A novel high step-up, low switching voltage stress DC-DC converter using leakage inductance for resonant boosting

A DC-DC converter with high boost and low switching voltage stress is proposed by combining switched capacitor (SC) and coupled inductor (CL) techniques based on a conventional boost circuit. The design methodology of this converter includes substituting SC for a single switch in the boost converter, combining CL, and integrating a resonant boost circuit for absorbing leakage inductance. The improved power switch topology in this design has lower voltage stress, lower diode current stress, fewer total components, and common ground than other conventional DC-DC converters. The operating modes and steady state analysis of the converter are provided in terms of leakage inductance utilization, with component stress derivation and theoretical efficiency analysis. In addition, comparisons with other dc-dc converters are made. Subsequently, experiments were conducted on a 200 W DC-DC converter prototype to verify the reliability of the converter. The presence of leakage inductance leads to voltage spikes in the switch and resource loss in the drive duty cycle, both of which are difficult to fully balance. In order to solve these problems, a switched-capacitor structure is used to replace the excitation switch of a conventional boost circuit. Experimental results demonstrate that the efficiency of the prototype is stabilized at over 94% in the laboratory state. image