9th Generation HAH Inverter

[CoreyS]

Hello everyone. My name is Corey and I love to start projects and not finish them
I've had an on/off interest in EVs for about 10 years now, but I am now at a place in life where I can really start exploring that interest. With that said, my first project isn't an EV project at all. It's a hybridization of an ICE car using a GM E-assist motor and an inverter that I picked up for $80 USD...actually, I grabbed 2 of them because it would be foolish not to at that price. Why hybrid? Because I enjoy the idea of bolt-on hp and torque. It also allows me to get my feet wet in the EV world and build up a solid knowledge base. Ok, enough of the intro.

This thread is intended to be a log of the hacking a 9th Generation Honda Accord Hybrid inverter. I have no clue what I'm doing, so the learning curve looks more like a wall. I'll need the communities help.

Let's go over some specs for this inverter:
It is VERY similar to the Toyota inverters in its construction (MG1, MG2 and buck/boost converter).
Rated for 124kW in the HAH.
Boosts voltage up to 700VDC.
Can take a battery input voltage of 320VDC nominal.
Liquid cooled.
Power module is integrated with the heat exchanger, eliminating the need for thermal paste and making thermal transfer more efficient.

https://info.ornl.gov/sites/publication ... b52422.pdf
Info grabbed from here, starts at page 21.

https://www.energy.gov/sites/prod/files ... _o_web.pdf
The beautiful thing about this inverter is that it seems all of the control signals are available at the 20 pin connector from the control board. On page 12, it looks like the "ORNL Controller" connects to the connector on the right side of the driver board. That's it.

So I did a bit more research...$25 and a few hours later I find that the 17 pins on that connector are for the upper and lower switches for the Traction Motor and Generator motor (total of 12 wires) and 5 wires named SCIGV, SCIVG, SCIMV, SCIVM, and GDEN. I'm assuming that GDEN is Gate Driver Enable? I'll figure that out as the thread continues. Honda has great wiring diagrams, btw. The OEM control board is nice, but I have no use for it. It has double of everything for the Generator and Motor sections, 2 micros, 2 resolver-to-digital. I technically *could* use the CAN signals to control it as I do have the dbc file, but it still a ton of work as it's around 1600 lines worth of signals to decode. I'll upload some photos later on.

[CoreyS]

Here are some external pictures of the inverter. Ran out of attachment space. It's a nice shoebox design, 20x14x7 inches (508x356x178 mm).

[CoreyS]

The Motor Control Module connector has a few inputs to the outside world which I have listed in the in the photo. The majority of them are resolver inputs, temperature sensors and water pump control. This shows me that the control of the inverter is done through the CAN inputs. I don't have the time for all that, so I'm going to crack this thing open and take a look inside.

[Mojave]

the DBC file should have a ton of info in it. Have you dug into it or are you committed to changing out the OEM control board?

I am interested in hybridizing a race car. Adding an extra ~100hp and using regen to charge it back up again every lap sounds real interesting.

[CoreyS]

The dbc has everything I need except the patience to sift through all the signals to get the "right" ones. I may still give it a try with the 2nd inverter. The inverter seems to be looking for DC bus voltage signals and maybe a heartbeat from the rest of the car. It's only transmitting about 8 IDs.

Honestly, I've been contemplating swapping out the micro on the OEM control board and putting a ST chip in its place. It sounds crazy, but I don't think it's that farfetched. I've found a company that makes BGA style "adapter boards" to replace QFP packages (https://www.advanced.com/products/packa ... p-adapters). If I were to reroute the pads to the right places, it would be a matter of dropping the ST chip on the board and configuring the I/O. That is simplifying it a lot, but it's the general idea. It would give me the OEM board quality and design, with infinitely adjustable controls. As of now, I'm mapping out the 144 pin V850 micro and seeing if that would work.

[CoreyS]

Here are some photos of the control board and the gate driver board. Interestingly, the Honda service manual states that two of the pins that are "not used" (pin 13 and 21 of the 33-pin connector) but they seem to be connected internally to the gate driver board from the cars 12v ignition and ground? Weird. Anyway, I'm working out the V850 pins now.

[CoreyS]

The micro was in the way, so I took it off. It gives me a clear view of the pads. Oh, did I every mention that the bottom of the board is a almost a mirror image of the top? The top and bottom micro are almost stacked on top of each other. I'll grab some more pics so you can see what I mean. The top controls the motor section and the bottom controls the generator section.

Removing the micro allowed me to easily figure out half of the pins. I have 72 remaining. The traces are annoying as most of the vias tie to the inner layers, and makes it slightly more difficult to follow.

I grabbed the datasheet for the V850 and traced the outputs that weren't configurable. Now I have to do the configurable ones. No telling where they go. The ADCs probably go the current sensors and temp sensors. I also know that the resolver-to-encoder spits out a 10 bit (12?) line.

[Envy_part]

Can I have more information on the capacity? How much output wattage?

[CoreyS]

Can I have more information on the capacity? How much output wattage?

The motor in the Accord Hybrid is rated for 135kw. The inverter must be able to handle at least that much power.

[ZooKeeper]

I hate to admit this, but I like that packaging better than those from 'Yota