An isolated three-port DC-DC converter with high power density in 10 cm × 5 cm × 0.8 cm card size for flexible automotive systems

A credit-card sized three-port dc-dc converter (TPC) has been designed and constructed. The TPC has three DC ports in one circuit, and DC power can be transferred without interference mutually. A dual active bridge converter (DAB) and a non-isolated bi-directional dc-dc converter (NBC) are integrated in the TPC by using a technique known as magnetic coupling inductor. Both thermal and soft-switching analysis are conducted to realize a high energy density of prototype, where a 750 W, 375 kHz, 18 W/cc is achieved. The efficiency and total losses have been measured in order to verify the validity of the proposed converter, and efficiency over 90% in wide range of output power is achieved by using Si MOSFETs.