JPH0215233Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a high-pressure air switch with an abnormal voltage suppressing element.

Purpose Currently, the most common failure of high-voltage air switches used in power distribution lines is insulation breakdown due to the penetration of shock wave voltage from lightning strikes.

The purpose of this invention is to provide a high-voltage aerial switch with an abnormal voltage suppressing element that can prevent damage to the high-voltage aerial switch due to lightning strikes on power distribution lines.

Embodiment Hereinafter, an embodiment in which this invention is embodied in a vertical high-pressure air switch will be described with reference to FIGS. 1 and 2.

A support 15 serving as a ground portion is attached to the utility pole 13 by two mounting bands 14, and the support 15
There are three main body insulators 1 at predetermined intervals in the vertical direction.
6 is fixed. Opposing the open lower surface of each main body insulator 16, three movable insulators 18 that can be rotated by rotating the handle 17 are attached to the column 15, and the movable insulators 18 are indicated by solid lines in FIG. The distribution line is opened and closed by entering the main insulator 16 as shown and separating from the main insulator 16 as shown by the broken line.

Wire connection terminals 3, which are live parts covered with insulation by terminal covers 4, are provided on both sides of each main body insulator 16. A water drain hole 4a is provided in the lower surface of the terminal cover 4. Ground electrodes 6a of six non-linear resistance elements 6 are fixed to the pillar 15,
The discharge electrode 6b of the non-linear resistance element 6 passes through the drain hole 4a of the terminal cover 4 to the wire connection terminal 3.
The discharging electrode 3a and the discharging electrode 6b are arranged opposite each other at a predetermined distance, and the gap between the discharging electrodes 3a and 6b is defined as a discharging gap G. And both discharge electrodes 3a, 6b
A sparkling horn 7 is constituted by a discharge gap G and a discharge gap G.

Now, the shock wave voltage generated in the power distribution line due to the lightning attack advances toward the wire connection terminal 3, and the flashing horn 7 is flashed. Due to this flashover, a flashover (discharge) current flows to the ground through the distribution line → wire connection terminal 3 → flashover horn 7 → nonlinear resistance element 6 → ground electrode 6a → pillar 15. The non-linear resistance element 6 has a characteristic that when a flashover current flows, the voltage between the discharge electrode 6b and the ground electrode 6a is kept almost constant, and the potential of the wire connection terminal 3 is a nearly constant voltage lower than the shock wave voltage. becomes. This constant voltage does not cause dielectric breakdown inside the air switch, and the high-pressure air switch will not be damaged by a lightning strike on the distribution line.

The voltage-current characteristic of the nonlinear resistance element 6 is expressed as I=kV a (I: current, V: voltage, k and a: constants), and in the case of zinc oxide, the value of constant a is different from that of silicon carbide (SiC), etc. It is extremely large compared to , and the change in current with respect to voltage change is large. Therefore, it has an excellent abnormal voltage suppressing effect. Furthermore, the instantaneous power withstand capacity during abnormal voltage suppression is larger than that of other semiconductor nonlinear resistance elements, and because it is a semiconductor element, it has excellent high-speed response.

As described above, the abnormal voltage generated in the power distribution line by the shunting horn 7 and the nonlinear resistance element 6 is suppressed.

In addition, the wire connection terminal 3 and the nonlinear resistance element 6
However, since it has a function as the discharge electrodes 3a and 6b of the discharge horn 7, there is no need to separately provide a discharge electrode for the discharge horn 7, and the structure is simple.

Furthermore, since the drain hole 4a of the terminal cover 4 is used, there is no need to separately provide a dedicated discharge hole in the terminal cover 4, and the work of retrofitting the nonlinear resistance element 6 can be easily performed.

Effects As detailed above, this invention has a drain hole in the lower part of the terminal cover located below the connection terminal, and an abnormal voltage suppression function provided outside the switch at a position below the connection terminal. By arranging a non-linear resistance element such as zinc oxide having There is no need to separately provide a dedicated discharge hole, the discharge gap can be easily formed, and the efficiency of the installation work can be improved. This has a great effect because the nonlinear resistance element can be easily attached using the terminal cover of the existing high-pressure air switch as it is.

[Brief explanation of the drawing]

FIGS. 1 and 2 show an embodiment of this invention, with FIG. 1 being a front view and FIG. 2 being a side view. 3... Wire connection terminal, 4... Terminal cover, 4a
...Drain hole, 6...Non-linear resistance element, 6a...
Ground electrode, 6b...discharge electrode, 7...flash horn, 15...post.

Claims (1)

[Scope of Claim for Utility Model Registration] Connecting terminals connected to fixed electrodes inside the main insulator are protruded from both sides of the main insulator, and the fixed electrodes are covered with terminal covers attached to the sides of the main insulator. In the high-pressure air switch, a water drain hole is provided in the lower part of the terminal cover located below the connection terminal, and an abnormal voltage suppressing function is provided at a position below the connection terminal outside the switch. A high voltage with abnormal voltage suppressing element, characterized in that a non-linear resistance element such as zinc oxide is arranged, and the non-linear resistance element and the connection terminal are opposed to each other via a discharge gap including a water drain hole of the terminal cover. Air switch.