Unlocking the Opportunities of Bidirectional GaN Devices in Isolated DC/DC Converters and Multilevel Inverters

Abstract:
Bi-directional power devices are based on four-quadrant operation to block a stress voltage in both polarities and to conduct symmetric current. Typically, their major utilization is either in resonant ac-dc rectifier with a power factor correction or in bidirectional inverters with two or multilevel output voltage. Their benefit can also be extended in solid-state circuit breakers, resonant tank with a variable switching frequency, and some inverters with soft-switched performance. Overall efficiency, power density and circuit functionality of such converters highly depend on realization and deployment of these devices with a lower on-state resistance/capacitance and their smooth and fast switching transition. Gallium nitride-high electron e-mobility transistors (GaN-HEMT) technology has this potential to realize such devices with different circuit packaging. However, its utilization from short circuit capability, power layout, and gate driver design perspectives needs further attention. The aim of this article is to investigate the potential of bidirectional-GaN-HEMT devices for the isolated dc-dc converters and new soft- and hard switched dc-ac converters. Besides, the challenges towards its reliability, gate driver consideration and dynamic/static characterization are studied.