Igbt design

hai,i am new to electronics.i have to get switching waveform of an igbt in 3 phase ac to dc converter.can anyone send me any basic circuit model?also i dont know how to give threshold value.all this i have to do in MATLAB version 7.6

i tried a bit.but error occurs.

Matlab is basicly useless for this unless your using simulink or have the correct equasions?

Why are you using IGBTs not thyristors for this? I assume its a rectifier design?

In general we need more details!

igbt again

u are right,am trying in simulink onlk only.this concept has been proposed in ieee paper(using igbt in flyback topology).i tried igbt switch in halfwave rectifier.got switching .now trying to implement flyback transformer.( four diodes with igbt switch).

clarify

circuit will be in discontinuous mode.lowpass filter have to use in input and capacitive smoothing will be used in output.diodes will be used to make three phase rectifier

Again why IGBTs and not Thyristors?? this complicates your switching signals.

I've attached a diagram of a 12 pulse (two six pulse series connection) rectifier i did a while back. I only needed a signal for the first thyristor trigger but the other trigger signals are there as well.

Basicly you compair your first phase against the prior phase, when 1st > earlier phase then your trigger thyristors on first phase.
When 2nd phase > 1st you trigger second phase thyristors .... and such