suddenly overcurrent without any particular changes

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Ben_VWeT3
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suddenly overcurrent without any particular changes

Post by Ben_VWeT3 »

Hello together,

At first I have to say sorry for my english, it is not the best... place ask, when I write strange things :)

What happend so far:
I bought a V6 Logic Board from Johannes and build it into a SDU.
I wired everything for a Benchtest with 2 Model S Batterymoduls (47Vdc).
I had a little bit trouble with the Precharge wiring and it takes a bit time until I noticed that the boost have to be higher for the 47V.
But finally the SDU was running and I was very happy.

I started welding a frame to put the SDU into my VW T3 bus. That tooks a lot of time - 3 months more or less.

Yesterday I wanted to test the SDU in the car, without the driveshafts!
I took 6 Batterymoduls with 140Vdc and changed all necessary parameters.
Now I can switch it on and precharge works.
For changing the mode from "waitstart" to "run" I puch my Startbutton and I can hear, that the main contactors switch on and immediately off again.

Then I have an overcurrent error...


I found this Solution:
viewtopic.php?f=10&t=1623
and the troubleshooting in the wiki, but it does not helped me so far.


What I tried to fix the Problem:

Changed ocurlim to -1200A

On Conn5 I tested fault A, B, C and HVLO: All 5V

I tried to test the voltage at R58 and R45. The Wiki says it should 1,65V.
My results: R45=0,33V and R58=3,30V
But does the troubleshooting count for th V6 SDU Board? Because the Wiki says the resistors are bottom right. The R58 is there, but the R45 is more or less in the center of the board. That irritates me.

I would be very happy, if somebody can help me with good ideas.

Another question: What is the different between HVLO and HVIL? Sorry, I am still learning. :)

Thanks in advance,
Ben
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johu
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Re: suddenly overcurrent without any particular changes

Post by johu »

Can you measure all pins 1-6 of IC5.
That one collects the various fault signals and they should all be high.
Pins 4-11 of IC4 are also interesting, they reveal some info about the overcurrent limits and the actual current sensor signals.
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Ben_VWeT3
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Re: suddenly overcurrent without any particular changes

Post by Ben_VWeT3 »

Thank you for your quick response,

I measured directly and found the following values:
IC5
Pin1: 4.96V
Pin2: 4.96V
Pin3: 3.75V before I press the startbutton and after trying to start: 0V
Pin4: 4.96V
Pin5: 4.96V
Pin6: 0V before and after the start attempt

IC4
Pin4: 1.45V
Pin5: 1.69V
Pin6: 1.45V
Pin7: 1.69V
Pin8: 1.69V
Pin9: 3.30V
Pin10: 1.69V
Pin11: 3.30V

Is there something wrong with the currentsensors?
Can I disable HVIL for testing with a bridge at the spot "HVIL DISABLE" on the PCB?

Thanks lot for the help!
Ben
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Re: suddenly overcurrent without any particular changes

Post by johu »

Thats would a good reply looks like!
Ok, lets translate that:

IC5
Pin1: 4.96V - Gate drive fault signal A - good
Pin2: 4.96V - Gate drive fault signal B - good
Pin3: 3.75V before I press the startbutton and after trying to start: 0V - comparator output goes bad after start
Pin4: 4.96V - Gate drive fault signal C - good
Pin5: 4.96V - Gate drive UVLO fault signal - good
Pin6: 0V before and after the start attempt - HVIL - bad. Consider closing the HVIL jumper

IC4
Pin4: 1.45V - ocurlim_neg - strange
Pin5: 1.69V - il1 - ok
Pin6: 1.45V - ocurlim_neg again
Pin7: 1.69V - il2 - ok
Pin8: 1.69V - il1
Pin9: 3.30V - ocurlim_pos - maxed out
Pin10: 1.69V - il2
Pin11: 3.30V - ocurlim_pos

So current sensors are good, ocurlim values are a bit surprising, can you check pin 4 and 9 of IC4 after start?
The most obvious issue right now is the missing HVIL signal (it's supposed to tell the inverter that the DC cables are not interrupted)
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Ben_VWeT3
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Re: suddenly overcurrent without any particular changes

Post by Ben_VWeT3 »

this is what a helpful answer should look like :)

At first I tried it with the HVIL-Jumper. It did not working. Then I checked the Parameters again and found out, that the OCURLIM was still negative from testing. I changed it and now it is working again with the jumper.

On Pin 4 and 9 I messured with postive OCURLIM the following values:
Power supply on: Pin4=0V and Pin9=1,45V
Startbutton pressed: Pin4=0,25V and Pin9=3,14V

Now, of course, I have the following questions :?: :? :?:
I tested everything without the highvoltage cables. Is that the reason for the missing HVIL-signal?
What happened with the HVIL-signal, the SDU was only stored for 3 months...
can I safely use the HVIL-jumper, or can it be dangerous?

I am so happy that the Inverter is working again!
:D

Thank you for this fantastic support!
Ben
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