Research On Dealing With Single-phase Earth Fault Based On Feeder Automation

Since there has no function of dealing with single-phase earth fault in feeder automation by now, we should do some research on this problem. Looking back this problem based on feeder automation, condition and requirement have changed obviously.The scheme for single-phase fault ,which advanced by this paper, absorb the idea of selecting fault line by computer. It combines feeder automation, and develops the fault identifying principle from one direction to two direction. So it enhances the redundancy of fault information, and improves the reliability of the fault location.We choose the transient zero current prior to others, for it is bigger than others mostly. This paper discusses the size of transient zero current and the method of analyzing it. Numeral simulation shows the feasibility of it. Negative current at fault line is differ distinctly from non-fault line. So it can be used for single-phase fault identifying. This paper discusses the size of the negative current and the method of analyzing it. Numeral simulation shows the feasibility of it.This paper analyses the test results gained by mixed simulation, and validates the reliability of the use of transient zero current and negative current in fault identifying. This paper also points out the applying localization, and puts forward the ameliorated steps. Analysis indicates that comparing from one direction has upper sensitivity, and more reliability from two directions.This paper discusses several problem about the dealing with single-phase fault based on feeder automation, especially the case of communication blackout with one or two FTU(feeder terminal unit ). The principles of selecting fault line in existence can also be used in feeder automation. These principles may increase the reliability of fault location greatly.