A High-efficiency DC/DC Converter with SiC Devices and LLC topology for Charging Electric Vehicles

Abstract

Eelectric Vehicles $(EV_{s})$ have developed fastly supported by governments to relieve pollution issues and energy crisis in recent years. However, with the continuous devlopment of $EV_{s}$, efficient and rapid charging will restrict its further development. So a kind of charging module which owns high-output power and high-efficiency is a feasible key to solve the charging problem. However, conventional charging modules with using Silicon (Si) devices couldn’t realize very high efficiency, as a lot of power losses caused by power semiconductors and magnetic devices. So reducing power loss of these devices is a useful way to realize very high efficiency. Hence, this paper plans to design a 15kW DC/DC converter with LLC topology and Silicon-Carbide (SiC) devices to reduce power loss and verify its high efficiency. The proposed converter could reach about 98.4% and higher about 3% than conventional converter at rated full-load condition. Power density and volume of this proposed converter increases 27.6% and decreases 21.9% than conventional converter, respectively. Other detailed comparison information about this two converters shown as Part-D of section-II in this paper. In the end, relaive experimental waveforms used to verify the correctness and rationality of design.