Comparison of main design concepts of auxiliary drives for DC catenary fed light traction vehicles: SiC JFET vs Si IGBT technology

Abstract

ABSTRACT This paper presents a comparison of prospective design concepts of DC/DC isolated converters for auxiliary drives of DC catenary fed light traction vehicles. Auxiliary drives are mostly dedicated to generate standard power grid supplying various on-board equipment and to charge on-board batteries. The DC/DC isolated converter consists of full-bridge (FB) converter feeding a high frequency transformer (HFT) and SiC diode rectifier which produces a DC voltage bus line for 3-phase voltage-source inverter. The input FB converter is in our case designed using 1200 V devices in discrete (Si IGBTs) and module (SiC JFETs) version. The comparison deals both the hard switching and soft switching topologies of the converters. The investigated design concepts are experimentally tested up to the switching frequency of 200 kHz. The main aim of this paper is to compare efficiencies of SiC JFET and Si IGBT LLC full bridge converters operated under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The introduced theoretical results and analyses are validated by the experiments made on developed prototype 8 kW, 400 V/600 V DC/DC isolated converter using SiC JFET and Si IGBTs