The 10 kV line of new distribution network is equipped with a large number of intelligent switches(FTU).The FTU,in case of a single-phase ground fault on the line,can quickly monitor the zero-sequence voltage and current electrical volume.The phase relationship of zero sequence voltage and current of faulty line and section is analyzed and compared with that of non fault line and section,which can quickly select line and section positioning.In this paper,zero-sequence network analysis for faulty sections containing FTUs on both sides is made,the node voltage equation is written so that the analytical formula of the fault distance and the zero-sequence voltage current on both ends can be obtained.The fault distance obtained by the formula is free from the influence of ground resistance and the calculated fault distance is more accurate.Through simulation and analysis,the effectiveness of single-phase grounding fault line selection,location and distance measurement by using zero-sequence voltage current under the new type of distribution network is verified.Finally,the handling flow chart of single phase ground fault of new type of distribution network is given,which can provide reference for actual single-phase grounding faults.
关键词
新型配电网/FTU/单相接地故障/零序网络/故障定位测距/零序电压电流
Key words
new distribution network/FTU/single-phase ground fault/zero-sequence network/fault location and ranging/zero-sequence voltage and current
维普
万方数据