Hi there,

I am currently trying to design a suitable snubber circuit for my MOSFET protection switch and i'm having some difficulty finding any material regarding snubber design. I have attached my simulink model demonstrating my test set up, shown is a capacitor being charged to 540Vdc with an IGBT carrying out the short circuit switching. The MOSFET is then set to trip at 180A which then generates the awful transient voltage spike across the switch. Any help on the method in which to design the snubber for this application would be appreciated.

Parameters:
Capacitor - 2200μf, ESR = 28mΩ
Line resitance = 0.23Ω
Line inductance = 3μH
Max fault current = 1800A
Trip current = 180A

 

Thatis more of a jumbled mess than a schematic. What is the power source, what is are the inputs and what are the outputs? Schematics are typically drawn from left to right, inputs on the left and outputs on the right.

... shown is a capacitor being charged to 540Vdc with an IGBT carrying out the short circuit switching. The MOSFET is then set to trip at 180A which then generates the awful transient voltage spike across the switch. Any help on the method in which to design the snubber for this application would be appreciated.

I am having trouble undestanding what you are trying to do. The capacitor is charging, and then what happens? What is the purpose of the mosfet, and the igbt?
What are you trying to protect? The cap, the igbt or the mosfet?

Also I suggest you download LTspice (free software from Linear Technology), since it is a defacto standard simulator on this forum, and many more members will be able to simulate your design and suggest improvements than if they have to redraw your schematic and go from there.