Design, analysis, fabrication and testing of a silicon carbide-based high frequency ZCS buck converter with over current protection

Abstract

Higher switching frequencies in power electronic converters result in reduction of size of the passive elements such as capacitors, inductors and transformers which lead to compact size, weight, and the increased power density of the converters at the cost of increased switching losses. The remedy for higher switching losses is the use of soft switching techniques like Zero-Current-switching (ZCS). Silicon Carbide (SiC) MOSFETs are now-a-days used in switched converters at very high frequencies for their known advantages. This paper presents a ZCS strategy-based buck converter, operating at 92kHz. Performance analysis and simulation of the converter has been done off-line using SEQUEL and other standard packages. Thereafter, a laboratory prototype has been fabricated and tested. The SiC MOSFET is driven by a gate driver card (tested upto 2 MHz), developed in the laboratory. Over current protection is also implemented. The experimental and simulated results are found to be in excellent agreement.