Power electronics for vehicles and energy systems

Abstract

Power electronics that enable DC-AC, AC-DC, or DC-DC conversion of electric power are one of the key technologies for the spread of electric-drive vehicles and renewable energy systems such as PV and wind turbine generators that address the global warming issue and contribute to energy saving. In particular, electrification of vehicles that eliminate about 20% of total CO2 emissions contributes to overall reduction of those emissions, and power electronics become an important technology in vehicle electrification. Wide-bandgap semiconductors such as SiC or GaN are important to future technical development of power electronics. Compared with Si, SiC has superior properties in that it has three times the bandgap, twice the saturation velocity, ten times greater breakdown field, and three times greater thermal conductivity. Given these characteristics, wide-bandgap power devices can be driven at high frequency and high temperature, and drastic downsizing of the converter and loss reduction are enabled. By replacing conventional Si power devices with SiC, significant energy saving is anticipated.