A New SiC-GaN-Based Two-Phase Interleaved Bidirectional DC-DC Converter for Plug-In Electric Vehicles

Wide Band Gap (WBG) semiconductor technologies such as Silicon Carbide (SiC) and Gallium Nitride (GaN) are considered as the future of power electronic devices. Especially, in hard-switching applications where switching power losses are important, GaN devices are more attractive because of their very low gate charge amount. On the other hand, universal dc-dc power converters in Electric Vehicles (EVs) are coming into attention to be replaced with two power electronic modules: dc-dc battery charger and dc-dc traction drive. Unfortunately, current lateral GaN devices are not applicable in high power dc-dc traction drive, neither in universal dc-dc converters because of their limited current rating. As a solution, a two-phase dc-dc converter is proposed in this paper in which one phase is SiC-based MOSFET and the other one is GaN-based transistor. To reach the maximum utilization of the GaN device, the output power will be shared through the two phases, based on the current rating of the GaN device. First, the power stage design and the average model of the converter are presented. Then, power losses and efficiency of the converter is investigated in comparison with an all-SiC converter through spice-based simulations. The simulation results highlight the higher efficiency of the proposed converter.