Rotary Phase Converter (Create 3-phase power from a single phase source)

[nhengineer]

I think there may be a very valuable point being missed here. All households in the USA have only 1 ph it is called split phase for a reason the 13.2 KV line on the pole needs onlu 1 hot and 1 earth to make the primary winding in the transformer function the secondary is tapped in the center or the (0) then tapped at the 120v stage on both ends this makes the 2 hot lines coming in the meter then to the main panel The only exception to this is the higher end larger homes that require 3 ph to run the HVAC equipment or on farms such as dairy which have lots of 3 ph equipment
Therefore Rorary phase converters used here in the US are receiving 2 hot lines at 180° once the Idler motor is running the output will be 3ph although without the use of tryristers it will not be true 120° ph to ph pure sine Most motors and some transformer induction equipment don't care it is only when the introduction of 3 ph CNC equipment to the system does the true sine 120°ph to ph matter.
In Australia the 1 hot could be considered to be just like the incoming pole line albeit at a much lower voltage.
so for a 10 HP idler motor one would need a simple multi tap transformer about 9KVA in size 1 hot 1 cold to the primary then tap the center for the neutral output and which ever voltage desired for the split phase output Normally in Au it would be around 415 across the to hot out lines but if you have 200/208, 220/240 3 ph equipment you are needing to run tap the transformer so you would have 120 -n-120 then to the idler. for the 3 ph output
Remember for 415v Single ph across the 2 lines you would want 230-n-175

Well Frank S, after further review, I believe you may be correct. See drawing below:


Image modified & copied from HERE

It appears that my design, slightly modified, will work for Australia and other former British Crown Colonies nations. All one would need is an appropriately sized transformer. I will work on that.

Reader comments welcome.