Transmission line fault detection method based on two-dimensional space of current-current derivative

Abstract

The invention discloses a transmission line fault detection method based on the current-current derivative two-dimensional space. Collect the current on both sides of the transmission line, start the fault detection according to the conventional sudden change current, calculate the current derivative at each moment of the quarter cycle after the original sudden change time, count the number of current derivatives greater than 0 or less than 0, and determine the two sides of the line During this period of time, the current derivative is in the quadrant of the current-current derivative two-dimensional space, check and determine the real sudden change time t 1 and the real end time t of the quarter period 2 , for t 1 to t 2 The current derivative at each moment is calculated to obtain the quadrant satisfaction rate on both sides, and the quadrant of the current derivative in the first quarter cycle after the sudden change of the current on both sides is accurately judged, and then the fault condition of the line is detected. The invention can accurately detect line faults under various fault scenarios, is not affected by transition resistance, does not require high synchronization of currents on both sides, and has strong anti-synchronization capability.

Description

technical field [0001] The invention relates to the technical field of fault detection of power grid transmission lines. Background technique [0002] At present, most of the existing protection algorithms use the Fourier algorithm, and the current signals of each phase are used for current protection, and can participate in the calculation of the directional element, but the current protection is easily affected by the transition resistance, and the directional element has a certain dead zone, which is affected by The influence of signal synchronization on both sides. [0003] Aiming at the shortcomings of existing current protection algorithms, the present invention proposes a transmission line fault detection method based on the current-current derivative two-dimensional space. Its advantage is that by using the current sampling values ​​of each phase on both sides of the line, the fault line can be accurately detected about 1 / 4 cycle after the fault occurs, and the amou...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a transmission line fault detection method based on the current-current derivative two-dimensional space, which can effectively solve the problem of fault detection of transmission lines in the case of high-resistance grounding faults, information asynchronous, etc.

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