IGBT snubber help

Discussion in 'General Electronics Chat' started by GBD, Jun 23, 2010.

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  1. GBD

    Thread Starter New Member

    Jun 23, 2010
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    I am building a DRSSTC and have ran into a small issue, the issue bieng is how to mount the snubbers on the IGBTs,
    does the perforamance of the snubber matter if it directly connected to the terminals of the IGBT? or if it is slightly above the bussbars (will be easier to mount)

    I am mostly worried about extra transients, and lack of protection caused by mounting the snubber capacitors further away from the IGBTs themselves.

    for additional information, this IGBTs switches 300V at around 800A peaks (running 5% duty cycle)


    Thanks for your help!
     
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Let me guess, this has something to do with high voltage and Tesla coils.

    Can you provide the actual circuit you are planning to build? What will your real voltage and current needs be, not just the parts' ratings?

    John
     
  3. GBD

    Thread Starter New Member

    Jun 23, 2010
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    DRSSTCbridgeschem.jpg

    this is the schematic of the bridge, and as Ive said, the voltage is 300VDC input, and the current bieng pulsed through the IGBTs is 800A (just under my current limiters threshold)

    (A and B on the gates denotes the gate driver signal going in, A bieng inverting and B bieng non-inverting)
    "F" is the filter capacitor bank, "L" is the primary coil "C" is the tank capacitor (LC are tuned, Hence dual resonant)

    "S" are the snubber capacitors, 10uF per half bridge section, the question bieng is if the snubbers are not mounted as close as possible, would this retard thier performance to protect the IGBTs?
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    The application is a tab beyond our intent, which is hobbyist level help and student assistance.

    My guess is that switching 240,000 watts may lie beyond most member's expertise. What is the application?
     
  5. GBD

    Thread Starter New Member

    Jun 23, 2010
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    The input to my coil is from an power SMPS, and no where near 240kW note the "F" filter capacitor, that is the key to such amperage, the capacitor supplys the several hundred amps on demand. the application is as stated, a DRSSTC (dual resonant solid state tesla coil)

    here is an exellent article about the system and its topology:
    http://stevehv.4hv.org/drsstc_design.htm

    the main question would be though is about the transients formed by where I place the snubbers.
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    The application is not one we can discuss here.
     
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