Lightning shielding failure risk assessment method for a power transmission line based on three-dimensional laser point cloud data

A lightning shielding failure risk assessment method for a power transmission line based on three-dimensional laser point cloud, comprising:

• S1:
• reclassifying three-dimensional laser point cloud data of a power transmission corridor and preprocessing the three-dimensional laser point cloud data and a three-dimensional laser point coordinate system;
• S2:
• acquiring lightning activity parameters for the power transmission corridor, wherein the lightning activity parameters comprise a lightning strike density, a lightning current probability distribution function, and a lightning incidence angle probability distribution function;
• S3:
• determining a wire point cloud striking distance, a ground wire point cloud striking distance, and a ground point cloud striking distance based on a magnitude of a given lightning current amplitude;
• S4:
• plotting a three-dimensional wire point cloud shielding arc surface, a three-dimensional ground wire point cloud shielding arc surface, and a three-dimensional ground shielding arc surface in the preprocessed three-dimensional laser point coordinate system by using the reclassified and preprocessed three-dimensional laser point cloud data, the calculated wire point cloud striking distance, the calculated ground wire point cloud striking distance, and the calculated ground point cloud striking distance;
• S5:
• performing orthogonal projection of the plotted three-dimensional wire point cloud shielding arc surface, orthogonal projection of the plotted three-dimensional ground wire point cloud shielding arc surface, and orthogonal projection of the plotted three-dimensional ground point cloud shielding arc surface according to different lightning incidence angles to obtain two-dimensional wire point cloud exposed arc surfaces, two-dimensional ground wire point cloud exposed arc surfaces, and two-dimensional ground point cloud exposed arc surfaces respectively and determining areas of the two-dimensional wire point cloud exposed arc surfaces, areas of the two-dimensional ground wire point cloud exposed arc surfaces, and areas of the two-dimensional ground point cloud exposed arc surfaces;
• and
• S6:
• looping through S3 to S5 to calculate the areas of the two-dimensional wire point cloud exposed arc surfaces, the areas of the two-dimensional ground wire point cloud exposed arc surfaces, and the areas of the two-dimensional ground point cloud exposed arc surfaces at different lightning incidence angles and different lightning current amplitudes, and determining a line trip rate based on the lightning strike density, the lightning incidence angle probability distribution function, and the lightning current probability distribution function;
• wherein the step S5 comprises:
• multiplying each point on a three-dimensional shielding arc surface by the following coordinate transformation matrix Ty(φ)
• T
• y
• (
• ϕ
• )
• =
• [
• 1
• 0
• 0
• 0
• cos
• ⁡
• (
• ϕ
• )
• -
• s
• ⁢
• in
• (
• ϕ
• )
• 0
• sin
• ⁡
• (
• ϕ
• )
• cos
• ⁢
• (
• ϕ
• )
• ]
• ;
• performing orthogonal projection along a Z-axis direction on the three-dimensional shielding arc surface rotated counterclockwise by an angle φalong a Y-axis to obtain a two-dimensional shielding arc surface, wherein a scale factor of the orthogonal projection is M;
• and
• counting a number of exposed wire arc surfaces and multiplying the number of exposed wire arc surfaces by the projection scale factor M to obtain areas of the exposed wire arc surfaces at different lightning incidence angles by the following formula, wherein the areas of the exposed wire arc surfaces at different lightning incidence angles are in units of km2:
• Sc(I,φ)=count(p.color=red)×M , wherein Sc denotes the areas of the exposed wire arc surfaces at different lightning incidence angles.