Thunderbolt attack distance of electric power transmission line lightning shielding failure based on electric geometric model and method for confirming the same

Abstract

The invention relates to a lightning striking distance based on the shielding failure of the power transmission line of the electro-geometric mode and a determining method thereof, and belongs to the lightningproof technical field of high-voltage transmission lines. The lightning striking distance D sv (I, h, V) provided by the invention is described as follows: D sv (I, h, V) is equal to (-0.004I <2> added with 0.221) h <0.625> <e> <Bv>; wherein, I is lightning current, and the unit thereof is KA; h is the height of a horizontal lead; V is the voltage of the horizontal lead. The determining method of the lightning striking distance includes that the quadratic polynomial of each height of the horizontal lead can be estimated; and the equation of the lightning striking distance D (I, h) related to the height of the horizontal lead can be obtained; when the voltage of the horizontal lead is between minor 1MV and plus 1MV, and when the lightning current is within 200Ka, the correction factor of lightning striking distances under different voltages, kv is equal to e <Bv>, can be achieved by the analog simulation, and finally, the lightning striking distance D sv (I, h, V) can be obtained. The lighting striking distance determined by the method provided by the invention can well meet the physical reality and can reduce the jumping rate of the lightning striking of the power transmission line, thereby guaranteeing the safe operation of power transmission lines.

Description

technical field [0001] The invention belongs to the technical field of lightning protection for high-voltage transmission lines, in particular to the lightning protection design of high-voltage transmission towers Background technique [0002] With the development of the economy, the requirements for the reliability of the power system are getting higher and higher. Statistics from China and other countries show that lightning strikes are the most important factor affecting the reliability of transmission lines. According to operating experience, shielding problems on EHV and UHV transmission lines are the main cause of power failures. Therefore, how to calculate more accurately The shielding of high voltage transmission lines is a new research topic. [0003] The Electrical Geometric Model (EGM) was proposed in 1945. In 1950, EGM was first used to analyze the shielding problem of 345kV transmission lines, and obtained the shielding rate of transmission lines, so as to guid...

AI Technical Summary

Problems solved by technology

Actual operation experience shows that if the high-voltage line design (especially UHV DC line) is carried out based on the lightning strike distance obtained by the traditional method, the lightning trip rate of the line is relatively high, which has a great impact on the line operation