Jez/Anil: I know of at least two home appliances that
use three phase motors driven from single phase
one is a washing machine that uses the speed control feature of variable frequency drives to enable delicate cycles and high speed spins without an expensive speed changing gearbox and the selector solenoids associated with it. The second use I have seen is a dish washer - same reason variable speed to cause variable water flow for delicate chrystal vs dirty pots then very high speed reverse for pump out. both controlers run from 120 vac 6hz. 1 ph.input.
I investigated both for a project that I was working on, but unfortunatly for me both were unuseable as they used a dedicated motor approach. Generic vfd's cost in at about $375cdn in small lots for lowest horsepower rated drives and rise from there . The largest
three phase motor that I have ever driven from a single phase source (240 vac.) with a vfd was 10 hp. To do it I took a generic 15 hp three phase drive and replaces the input rectifier and capacitor bank to get the same ripple as the original had on three phase. It was not cost effective, but this was a must have project and has worked untended for over ten years now. I have refused several similar projects due to the cost of converting off the shelf drives, I have not yet had enough inquirys to warrant developing my own, but I see a bright future for singe phase in /three phase out controlers once the initial cost barrier is removed. One final note several motor manufacturers, Baldor for one offer integrated packages for this. They are pricey and come only up to about 3 hp or at least did the last time I checked. Terry