openinverter forum

catphish wrote: ↑Mon Feb 07, 2022 11:47 pm All this leads me to assume that I have destroyed an IGBT in the LDU power stage, but I'm not at all sure how or why. I don't believe there was ever a contactor event during the failed high voltage tests, even though this is the most obvious explanation. I will test continuity of the power stage and see what I find, but definitely fearing the worst.

catphish wrote: ↑Mon Feb 07, 2022 11:47 pm Would someone be able to point me in the direction of the current "starting point" parameters for the LDU (including hidden ones)?

jon volk wrote: ↑Mon Aug 17, 2020 11:07 pm Updated parameter set. Same car/setup, just improved performance and driveability.

Further details on the what/why behind the changes can be found here.

https://openinverter.org/forum/viewtopi ... 6&start=40

P.S.Mangelsdorf wrote: ↑Mon Feb 07, 2022 11:55 pm Jon's parameters have worked very well for me.

catphish wrote: ↑Mon Feb 07, 2022 11:47 pm Today I powered up an LDU in a vehicle I've been working on and it's dead! I'm not at all sure what killed it, but I will try to detail the exact series of events that lead to its death.

1) The LDU was tested and working at low voltage (60v testing). The parameters were not configured by me, but were confirmed working.
2) The LDU was installed into a vehicle, including complete replacement of its wiring loom.
3) High voltage was applied, the inverter worked, but the motor would only make small vibrations, followed by an overcurrent fault. This failure was repeated a couple of times.
4) Assuming the problem was the encoder, the wiring to the encoder was replaced.
5) Subsequent attempts to power up the vehicle failed with a precharge issue caused by the BMS underreading the DC link voltage. This is probably not relevant, as I don't believe it would have opened the contactors as a result of this, but it was an annoying twist.
5) Several days later, with a new BMS contactor controller in hand, the next attempt, the LDU starts up, but fails with an overcurrent fault the moment it attempts to apply any current to the motor (ie when >0% throttle is applied).

All this leads me to assume that I have destroyed an IGBT in the LDU power stage, but I'm not at all sure how or why. I don't believe there was ever a contactor event during the failed high voltage tests, even though this is the most obvious explanation. I will test continuity of the power stage and see what I find, but definitely fearing the worst.

Not looking for any particular advice about the above, but thought I'd document it while it's fresh in my mind and I'm still upset about it!

The second problem is that I don't believe this inverter was configured correctly originally. I can definitely see that udcgain was incorrect, which leads me to suspect the device may not have been running a configuration designed for an LDU at all. Unfortunately, most other parameters I can't check because the backup I took didn't include hidden values, and most were replaced when I installed a config example provided in another thread by Damien.

While I realise that most misconfigurations shouldn't lead to inverter destruction, I am keep to make sure in future I start with the correct parameters. Would someone be able to point me in the direction of the current "starting point" parameters for the LDU (including hidden ones)? I'd like to get things back to a safe starting point. I'm particularly concerned about those parameters that shouldn't be adjusted, like voltage and current sensor gains, inverter frequency, and dead times, which most people don't need to touch, but I suspect I don't have correct values for.

johu wrote: ↑Tue Feb 08, 2022 8:52 am The parameter database openinverter.org/parameters contains also the hidden ones
You can pull a full dump with 192.168.4.1/cmd?cmd=json%20hidden

Boxster EV wrote: ↑Tue Feb 08, 2022 7:26 am What error messages are you seeing (just overcurrent?). Any reason why you’re allowing the BMS to control the contactors over the OI logic board?

Boxster EV wrote: ↑Tue Feb 08, 2022 7:26 am When you say the wiring to the encoder was replaced, do you mean that the A and B signals were swapped over?

Boxster EV wrote: ↑Tue Feb 08, 2022 7:26 am What firmware pare you using and can you post your parameter file?

Boxster EV wrote: ↑Tue Feb 08, 2022 1:13 pm Hmm. I’m not familiar with the Zero EV contactor control logic. Although the original issue does sound encoder related if the motor was just oscillating before it fully let go.

Either way, sounds like you need to remove the cover and test the IGBTs.

I have some spare inverter parts if you get stuck.

Boxster EV wrote: ↑Tue Feb 08, 2022 1:13 pm Either way, sounds like you need to remove the cover and test the IGBTs.

johu wrote: ↑Wed Feb 09, 2022 5:23 pm the motor windings are still connected? So even one blown phase leg would show up on all 3 phases because the motor essentially is a dead short.

jon volk wrote: ↑Wed Feb 09, 2022 10:23 pm There’s a light on each Tesla phase gate driver board that will illuminate during a desat fault. That’ll tell you for sure it’s a hardware issue. I don’t have a photo immediately handy.

EDIT. Found my old pic from Instagram.

jon volk wrote: ↑Wed Feb 09, 2022 10:23 pm There’s a light on each Tesla phase gate driver board that will illuminate during a desat fault. That’ll tell you for sure it’s a hardware issue. I don’t have a photo immediately handy.

EDIT. Found my old pic from Instagram.

Jackk wrote: ↑Fri Feb 11, 2022 9:35 am Haha out of interest does this light illuminate the time ? Or does HV need to be connected?