Wow.. 10 to 25 hp is big!
We have a 5 hp solid state single to 3 phase inverter here- but it wants to be connected directly to the motor it is to drive, and is a soft-start.
It also will NOT start a delta wound motor (or is it a star wound motor) one of the other anyhow.
It was about $360 on fleabay... from China, but sold by a local company.
We have a rotary converter we bought 10 years ago - a finished box, with processor-controlled capacitor banks inside.
It runs the spindle on the cnc router - only a 3hp unit.
It's great, but getting tired and sometimes won't switch on.
It cost $2200. Made by a company about 1800 km south of here.
I build a rotary converter 10 months ago, and it's great. 5 hp.
It started life as a static converter- but there was too much heat, noise and losses, although it did technically 'work'.
So I added an idler, and retweaked the capacitors, and it was better- then I added a 2nd idler, and it was even better again.
More testing and re-evaluating, and pulling to pieces and rebuilding it better...
We run the big drill press and metal lathe on it.
The learning curve in building it was tremendous, as was the time spent tweaking and testing various capacitor values for optimal balance on the phases.
BUT... it won't start something easily (or at all) if the switchgear takes its control current from a generated phase, instead of from the original active phase...
I'm going to add a third idler motor in parallel soon - the more you add in, for a while, the more efficient it actually gets. That principle takes some getting used to. When I first turn it on, it's drawing 11.5 amps from the mains.
Then after turning on the 2nd idler, it drops to 5.5 amps draw. When you then turn on the machine you intend to use, the current draw is finally around 4.3 amps, or 1 kw and that changes mildly as you use it.
A few hours running and it's not even warm.
The static converter-the original one - would get uncomfortably warm in 7-10 minutes.
And we have a 3 phase gen-set, diesel, for the bigger needs.
I'm not so sure I'd be comfortable running a 10 to 25 hp motor via a static unit- but then it should work - but a rotary one would be better - you might well need a starter motor though, to help get it spinning. Also, you won't get 5 hp from a 5 hp motor, if using a static or rotary unit - expect losses of 1/3 or so.
Hope this helps...!