openinverter forum

So I saw an ad for a 2014 Fusion inverter for $60 locally, figured why not try to figure out if it's usable or not, since the only teardown I've seen online is by Weber auto.

And well, I figured out the gate drive pwm signals for the main gate driver board, and then decided to try the boost converter pwm signals.

Well that's when it went pear shaped, I was putting in 3.3v 50% square wave at maybe 100hz pwm to see if I got any response, found 2 test pads next to each other labeled VVC-L and VVC-H, tried turning on L for boosting (without realizing that the igbt has to have high side on always except when boosting. I guess it shorted out the igbt and toasted it. Crazy b/c all I am using is a 10A bench psu at 14v and the only capacitor was the smallish one for the boost converter. And this module is beefy, weighs at least 2.5x as much as a 1200v 300A Mitsubishi half bridge I have here.

Tested the module and it's 100% shorted out on the low side, basically shorting out the inductor (whose other end is directly connected to hv battery +) to battery -.

Tried taking it apart but this thing is something else... Never seen an igbt like this, especially with so many connections, a total of 20 soldered connections plus the 3 high current screw terminal ones.

Seems to have some sort of faraday cage under the cover, but I couldn't dig any deeper because whatever potting compound they used is crazy strong, knife can barely scratch it.

Wondering if this is one of those weird SiC IGBT hybrids.

Btw this whole thing is apparently made by Toshiba in japan, their logo is on all PCBs and the module as well.

Here's some close up pics of the main board. It's crazy how detailed the Toshiba engineers are given the amount of test points they put, and -most- are labeled enough to understand. Except the boost converter and that threw me for a loop.

Also some measurements and pics of random stuff if anyone is interested. The inductor uses a flat copper conductor of 1.75mmx6.5mm, no idea how this compares to say the Prius boost inductor current capacity wise.

Man I am so bummed that I killed the boost converter without even getting to use it haha... I was so excited thinking I could make a little mod board and just tap into the points. Still can use the inverter portion I suppose but my main concern was the boost converter and with my luck it's the only thing that I blew up lmao.

But seriously these igbts are not normal, I have been throwing it (the boost IGBT) around my hands and it weighs around 3x as much as a CM300DX-24S I have here, and that's a 1200v 300A part. Like it's full of lead or something. Sucks there's no datasheet, probably wouldn't have fried it if I knew wtf it was and why a half bridge needs to have 20 control connections...

Nice pics!
Could you just throw in a Prius power module from the Gen2? Of course then the bus bars don't fit nicely.

johu wrote: ↑Wed Sep 07, 2022 4:51 pm Nice pics!
Could you just throw in a Prius power module from the Gen2? Of course then the bus bars don't fit nicely.

Maybe, the footprint seems to be standard but I think the Prius one is significantly taller so might be a pain to modify the busbars.

Regardless I kind of have no use for this inverter, I got it just to experiment and document the inside if anyone is interested in it, figured for $60 why not, been burning away tens of thousands of dollars in college to learn nothing so what's $60 more haha.

If anything I could maybe use it as an upgraded DC motor controller for our golf cart, was thinking if I could get the boost converter to work could use it as a mppt solar charger too. Too late for that lol.

Fantastic piece of engineering. Thanks for sharing.