I'm working on a standard (AFAIK) 3-phase, 6-pulse inverter. I'm testing it under single-phase conditions to see what the de-rating will be.
My understanding: With everything else staying the same, if I pull one of the AC phases, I should end up with effectively 1/3 the RMS current out because I now only have 1/3 the number of pulses. But the peak currents seen by the transistors should stay pretty much the same because that's controlled by the differential voltage across the choke and transistors... and the voltages haven't changed.
My question is: Can I rewire the 3-phase choke within my system so that the third winding (which normally would not be used for single-phase operation) is in series with one of the other windings? Like so:
This would allow me to increase the inductance value without needing to have different parts for 1 vs 3 phase operation.
My concern is whether the physical asymmetry in the inductance values will cause a problem. On paper, there is only one current path so everything is in series. In reality, the factory AC grid is in the middle... so who knows what goes on out there.