Method for computing lightning induced voltages of insulators of low-voltage lines when earth is struck by lightning

Abstract

The invention discloses a method for computing lightning induced voltages of insulators of low-voltage lines when the earth is struck by lightning. The method for computing the voltages includes respectively computing lightning induced voltages of two ends of each insulator to acquire potential difference between two points of the insulator. The potential difference between the two points of each insulator is the lightning induced voltage born by the insulator. The potential difference between the two points of each insulator is computed by means of computing of surrounding space electromagnetic fields of lightning current channels, computing lightning induced voltages of overhead distribution lines, computing induced lightning voltages of towers and subtracting the computed induced lightning voltages of the towers from the computed lightning induced voltages of the overhead distribution lines so as to compute the lightning induced voltages and composite voltages of the insulators. The method has the advantages that the method is a complete theoretical method for computing the lightning induced voltages of the insulators of the low-voltage lines when the earth is struck by the lightning, accordingly, an existing gap in theoretical research is filled, a reference basis can be provided for selecting models of insulators of low-voltage distribution lines, and lightning protection levels of the lines can be improved.

Description

technical field [0001] The invention relates to a method for calculating lightning induced voltage of low-voltage line insulators when lightning strikes the ground, and belongs to the field of lightning protection design and insulator type selection of low-voltage distribution lines. Background technique [0002] Insulators play an important role in overhead transmission and distribution lines, and are used to support and fix live wires, and to provide sufficient distance and insulation between live wires or wires and the earth. One end of the insulator is connected to the running phase conductor, and the other end is connected to the tower. Under normal circumstances, the total voltage that the insulator bears is roughly equal to the operating voltage of the phase conductor. When lightning strikes the ground near the tower, the powerful lightning transient electromagnetic pulse (LEMP) will induce voltage on the transmission and distribution lines and the metal tower, there...

AI Technical Summary

Problems solved by technology

However, according to the current literature search, there is basically no analysis and calculation of the induced lightning voltage of the insulator when the lightning strikes the ground.

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