Analysis and Design of DC/DC Converters for Electric Vehicles Fast Charging applications implemented with Wide Bandgap Semiconductor devices

A single charger module is analyzed and designed, using innovative wide band-gap semiconductor devices to enable the DC fast charging capability. Electric vehicles charging systems and supply equipment are introduced, classifying them according to their characteristics and features. The charging profiles, the multistage architectures and the modular chargers, as well as the isolated systems, are also discussed. A detailed and compared analysis of some isolated DC/DC converter typologies for high power operations is done. An example of an high power and voltage SiC-based DC/DC converter is presented, designed and simulated to operate according to the fast charging conditions. The PWM-Full-Bridge converter is simulated at different switching frequency conditions, analyzing the power loss by separating switching and conduction loss phenomena for each device. The efficiency performances are evaluated for the converter simulated with Si, SiC and GaN devices. A size and cost comparison is then proposed, by considering SiC, GaN and Si converters designed to operate at fixed efficiency. Finally, a similar analysis is also proposed at higher temperature conditions to investigate the high temperature capabilities of converters realized with WBG semiconductor devices