openinverter forum

Ok but if power is lost of the buffer the outputs go to?

EV_Builder wrote: ↑Wed Apr 13, 2022 6:23 pm Ok but if power is lost of the buffer the outputs go to?

I'm not sure about that, it wasn't the focus of my testing. I don't know if there are already pulldowns in the power stage. If 12v power is lost the IGBTs will also not be powered, but I don't know the exact order in which this will happen. Pulldowns on both sides of the buffer are a god idea really.

catphish wrote: ↑Wed Apr 13, 2022 6:15 pm
They should be pull-downs (probably 10k) on the lines between the STM32 and the 74HC buffer.

That was exactly what i used to actively pulled down non active gates since volt inverter used active low commands. I even used 6k8 resistors for more pulldown power. I used hex inverter with active high signals and did not trust stm32 signal inversion.
At first when i was playing with signals i would get a jolt when resetting controler. Then i figured it was bootloader...

catphish wrote: ↑Wed Apr 13, 2022 7:49 pm I'm not sure about that, it wasn't the focus of my testing. I don't know if there are already pulldowns in the power stage. If 12v power is lost the IGBTs will also not be powered, but I don't know the exact order in which this will happen. Pulldowns on both sides of the buffer are a god idea really.

No prob. we try to make best decision. I need to see datasheet.
Also we should make a scope recording of a reset and reboot etc.
pull-up/down to be sure nothing strange happens.

Loaded up the new firmware and had some success until today.

Looks like I might need a 3rd drive unit... everything was running with the new firmware at 48V. Ran fine at 340v with wheels In the air. Went to take a test drive today and blew the 350A fuse when closing the contactors.... 0.2 ohms at the hv input... again.

Did you pre-charge? Before closing the contactors?

Yes, I had the precharge set for a fixed time, of 1s from the BMS. it worked fine the day before..
based on the 14 ohm resistor and 340 pack voltage, that should limit the inrush to a reasonable 24A.

Beginning to think it has something to do with HV applied but no 12V. I had the car on the charger all day harvesting solar energy, so the HV was on but the inverter 12V was switched off.

js1tr3 wrote: ↑Sun Apr 24, 2022 10:41 am Beginning to think it has something to do with HV applied but no 12V. I had the car on the charger all day harvesting solar energy, so the HV was on but the inverter 12V was switched off.

I'm sorry about your drive unit :'(

While I'm not certain of the details, I would suggest that applying HV and not +12V is dangerous for the same reason that applying HV during a firmware update is. The IGBTs are in an undefined (possibly floating) state.

With that said, I don't understand why HV would ever be applied if there was no +12v, as the contactors shouldn't be closed, and the charger would be on the battery side of the (open) contactors. Is this not the case in your setup?

No the contractors are between the battery and everything, Actually I have two mid-pack Contractors since the pack is split front/rear and the HV leads run through the heating ducts from front to rear. something in my mind thought that leaving the inverter unpowered was acting as a charge lockout to prevent drive away under charge.

I will add a 2nd separate contractor and precharge for the motor and one for DC/DC and Brusa charger, I had everything controlled by the BMS... since I was running a Soliton1 controller with a warp11 motor previously.

guess its time to move the contractor and precharge control over to the SDU, and re-wire the 12V

anyone have a good source for just an inverter?

Some progress.

Gooey gooey

http://warpedporsche.blogspot.com/2022/ ... rdown.html

After picking potting compound for an hour I realized Everything is resistance welded.
Now I need that hacksaw!!!

js1tr3 wrote: ↑Tue Apr 05, 2022 3:31 am Got it apart, once I figured out how the Rosenberger hpk connectors work. Pictures added on the blog.
I was right the little purple lock rings were key. Then simultaneously lifting the four fingers that hold the pins in place. I lifted each the slid a small zip tie into the slot to hold it unlocked.

https://www.rosenberger.com/product/hpk/

Thank you js1tr3 for posting all the info and pics, must have taken a whole lot effort and patience, much appreciated