinverter firmware somewhat achieves this when in boost mode, i.e. it boosts more in the sine "valley" and boosts less at the peak.

Boost mode would require a (discharged) battery voltage below peak voltage (said 310V) and a rectified voltage to be fed in to the original battery input. Not sure if the atmega software supports this though.

[FFMan]

After some board issues and self confessed muppetry I've got to a point where my Prius Gen3 motor kinds of works in sine mode. Due to the muppetry i can say i get the same behaviour on 2 inverters so i think they're probably ok. This is the setup https://www.dropbox.com/s/4fhrdcbom7ovo ... 2.jpg?dl=0

Have tried using HV at 40v and 80v from lithium and 80v from daisy chained supplies. All give the same results though with varying vigour as one might expect. I did this to rule out any issues with a supply not providing enough current.

Not sure if you can see this video https://www.dropbox.com/s/6vesflonunjh5 ... 4.MOV?dl=0 of the issue


When i start the inverter and set fslipspnt to 10 and ampnom to 100 with throttle pot at zero (other parameters as specified in wijki for testing), i get a knocking almost rotation from the shaft (parking brake is removed). As i increased the throttle, the knocking increases to a point the shaft just about rotates but knocks back and forth a bit. If i switch the cable to MG1, the situation is slightly better, at full throttle i get smooth rotation but knocking at lower settings. I tried swapping two motor wires over but got the same result.

Can anyone advise on a known good set of params Prius gen3 inverter and gearbox combination ?

Of importance seem to be but i'm sure there are others that needs tweaking:-

polepairs
deadtime
numimp

thanks

[catphish]

After some board issues and self confessed muppetry I've got to a point where my Prius Gen3 motor kinds of works in sine mode

I'm confused. Isn't that a synchronous motor? I've never quite worked out what sine mode does, but doesn't it only exist in the sine version of openinverter?

[FFMan]

I'm confused. Isn't that a synchronous motor? I've never quite worked out what sine mode does, but doesn't it only exist in the sine version of openinverter?

As i understand the sine f/w is a version that doesn't require any motor feedback. Use of it to test components is a recommended step before trying to load the FOC f/ware with resolver connections etc

[catphish]

As i understand the sine f/w is a version that doesn't require any motor feedback. Use of it to test components is a recommended step before trying to load the FOC f/ware with resolver connections etc

That's absolutely incorrect. The sine version is for use with induction motors and definitely requires motor feedback. It won't work with the feedback provided by a synchronous motor.

In order to test without feedback, you would require a special mode that ignores the throttle and all feedback and just sends a fixed frequency and voltage to the motor. Hopefully somebody else can comment as to whether this mode exists or not.

On a related note, what is "MOD_SINE" mode? I could never figure it out. Is it related to testing like this, or something else entirely?