I know there's industrial single-phase to 3-phase converter units, that use a standard single-phase AC motor to drive a 3-phase generator. However, these are very expensive, and involve working with dangerous high voltage (single-phase motor runs on 120VAC, and the generator output is 277VAC phase-to-ground and 480VAC phase-to-phase). I also know there's cheaper and safer (low voltage 3-phase) solid-state signal generators out there, because years ago, I saw on a website that sold electronic equipment for use in schools and colleges, and they had one that just plugged into a regular 120V outlet, and the front panel of the device had 4 banana-plug sockets (one for each phase, and one for neutral) for the outpout. But for the life of me, I don't remember what website it was that was selling it, or who manufactured this solid state 3-phase AC signal generator.
If anybody here knows of a lab or demonstration type solid-state 3-phase AC signal generator, that's currently being manufactured and sold, please let me know where to find it.