I am trying to build a tiny 40 watt rotary converter, components :- 12 volt 60 watt dc motor, driving a 240 volt 40 watt squirrel cage motor connected to 240 volt ac, in the past when I have driven large 3 phase motors above sync speed, they have produced power into the grid and yet this little set up won't, principal seems to be the same, am I missing something ?
And yes, before you ask, I do have the necessary protection relays in place, should the grid fail
