摘要
在大容量、高电压可控硅的应用中,常出现可控硅局部过热而损坏的事故。究其原因,大多是因可控硅电流扩散速度远小于线路 di/dt 数值所致。其解决办法是:采用扩散速度快的可控硅,但因其价格昂贵而无法推广。现根据可控硅触发电流大,扩散速度亦大的特点,可采用强触发方式,当感性负载时还必须用双强窄脉冲触发,也可以在主回路中串接空心电感及在过压保护回路中串联一定的电阻来限制 di/dt 的数值,文中还就脉冲变压器的设计问题作了说明。
In the case of appliod large power and high voltage SCR The SCR's damage is often caused by partial Overheat.The reason is that the spreading rate of SCR's current is much less than the volume of the line(di)/(dt).It is settled.by the ways as fallows:we can use the SCR of high spreading rate,but it is too expensive for user;According as the higher the triggering.current as the higher the spreading rate of SCK,we'd rather use the methed of the power trigger or the double narrow impulse to do it for the inductive circuit. We can serially connect a hollowinductive coil in the SCR's circuit and some resistors in the protective circuit of over voltage for reducing(di)/(dt)caused by capacitors. The design of impulse tranformer is also introduced in this paper.
