JPH0250570B2 - - Google Patents

Description

[Detailed description of the invention]

Purpose of the Invention (Industrial Application Field) The present invention quickly discharges high voltage caused by lightning when it is applied to a power transmission line, and
This invention relates to a lightning arrester device for overhead power transmission lines (suspension towers) that can prevent ground faults caused by follow-on arcs that occur thereafter. (Prior Art) In general, in a lightning arrester device that installs a lightning arrester insulator with a predetermined air discharge gap to a power transmission line, especially when the surface of the insulator is soiled or wet with rainwater, Even under conditions in which the lightning arrester operates due to a lightning strike and the surface leakage current of the lightning arrester is likely to increase significantly compared to when the surface of the insulator is cleaned afterwards, it is necessary to interrupt the follow-on arc in a short time. In order to solve this problem, a lightning arrester insulator for overhead power transmission lines has been disclosed, for example, in Japanese Utility Model Application Publication No. 137838/1983. As shown in FIG. 6, a hanging insulator 32 is suspended from the support arm 2 of the steel tower via an insulator mounting bracket 31, and an electric wire 34 is attached to the lower end of the insulator 32 via a clamp 33. Supporting and upper cap metal fittings 3
5, a lightning arrester 37 is cantilever-supported diagonally through a support fitting 36, and an arcing horn 38 fixed to the lower end of the lightning arrester 37 and a cap fitting 39 fixed to the lower end of the hanging insulator 32 are attached. There was one with the arching horn 40 facing the other. (Problems to be Solved by the Invention) However, in the conventional lightning arrester device for an overhead power transmission line, since the lightning arrester 37 is installed offset with respect to the hanging insulator 32, the central axis of the insulator 32 is Because of this, it was difficult to maintain a stable shape during erection, and installation work was time-consuming. In a lightning arrester device having such a configuration, when the lightning arrester element has a small discharge withstand capacity, a low level of pollution resistance, and the lightning arrester 37 is relatively smaller and lighter than the hanging insulator 32, the hanging insulator 32 The effect that the lightning arrester 37 alone, which was directly attached to the lightning arrester 37, had on the behavior of the entire insulator device was negligible. However, as the scope of application has expanded and the lightning arrester 37 has become larger due to increased discharge capacity, implementation of safety measures, and demands for improved antifouling properties, the drawbacks of this pole mounting method have become impossible to ignore. In other words, there is insufficient clearance due to static balance when there is no wind, or abnormal vibration when the track oscillates in the direction of the track or perpendicular direction under strong winds, or when the suspended insulator 3
Insufficient strength due to the bending load due to the dead weight of the lightning arrester 37 and the inertial force due to vibration being applied to the cap fitting 35 of No. 2. In order to ensure the insulation strength and air gap length of the lightning arrester 37, the lightning arrester 37 is placed in a nearly horizontal state. By attaching it, the width under the line can be expanded. Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention attaches the connecting fitting 5 to the support arm 2 of the tower body so as to be rotatable in the track direction and in the same orthogonal direction. At the same time, a connecting link 7 is connected to the lower end of the connecting fitting 5 by a connecting pin 6 so as to be rotatable in the track direction.
A hanging insulator 9 of a power transmission line is attached to a connecting pin 10 at the lower end of the
The suspended insulator 9 is suspended rotatably in the line direction, and a discharge electrode 18 on the power supply side is extended in the line direction at a position displaced a predetermined distance upward from the power transmission line at the lower end of the hanging insulator 9, while the connection Mounting arm 1 is attached to link 7.
9, the lightning arrester 20 is suspended and fixed so as to be displaced laterally in correspondence with the discharge electrode 18 on the energized side, and the discharge electrode 23 supported on the lower electrode 22 of the lightning arrester 18 and the energized The side discharge electrodes 18 are opposed to each other with a predetermined air discharge gap G, and arcing horns 17 are arranged above and below the hanging insulator 9.
16 is provided, and the ratio L/
A measure is taken to set H to approximately 6 or less. (Function) By adopting the above-mentioned means, the present invention functions as follows. When an abnormally high voltage caused by a lightning strike is applied to the power transmission line, the voltage is discharged from the discharge electrode 18 on the power supply side to the discharge electrode 23, passes through the non-linear resistance element built into the lightning arrester 20, and reaches the tower body side. The flow is grounded.
Further, the subsequent arc generated thereafter is blocked by the above-mentioned aerial discharge gap G and the non-linear resistance element. The present invention provides both upper and lower connecting pins 6 and 1 of the connecting link 7.
0 and the distance H from the connecting pin 6 to the lightning arrester 20.
Since the ratio L/H to the horizontal distance L to the center of gravity of
The amount of displacement D is kept at an allowable value, and the discharge characteristics are stabilized. (Example) Hereinafter, an example embodying the present invention is shown in Figs.
