Electric transmission line single-terminal positioning method based on fault transient state and steady-state signal wave velocity difference

Abstract

The invention discloses an electric transmission line single-terminal positioning method based on a fault transient state and a steady-state signal wave velocity difference. According to different fault types, different phases are selected as datum phases, phase-mode transformation is carried out on a transmission line fault current traveling wave signal and the fault current traveling wave mode signal for fault positioning is obtained; continuous wavelet transformation is carried out on the mode signal, the mode maximum value and the time corresponding to the mode maximum value of a wave tip wavelet transformation coefficient of a transient state initial traveling wave are extracted and the mode maximum value and the time corresponding to the mode maximum value of a wavelet transform coefficient on the scale corresponding to a steady-state signal are extracted. According to the propagation velocity difference of the mode signal and a transient state signal, the fault distance of an electric transmission line is comprehensively calculated. By means of the propagation velocity difference between the fault steady-state signal and the transient-state signal, the propagation velocity of the corresponding frequency is accurately determined according to the wavelet transform, and therefore the fault distance of the electric transmission line can be accurately calculated.

Description

technical field [0001] The invention relates to a single-end positioning method for transmission line faults in a power system. Background technique [0002] The traveling wave fault location method has the advantages of positioning accuracy, high reliability, good stability, and little influence by fault resistance. At present, the traveling wave fault location methods include the fault traveling wave location method based on double-ended electrical quantities and the fault traveling wave location method based on single-ended quantities. Among them, the fault traveling wave location method based on double-ended electrical quantity needs to use double-ended data, so a time synchronization device needs to be added, which not only increases the economic cost of fault location, but also reduces the reliability of the positioning system; while the current method based on single-ended Quantitative fault traveling wave location methods need to use the arrival time of the initial ...

AI Technical Summary

Problems solved by technology

Among them, the fault traveling wave location method based on double-ended electrical quantity needs to use double-ended data, so a time synchronization device needs to be added, which not only increases the economic cost of fault location, but also reduces the reliability of the positioning system; while the current method based on single-ended Quantitative fault traveling wave location methods need to use the arrival time of the initial traveling wave and reflected wave to determine the specific fault, so the accuracy of its location is affected by the detection of the arrival time of the traveling wave head and the propagation speed of the traveling wave. The identification of is the main factor restricting the reliability of the single-ended traveling wave positioning method

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