So you want to take power from the wall in your house and some how turn it into 480 hz. Then run it through a transformer.
The idea of getting more power through smaller transformers is old. Airplanes use 400hz AC so the size (weight) is smaller. But they have 400hz power lines.
How about this: Rectify and filter some. Use a 400,000 hz oscillator. Use a very small ferrite transformer. (voltage and current feedback, opto isolators etc) Now you only need a small capacitor because you are filtering high frequencies. (oh, wait.....that is a line powered switching power supply) There are every where, in your computer for example.