I talked to several electric motor gurus and a couple of electricians and everyone either did not know anything about it or knew something about a static converter that used another motor to generate three phase. It was pretty involved and expensive. My car building bud made a belt sander at his shop. He has three phase already but this is a “ ac motor speed control Hybrid Drive”. You get them on eBay and it is great for making speed changes with instead of changing belts. It has single phase input and three phase output.