Assemble a mosfet module for hundreds of kiloamperes

[v48371]

I need to make a switching power supply with a conversion frequency of about 100 kHz with a supply voltage of about 12V and a current consumption of hundreds of thousands of Amps and this is no joke. I need to use MegaJoules of energy per pulse, and the most compact solution is batteries.
I don't want to waste time, this is expensive time of my life, during which I could earn money, clean the house or prepare firewood. “Do better, the worst comes naturally” is a principle of life and I created the topic not for jokes.
My budget is limited and I need to use inexpensive mosfets connected in parallel. I need a ready-made working diagram.
100kHz, 12V, 100kA

 

[danadak]

MrAi, consider posting some of the issues you have experienced working at high power.

I would find them helpful filling the holes in my knowledge. I worked with high power
Plasma and welder designers as a field engineer, and they were tight lipped, but figure
I absorbed maybe 5% of the issues addressed in MOSFET and general switching. Much
of their proprietary seemed to center on magnetics, and that is my Achilles heal.

So in short would welcome anything you would consider sharing.

Regards, Dana.

 

[schmitt trigger]

I will add the first one: ultra-high voltage spikes generated by the leakage inductance and the dI/dt.

Let’s run some numbers: For high efficiency, the rise time should be no more than 2% of the switching period. This means 200 nanoseconds.
If the current being switched is 100 kA, and a leakage inductance of 10 uH, L*dI/dt gives a voltage of 5 Mega volts.
And let me say that for such a gigantic array of Mosfets, achieving such a low leakage inductance of 10 uH may be impossible.
You say, well, let’s clamp it. But you are talking 50 kilojoules of energy contained on each spike.