高海拔地区晶闸管宇宙射线失效等效加速试验研究

Research on Equivalent Accelerated Test of Thyristor Cosmic Ray Failure in High Altitude Area

大气环境中的高能中子、γ射线和电磁脉冲以及空间辐射环境中的高能电子和质子等,都能造成半导体材料性质变化和器件性能蜕变以至失效,而在大气层内宇宙射线引起功率器件失效的主要原因是高能中子导致的单粒子烧毁(single event burnout,SEB)。白鹤滩—江苏±800 kV特高压直流输电工程布拖换流站位于北纬27°,东经102°,海拔2500 m。中子通量是水平面4倍以上,将导致器件的失效率大幅上升。为验证工程中8.5 kV晶闸管在额定条件下的失效率不超过100FIT,该文采用200 MeV质子源进行辐照加速试验,根据当地大气中子通量核算中子总注量,对比研究不同电压、温度对晶闸管失效率的影响规律,试验结果给出晶闸管在高海拔地区宇宙射线SEB平均失效率,为换流阀中晶闸管工作电压设计提供依据。

High-energy neutrons,gamma rays and electromagnetic pulses in the atmospheric environment,high-energy electrons and protons in the space radiation environment,etc.,can cause changes in the properties of semiconductor materials,deterioration of device performance and even failure.The main reason for the failure of power devices caused by cosmic rays in the atmosphere is that high-energy neutrons cause single event burnout(SEB).Baihetan-Jiangsu±800 kV UHVDC Transmission Project Butuo Converter Station is located at 27°N latitude,102°E longitude,and an altitude of 2 500 m.The neutron flux is more than 10 times that of the horizontal plane,which will lead to a significant increase in the failure rate of the device.In order to verify that the failure rate of the 8.5kV thyristor in the project does not exceed 100FIT under rated conditions,a 200 MeV proton source is used for accelerated irradiation tests.Atmospheric neutron flux is used to calculate the total neutron fluence,and the effect of different voltages and temperatures on the failure rate of thyristors is compared and studied.According to the test results,the average failure rate of cosmic ray single event burnout of thyristor in high altitude area is calculated,which provides a basis for the design of the working voltage of the thyristor in the converter valve.