Design consideration for contactless DC connector in high power density future 380 V DC distribution system

Design consideration for the contactless DC connector has been conducted for future high power density 380 V DC distribution system. The power density barrier of 1.2 kW 384 V-192 V inductively-coupled connector based on the LLC resonant converter topology using GaN transistors has been evaluated taking the influences of the circuit configurations, parameters related to the transformer and the semiconductor power devices into account. The LLC topology with full-bridge rectifier using GaN transistors and Si-SBDs have the potential to realize higher power density connector compared with the configurations using center-tapped transformer and the half-bridge rectifier with SiC-SBDs. A prototype of a 1.2 kW 384 V-192 V contactless connector using GaN-HEMTs and Si-SBDs has been fabricated, and the efficiency of over 96.0 % and the ideal power density of 5.0 W/cm³ have been confirmed experimentally under 500 kHz operation. Design consideration has also shown the potential to achieve higher power density of 10 W/cm³. The proposed connector contributes to realizing high power density DC distribution system, because functions for both the isolated DC-DC converter and the conventional connector are integrated in a single instrument.