贵广、天广工程直流保护系统“三取二”逻辑比较

Comparison of "Two-out-of-Three" DC Protection Logic Between Guizhou – Guangdong and Tianshengqiao – Guangzhou HVDC Projects

为加深对贵广直流工程和改造后天广直流工程直流保护系统"三取二"逻辑的理解,为直流保护冗余设计及其现场运行提供借鉴,对此逻辑在两个直流保护系统中的实现原理及应用情况进行了比较。结果表明,两个直流保护系统"三取二"逻辑实现的原理是相同的,但后者的"三取二"逻辑配置具有一定的优势,该直流保护系统在两套"三取二"逻辑装置全部因故退出运行时,直流保护动作出口信号仍可从极控系统中相关出口回路输出,以维持保护系统正常运行。

In order to understand the two-out-of three DC protecton logic in Guizhou – Guangdong and Tianshengqiao – Guangzhou HVDC Projects so deeply that certain reference is possible for the redundance design and operation of DC protection systems,this paper compares two cases of the logic system in these projects in terms of principle and application.The results show that the realization principles of the logic in the two DC protection systems are the same,but the two-out-of three logic configuration in the latter DC protection system is better as the export signal of DC protection is able to realize through the relative export circuit of the pole control system so to maitain the regular service of the DC protection system even when both the two logic sets are off somehow.