Performance Analysis of Novel Bidirectional DC-DC Converter With L-D Based Modified GaN-FET Driver

Gallium nitride (GaN)-FET devices are capable to provide high efficiency operation of dc-dc converter at higher frequency. The major problem of using GaN-FET in dc-dc converter lies in driver stage, which creates switch voltage ringing and high dv/dt during switching event. This creates false triggering of GaN-FET due its inherent low turn on threshold voltage. In this article, a novel nonisolated coupled inductor based bidirectional dc-dc (CIBDC) converter is proposed and tested with a modified inductor diode (L-D) based GaN-FET driver to verify higher efficiency operation as well as low switch voltage ringing and low dv/dt. The proposed converter is capable to provide higher voltage conversion ratios in both buck and boost mode. Due to parallel path structure the input current ripple is also less in the proposed CIBDC. The steady state performance like switch voltage ringing, dv/dt immunity, voltage stress, current stress, efficiency, etc. of this topology is tested on a 250 W prototype using L-D based driver.