To explain based on FIG. 4, a hanging metal fitting 4 is fixed to the bottom surface of the tip of the support arm 2 of the steel tower 1 with a bolt 3, and a connecting metal fitting 5 is attached to the hanging metal fitting 4 for the railway line (left and right in Fig. 1). A connecting link 7 which also serves as a horn mounting bracket is connected to the connecting fitting 5 by a connecting pin 6 in a rotating direction in the railway direction. A hanging insulator 9 made of an insulator chain in which a number of suspended insulators 8 are connected in series is suspended by a connecting pin 10 so as to be rotatable in the track direction. A horn mounting bracket 1 is attached to the lower end of the hanging insulator 9.
1 are connected to be rotatable in the track direction, and a connecting link 13 is connected to the lower end of the mounting bracket 11 via a connecting pin 12 so as to be rotatable in the track direction.
A wire clamp 14 is attached to the lower end of the connecting link 13.
A power transmission line 15 is supported via. The connecting link 7 and the horn mounting bracket 11 are provided with arcing horns 16 on the energizing side and the grounding side for capturing the arc that flashes across the surface of the hanging insulator 9 during a lightning strike and preventing the insulator 9 from melting. 17 is supported in a cantilevered manner. Further, a discharge electrode 18 on the energizing side is supported in a cantilever manner by the horn mounting bracket 11 so as to be located on the opposite side from the arcing horn 16. On the other hand, a mounting arm 19 for the lightning arrester 20 is supported in a cantilever manner by two bolts 26 and 27 at the upper end of the connection link 7 in the direction of the railway line. Among these bolts 26 and 27, lightning arrester 20
The insertion hole 19a of the mounting arm 19 through which the side bolt 27 is inserted is formed to be long in the vertical direction, and the mounting arm 19 is rotated in the vertical direction around the bolt 26.
The angle at which the arm 19 is attached to the connecting link 7 can be adjusted. An upper electrode 2 of a lightning arrester 20 having a built-in resistance element (not shown) with non-linear voltage-current characteristics is provided on the lower surface of the tip of the mounting arm 19.
The discharge electrode 1 on the energized side is fixed to the lower electrode 22 located at the lower end of the lightning arrester 20.
A discharge electrode 23 is attached facing downward so as to face the discharge electrode 8 . Arc rings 24 and 25 are attached to the upper and lower sides of the lightning arrester 20, and the lower arc ring 25
The distance F between the suspension insulator 8 and the cap fitting 8a located at the upper end of the suspension insulator 9 is
It is set to be 1.1 times or more the gap K of No. 4, 25.
Also, the upper and lower arcing horns 16, 1 of the hanging insulator 9
The distance E between the discharge gaps 7 and 7 is set to be 1.3 times or more the discharge gap G. This ensures that discharge occurs in the discharge gap G. By the way, the vertical load acting on the hanging insulator 9 by the power transmission line 15 is W1, the dead weight of the lightning arrester 20 is W2, and the distance between the connecting pins 6 and 10 is H.
Further, if the distance from the connecting pin 6 to the center of gravity of the lightning arrester 20 is L, and the angle at which the connecting link 7 and the mounting arm 19 rotate due to the balance of forces is θ, then the following approximate formula holds from the balance of forces. . tanθ≒W2・L/W1・H……(1) In other words, if the vertical load W1 on a certain steel tower is known, if the connecting link 7 is manufactured in consideration of the rotation angle θ in advance, the installation will be easier. It is possible to create an equilibrium state in which the arm 19 is held horizontally and the lightning arrester 20 is held vertically. However, the vertical load W1 acting on the hanging insulator 9 changes greatly depending on environmental conditions, such as snow, ice, strong winds, and the like. Therefore, the rotation angle θ of the connecting link 7 changes, and therefore the lightning arrester 20
The position of G increases and decreases, which causes the discharge gap G to fluctuate. In order to keep the discharge characteristics within a certain range, it becomes necessary to keep the rotation angle θ within a certain range. That is, as the discharge gap G increases, the insulation strength increases accordingly, and flash shorting occurs in the hanging insulator 9. On the other hand, if the discharge gap G decreases, the discharge gap G will cause a flash fault due to the surge caused by the opening of the circuit breaker, which will cause a ground fault, so it is necessary to keep the displacement amount of the discharge gap G within an allowable value. be. The amount of upward displacement of point P when changing the ratio L/H mentioned above, that is, the amount of displacement D of discharge gap G
is determined by the following approximate formula. D≒L・sin (tan ⁻¹ W2・L/W1・H) (2) Here, a specific example will be shown. Considering icing as one of the factors that change the vertical load W1, a 6mm sleeve (specific gravity
0.9). The distance L from the connecting pin 6 to the center of gravity of the lightning arrester 20 is set to 600 mm in order to ensure the distance F between the arc ring 25 of the lightning arrester 20 and the cap fitting 8a of the suspension insulator 8, and also for ease of construction. degree is required. Also, for 66kV to 154kV transmission lines, ACSR410 to
The average value is 810sq single conductor and a span of about 300m. ACSR410sq single conductor has outer diameter 28.5mm and weight 1.97
Kg/m, ACSR810sq single conductor outer diameter 38.4mm, weight
It is 2.70Kg/m. If the span is 300 m, the average value of the vertical load W1 of the hanging insulator 9 will be 655 kg. Further, the average value of the increase amount ΔW in the vertical load W1 when 6 mm of icing occurs is 200 kg. The table below shows the calculation results of the displacement D using the above equation (2) when the ratio L/H is changed using the above specifications. However, θ1 indicates the initial rotation angle of the connecting link 7 when W1 is 655 kg, and θ2 indicates the rotating angle of the connecting link 7 at the time of icing when W1+ΔW is 855 kg.

