Lossless passive soft-switching methods for inverters and amplifiers

This paper proposes lossless passive soft-switching methods for inverters developed from a synthesis procedure applicable to all pulsewidth modulation (PWM) converters. The lossless passive soft-switching converter properties and synthesis procedure are derived for inverters. Promising full-bridge and half-bridge soft-switching inverter examples are shown from the synthesis results. These include a new soft turn-on full bridge that contains only six components and a new soft turn-on and turn-off half bridge that contains 12 components. The voltage stress across the active switches can be easily maintained below 125% of V/sub bus/. Additionally, no transformers are used for energy recovery, eliminating their associated diode stress and leakage inductance problems. The theoretical and experimental waveforms and analysis are given.