A new high efficient energy conversion system is proposed for the automotive application and the renewable energy generation. It provides a partial boost switching technique which realizes extremely high efficiency chopper for battery voltage fluctuation. First prototype unit of dual active bridge converter using silicon carbide metal-oxide-semiconductor field-effect transistor was fabricated and evaluated by its system test. The experimental results show the verification of highest of over 99.19 % at 8.1 kW under the frequency of 20 kHz.