[Table] The results of the table can be plotted in a graph as shown in Figure 4. By the way, for a power transmission line of about 66 to 154 kV, the above-mentioned displacement D is limited to about 30 to 40 mm in lightly polluted areas where the insulator connection function is low due to critical continuity characteristics, so the ratio L/H is approximately 6. The following are required. Next, the operation of the lightning arrester device for overhead power transmission lines constructed as described above will be explained. Now, when an abnormally high voltage is applied to the power transmission line 15 due to a lightning strike, this voltage is applied to the wire clamp 1.
4. Via the connecting link 13 and the horn mounting bracket 11, the discharge is discharged from the discharge electrode 18 on the power supply side to the discharge electrode 23, and further flows through the nonlinear resistance element in the lightning arrester 20 to the mounting arm 19, and then the support arm 2
and is grounded via the steel tower 1. Thereafter, the generated follow-on arc is interrupted by the air discharge gap G and the non-linear resistance element, thereby preventing a ground fault and also preventing both discharge electrodes 18 and 23 from being blown out by the arc. In particular, in this embodiment, as mentioned above, the ratio L/H
is set to approximately 6 or less, it is possible to stabilize the discharge characteristics by suppressing the displacement D of the discharge gap G of the lightning arrester 20 to an allowable value, that is, approximately 30 to 40 mm, in a power transmission line of about 66 to 154 KV. can. Incidentally, the case in which the vertical load W1 decreases occurs only under extremely rare conditions such as a three-way jump, and generally there is no need to consider it. Note that the present invention can also be embodied as follows. (1) A long-stem insulator (not shown) should be used for the hanging insulator 9. (2) The hanging insulator 9 is used as a hanging insulator for jumper wire (not shown). In this specification, when power transmission lines are referred to, jumper wires are also included. (3) As shown in FIG. 5, the connecting link 7 and the mounting arm 19 are integrally formed and extend in the track direction, and the connecting link has an arcing horn 1.
7 can be attached to the mounting arm 19, and a lightning arrester 20 can also be attached to the mounting arm 19 in a diagonal manner such that the lower end thereof is further away from the hanging insulator 9. Effects of the Invention As detailed above, according to the present invention, the lightning arrester can be easily attached, and the discharge electrode on the energizing side can also be easily attached using the existing horn mounting bracket. Furthermore, in the present invention, the lightning arrester is displaced in the direction of the line in correspondence with the hanging insulator, and furthermore, the discharge electrode on the energized side corresponds to the discharge electrode on the ground side above the transmission line, so that the lightning arrester and A sufficient air insulation gap with the steel tower can be secured, and the arc can be prevented from touching the power transmission line during discharge, thereby preventing the power transmission line from fusing. In particular, the present invention sets the ratio L/H of the distance H between the upper and lower connecting pins 6 and 10 of the connecting link 7 to the horizontal distance L from the connecting pin 6 to the center of gravity of the lightning arrester to approximately 6 or less. Therefore, in a power transmission line of about 66 to 154 KV, the displacement amount of the discharge gap can be kept within the allowable range, and the discharge characteristics can be stabilized.

