18kV/125A碳化硅IGBT器件研制及串联应用关键技术研究

Research on Key Technologies for Development and Series Application of 18kV/125A SiC IGBT Device

高压碳化硅(silicon carbide,SiC)器件因具有耐高压、耐高温、低损耗等优异特性,已成为支撑未来新型电力系统建设的新型电力电子器件。文中基于自主研制的18kV/12.5A高压SiC绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)芯片,提出18kV SiC IGBT单芯片子模组及10芯片并联封装设计方案,研制18kV/125A SiC IGBT器件,功率等级达到国际最高水平。搭建高压碳化硅功率器件绝缘、静态特性和动态特性测试平台,测试单芯片子模组及10芯片并联器件的绝缘及动态特性,18kV/125A SiC IGBT器件具备18kV静态耐压且可以在13kV直流母线电压条件下关断130A电流,验证了所研制器件的高压绝缘及高压开关能力。此外,采用18kV/125A SiC IGBT器件串联搭建24kV换流阀半桥功率模块,提出器件串联均压方法,完成半桥功率模块的1min静态耐压试验和开关试验验证,结果表明,所研制的18kV/125A SiC IGBT器件运行良好,满足串联应用要求,同时,所提的均压方案可以保证半桥功率模块静态电压不均衡和动态电压不均衡程度分别低于0.4%和15%。该研究可以为基于SiC IGBT器件在柔性直流输电工程中的应用奠定基础。

High voltage silicon carbide(SiC)devices,as new power electronic devices,have been supporting the construction of new power systems because of their advantages in high voltage,high temperature and high frequency.In this paper,based on the 18kV/12.5A high-voltage SiC insulated gate bipolar transistor(IGBT)chip developed independently in China,the packaging design method of the 18kV SiC IGBT single-chip sub-module and 10-chip parallel packaging structure is proposed.The first 18kV/125A SiC IGBT device with the maximum power level in the world is developed.Then,the experimental platforms for insulation,static and dynamic characteristics of high-voltage SiC power devices are built.The insulation and dynamic characteristics of the single-chip sub-module and 10-chip paralleling device are measured.The results show that the developed 18kV/125A SiC IGBT device can withstand static voltage at 18kV and can turn off at 13kV/130A,which verifies the high-voltage insulation and high-voltage switching ability of the developed device.In addition,the developed 18kV/125A SiC IGBT devices are used in series to build the 24kV converter valve half bridge module.The corresponding series voltage equalization method is proposed.Finally,the 1min static voltage withstand test and switching verification of half bridge module are conducted.The results show that the developed 18kV/125A SiC IGBT devices can meet the requirements of series application.At the same time,the proposed voltage sharing method can ensure that the static voltage and dynamic voltage imbalances of the half bridge module are less than 0.4%and 15%,respectively.The presented results in this paper can lay a foundation for the application of SiC IGBT devices in flexible DC transmission systems.