三端线路光纤保护的研究

首先用节点电压法分析了一种典型三端线路结构的负序网络，提出了在该结构下发生内部故障时负序电流流出的判据，并据此得出在该结构下发生内部故障时负序方向元件一般不会误判的结论；然后提出在这种网络结构中可以将三端线路保护与另一双端线路保护相结合的综合保护方案；最后从经济性、软硬件的复杂性和同步方法上比较分析了各种拓扑结构的优劣。

RESEARCH OF RELAY PROTECTION OF THREE-TERMINAL POWER TRANSMISSION LINES USING OPTICAL FIBER CHANNEL

Firstly, this paper analyzes the negative sequence equivalent network of a typical three terminal line structure by nodal voltage method, and proposes a criterion of negative current flowing out during inner faults. The conclusion has been drawn out that negative sequence directional element usually can not make a wrong judgement during the inner faults in this kind of transmission line structure. Secondly, combining the protective relaying of three terminal line and another parallel two terminal line as a unit, an integrated protective scheme is proposed. Finally, all kinds of topologic structures of optic fiber network are analyzed and compared in their costs, complexity of software and hardware and synchronizing techniques.