[Brief explanation of drawings]

Figure 1 is a front view showing one embodiment of the present invention, Figure 2 is a front view showing one embodiment of the present invention;
The figure is a right side view with the lightning arrester in Figure 1 omitted, Figure 3 is an enlarged front view of the vicinity of the mounting arm, and Figure 4 is a graph showing the relationship between the ratio L/H and the displacement of the discharge gap. , FIG. 5 is a front view showing another example of the present invention,
FIG. 6 is a front view showing a conventional example. 1... Steel tower, 2... Support arm, 6, 10...
Connecting pin, 7... Connecting link, 9... Hanging insulator,
11...Horn mounting bracket, 13...Connection link,
14...Electric wire clamp, 15...Power transmission line, 16,
17...Arching horn, 18, 23...Discharge electrode, 19...Mounting arm, 20...Lightning arrester,
G...Discharge gap, E...Distance between the upper and lower arcing horns 16 and 17 of the hanging insulator 9, F...Distance between the cap fitting 8a and the arc ring 25, θ...Inclination of the connecting link 7 and the mounting arm 19 Angle, D...
...displacement amount of the discharge gap G, W1...vertical load acting on the hanging insulator 9, W2...self weight of the lightning arrester 20,
L: Distance from the connecting pin 6 to the center of gravity of the lightning arrester 20, H: Distance between the connecting pins 6 and 10.

Claims (1)

[Scope of Claims] 1. A connecting fitting 5 is attached to the support arm 2 of the tower body so as to be rotatable in the track direction and in the perpendicular direction, and a connecting link 7 is attached to the lower end of the connecting fitting 5 with a connecting pin. A hanging insulator 9 of a power transmission line is suspended from the lower end of the connecting link 7 so as to be rotatable in the track direction by a connecting pin 10. At the lower end, a discharge electrode 18 on the energized side extends in the direction of the line at a position displaced upward from the power transmission line by a predetermined distance, and on the other hand, a lightning arrester 20 is attached to the connecting link 7 via a mounting arm 19 on the energized side. The lower electrode 22 of the lightning arrester 20 is suspended and fixed so as to be displaced laterally corresponding to the discharge electrode 18 of the lightning arrester 20.
The discharge electrode 23 supported by the discharge electrode 23 and the discharge electrode 18 on the energizing side are opposed to each other with a predetermined aerial discharge gap G, and arcing horns 17 and 16 are provided above and below the hanging insulator 9, The distance H between the upper and lower connecting pins 6 and 10 of the connecting link 7, and the horizontal distance L from the connecting pin 6 to the center of gravity of the lightning arrester 20.
1. A lightning arrester device for an overhead power transmission line, characterized in that the ratio (L/H) is set to approximately 6 or less. 2 Upper and lower arcing horns 16, 1 of the hanging insulator 9
The lightning arrester device for an overhead power transmission line according to claim 1, wherein the distance E between the discharge electrodes 18 and 23 is set to be 1.3 times or more the discharge gap G between the discharge electrodes 18 and 23. 3. The lightning arrester device for an overhead power transmission line according to claim 1, wherein the discharge electrode 18 on the energizing side is cantilevered by a horn mounting bracket 11 attached to the lower end of the hanging insulator 9. 4. The lightning arrester device for an overhead power transmission line according to claim 1, wherein the mounting arm 19 is attached to the connecting link 7 so that the mounting angle in the vertical direction can be adjusted. 5 The connecting link 7 and the mounting arm 19 are integrally formed and oriented in the track direction, and the connecting link 7
Attach arching horn 17 to the
2. The lightning arrester device for an overhead power transmission line according to claim 1, wherein a lightning arrester 20 is attached to the mounting arm 19 in an oblique manner such that the lower end thereof is further away from the hanging insulator 9.