Detailed terrain data-based transmission line failure-shielding and lightning-protection performance evaluation method

Abstract

The invention discloses a detailed terrain data-based transmission line failure-shielding and lightning-protection performance evaluation method. The method comprises the following steps of: acquiring statistical lightning data of a line corridor in a specified time period by a lightning parameter statistical method by adopting line basic information, line geographic information, line structural characteristics and line insulation characteristics; scanning a three-dimensional coordinate of a transmission line corridor by using geographic information system (GIS) software; determining the landscape along a line and a ground angle according to the three-dimensional coordinate in the direction vertical to the line corridor; determining wire-to-ground height variation caused by surface undulation according to the three-dimensional coordinate in the direction along the line, and acquiring detailed terrain data along the line by three-dimensional GIS scanning; calculating the shielding failure trip-out rate of each base tower according to the detailed terrain data extracted based on the GIS scanning; and acquiring real line failure-shielding and lightning-protection evaluation data in the specified time period by comparing a design value, a specified value or an operation experience value of the line failure shielding trip-out rate with a reference value of the line failure shielding trip-out rate. Therefore, the line failure-shielding and lightning-protection performance evaluation is realized.

Description

technical field [0001] The invention relates to the field of power grid lightning protection, in particular to a performance evaluation method for shielding lightning protection of transmission lines based on fine terrain data, which is suitable for evaluating the shielding lightning protection performance of high-voltage, ultra-high voltage and ultra-high voltage overhead transmission lines in power systems. Background technique [0002] China's existing power grid lightning protection system is mainly composed of the external defense of the transmission line and the core defense of the substation. According to relevant information, because the transmission line is located in the wilderness and stretches for thousands of miles, it is the ground facility that is most likely to be struck by lightning. Although the relevant departments A variety of lightning protection technical measures have been taken, but line tripping caused by lightning strikes still ranks first among all ...

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Problems solved by technology

At present, landform extraction is usually determined by manual estimation by power grid operators; because the on-site measurement of ground inclination is very difficult, the current extraction of ground inclination is also basically based on manual estimation, and the estimated results are very different from the actual situation; the conductors caused by ground undulations The change of ground altitude is basically not considered in the current shielding lightning protection calculation, but for mountainous large-span towers, due to large fluctuations in the ground, especially across large valley areas, the ground altitude changes greatly, resulting in The height of the wire in the center of the span to the ground is significantly higher than that at the tower, and the lightning shielding effect of the ground on the wire is significantly reduced. At this time, only the height of the wire at the tower is used to evaluate the lightning protection performance of the tower, which obviously does not meet the conditions. It will cause the calculated value of the shielding trip rate to be significantly smaller, resulting in the inability to accurately reflect the impact of terrain on the performance of shielding lightning protection

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