Very interesting topic and I wish I could help you with schematic and codes.
I haven’t worked on power electronics, but I’ve this idea.
The inverter circuits are already available which can convert 12V DC to 220V AC, with 100W or more power. My idea is to use high power electronic components like SCR to rectify that AC output to DC.
Not such a perfect idea for a Thesis work, but you can try this too, what you think?