igbt gate volt or current controller?

Discussion in 'The Projects Forum' started by pastinsain, Aug 25, 2012.

  1. pastinsain

    Thread Starter Member

    Aug 25, 2012
    160
    2
    I recently purchased a couple of Mitsubishi MG400Q1US41(EP) IGBT Modules 400Amp 1200Volt
    I want to control them with a cheap lm317 dc power supply using 17v 1.5 amps. or Should I UP THE AMPS TO 3amp power supply?
    Can I just connect the igbts to a full wave rectfier after the 3800uf 450v caps?
    Then manually control them using the lm317 power in a separate power supply ?

    at this point, im just testing them out to see what happens.

    I will be feeding the 35amp 800v full wave rectifier with a 10amp variac and using a dummy load.
    what would be a good dummy load? or resister wattage and ohm ?
    maybe I can use the igbts somehow in a welder or high power supply.
    I can always use a few extra amps for something

    Thanks for the advise
     
    Last edited: Aug 25, 2012
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    You appear to be working on what may constitute a transformer-less mains operated device.

    As such it probably would be regarded as a restricted topic. See Terms of Service

    http://www.allaboutcircuits.com/l_tos.html

    If you confine your questions to low voltage IGBT gate drive matters the thread may be permitted.

    Remember IGBT means Integrated Gate Bipolar Transistor. You don't need substantial gate current since the gate is essentially a voltage driven entity. The gate drive control current capability only becomes relevant when the gate capacitance current requirement [usually at at higher switching frequencies] becomes significant.
     
  3. pastinsain

    Thread Starter Member

    Aug 25, 2012
    160
    2
    Thus I will only use a variac or computer power supply to power this this.
    Im only working on low voltage applications and experimenting with the igbts .
    thank you for your concern however.

    so I need not be concerned about current using these igbts?
    The data sheets recommended I believe were 2 amps 17v to deliver the gates. Correct me if not. also what resistance dummy load ohm watt rating will I need?

    thanks for the feedback
     
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    If you have a link which points to the data sheet or are able to post the data sheet (pdf) then it would make it easier to make an informed comment.
     
  5. pastinsain

    Thread Starter Member

    Aug 25, 2012
    160
    2
  6. pastinsain

    Thread Starter Member

    Aug 25, 2012
    160
    2
    4.2 Gate Drive Recommendation
    (1) Gate Drive Design
    For turn-on a positive gate voltage of 15V±10% is
    recommended, and for turn-off a negative gate voltage from
    -5V to maximum minus voltage is suggested. In order to
    ensure that the IGBT stays in its off state when dv/dt noise is
    present in the collector-emitter voltage a reverse bias must be
    used. A series gate resistor is used to limit current flowing
    through the gate. The minimum series gate resistance is given
    in datasheet. ​
    In theory, there is no maximum requirement for
    gate resistance. However, big gate resistor may lead to

    switching loss (time) increase

    oscillation in conjunction with the gate-emitter capacitance
    and any stray inductance in the gate drive wiring.
    Therefore, the recommended maximum gate resistance is
    10 times of the minimum value.
    Standard resistance given in datasheet is
    600V class
    625 (A)/current rating (A)

    1200V class
    313 (A)/current rating (A)
     
  7. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    I checked Mitsubishi's website but could not find your device type number listed. It may no longer be in production.

    As I intimated earlier the gate drive design would include a (careful) consideration of the gate-emitter capacitance which must be charged and discharged at each successive on / off cycle.

    The link below has useful app notes - particularly on the practical use of Mitsubishi's IGBT's. The pdf entitled "Using IGBT Modules" considers gate drive in some detail.

    http://www.mitsubishielectric.com/semiconductors/products/powermod/note/
     
  8. pastinsain

    Thread Starter Member

    Aug 25, 2012
    160
    2
    Yes like many companies , they don't support their old products.
    Its next to impossible to find the datasheets. I did find a cross reference
    to toshiba with similar numbers

    http://pdf1.alldatasheet.com/datasheet-pdf/view/31060/TOSHIBA/MG400Q1US41.html

    , however, there could be small
    differences . Same numbers small differences? who knows?

    Anyhow you mentioned to watch out for capacitance ? I have read
    that you can blow these up if you don't adhere to the perimiters.
    crash and burn! I will keep safe a distance as I test these.

    Any ideas ?

    thanks for your info
     
    Last edited: Aug 26, 2012
Loading...