ZVS Realization of H-Bridge Low-Voltage High-Current Converter via Phase-Shift and Saturable Control

Abstract

A zero-voltage switching (ZVS) H-bridge phase-shifted low-voltage high-current converter with saturable inductors is proposed in this paper. The introduction of saturable inductors solves the short circuit problem caused by high-frequency on–off of the power tube, and effectively inhibits high-frequency voltage oscillation and voltage spikes of the rectifier tube. In addition, when the current flowing through the saturable inductor does not change rapidly, it exhibits a low impedance and consumes very little power. The detailed design process of main parameters in the converter is presented to provide design reference for power supply workers. To verify the effectiveness of design, a 3 kW(15 V/200 A) prototype converter is built. This low-voltage high-current prototype has around 90% efficiency, and can suppress high-frequency voltage oscillation and voltage spikes, avoiding the short circuit problem of power tube, all of which are verified by experimentation.

Keywords

• ZVS h-bridge phase-shifted converter
• high-frequency resonance
• saturable inductors
• spike suppression