Fault location method based on single-ended ranging

Abstract

The invention provides a fault location method based on single-terminal location. The method is characterized by using a transmission line travelling wave fault location device to measure the power frequency quantity of a home terminal bus of a transmission line when short circuit happens to the transmission line, determining the fault point range by an impedance method and estimating the transition resistance; then analyzing the transient voltage / current travelling waves through wavelet transform and adopting a single-terminal travelling wave method combined with the length of line to directly compute the positions of the fault points if the faults are judged to be common short circuit faults; and adopting a transmission line single-terminal fault location method combining the impedance method and the travelling wave method to compute the positions of the fault points if the faults are judged to be special short circuit faults. The method has the following beneficial effects: the accuracy of fault location is ensured by utilizing the single-terminal travelling wave method, can be within 500m and is not affected by such factors as the length of line and the like; and the method can adapt to fault location under the condition of different fault types and is basically not affected by such factors as the transition resistance, the line structure, the system operation mode and the like.

Description

Technical field: [0001] The invention relates to the field of power system automation, in particular to a fault location method based on single-end ranging. Background technique: [0002] After the transmission line fails, even if the reclosure is successful, line inspectors are required to find the fault point, and judge whether the line can continue to operate or whether it needs to be powered off for maintenance according to the degree of damage caused by the fault, so as to eliminate hidden dangers. Therefore, quickly finding the fault point after the line fault becomes a key technology to ensure the safe and stable operation of the power grid. Among them, in 110kV and above power grids, transmission line fault location devices are widely used in power stations where the neutral point is directly grounded, which fully demonstrates its importance to the safe, stable and reliable operation of the power system. [0003] With the development of smart grid construction, the ...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems existing in the operation of existing distance measuring devices and the problem that intelligent substations cannot realize double-terminal ranging at the present stage, it is necessary to develop a reliable and effective single-ended traveling wave ranging algorithm, while the existing single-ended impedance method or Both single-ended traveling wave methods have problems with reliability or ranging accuracy

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