SiC devices performance overview in EV DC/DC converter: A case study in a Nissan Leaf

This paper presents the technical and economical merits of using low losses fast switching Silicon Carbide (SiC) accumulated gate field effect transistor (ACCUFET) switches in comparison with a Hybrid module of Silicon (Si) IGBT with anti-parallel schottky barrier diode (SBD) in DC/DC converter applications of the Nissan Leaf electric vehicle (EV) motor drive. The performance of the car, at steady state conditions, is studied at different temperatures. The power losses, current, voltage, torque and speed results are given. The results showed lower total switching power losses with the SiC ACCUFET. This reduction in losses was recorded at different switching frequencies in comparison to the hybrid switch. The fast switching of SiC Trench ACCUFET reduces current-voltage cross-over losses and enables high frequency operation thus achieving high record efficiency. The high frequency operation will result in a smaller foot print of the converter together with a weight reduction; thus making the car lighter. It is expected that a lighter car will result in a longer range Nissan Leaf with the same battery. Increasing the car mileage of the battery and lowering the cost of magnetic components in the EV will surpass the higher cost of the SiC ACCUFET from an economical point of view.