Electric transmission line fault detection method based on voltage traveling wave prediction

Abstract

The invention belongs to the technical field of power system relay protection, and discloses an electric transmission line fault detection method based on voltage traveling wave prediction. The method comprises the following steps of: firstly, acquiring voltage and current traveling wave components at the two ends of an electric transmission line at each sampling moment in real time, and performing phase-mode transformation to obtain 0, alpha and beta mode voltage and current traveling wave components on the two end sides of the electric transmission line at each sampling moment; secondly, computing a voltage traveling wave prediction component of an electric transmission line end at a moment t; thirdly, computing a three-phase voltage traveling wave prediction component at each sampling moment according to the prediction component; and lastly, subtracting the three-phase voltage traveling wave prediction component at the end of the electric transmission line acquired in real time respectively, obtaining an absolute value, and performing setting judgment according to the absolute value. According to the method, the voltage traveling wave component at each sampling moment is not required to be evaluated through interpolation operation, so that operand is reduced, a fault detection function can be completed in a short data window of a quarter of period, and protection action speed is high; and the method is suitable for performing traveling wave protection in the entire transient fault process of electric transmission lines of various voltage classes.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a transmission line fault detection method based on voltage traveling wave prediction. Background technique [0002] Because it is not affected by the system operation mode and grid structure and has a natural phase selection function, the current differential protection has always been the main protection of various voltage levels of transmission lines. In the 220kV and below voltage level transmission lines, because the distributed capacitance current along the transmission line is very small, the distributed capacitance has little influence on the operation performance of the current differential protection. However, the voltage and current transmission of EHV / UHV AC transmission lines has an obvious wave process, and the distributed capacitance current along the line is very large. The protection is faced with the large starting current of the ...

AI Technical Summary

Problems solved by technology

Some of the transmission line traveling wave differential protection methods even require wavelet transform, which requires a large data window, which prolongs the time for protection to detect faults, and cannot meet the requirements of relay protection for quick action.

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