truesine split phase inverter options

[Jamie Morken]

Hi,

I am making a truesine split phase inverter that outputs two phases of
120VAC and a neutral phase, the switching frequency is between 100kHz
and 200kHz, I have some different options for the circuit I am thinking
about, I think circuit1 is the best to use but any input would be
appreciated on the tradeoffs between the different circuits. The
circuit is composed of three halfbridges, one for each 120VAC phase and
one for generating the neutral phase. The input to the circuit is a
400VDC and 200VDC rail. The neutral can be optionally tied to the
200VDC (local to the powersupply) rail and then the 120VAC phases will
be sine waves centered on this rail.

"http://www.rocketresearch.org/new/split phase 240VAC inverter/split phase inverter circuit1.png"
"http://www.rocketresearch.org/new/split phase 240VAC inverter/split phase inverter circuit2.png"
"http://www.rocketresearch.org/new/split phase 240VAC inverter/split phase inverter circuit3.png"
"http://www.rocketresearch.org/new/split phase 240VAC inverter/split phase inverter circuit4.png"

All four circuits:
"http://www.rocketresearch.org/new/split phase 240VAC inverter/split phase inverter circuits.png"

cheers,
Jamie