单相接地故障综合选线的研究

为了解决谐振接地系统，发生单相接地故障时基于单一暂态或稳态的选线策略的故障选线装置的选线误判率过高的问题，本文提出了一种基于综合选线的策略即零序电流增量法和暂态零序电流方向互异法。实现了对稳态和暂态两方面进行零序故障电流的综合选线，从而进一步提高选线的准确性。基于这种综合选线策略的谐振接地选线装置被研制出来，并在模拟电网进行实验。实验结果表明：该装置具有实时记录并显示谐振接地系统发生单相接地故障时故障线路和非故障线路零序电流的稳态增量的变化和故障线路零序电流暂态方向的不同，并通过DSP对故障线路做出准确、可靠的判断。

Study of Line Selection Strategy Used in Case of Single-phase-to-Ground(SPG) Fault

In this paper, an integrative line selection strategy-increment of zero sequence current and differenti- ation of the direction of transient zero-sequence current flow - is put forward, based on which, the design of faulty line detection device for single-phase-to-ground fault on resonance grounding system is presented. For the purpose of testing and validating the operating principle of the integrative line selection strategy and experimental perfor- mance of the device, a simulation experiment is conducted. The results show that the device can record and display the changes in increment of zero-sequence stable current of faulty line and non-faulty line as well as the difference of transient current flow in resonance grounding system. The faulty line can be detected quickly and accurately by DSP.