A method for suppressing three-phase unbalance of multi-circuit transmission lines on the same tower

Abstract

The invention relates to a three-phase unbalance restraining method of a same-tower multi-circuit transmission line. A line impedance matrix is worked out according to the conductor type, the conductor division method, the rod tower type and the connecting method of a lightning conductor; the current and voltage equation of the transmission line is provided according to the conditions of the transmission line, the negative sequence and zero sequence current expressions each time are obtained through matrix transformation and conversion of symmetrical components; negative sequence and zero sequence current sensitive impedance parameters are found according to the obtained negative sequence and zero sequence current expressions; compensation capacitors are configured according to the obtained sensitive impedance parameters, the sensitive impedance parameters are compensated for to the minimum in order to restrain negative sequence and zero sequence current. By compensating for the negative sequence and zero sequence current sensitive impedance parameters, adjustment of line parameters is achieved, the unbalance problem of the same-tower multi-circuit transmission line can be effectively restrained, and theoretic basis and guidance for safe, stable and economical operation of the same-tower multi-circuit transmission line are provided.

Description

technical field [0001] The invention relates to the technical field of multi-circuit power transmission on the same tower, in particular to a method for suppressing three-phase unbalance of multi-circuit power transmission lines on the same tower. Background technique [0002] The multi-circuit power transmission technology on the same tower refers to a new type of power transmission technology that uses the same tower to erect two or more power transmission lines for power transmission. It has many advantages such as saving line corridors, increasing transmission capacity, and reducing power construction costs. It can well adapt to Due to the rapid economic development, the tension of transmission line corridors and the increase in power demand have been widely used throughout the country, and significant economic benefits have been achieved. [0003] Due to the compact structure of the multi-circuit transmission line on the same tower, the arrangement of the lines is compl...

AI Technical Summary

Problems solved by technology

[0005] The present invention is aimed at the problem that the unbalance degree of the transmission line cannot meet the requirements by using the optimal phase sequence arrangement of the line, and proposes a three-phase unbalance suppression method for multi-circuit transmission lines on the same tower. Compensate the asymmetrical parameters to realize the adjustment of the line parameters, so that the negative sequence and zero sequence currents of the line can be minimized, fundamentally suppress the unbalance problem, and ensure the safe, stable and economical operation of the multi-circuit transmission line on the same tower

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