The NCP1381 looks like a good PWM SMPS supervisor IC. However, a 0 to 100V, 0 to 25A, 2.5KW power supply is a HUGE undertaking that would be a significant amount of work even for a seasoned SMPS design engineer. Serious. Could it be done by a beginner? Anything is possible. What do I think the likelihood of someone "quite new to SMPSs" pulling this off successfully? Pretty slim-to-none.
Honestly, I love to help people get projects working and love to work on power supplies of all topologies, but I really think you should look into a 3KW Sorensen SMPS. I posted the schematics on another post. Just the fact that I posted schematics for something just like your project, and you're still asking for help worries me.
Answer these questions:
1) Are you ready to spend $500 on this project?
2) Can you have professional PCBs made? (You have a PCB CAD program?)
3) Do you have a dedicated electrical 220V, 50A line available to run your project?
4) Can you look at the 3KW Sorensen schematics I posted and understand each page and what all the major circuit blocks do?
5) Do you have about 100 or so hours free to dedicate to researching, prototyping, modifying, building, and testing this beast?
If you don't have an easy YES answer to all these questions, then you may want to seriously reconsider this project. I'm not being mean, I promise. I'm just being realistic about a project of this magnitude.
