I'm pretending to make a system that charge batteries (or a single battery) and then produces 3 independent AC outputs (all having the same common, in a star connection).
But I want to have independent control of the frequency, (relative) phase angle and voltage of each output, as the intention isn't necessarily to feed a 3-phase motor. For instance, I wish to be able to completely turn off one of the outputs and produce just 2 phases in 90 º if I want.
Or put all the outputs in phase and parallel them to have a higher current single-phase output.
I guess that the outputs will be driven by 3 independent PWM circuits which I'll control with a micro-controller, but that isn't my question right now.
My question is what is the best scheme for the conversions needed, from the AC network to the AC outputs.
I guess that the cheapest and most practical solution for the battery side is using a 24 V 20 A power source with a current regulation circuit to charge a car battery.
The problem is what I do after that. Should I use an inverter to step up those 12 V to 300 V (for example), rectify and filter that to 300 V DC and then use the PWM circuits with those 300 V (with their output directly feeding the loads)?
Is there another better scheme for all of that?