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  1. #21
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    Re: IGBT Short Circuit problem

    Quote Originally Posted by kratosrazor View Post
    do you mean your igbt gets short circuit even without giving any pulse?
    In this case, put a 1k resistor on Gate emitter across each IGBT. maybe your problem would fix.
    I have tried with the resistor, but the gate is not a problem the signals are crisp and clear.

    I tried now with a MOSFET, same result, maybe the igbt is not the problem then.



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    Re: IGBT Short Circuit problem

    post a pic of the gate drive please ...



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  3. #23
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    Re: IGBT Short Circuit problem

    Quote Originally Posted by Easy peasy View Post
    post a pic of the gate drive please ...
    What, you mean me? Won't I go to the penalty box for hijacking someone else's post?

    Click image for larger version. 

Name:	gatedriver.png 
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ID:	154225



  4. #24
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    Re: IGBT Short Circuit problem

    STGW25H120F2 is a diode-less IGBT. It may damaged by applying high negative Vce.


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  5. #25
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    Re: IGBT Short Circuit problem

    I meant for the OP to post the gate drive waveform - Swend even 10E for turn off R may be too high ..



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  6. #26
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    Re: IGBT Short Circuit problem

    Quote Originally Posted by Easy peasy View Post
    the total turn off time for the IGBT can be as high as 354nS ( see data sheet ) so it it likely that minor shoot thru is killing them, try 500nS dead time for the IGBT ...
    :D Again making theories about something which has already been tested. Why you do this easypeasy ??



  7. #27
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    Re: IGBT Short Circuit problem

    Dear kripacharya, your post appears to show a limited understanding - minor shoot thru is caused by transient gate rise when the other device turns on - on another matter it appears you are now stalking me on this site - please refrain.



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    Re: IGBT Short Circuit problem

    you may not know this 'peasy', but I have been a contributer to this project from the beginning. You have not. YOU are the interloper.
    So kindly do not infer & imply self-serving garbage. Keep your silly comments to yourself.
    Thank you.



  9. #29
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    Re: IGBT Short Circuit problem

    Dear kripacharya, I believe you are somehow confusing the threads. Your first contribution to this thread is post #26, Easy peasy dropped in with post #6, giving valuable suggestions.


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  10. #30
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    Re: IGBT Short Circuit problem

    Quote Originally Posted by FvM View Post
    Dear kripacharya, I believe you are somehow confusing the threads. Your first contribution to this thread is post #26, Easy peasy dropped in with post #6, giving valuable suggestions.
    you are correct. sorry to add to your load. I'm out.
    Swend.. you're on your own dude. All the best.
    Last edited by kripacharya; 10th July 2019 at 22:45.



  11. #31
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    Re: IGBT Short Circuit problem

    I fixed the overshoot problem by adding cap on Drain Source but my problem still exits.
    always the MOSFET or IGBT gets short circuit at start of the control, not during the control. why?
    the last time I have tested (DC link volatge was 150V) the circuit worked fine but as soon as I turned the microcontroller off, mosfet got short circuit again.
    any advice about output filter?
    Last edited by kratosrazor; 17th July 2019 at 15:10.



  12. #32
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    Re: IGBT Short Circuit problem

    it appears your uP is issuing commands to the IGBT's at power down - this is a common oversight. You need to ensure, by hardware methods usually, but also in the setup part of the firmware on the I/O pins - that the IGBT gate drive cannot go high at power up or power down, until the uP control is properly established.



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