Quote Originally Posted by Neale View Post
I use an "inverter" that works on the voltage-doubler principle - it was a bit of a bodge by a now-out-of-business company who grafted a voltage-doubler to the front of what is quite a nice ABB 380V VFD but it does mean single-phase 240V in and 400V or so 3-phase output. It works fine until you put a heavy load on it when the effectively half-mains frequency input means that the DC voltage sags too much between cycles and the VFD trips.
Sounds like they missed a trick and only used a half wave voltage doubler and/or got the capacitor sizes too small. The full wave voltage doubler circuit works pretty well if you do the sums for the output power and choose the right size caps, but it does have twice the component count of the simple circuit.