openinverter forum

working with a V4 SDU, and getting Stop overcurrent errors.

[60813]: WARN - HICUROFS1
[60813]: WARN - HICUROFS2
[66241]: STOP - OVERCURRENT

Tracked back to the Op-AMP.

Sensors are putting out 2.5V

R48 is correctly setting 2V
C18 and C19 are sitting near 2.6 V
C21 seems right at 3V,
but C22 is reading about the same and does not change with ocurlim.
is the Micro dead?
what should be the next debugging step?

C18/19 should be sitting at 1.65V. That would explain HICUROFS1/2
Of course then 3V on C22 still doesn't make much sense. Are the sensor gains correct? Defaults here: https://openinverter.org/parameters/view.html?id=15

Yes,

Gains are correct. Beginning to suspect the mcu. Maybe I should order a new board for debugging.

I've got 1.7ish at pins 1 and 7 of IC 7, so its doing its job, but the current is flowing back through R3 and R7...
So I'm guessing IC4 or the MCU is gone.
ordered a new board from the webshop.

Does the test mode work for the SDU board?

That's funky. New board on the way.
By test mode you mean "Manual Mode"? Yes that works

I was actually thinking of your test code.
https://github.com/jsphuebner/stm32-test

do you have a similar setup for testing the SDU boards with the current sensors?
I'll try to see if I can compare the schematics and come up with the resistor network needed to test.

Yes that could be done. It's a sort of self-stimulating test rig, so you need to connect inputs to outputs and fill out the according table. Also some special code would be needed e.g. for testing the temp sense mux.

In the beginning that's what I wanted to do but never got around to building the mechanical test rig. So I test manually.

Thanks Johannes,

I got the new board installed in another drive unit. I replaced my welded contactor and burned precharge resistor with a new and a 100ohm precharge R.
I'm starting off at 48V DC with 3 60W mains lightbulbs in a delta configuration connected to the 3 motor phases. the precharge controlled by the SDU is working fabulously (53 Volts measured as UDC by the SDU) but the main contactor doesn't close when I press the start button. no errors on the web interface, and it goes into manual mode just fine when choosing start on the web interface, but since the main is not closing the capacitor just discharges in a second or so. I checked the wring and everything looks good. The contactor works fine when grounding pin 3 of the harness...

any thoughts on debugging.

js1tr3 wrote: ↑Mon Jun 20, 2022 2:22 am any thoughts on debugging.

the value of the "status" variable

its zero, until it goes to 4,
based on the header file I understand 4=UdcBelowUdcSw, which is consistent with the main contactor not closing and trying to run on the precharge.

udcsw is set to 45V and the battery is at 53.

Does the SDU know that your battery is 53V? I.e. the value of "udc"

Yes it definitely is measuring the voltage correctly for UDC.
The precharge comes on correctly with key switch. but when I choose manual run on the web interface it does not pull in the main contactor. no errors, but it seems to open the precharge without closing the main.

I added the start wire, and when momentarily connecting to power it correctly pulls in the main contractor.

I don't have wires for drive (since this is just a bench top testing harness with 4 lead acid batteries).

oh, now I get it! Manual Mode doesn't pull the contactor. Just turn it on manually or (hopefully possible by now) first going into Run then manual run

Ok that makes a lot more sense. I was tracking what I thought was bad wiring that turned out to be fine.
I was able to use the start switch to get into run mode, then choose manual run on the web interface and everything looks good.
but I'm not lighting the bulbs that I connected to the motor phases wires in a delta configuration. I've got HVIL jumpered and there are no errors aside from "warn throttle 1" (its not connected).
following the Wiki

https://openinverter.org/wiki/Open_Inverter_Testing

I set fslipspnt - 1 ampnom - 70%, but not lights. basic ohms law saws the bulbs should draw about 3A at household mains current. since Im down at half that current draw should be only an amp or so.

I have the nominal voltage parameter set to zero, does this impact the ampnom (or boost?) in mannual mode?

Yeah I was hoping I had fixed that issue. So then after some precharging just manually turn on your main contactor and make a note about it on the wiki

Hopefully just one more question...
Even after a manual precharge and bypassing the main contactor, I dont get any PWM output in manual mode after setting the fslipspnt - 1 and ampnom - 70%.

Any Idea why?

I added the wires for start, forward and a VW GTI pedal. I can press the start switch, 12V on Fwd input and stop the pedal. but only 2 of the three bulbs light up. (I also pushed the boost to 8000 to get the bulbs to light).

I assume because the encoder is not connected only 2 of the bulbs light, or do I have a problem with the board?

-J

I figured out why the middle bulb wasn't lit. it was a switched socket (and the switch was off). now I get all 3 bulbs lit!

still getting nothing in manual mode (mode 2) when starting from the web interface (with a manual precharge at 48V).

Rebuilt with the new inverter, re-installed in the drive unit and it spins!!! YAY!!!
Contactor control with trip-mode "on" based on the discussions for the safety of the drive unit. I'll add an inertia switch on the power feed to the contactos just in case of an accident to de-energize the HV, and I'll pull the MSD for any future firmware upgrades! might even remove the wifi once I get it sorted.

Now I just have to bolt the wheels back on and re-align the rear trailing arms...