JPS6398922A - Arresting insulator for transmission line - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Purpose of the Invention (Industrial Field of Application) The present invention provides a method for detecting abnormally large currents flowing through power transmission lines due to lightning strikes.
The present invention relates to a lightning insulator device for power transmission lines that can quickly discharge lightning to the ground through its protection function, suppress and interrupt follow-on current, and prevent permanent ground faults.

(Prior Art) Conventionally, as shown in FIG. 5, as a lightning arrester device for a power transmission line, a +Q suspension insulator chain 6 for a power transmission line 9 is supported on a support arm 1 of a steel tower. The lightning arrester 14 is suspended and fixed at a predetermined distance from the lower horn mounting bracket 7 via a support member (not shown), and the arcing horn 18 is attached to the lower horn mounting bracket 7.
The arcing horn 17 provided at the lower end of the lightning arrester 14 and the arcing horn 18
A predetermined air discharge gap G was provided between the two.

(Problems to be Solved by the Invention) However, in the conventional lightning arrester device for power transmission lines, since the arcing horn 18 is supported by the lower horn mounting bracket 7, the suspension insulator chain 6 swings in the line direction. Then, the sixth
As shown in the figure, since the horn mounting bracket 7 also inclines in the same way, the inclination of the arcing horn 18 also increases, and therefore the amount of downward displacement of the tip of the arcing horn 18 increases, and the arcing horns 17, 18 The discharge gap G tends to fluctuate, and as a result, there is a problem in that the discharge characteristics deteriorate and the reliability as a lightning arrester device is lacking.

Here, the rotation fulcrum at one end of the suspension insulator chain 6 is defined as Z, the vertical distance from the rotation fulcrum Z to the tip of the arching horn 18 is Ll, and the center line of the suspension insulator chain 6, that is, the If the horizontal distance from the perpendicular Y passing through the pivot point Z to the tip of the arching horn 18 is L2, and if the suspension insulator chain 6 further tilts by an angle θ about the pivot point Z as shown in FIG. , the distance LL is Lla, and this distance L 1 a is (1-, 1r, os θ+L2
sin θ). Arching horn 1 shown in Figure 5
The vertical distance from the tip position of the arcing horn 18 to the tip position of the horn 18 shown in FIG. be done.

δ=(Llcos θ+L2sin θ)−Ll Therefore, the above L1=1400mm, L2=600■l, θ−2
If a specific numerical value is calculated assuming 0°, δ=121 m², which shows that the change in the discharge gap G is large and that reliability is lacking.

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a support insulator that can be rotated in the direction of the railway line and in the orthogonal direction by means of an upper hanging bracket with respect to the support arm of the steel tower. A power transmission line is supported at the lower end of the supporting insulator via a lower hanging metal fitting and a wire clamp, while the lightning arrester is attached using the supporting arm side or the upper hanging metal fitting of the supporting insulator. The electric wire clamp supports the discharge electrode attached to the energized side end of the lightning arrester so as to face the discharge electrode with a predetermined air discharge gap.

(Function) By adopting the above-mentioned means, the present invention functions as follows.

Since the arcing horn is supported by a wire clamp that is difficult to displace vertically even when the support insulator is tilted, the tip of the arcing horn is difficult to displace vertically when the support insulator is tilted. The discharge gap between the lightning arrester and the discharge electrode is maintained substantially constant, the discharge characteristics are improved, and the reliability of the lightning arrester device is improved.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 4.

A connecting fitting 2 is fixed to the tip of the support arm 1 of the steel tower, and a suspension insulator 5 is connected in series to the connecting fitting 2 via a U clevis link 3 and a horn fitting 4. A lever chain 6 is supported so as to be swingable in the track direction and in the orthogonal direction. In this embodiment, the connecting fitting 2, the U clevis link 3, and the horn mounting fitting 4 constitute an upper hanging fitting. A power transmission line 9 is connected to the horn mounting bracket 7 at the lower end of the suspension insulator chain 6 via a connecting link 8.
A wire clamp 10 is supported. In this embodiment, the horn mounting fitting 7 and the connecting link 8 constitute a lower hanging fitting.

An arcing horn 11.12 for preventing creeping flash of the suspension insulator chain 6 is attached to the horn mounting bracket 4.7.

A mounting adapter 13 is fixed to the tip of the support arm 1 with a bolt, and a lightning arrester 14 is attached to the mounting portion 13a vertically fixed to the tip of the adapter 13 with an electrode fitting 15 on the ground side of the line (horizontal). ) direction and is supported cantilevered by bolts. Further, an arcing horn 17 serving as a discharge electrode is supported by an electrode fitting 16 on the power supply side provided at the tip of the lightning arrester 14. On the other hand, as shown in FIG. 1, on the wire clamp 10, an arcing horn 18 serving as a discharge electrode is cantilever-supported by a bolt 22 substantially in the line direction, and a predetermined distance is provided between the arcing horn 18 and the arcing horn 17. An air discharge gap G is provided.

