1 kW High Efficiency High Step-Down DC-DC Converter for Electric Vehicle

Abstract

A 1 kW high efficiency high step-down dc-dc converter is proposed for charging an auxiliary battery of an electric vehicle. The proposed system consists of an active-clamp converter and an output stage. The active-clamp converter operates under zero-voltage switching (ZVS) for the power switches and the output stage is composed of a current doubler and a synchronous rectifier for reducing conduction loss. The proposed dc-dc converter system is analyzed and its design considerations are discussed in detail. Experimental results for 1 kW (14.3 V/70 A) prototype at a constant switching frequency of 50 kHz are presented to verify the analysis and to show the performance of the proposed system.