"Sjouke Burry" wrote in message
...
Start with DC, and put a set of high power automotive audioamps to work?
They come in quite compact blocks of up to 400 watts .
One for single phase, and 3 for the 3phase supply?
Then you only need to build a small board producing 3 outputs of the
correct phase.


Ah, that takes me back. Forgot about that design till you jogged my memory.
In the '70s, we had to run a military (Navy?) 115V data recorder from 28Vdc.
Made a 60Hz oscillator that had 90 deg phase shift outputs. Ran them to a
pair of RCA hybrid 'can' amplifier to drive step-up transformers. This gave
us 60Hz, 115V in quadrature, which we used to run the PSC (permanent split
capacitor) drive motors.

You can get some decent class D audio amplifiers that with a bit of
filtering do rather well