可控硅的反向恢复触发保护探讨

可控硅是直流输电系统的核心元件,因此对可控硅保护的研究十分必要.可控硅在熄灭过程中,如果突然承受正向电压,可能出现局部导通产生局部过热导致可控硅遭受破坏的情况.为避免这种情况的发生,设置了反向恢复触发保护,该功能向可控硅发一触发脉冲使之均匀导通.对可控硅反向恢复期的情况进行了介绍,分析了现有反向恢复触发保护电路的工作原理及存在的缺陷,并从如何改进保护动作的灵敏性和可靠性方面提出了建议.

Discussion on HVDC Thyristor Recovery Protection and RP Test

Thyristor is the core element of DC power transmission system.The research on the its protection is very important. If the thyristor withstands active voltage suddenly in the closing process; partial overheat would be appeared because of the partial conduction and the thyristor may be damaged. In order to avoid this phenomenon, recovery protection firing is used. This function can send a firing impulse to the thyristor and the thyristor can be conducted uniformly.In this paper,the positive recovery time is introduced.The working theory and the shortcoming of existed recovery protection is analyzed.Suggestions are proposed on the aspects of modification of sensitivity and reliability of the protection action.