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This article investigates the synthesis of lossless snubbers and passive soft-switching converters, as well as their general properties, including topological properties and electrical properties. The aim is to find the possible simplest snubbers and soft-switching converters and to give suggestions on applications of the snubbers and the soft-switching converters. On one hand, the synthesis and the topological properties of the snubbers and the converters determine the complexity of the topologies and help find the least requirement that passive soft switching needs to fulfill. The topological properties are investigated by addressing the basic issues induced by the inductor/capacitor added for passive soft switching. Based on the topological properties, the snubbers and the converters are synthesized. On the other hand, the electrical properties determine the performance of the snubbers and converters, help understand the limitations and are investigated by two case studies accompanied with experimental verification. By investigation of the general properties, the possible simplest snubber is given, the tradeoff between the complexity and performance is discussed in detail, the suggestion of snubber applications is presented, and three kinds of reported passive soft-switching converters which are believed to have the most potential of wide application are discussed. [ABSTRACT FROM AUTHOR]

A wide-range soft-switching high-efficiency cycloconverter-type high-frequency-link inverter with dual-phase-shift modulation strategy is proposed in this paper. By adding an auxiliary inductor in primary-side full bridge circuit and adopting center-tapped four-winding transformer structure, the soft-switching range for primary-side switches has been extended. The secondary-side active clamper network is designed to recycle leakage inductor energy, and suppress voltage spikes caused by the resonance of the leakage inductor and the parasitic capacitance of switches. One feature of the proposed inverter is that both the primary-side full-bridge and active clamper network employ phase-shift modulation technique where all switches are driven with nearly 50% duty cycle square signals, hence a simple and reliable transformer-isolated gate drive circuit with small transmission delay is presented. Moreover, all switches in the proposed inverter achieve zero voltage switching, which contributes to higher conversion efficiency as well as higher switching frequency. Analysis, design, and implementation of the proposed inverter are discussed in detail. A 200-kHz laboratory prototype for the high-voltage audio amplifier application is developed and the experimental results are presented to validate the analysis and performance of the proposed inverter. [ABSTRACT FROM AUTHOR]