Highly-Efficient and Compact 6 kW/4 × 125 kHz Interleaved DC-DC Boost Converter with SiC Devices and Low-Capacitive Inductors

Abstract

This paper describes a four-leg interleaved DC-DC boost converter built on the basis of Silicon Carbide (SiC) devices (Metal-Oxide Semiconductor Field-Effect Transistors—MOSFETs and Schottky diodes) and improved, low-capacitive magnetic components. A combination of wide-bandgap semiconductors capable of operating at elevated switching frequencies and an interleaving technique brings substantial benefits, such as a cancellation of the input/output current ripples, a reduction of weight, dimensions and increase of power density. The 4 × 125 kHz DC-DC boost converter characterized by a volume of 0.75 dm3 reaches an efficiency above 98.7% at nominal power of 6 kW. A special effort has been made to develop and test inductors with low parasitic capacitance. It is clearly proven that an improved design has an impact on the converter performance, especially on power losses. Reduction of the power losses is higher than 25% in reference to a standard design of the inductors and the efficiency is in excess of 99%.

Keywords

• Silicon Carbide (SiC) devices
• DC-DC power converter
• parasitic capacitance