Any real one probably has a totem pole of 2 transistors per phase with some cunning 'flying deck' electronics to ensure the transistor turn on/off  voltages to follow the output voltage up and down without accidentally turning the transistors back on at the wrong moment.   Actually many small inverters single and 3 phase are a bit like a fully floating version of this where the batteries are replaced by a pair of smoothing capacitors charged by some supersonic screamer of an inverter. The clever ones even modulate the target output voltage  of the inverter to create an approximate  half sine profile at 100Hz , while the 3 phase ones instead go for a static DC bus value and pulse-width modulate the totem pole transistors to give a rectangular thing whose average if smoothed out over many cycles of the supersonic frequency provides the desired sine-like profile.
mike.

Any real one probably has a totem pole of 2 transistors per phase with some cunning 'flying deck' electronics to ensure the transistor turn on/off  voltages to follow the output voltage up and down without accidentally turning the transistors back on at the wrong moment.   Actually many small inverters single and 3 phase are a bit like a fully floating version of this where the batteries are replaced by a pair of smoothing capacitors charged by some supersonic screamer of an inverter. The clever ones even modulate the target output voltage  of the inverter to create an approximate  half sine profile at 100Hz , while the 3 phase ones instead go for a static DC bus value and pulse-width modulate the totem pole transistors to give a rectangular thing whose average if smoothed out over many cycles of the supersonic frequency provides the desired sine-like profile.
mike.