Buck/Boost DC–DC Converter Topology With Soft Switching in the Whole Operating Region

Abstract

This paper proposes a buck/boost dc–dc converter topology based on the principle of auxiliary resonant commutated pole. The used snubber is fairly simple yet effective in reducing the switching losses. All active devices operate with soft switching, and switching noise is suppressed as much as possible. In addition to the conventional active switch loss reduction, the snubber participates in suppression of output diode reverse recovery. Moreover, complete soft switching in the whole operating region is achieved through controlled extended reverse conduction of synchronous rectifier. The topology was implemented in a 14 kW converter prototype operating at 62.5 kHz and tested with complete closed-loop control. Experimental efficiencies in the range of 98.5% show that the proposed circuit is highly capable while remaining sufficiently simple.