Research On Diagnosis Method Of Grounding Fault In Power System

You can quickly restore power supply and isolate the fault condition is scene accurate fault location and fast, with a very critical significance to guarantee the safe and stable operation of the distribution network. For a long time, the fault location of distribution network single-phase grounding is a topic that has been our industry is difficult to solve the problem. This article through the analysis and Research on this topic home and abroad literature, focusing on the online monitoring and grounding fault makes a deep research on the calculation of these two aspects.Through the analysis of single-phase ground fault on the research of fault features of distribution network, this thesis quoted joined the excitation signal diagnosis method, calculate the corresponding positioning fault segment of the fault point. In the beginning, the three-phase symmetrical transposed line by numerical calculation and repeated a lot of formulas for fault location, and fault analysis of function related spectrum phase, amplitude and frequency characteristics in the frequency domain, at the same time put forward reasonable judgment according to the corresponding. After a large amount of measured data and simulation show that this method for straight line localization grounding fault is very effective, but also suitable for tree branch distribution network. Of course, in actual use also appear many problems need to be further discussion of its. Secondly, this paper is based on the radial feeders at any one point ground fault occurred when the in-depth analysis and research, established the fault function and fault location of single-phase short circuit judge in distribution line. The fault branch discrimination by the tree network with single end fault location information, and the transition resistance value operation. Many fault location data calculated from the simulation, the method is very effective in the grounding fault location. In view of this thesis also made for application of computer program location method of single-phase grounding fault. This approach is not only subjected to load parameters is not influenced by the transition resistance value influence. Terminal measurement information is used to complete the initial fault feeder, ranging device has the advantages of low cost, no communication or the requirements of real-time monitor, showed a good momentum of development.To complete the ground fault automatic detection function, isolation function, which is the extension direction of feeder automation distribution network. After analysis of change of voltage and current in single phase to ground fault in feeder values derived rules, and research and analysis, this paper put forward the implementation of intelligent positioning method of feeder terminal FTU. This method will feeder voltage changes before and after volume as the important basis for judging the fault point, in order to carry out monitoring and automatic positioning, and fast fault isolation, power is restored to normal section. Compared with current methods, this method is more reliable, and are not affected by the grounding line, can be used for complex network structure.