【作者】 黄波；

【导师】 郑琼林；

【作者基本信息】 北京交通大学 ， 电气工程， 2016， 硕士

【摘要】 随着电力电子技术高频化和高功率密度化的发展,开关电源对电力电子器件性能和可靠性的要求日益苛刻,以硅(Silicon, Si)材料为基础的传统电力电子功率器件已逐步逼近其理论极限。作为第三代宽禁带半导体材料的典型代表,氮化镓(Gallium Nitride, GaN)具有比Si更优异的物理特性,是高频、高温、高压和大功率应用的优良半导体材料,具有广阔的市场前景。2010年以来,GaN功率器件的研究成果日益显著,但与碳化硅(Silicon Carbide, SiC)器件相比,其器件特性与应用的研究尚处于初步阶段,有待更深入和更系统的研究。本文主要研究对象为Cascode GaN晶体管和GaN二极管。首先介绍GaN功率器件的研究背景与国内外发展现状,对比分析单体增强型GaN晶体管与CascodeGaN晶体管的优缺点及适用场合。其次基于器件结构的分析与器件特性的测试,研究了Cascode GaN晶体管与GaN二极管的静态特性,给出相应的静态特性数学模型。然后基于Cascode GaN晶体管带寄生参数的等效电路,分析其动态特性,给出开通与关断损耗的数学模型,并通过仿真与实验进行验证；通过实验手段测试了GaN和SiC二极管反向恢复情况,并进行对比分析。本文还提出适合高频场合的Cascode GaN晶体管过流保护电路,并通过仿真与实验验证了该电路的可行性。最后从功率变换器的角度,把GaN功率器件应用于Buck变换器与单相全桥逆变器中,基于本文得出的GaN器件静态特性与动态特性的数学模型对变换器进行损耗分析,并搭建实验样机,用实验验证了理论分析的正确性。本课题所做的理论分析、仿真分析和实验分析均表明Cascode GaN晶体管具有十分优异的高频特性,且GaN二极管也具有与SiC肖特基二极管同样出色的高频特性,非常适用于高频、高功率密度的中小功率应用场合。更多还原

【Abstract】 The power electronic technology development of high frequency and high power density, switching power supply for power electronics device performance and reliability requirements are increasingly strict. Traditional silicon based power electronics power device has been increasingly close to limit determined by the physical properties of material theory. As a typical representative of the third generation of wide bandgap semiconductor materials, gallium nitride (GaN) has many more excellent physical properties than Si material, which is the excellent semiconductor material of high frequency, high temperature, high pressure and high power application of, and the market prospect of it is very broad. Since 2010, the research of GaN power device is becoming more and more significant. However, compared to the silicon carbide (SiC) power device, the research of characteristics and application of GaN power device is still in its preliminary stage and its device characteristics remains to be more deep and system research.This article mainly discusses the characteristics and applications of cascode GaN transistors and GaN diodes. Firstly this paper expounds the research background and development situation of GaN power devices. And then analysis the advantages and disadvantages and applicable occasions between monomer enhanced GaN transistor and cascode GaN transistor. Secondly based on the structure and the characteristics test of power device, this paper studies the static characteristic of Cascode GaN transistor and GaN diode and the corresponding mathematical models are given. Based on the equivalent circuit of cascode GaN transistor with parasitic parameters, this article detailedly analysis the the turn-on and turn-off dynamic process of cascode GaN transistor, and the mathematical models of their turn-on and turn-off loss are presented. The models are verified by simulation and experiment of the double pulse test circuit, and through the experimental prototype the reverse recovery characteristics of GaN and SiC diodes are tested. In order to improve the working reliability of the cascode GaN transistor, this article puts forward a suitable for high frequency occasions cascode GaN transistor overcurrent protection circuit, and its feasibility and effectiveness are verified by simulation and experiment. Finally, through the Buck converter and single phase full bridge inverter, the performance of cascode GaN transistors and GaN diodes are further assessed.The theoretical analysis, simulation and experiment of this article show that the high frequency characteristic of cascode GaN transistors is very excellent and the performance of GaN diode is as well as SiC diode.They are very suitable for high frequency, high power density of small and medium-sized power applications.更多还原