Lightning protection insulator operation life evaluation method for power transmission line without ground wire

Abstract

The invention provides a lightning protection insulator operation life evaluation method for a ground wire cancelling power transmission line. The method comprises the steps of obtaining lightning distribution parameters, a tower structure, wire parameters, environmental meteorological parameters and lightning protection insulator technical parameters of a to-be-cancelled ground wire power transmission line; calculating the energy consumed by the lightning protection insulator when the tower is directly struck by lightning every year; calculating energy consumed by the anti-thunder insulator when thunder and lightning directly strike a lead of the line every year; calculating lightning energy consumed by the lightning protection insulator when the line suffers from inductive lightning stroke every year; calculating the total lightning impulse discharge energy averagely consumed by the lightning protection insulator every year; carrying out continuous lightning current impulse tests on the whole lightning protection insulator to obtain total lightning impulse discharge energy owned by the lightning protection insulator; and calculating the expected natural operation life N of the lightning protection insulator. The method can be used for calculating and evaluating the service life of the anti-thunder insulator of the ground wire power transmission line, and provides an accurate criterion for replacement of the anti-thunder insulator.

Description

technical field [0001] The invention belongs to the technical field of state evaluation of transmission line equipment, and in particular relates to a method for evaluating the service life of lightning protection insulators suitable for canceling ground wire transmission lines. The method can be used for lightning protection for canceling ground wire transmission lines in ice-covered areas Calculate and evaluate the expected operating life of the insulator, and provide a criterion for whether to replace a new lightning protection insulator. Background technique [0002] High-voltage overhead transmission lines are vulnerable to the threat of icing disasters when passing through high-altitude mountainous areas with complex terrain. Compared with transmission wires, the ground wires of overhead lines have no current Joule heating effect and are located above the wires. Accidents such as broken ground wires and ground wire discharges caused by icing cause power interruptions. ...

AI Technical Summary

Problems solved by technology

However, after the ground wire is removed from the transmission line, the lightning current borne by the lightning protection insulator is mainly a large-scale direct lightning strike (generally ≥ 40kA), and the fault type is mainly manifested as thermal breakdown caused by the combined effect of lightning impulse current and residual voltage (lightning energy) Or shattering burst, at this time, if the lightning impulse current or charge is still used as the criterion for calculating the life of lightning protection insulators, it is obviously inconsistent with the actual situation

And under the condition of canceling the ground wire, due to the change of the structural parameters of the "tower-line" system, the calculation method of the lightning current and residual voltage of the high-current lightning protection insulator during a lightning strike is also different from that before the ground wire is cancelled.

To sum up, the existing calculation method of arrester operating life is not suitable for the life evaluation of lightning protection equipment under the condition of canceling the ground wire

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