Abstract: A current stiff power conversion system, such as a rectifier, inverter, or AC-to-AC converter is provided wherein power converter switching devices in the power conversion system may be switched at or near zero voltage conditions to minimize or eliminate switching losses and increase switching frequencies. Zero voltage switching conditions are achieved by providing a snubber capacitor across each switching device in the power conversion system, and connecting an active commutation unit, including an inductor and an active commutation unit switching device connected in series across DC bus lines in parallel with the bridge of power conversion switching devices.