AC drive IGBT triggering

Discussion in 'General Electronics Chat' started by jamers, Feb 13, 2008.

  1. jamers

    Thread Starter Member

    Jan 24, 2008
    Hello again all,

    I am trying to build an adjustable frequency AC Inverter drive, and I am being stumped by trying to do pulse width modulation, even to square wave AC. I know that 555 timers are sometimes used, however I am not very familiar with pulse width modulation, I know the concept, just designing the actual PWM circuit has always been a bit of a stumper for me.

    I saw at some point on these forums, however at that point I did not pay much attention, that a gentleman had posted an IC that would do three Phase PWM to trigger the standard 6 igbts for you. Does anyone have a link to any IC's like this or where to purchase one?

    I know many of you probrably have a good concept of how to design something like this. Could you refer me to some good online reading material about how to create a functioning circuit to do this? Designing PWM for one phase doesnt seem "that" hard. However making three phases all 120degrees apart that has adjustable frequency seems quite complicated too me.

    Sorry for the rant, basically: does anyone know of any ICs that would do PWM to trigger IGBT's for this purpose? Or does anyone have any reading material on designing the circuit for PWM?

    Any of these would be good :)

    Thank you for your time.
  2. scubasteve_911

    AAC Fanatic!

    Dec 27, 2007

    I found these two documents, which pretty much match my power electronics book's information.

    Obviously, these are theoretical circuits, but they should give you an understanding of circuit operation. In real life, there would be suitable drivers, snubbers, etc.

  3. thingmaker3

    Retired Moderator

    May 16, 2005