A method for checking the lightning shielding performance of lines

Abstract

The invention provides a lightning shielding performance checking method, which divides the span of each line along the entire line into a specified number of sections, and uses a computer to check the relative geometric positions of the ground wires along the line, lightning parameters, topography along the line, and operating voltage of the line in each section. According to the sorting results, the lightning tripping rate calculation method is used to calculate the shielding tripping rate of the line and each span, and according to the relative deviation of the lightning shielding tripping rate of each span to accurately locate the lightning shielding weak point of the line. The present invention checks the lightning shielding performance of the transmission line and takes into account the influence of the terrain condition change of each section in the line span, the relative geometric position change of the ground wire and the phase change of the working voltage of the line, and the evaluation result of the shielding performance of the transmission line is more accurate. Accurate, more authentic and reliable.

Description

technical field [0001] The invention relates to the field of power grid lightning protection, in particular to a lightning shielding performance checking method for a line, which is suitable for evaluating the lightning shielding performance of an overhead power transmission line with a voltage level of 500kV and above in a power system. Background technique [0002] The number of lightning strike trips of overhead transmission lines with a voltage level of 500kV and above in the power system accounts for a relatively high proportion of the total trips. Especially for UHV transmission lines, the probability of other types of faults is very small, and the main fault is lightning shielding trips. The lightning tripping rate of UHV lines in the former Soviet Union accounted for 84% of the total tripping times. From 1993 to September 2007, 1000kV lines in Japan had a total of 68 trips, of which 67 were lightning trips, accounting for 98% of the total trips. Therefore, the verif...

AI Technical Summary

Problems solved by technology

[0005] 1) It cannot reflect the influence of terrain condition changes between the two towers (that is, within a span) on the shielding trip rate;

[0006] 2) It cannot reflect the influence of the change of the relative geometric position along the line between the two towers (that is, within a span) on the shielding tripping rate;

[0007] 3) The influence of line operating voltage on shielding tripping rate is not considered

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