Full bridge PWM converter

[Archit]

Hello people,
I want to generate 350V from 40V using phase shift full bridge topology. Can anyone tell me where I am going wrong? How to choose magnetizing inductance? I have attached my model. Frequency of operation is 100KHz.Thanking in anticipation.Please Help

 

[ronsimpson]

I want to generate 350V from 40V

350V & 25 ohms = 4900 watts. Is that right?
40V & 120A = 4900 watts. You are using 800 V MOSFETs and you should be using 60V and much lower Rdson parts.

Also changed the diodes from 0.2A to 5A. Should be 10A but no problem in SPICE.

 

[Archit]

350V & 25 ohms = 4900 watts. Is that right?
40V & 120A = 4900 watts. You are using 800 V MOSFETs and you should be using 60V and much lower Rdson parts.

Also changed the diodes from 0.2A to 5A. Should be 10A but no problem in SPICE.

Changed the switch but still not working.

 

[ronsimpson]

Changed the switch but still not working.

Then try the file I posted. I removed one inductor because you can not ramp 30uH from 100A to -100A in a very short time.

 

[alec_t]

You need to revisit the gate drive arrangements. At the moment you're getting a nett 12A or so standing current through the primary winding.

 

[Archit]

Then try the file I posted. I removed one inductor because you can not ramp 30uH from 100A to -100A in a very short time.

but I need that leakage inductance for Zero voltage switching of my mosfet. Also, I have one more confusion, that transformer practically implementable?

 

[ronsimpson]

but I need that leakage inductance for Zero voltage switching of my mosfet.

OK, You need some. But you can not force +/-100A through a 30uH inductor with only 40 volts. Add back the inductance and make it small like 30nH. (I don't know but you need to move from -120A to +120A in 5% to 10% of your switching time, with 40V across the inductance.)
10%=1uS, 5%=500nS 2.5%=250nS
delta current 240A
Voltage =40V

transformer practically implementable?

This is hard. You need to start another thread. Read a book.

 

[Archit]

OK, You need some. But you can not force +/-100A through a 30uH inductor with only 40 volts. Add back the inductance and make it small like 30nH. (I don't know but you need to move from -120A to +120A in 5% to 10% of your switching time, with 40V across the inductance.)
10%=1uS, 5%=500nS 2.5%=250nS
delta current 240A
Voltage =40V

Thankyou. I have one more doubt.Does magnetizing inductance be 30uH or 30uH+(3/n^2)mH. Will the secondary side also reflected in magnetizing inductance?