Investigations on Gallium Nitride based Power Electronic Technologies for High Frequency Converter Applications

Abstract

With the advent of Power Electronics (PE), dc-dc converters are widespread in industrial designs addressing various voltage and power levels. This provides sophistication at the source as well as at the load, demanding high performance such as reduced no-load and full-load losses to open up new application areas. Silicon (Si) MOSFETs, termed first-generation semiconductors was used for the past three decades to address the industry needs. Further, an increase in performance could be achieved with second-generation materials like Gallium Arsenide (GaAs). The recent research in power electronics has focused on the application of switching devices made with a third-generation semiconductor material, characterized as a wide gap, represented by Silicon Carbide (SiC) and Gallium Nitride (GaN). Si-based transistors have reached close to their practical limit and wide band gap based semiconductors outperform Si in most applications. The GaN dominates at low power levels with high-frequency switching to meet higher performance requirements. newlineGaN devices have a better figure of merit for the high frequency of operation as compared to Si devices. However, significant challenges are faced while handling the low parasitic inductance connections at the wafer level with crucial individual packaging of GaN devices. Complexities galore in the PCB-level designs for the subsystems like gate drives, control electronics circuits, and thermal management. GaN has opened up the choice of simple subsystem designs with hard switching compared to the Si-based converters that operate with complex circuited soft switched for high performance requirements. The challenge is in evolving subsystems for individual GaN device specifications and their operations in the converter topology. newlineThis research work includes the design and development of power electronics technologies for 500 kHz frequency-switched GaN-based power converters. Gate drives, control schemes, PCB layout, thermal management, and other high power density subsystem required in the