The lightning arrester 14 is mainly composed of a cylindrical tension insulating tube (shown in the diagram) made of a tensile material such as F'RP, and zinc oxide (ZnO) housed in series inside the tube. A lightning arrester element (as shown in the diagram) having a non-linear voltage-current characteristic, cap-shaped electrode fittings 16 and 15 on the power-supplying side and the grounding side that are fitted and fixed to both ends of the tension-resistant insulating tube; It is formed by a rubber mold 19 provided on the outer periphery of the insulating cylinder.

Incidentally, both electrode fittings 15 and 16 of the lightning arrester 14 are provided with arcing rings 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 32, 42 arcing rings for minimizing damage to the lightning arrester 15, 16, 15, 16, and 16 when the lightning arrester is depressurized, or when damage occurs during creeping flash or air flash.
21 are provided.

Next, the operation of the lightning arrester device for power transmission lines constructed as described above will be explained.

Now, when an abnormally large current that exceeds expectations is applied to the power transmission line 9 due to a large-scale lightning strike, this current is discharged from the wire clamp 10 and arcing horn 18 to the arcing horn 17 through the discharge gap G, and from the electrode fitting 16 to the lightning protection It flows into the lightning arrester element (path shown) of the insulator 14, flows through the electrode fitting 15 and the mounting adapter 13, flows to the support arm 1, further flows to the steel tower, and is discharged to the ground. Subsequent currents that occur thereafter are suppressed and blocked by the lightning arrester and the discharge gap G.

Now, in the above embodiment, when a large load is applied to the power transmission line 9 due to wind pressure, snow cover, etc. from the stationary state of the insulator device shown in FIG. When rotated around the dynamic fulcrum Z, the lower end of the connection link 8 and the connection point P between the electric wire clamp 10 will be in almost the same inclined state, but since the electric wire clamp 10 is fixed to the power transmission line 9 , the arcing horn 18 does not incline much in the vertical direction, and therefore the amount of displacement δ of the tip of the arcing horn 18 becomes small. The vertical distance from the pivot point Z to the arcing horn 18 in a stationary state is L, and the same distance in a tilted state is L.
If a, then this distance (, a is (L cos θ), and the displacement δ is L - La, that is, δ = LL cos θ.Here, assuming L = 1600 dragons and θ = 20 degrees,
When a specific numerical value is calculated, it becomes δ #96*婁, which is found to be significantly smaller than the conventional displacement amount δ (121 m). As a result, the discharge gap G between the arcing horns 17 and 18 can be kept almost constant at all times, the discharge characteristics can be stabilized, and the reliability of the lightning arrester device can be improved.

Note that the present invention can also be embodied as follows.

The lightning arrester 14 is supported by the upper horn mounting bracket 4 shown in FIG. Also, support the lightning arrester 14 in the vertical direction.

Effects of the Invention As explained in detail above, even if the power transmission line is shaken by wind pressure, snow cover, etc., the vertical displacement of the discharge electrode attached to the wire clamp is small. The discharge gap between the lightning arrester and the discharge electrode can be maintained substantially constant, which has the effect of stabilizing the discharge characteristics and improving the reliability of the lightning arrester device.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment embodying the present invention in a stationary state, FIG. 2 is a front view of a supporting insulator in a swinging state, and the third (2I is a right side view of FIG. 1). Fig. 4 is a plan view of Fig. 1, Fig. 5 is a front view of the conventional example in a stationary state, and Fig. 6 is a plan view of Fig. 1.
The figure is also a front view of the swinging state. ■...Support arm, 6...Suspension insulator chain as support insulator, 9...Power transmission line, 10...Wire clamp, 14
...Lightning insulator, 17.18...Arching horn as discharge electrode, G...Discharge gap, Z...Upper rotation support of suspension insulator chain 6, Y...Rotation support point Z perpendicular line passing through,
P... Connection point between connection link 8 and wire clamp 10, L
... Vertical distance from the pivot point Z to the arcing horn 18 in a stationary state, La... Vertical distance from the pivot point Z to the arcing horn 18 in a tilted state, δ... From the distance The amount of displacement of the arching horn 18 after subtracting the distance MLa.

Claims (1)

[Claims] 1. A support insulator is suspended from the support arm of the tower using an upper hanging bracket so that it can rotate in the direction of the line and in the orthogonal direction, and a lower end of the support insulator is attached to the lower end of the support insulator via a lower hanging bracket and a wire clamp. A power transmission line is supported, and on the other hand, a lightning arrester is attached to the support arm side or using the upper hanging fitting of the support insulator, and the wire clamp has a discharge electrode attached to the energized side end of the lightning arrester. A lightning arrester device for a power transmission line, characterized in that discharge electrodes are supported so as to face each other with a predetermined aerial discharge gap.