光控晶闸管正向过电压自保护机理研究

Research on Forward Overvoltage Self-protection Mechanism of Light-triggered Thyristor

介绍了新型光控晶闸管(LTT)内部集成的一项非常重要的电气功能,即正向过电压自保护功能。通过在LTT光敏区内集成转折二极管(BOD),实现LTT正向过电压自保护功能。如果集成BOD转折电压太高,则不能有效保护晶闸管;如果集成BOD转折电压太低,则达不到LTT设计的阻断电压要求。这里通过计算机仿真技术和工艺实验验证的方法,成功揭示了LTT内部集成的正向过电压结构机理与硅单晶材料电阻率、PN结结构尺寸和温度的关系,从而精确设计和制造了LTT内部的转折电压,成功研制了5英寸3125 A/7600 V特高压LTT,并成功应用于"云南-广东±800 kV/5000 MW"特高压直流输电工程。

A new type of light-triggered thyristor(LTT)is proposed which integrates a very important electrical function,namely forward overvoltage self-protection function.By integrating the break-over diode(BOD)in the LTT’s sensitive region,it can achieve the forward over-voltage self-protection function of LTT.If the break-over voltage of the integrated BOD is too high,it can not protect the thyristor effectively.If the break-over voltage of the integrated BOD is too low,it can not reach the blocking voltage design requirements of the LTT.By using computer simulation technology and process experimental methods,the relationship between forward overvoltage structure mechanism integated in LTT and resistivity of silicon material,size and structure of the PN junction and temperature is revealed successfully,and the break-over voltage of LTT is designed accurately,a 5 inch 3125 A/7600 V ultra high voltage LTT is successfully developed,and is successfully applied in"Yunnan-Guangdong±800 kV/5000 MW"ultra high voltage direct current transmission project.