Blown Gen Three inverter. Dual motor.

[Dylan Witt]

This is the second inverter that has been blown. So question would be what was I doing wrong? Since my last video of driving the electric Mazda rx8 I updated the foc firmware for the original V1C single motor board with upgraded 3.3 volt power supply, the car was driving good. I spent hours on the forum reading and scrolling though the wiki. Why did I change the control board if this one was working? So that I could use the generator motor coupled to a battery small engine. The original board was damaged while soldering electrical connections on the car, I had mistakenly forgot to assemble the inverter and a glob of solder hit right onto the micro controller soldering multiple pins together, I attempted to revive the board with no luck, which was the second reason for purchasing the dual motor board. Fast forward to the updated foc firmware which after rewriting the idc connector I was able to get the car to attempt to move but never went any where, the motor just shook, so I went though the tune of process with no luck. I used the same settings as the original board and still no luck driving the car. So, I went and purchased new contacts, same as Damien used in his builds.

What did I do wrong? Parameters posting with this information.

You can see the inverter as the power drivers for the igbt blew. Why would this have happened on two separate inverters, the other one actually blew the boost converter igbts, full ground when powered up but was able to drive the car then went to regen and instantly blew the igbts. Same parameters on both boards and inverters

[Dylan Witt]

I have one spare inverter and I don’t want to blow it, I also have a V1c block iv with the wemos d1 mini connectors. Same thing with it but it blew the boost converter igbts instead of the inverter board

[Pete9008]

Going to need a lot more information before anyone can help on this.

In particular how are you connecting power to the inverter (the boost igbts blowing suggest you might be using the original Prius input connection rather than the DC link bus bar connection)?

Are you using the buck/boost block for anything?

[Dylan Witt]

I’m using the same connections in the wiki, backside of the inverter, fused link 125amps, fuse never blew.

[Pete9008]

Not a lot of information to go on there!

My best guess is that you are powering it through the boost converter. In this mode normal drive current will go through the top boost igbt reverse parallel diode. When regen happens there is then nowhere for it to go so instead it pumps up the DC link voltage until something fails due to overvoltage. Normally the bus caps would fail first but I suppose its possible for the IGBTs to go first??

If powering through the boost converter you can also get some funny effects with boost inductor resonance.

The other possibility is that your contactor opened on a trip and again there was nowhere for regen power to go which again would cause an overvoltage.