反向恢复特性在高功率晶闸管检测试验中的应用

Application of Reverse Recovery Characteristics in High Power Thyristor Testing

为研究高功率晶闸管的检测方法,围绕晶闸管换流阀例行检测试验中涉及的晶闸管反向恢复特性同外电路之间的关联关系展开了研究。实验研究了正向电流参数对高功率晶闸管反向恢复过程的影响,并结合直流输电工程的实际情况,研究了工频条件下晶闸管的反向恢复特性,得到了工频电流幅值与反向恢复时间的关系,提出了换流阀用高功率晶闸管实际工作时的物理模型。结果表明:正向电流幅值是反向恢复时间的主要影响因素,晶闸管检测试验参数需要根据晶闸管正向导通电流幅值的变化而改变;晶闸管关断时间与反向恢复时间的比值不小于1.18。该研究可为晶闸管控制保护单元的设计及其试验检测提供参考依据及理论支持。

To discuss the testing method of high power thyristors, we present the research work focusing on the relation- ship between reverse recovery characteristics and external operating conditions involved with the routine test of thyristor valve. The effect of forward current on reverse recovery characteristics of high power thyristors is experimentally inves- tigated. Combined with the actual situation Of HVDC project, the thyristor reverse recovery characteristics under the condition of power frequency is studied. The relationship between the amplitude of power frequency current and the re- verse recovery time is obtained, and the physical model of actual operation of high power thyristors in thyristor valve is proposed. The results show that the peak forward current is the main influential factor on the reverse recovery time, therefore, the parameters of thyristor testing need to change according to its forward current amplitude; the ratio of turn-off time and reverse recovery time for the thyristor is less than 1.18, which can provide references and basic data for design of thyristor control unit and routine test of thyristor valve.