A power inverter comprises a push-pull inverter circuit that includes a transformer having a primary winding coupled to a DC bus and a secondary winding coupled to an AC bus, main power switches coupling each end of the primary winding to a DC return, and one or more supplemental power switches coupling at least one end of the primary winding to a snubber bus. The supplemental switch at a given end of the primary winding forms a buck-mode converter in combination with the primary winding and the associated free-wheeling diode at that end of the primary winding, and can be controlled by a switching controller to effect energy transfer between the snubber bus and DC bus. The switching controller can be configured to control power flow between the DC, AC, and snubber buses by controlling the common-mode and differential-mode voltages of the primary winding via main/supplemental power switch control.