Dynamic-real-time-parameter-based along-line voltage cross correction fault ranging method of T type line

Abstract

The invention relates to a dynamic-real-time-parameter-based along-line voltage cross correction fault ranging method of a T type line. On the basis of electrical information of a T type line under the normal operating condition, real-time parameters of three-terminal lines are calculated dynamically in real time and calculation errors of the real-time parameters of the lines are corrected based on a genetic algorithm; after a fault occurs at one line, voltages of T nodes are calculated respectively based on a line distribution parameter line model under the modified parameters and a fault branch is determined by voltage comparison; two non-fault branches are equivalent to T terminals and form, together with one end of the fault branch, a two-terminal power transmission line model; and then two straight lines are formed by measuring voltages at two sides and calculating opposite-side voltages and an intersection point is calculated based on intersection of the straight lines, so that afault ranging method is formed. Therefore, the line parameter error can be adjusted dynamically in real time; the fault ranging precision is improved; and the engineering practicability is high.

Description

technical field [0001] The invention relates to a fault distance measurement method for a T-shaped transmission line, in particular to a fault distance measurement method based on a dynamic real-time parameter cross-correction fault distance along a T-shaped line. Background technique [0002] With the development of the power system, when limited by the power supply radius, corridors, etc., T-shaped transmission lines are often used for power transmission. When a line fault occurs, accurate fault location plays an important role in the safety, stability and economic operation of the power system (Lin Fuhong, Wang Zengping. The principle of double-circuit line fault location using the same direction positive sequence fundamental frequency components[J]. China Chinese Journal of Electrical Engineering, 2011,31(4):93-98.). At present, the distance measurement of transmission lines often uses electrical parameters of line power frequency, but in actual operation, electrical pa...

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Problems solved by technology

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention proposes a method based on dynamic real-time parameters along the T-type line voltage cross correction fault distance measurement method, which mainly solves the following problems: 1), solves the problem that the transmission line parameters in actual engineering are easy to change However, the problem of affecting the distance measurement accuracy can realize dynamic real-time correction of transmission line parameters; 2), overcome the problem of dead zone of T node identification in T-shaped lines, and ensure that no matter the fault occurs in a branch or near the T node, it can be correctly identified ; 3), ensure high-precision distance measurement for line faults, and solve the problems of complex calculation and many iterations required by many existing distance measurement schemes

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