High-power step-up converter with high efficiency and fast output voltage dynamics

Abstract

A high-power step-up converter, which is based on the dual converter topology and is operating at a constant duty cycle, is proposed. It employs an auxiliary circuit and the output voltage is controlled with a phase-shift between two dual converters. It features a high efficiency due to the greatly reduced switch turn-off stress and a fast output voltage response with low influence of the right half-plane (RHP) zero. A 50 kHz 800 W 350 Vdc prototype with an input voltage of 20-32 Vdc has been constructed to validate this converter. The proposed converter compares favorably with the conventional pulse-width-modulated (PWM) counterpart and is considered well suited to high-power step-up applications.