An efficient high frequency high power off-line DC-DC converter topology

Abstract

A full-bridge switch mode PWM (pulse-width modulation) DC-DC converter topology is discussed. It minimizes switching losses and resulting stresses through the use of a DC bus active snubber. This circuit ensures that the switch parasitic (or discrete) capacitances are discharged before switch turn-on and the associated energy is returned to the DC bus. The resulting converter performance includes near-zero switching losses as well as protection from DC bus shoot-throughs. A complete analysis and design procedure are presented. Theoretical results have been verified experimentally on a 2 kW, 20 kHz laboratory prototype.<>