An Ultra-High Step-Up DC–DC Converter With Extendable Voltage Gain and Soft-Switching Capability

Abstract

In this article, a new high step-up dc-dc converter with soft-switching capability is presented. In this converter, all of the main and the auxiliary power switches operate under soft-switching condition. In addition, the leakage inductances of the coupled inductors control the current falling rate of the power diodes. Therefore, the reverse recovery losses are reduced significantly. In addition, the voltage stresses across the power semiconductors and clamped capacitors are limited to lower values. In this converter, coupled inductors and diode-capacitor voltage multiplier (VM) cells are utilized simultaneously to provide higher voltage gain. This combination increases the flexibility of the proposed converter, because the turn ratios of the coupled inductors and the number of VM cells are the degrees of freedom which can be used to regulate the voltage stress across the semiconductors. In this article, detailed analysis, elements design, and comparison results are presented. Furthermore, in order to validate the theoretical analysis, a 500-W, 19-60-V/400-V laboratory prototype of the proposed converter is built, and the related results are investigate.