The Method of Protecting against Lightning Disconnection of Insulated Overhead Lines

Abstract

The present invention discloses a lightning-caused breakage preventing method for an insulated overhead line, comprising the steps of: stripping and cutting an insulated conductor at the position of an insulator to obtain a section of bare section; parallelly and fixedly arranging a bare conductor of which the length is greater than the length of the bare section to the insulated conductor at the position of the insulator, wherein one end of the bare conductor is bound and fixedly connected with the bare section; and performing sealing for the connecting position between the bare conductor and the bare section. According to the lightning-caused breakage preventing method, one section of the bare conductor is installed on the insulated conductor, one end of the bare conductor is bound and fixedly connected with a metal wire in the insulated conductor, then sealing is performed, when a direct lightning or lightning induced voltage acts on the bare conductor to cause an insulator arc-over, continuous power-frequency short-circuit current arcs move along the axial direction of the bare conductor under the effect of electrodynamic force, thereby greatly reducing the probability of severe burn of the insulated conductor, and greatly reducing the cost, in addition, a simple structure and convenient operation are achieved, and operating efficiency is improved.

Description

Technical field [0001] The invention relates to a power distribution overhead line, in particular to a lightning protection disconnection method for an overhead insulated line. Background technique [0002] In the 10kV insulated overhead line, the disconnection of the insulated wire caused by lightning strikes often occurs. The reason is that the lightning overvoltage first breaks down the wire insulation and then causes the insulator flashover. The broken down insulation layer is in the shape of a pinhole, and the power frequency is connected. The short-circuit current arc is blocked by the surrounding insulating layer, and the arc root can only burn at the pinhole, and the wire will be burned in a very short time. In the prior art, there are three general methods to solve the above problems: The first is to prevent phase-to-phase insulation flashover during lightning strikes by improving the insulation level of the line, installing lightning arresters, installing overhead groun...

AI Technical Summary

Problems solved by technology

[0002] In 10kV insulated overhead lines, lightning strikes on insulated wires often cause disconnection. The reason is that the lightning overvoltage first breaks down the insulation of the wires and then causes the insulator to flash over. The short-circuit current arc is hindered by the surrounding insulating layer, and the arc root can only burn at the pinhole, and the wire will be burned in a very short time; and in the prior art, there are three general methods to solve the above problems: The first is to prevent phase-to-phase insulation flashover during lightning strikes, which is achieved by improving the insulation level of the line, installing lightning arresters, installing overhead ground wires, installing shielding wires, etc.; the second is to prevent line flashover from igniting power frequency freewheeling. It is realized by installing the outer gap arrester, the inner gap arrester, and the long flashover path arrester, etc. The third is to prevent the thermal effect of power frequency continuous flow and the electric (magnetic) dynamic action from causing disconnection measures, by installing arc-resistant puncture fittings, etc. The main disadvantages of the first two methods are that the construction cost and later maintenance cost are high, and the economic cost is relatively high, while the arc-resistant puncture fittings generally used in the third method are easy to damage the metal wire in the insulated wire and cause strand breakage, and the insulated wire The sealing performance is not good, and the cost is relatively high

Images