Design Consideration for High Power Density GaN Buck-Rectifier in ISOP-IPOS Converter based dc Distribution, System

GaN （gallium nitride） buck-rectifier has been proposed to realize high power density ISOP （input series and output parallel）-IPOS （input parallel and output series） converter-based dc distribution system. The ultra-low loss bi-directional switch can be developed by the GaN power device because of the low on-resistance, the high-speed switching behavior and its own device structure. The buck-rectifier using the GaN bi-directional switches has the potential to achieve higher power density than the commonly utilized boost-rectifier. Availability of the GaN-HEMT （high electron mobility transistor） for the buck rectifier has been verified taking the theoretical limit of the on-resistance and the switching loss energy into account. Design consideration for a high power density buck-rectifier has been also conducted and the application effect of the GaN bidirectional switches has been evaluated quantitatively. The ISOP-IPOS converter-based dc （direct current） distribution system takes full advantage of the buck-rectifier and the rectifier using GaN devices contributes to realizing higher power density dc distribution system.

A Review of WBG and Si Devices Hybrid Applications

In recent years,next-generation power semiconductor devices,represented by silicon carbide(SiC)and gallium nitride(GaN),have gradually emerged.Because wide-bandgap(WBG)devices have better electrical characteristics than those of silicon(Si)based devices,they have attracted increased attention both from academic researchers and industrial engineers.Employing WBG devices will further improve the efficiency and power density of power converters.However,the current price of WBG devices remains extremely high.Thus,some researches have focused on the hybrid utilization of WBG devices and Si-based devices to achieve a tradeoff between the performance and cost.To summarize the current research on WBG/Si hybrid applications,the issues mentioned above with representative research approaches,results,and characteristics,are systematically reviewed.Finally,the current research on WBG/Si hybrid applications and their future trends are discussed.