Electronics > Projects, Designs, and Technical Stuff
Single phase to three phase sinewave converter
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capt bullshot:
Just a hint across the pond:

In Europe, a "rotary converter" in general refers to a Motor-Generator set on the same shaft. Could be anything including DC / single phase AC / induction / synchronous and even different frequencies.

I had read about the Uncle Sam style "rotary converter" before, there's no such thing here.
MrAl:
Hi,

Back when i worked with a power converter company we used our own special designs to do single phase and three phase low distortion sine converters.  We were able to get high efficiency and very low distortion.
The main idea is to use a three phase bridge circuit with PWM.  The PWM comes from a controller board that generates the signals alone with driver boards that drive the main transistors of the 3 phase transistor bridge.  Power levels could go up to 30 kilowatts.

I see your power requirement looks low however.  Maybe you could look into 3 phase brushless motor drivers.
You can also type in "Three phase controller chip" and get some links to look at.

Yansi:
I have already suggested using a suitable microcontroller plus a 3phase power stage.

BLDC controllers would not very likely suit, because BLDC is typically (but not always, mind you) driven by square wave.  Any smarter controllers than that will likely have numerous feedback loops and it'll become quickly a mess, to make it produce a static voltage in open-loop mode.
Yansi:

--- Quote from: T3sl4co1l on January 14, 2019, 04:52:32 am ---An "isolated" converter that is literally no more than a genset would indeed require a synchronous machine to produce synchronous output, and one made from induction motors would... hmm, I'm not sure offhand which way the field slips in generator mode actually, but that's rarely used anyway, so, a pair of sync machines it would be.

--- End quote ---

In an asynchronous generator, you would need to up the speed above the synchronous speed, to obtain the synchronous frequency.

Induction generators are used too, not that often, but nothing that special.  You just connect a typical induction motor to the mains and then drive it above the synchronous speed, where you put it in a negative slip ratio, which is the generator mode. (Slip ratio above 1 is a braking mode).
T3sl4co1l:
Negative slip, of course!  It would need gearing to account for two slip's worth.

Tim
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