Prius Gen2 A/C compressor inverter

[imwoody36]

sure! i can confirm the gen2 a/c compressor is just a 3 wire connection from the bottom half of the inverter.
I will look for and document signals.
if anyone has a specific area of interest, it will speed up the process so I dont have to start from scratch with the schematics.
and I have a new siglent scope im eager to use
should we move that discussion somewhere ?... just give me direction

[MattsAwesomeStuff]

I'm just a cheerleader. I don't even know enough about what to ask, to ask.

*prods Johannes*

How he test make AC work good for all peoples?

I'm not even familiar with the whole Wish List of future development and what help might be needed.

[SciroccoEV]

It's well established that the aircon inverter drive is on the same PCB as the DC/DC converter on a Gen 2 Prius and runs at battery voltage.

[Ev8]

Yes but I don’t think anyone has logged the a/c control messages which could be super useful, unfortunately it’s not can bus but the Toyota Bean protocol which I believe is a 12v single wire multiplexed network.

[MattsAwesomeStuff]

It's well established that the aircon inverter drive is on the same PCB as the DC/DC converter on a Gen 2 Prius and runs at battery voltage.

It's not on the wiki, therefore, it might as well not exist.

Though, yes, I'm aware that's been known for a while. But, Johannes has specifically asked for someone to track the signals to the AC so that he can write something that emulates them. So, I'm just connecting people with knowledge with people that can use the knowledge.

[johu]

So to start out the pin mapping of the grey 6-pin LV connector of the A/C inverter needs to be researched. Apparently it runs some sort of serial protocol. In a second step that would need to be recorded with a protocol analyzer at various operational states. Most obviously A/C on and off.

The connector is on the same side as the DC/DC control connector and located below MG2 power output

[turnip73]

Link to prius wire diagram:
https://priuschat.com/attachments/prius ... pdf.33780/
See page 350

Connector:
I11(C)
(I11 Inverter 90980–10988)

1C GND
2C ITE/TOECU
3C ETI/TOINV
4C CLK
5C STB
6C IG

imwoody36 I can send you a man in the middle board if you are interested:
viewtopic.php?t=2516

[johu]

Is any meaning known? Sounds like 2C/3C is like MISO/MOSI style and 4C obviously the clock. But what are the other 2?

[turnip73]

IG 6C 12 when ignition is on
STB 5C 12/14v while inverter is starting up then drops to ~1.5v. Didn't seem to change when a/c was turned on. I'll verify when my pack is changed.

[johu]

Cool, thanks. So these seem to be pretty static leaving only pins 2,3,4 to be connected to a logic analyzer, perhaps in SPI mode.

[linda.ljungdahl]

Would it be possible to use the ac-inverter as a 240 or 400v ac sine inverter to drive thing like tv, computer i.e if we get it running?
Tha would be super sweet

[johu]

Not really, it is targeted to drive a motor and will run on Toyotas firmware. So unlike the "real" inverters we can't clock out arbitrary waveforms

[SciroccoEV]

An off the shelf VFD would probably drive the compressor just fine. Most of my machine toolks are using HuanYang inverters and that includes the router with the 24,000rpm synchronous spindle motor.

You can just bypass the input rectifier and go straight to the DC bus. I haven't bought one for a while (the oldest has been in use for over a decade on my lathe), but I was paying about £80 delivered for a 2.2kW unit.

[linda.ljungdahl]

An off the shelf VFD would probably drive the compressor just fine. Most of my machine toolks are using HuanYang inverters and that includes the router with the 24,000rpm synchronous spindle motor.

You can just bypass the input rectifier and go straight to the DC bus. I haven't bought one for a while (the oldest has been in use for over a decade on my lathe), but I was paying about £80 delivered for a 2.2kW unit.

yes, that would work, but we already get the ac-inverter "for freee", also its quite small compared to its air cooled VFD counterpart.

[NiHaoMike]

What chip is providing the PWM signals? Could it be reprogrammed or replaced with a generic digital power microcontroller on an adapter board?

[turnip73]

I've captured a log turing the A/C on and off with pico scope.
channel A is ITE channel B is ET1:
https://github.com/hakanrolsson/PriusHV ... 43.picolog
to view see:
https://www.picotech.com/downloads (2205A)

[xp677]

Here is some data I captured a few years back. All files generated in Sigrok. I have no more information on them and have forgotten all about this project now.

[johnspark]

xp677 you added some really good info at the other site: Denso ES27C AC Compressor control (Toyota/Lexus).

I am adding crumbs to this at the moment.

Probably there are many similarities between these Denso AC compressors...

[Jacobsmess]

Question from a layman, could the AC inverter potentially drive a 3rd motor? If so, any idea on the voltage/current/power limits? It's mentioned above that it's battery voltage so around 220V in the gen2 Prius.
Also, do any of the lexus inverters also have an integrated AC inverter or is it just the gen2 Prius? Thanks

[johu]

Since it has no position feedback I doubt it can run a drive motor. I forgot the exact rating of the IGBTs. They are TO-247 types and judging by the track width good for 20-30A

[turnip73]

I'm trying to figure out how make the gates stay permanently low so we can use the A/C compressor inverter as a rectifier without modifications see johu comment here:
viewtopic.php?f=14&p=61039#p61039

- Removed 4 IGBTs of the A/C inverter and replaced them with a bridge rectifier (maybe making sure the gates are permanently low achieves the same)

I've taken an A/C compressor inverter card out of an inverter.

1) If I connect IG to 12V and GND to GND on the A/C compressor inverter card it draws no current.
2) If I feed the HV ECU and A/C compressor inverter card 12V (IG) the HV ECU sets ETI, CLK and STB to 12V. ITE stay 0V.
3) If I connect IG to 12V and STB and GND to GND on the A/C compressor inverter card it draws some current (0.01A).

I've been measuring the legs of the gates for changes... not sure exactly what to expect or look for to show that gates are low

See in previous post on this thread for previous tests in the car and below from manual

[turnip73]

Conncted an ardunio nano with software from xp677 on the Denzo ES27C thread viewtopic.php?p=2744#p2744 Edited the software to send all the messages and now the A/C inverter is drawing 0.01 then 0.02 then 0.03 A.

Code: Select all

void loop()
{
  transferpacket(1);
  serialdiag(1); 
transferpacket(2);
  serialdiag(2);
transferpacket(2);
  serialdiag(2);
transferpacket(3);
  serialdiag(3);

}

STB is connected to ground

From the Denzo ES27C thread seems I now need to connect high voltage to get the inverter to wake up.

[turnip73]

Using a logical analyser and sigrok I've captured:
2C ITE/TOECU (D0)
3C ETI/TOINV (D2)
4C CLK (D1)
5C STB (D3)

Turned ignition on, turned a/c on, off and then ignition off.
See attachments
I will test sending messages back to inverter using xp677 software and hardware solution from Denso thread.

[MattsAwesomeStuff]

Fantastic work. Looking forward to having AC

[turnip73]

No luck testing in the car. I tried with both msb and lsb from captures... Any ideas?