Fault diagnosis comprehensive positioning method for intelligent distribution network

Abstract

The invention discloses a fault diagnosis comprehensive positioning method for an intelligent distribution network, and belongs to the field of fault monitoring. Based on a fault indicator, a wirelesscommunication technology and a ground fault line selection technology, the method comprises the following steps: monitoring zero-sequence voltage of a transformer neutral point in real time, startingzero-sequence fault diagnosis when detecting that a zero-sequence voltage change value exceeds a preset value, and identifying whether the zero-sequence voltage change value is a single-phase grounding fault; if the zero-sequence voltage change value is single-phase grounding fault, performing grounding line selection through a fault diagnosis device in a station, and positioning the grounding fault on a certain phase of a certain line; when the single-phase earth fault is judged to be a stable fault, recalling the real-time current data of the fault indicators on the fault phase line, comparing the signals collected by the fault indicators, comparing the difference of the real-time current data before and after a fault point, judging the two fault indicators with abrupt changes, and thendetermining the specific section of the fault. The method can be widely applied to the field of power distribution network operation fault monitoring and positioning.

Description

technical field [0001] The invention belongs to the field of fault monitoring and diagnosis, and in particular relates to a fault diagnosis and positioning method for distribution network. Background technique [0002] With the rapid development of contemporary economy, society's demand for electricity is increasing day by day, and the density of distribution network is also increasing day by day. [0003] The realization of distribution automation is a key means to ensure the reliability of power supply, realize the economic operation of the power grid, and improve the efficiency of the power grid. It is also an important factor related to the level of social production and the quality of life of the people. [0004] At present, most of the neutral points of my country's 3-66kV distribution network are grounded with small currents, so the distribution network can be called a small current grounded system or a neutral point not directly grounded system, which includes the ne...

AI Technical Summary

Problems solved by technology

Since the 1980s, with the continuous maturity of microcomputer protection technology, different manufacturers have developed a variety of online automatic line selection devices and put them into use. However, from the opinions returned by users, the reliability of line selection is not high, and the effect is not good. Not good, it fully reflects that the line selection technology is not very mature

[0009] As the current key research direction, the fault section positioning technology also has many problems, such as unreliable positioning principles, inability to accurately synchronize signals from different monitoring points, and difficulty in obtaining fault signals.

In addition, most of the current methods are still in the theoretical research stage, and there are few technologies that are actually applied in the field. Therefore, the small current ground fault location technology has not made a substantial breakthrough.

[0010] The small current grounding method increases the complexity of the distribution network structure, making fault line selection and location a recognized problem

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