JPH05282947A - Suspension type lightning protective insulator - Google Patents

Abstract

PURPOSE:To easily detect a failure of insulators by averaging an electrostatic capacity over the whole length of the insulator series so as to enhance a corona characteristic, and equalizing a voltage load over the whole length of the insulator series. CONSTITUTION:A plurality of suspension type lightning protective insulators 6 each incorporating therein a current limiting element 19 and having a large diameter are alternately connected to a plurality of suspension insulators 7 having a small diameter each of which has no lightning protective function. In the suspension type lightning protective insulator 7, electric discharging electrodes 22, 23 are projected on electrodes 20, 21 at both ends of the current limiting element 19. The tips of the electric discharging electrodes 22, 23 face to each other with a predetermined electric discharging gap G in the intermediate position between the outer periphery of the suspension type lightning protective insulators 6 and the outer periphery of the suspension insulator 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension type lightning arrester device for a power transmission line.

[0002]

2. Description of the Related Art As a conventional suspension type lightning arrester device for this type of power transmission line, a structure described below is known. In this conventional configuration, a plurality of large-diameter suspension type lightning arresters with built-in current limiting elements are connected, and the current limiting elements in each suspension type lightning arrestor are electrically connected via lead wires, etc. A plurality of small-diameter suspension insulators that do not have a lightning protection function are connected to the lightning arrestor series, and the discharge electrodes on the power-supply side and the ground side are attached to both ends of this suspension insulator series, and the tips of both discharge electrodes are attached. They are arranged to face each other with a predetermined air discharge gap.

[0003]

However, in the conventional lightning arrester device, in contrast to a lightning arrester string composed of a plurality of suspension type lightning insulators, a string of suspended insulators composed of a plurality of suspended insulators having no lightning protection function. Are connected in series,
The suspension insulator series side has a smaller electrostatic capacitance than the lightning striker series side, and corona discharge is more likely to occur on the suspension insulator series side, and there is an imbalance in the voltage sharing between the lightning striker series and the suspension insulator series. As a result, the suspension type lightning protection insulator series has a problem that it is difficult to detect the failure of the insulator.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and an object thereof is to provide a suspension type lightning arrester and a series of insulators composed of suspension insulators. Capacitance can be averaged over the entire length, corona characteristics can be improved, and voltage distribution can be equalized over the entire length of the insulator string, so that failure detection of each insulator can be achieved. It is an object of the present invention to provide a suspension type lightning arrester device for a power transmission line, which can be easily carried out and can avoid damage from birds and wind pressure.

[0005]

In order to achieve the above object, in a suspension type lightning arrester device for a power transmission line of the present invention, a large diameter suspension type lightning arrester having a current limiting element is incorporated, and a lightning protection function. A plurality of small-diameter suspension insulators that do not have an alternating current are alternately connected, and discharge electrodes are projected on the electrodes at both ends of the current limiting element in each suspension-type lightning arrestor, and the tips of those discharge electrodes are suspended-type lightning arresters. In the intermediate position between the outer circumference of the insulator and the outer circumference of the suspended insulator, they are opposed to each other with a predetermined discharge gap.

[0006]

[Operation] In the suspension type lightning arrester device for a transmission line configured as described above, since a plurality of suspension type lightning arrestors and suspension insulators are alternately connected, static electricity is provided over the entire length of the insulator string. Capacitance can be averaged, corona characteristics can be improved, voltage distribution can be equalized over the entire length of the insulator string, and failure detection of each insulator can be easily performed. .

Further, the tips of the discharge electrodes projecting from the electrodes on both ends of the current limiting element are disposed so as to face each other with a predetermined discharge gap at an intermediate position between the outer circumference of the suspended lightning arrestor and the outer circumference of the suspended insulator. Therefore, it is possible to prevent bird damage such as birds stopping on the discharge electrode, and to prevent lateral vibration from occurring in the insulator string due to wind pressure or the like.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a suspension type lightning arrester device for a power transmission line embodying the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, the hanging metal fitting 2 is attached to a support arm 1 of a steel tower, and an upper horn mounting metal fitting 4 is connected to the hanging metal fitting 2 via a U clevis 3. The insulator string 5 is suspended and supported by the upper horn mounting bracket 4 so as to be swingable in the line direction and the direction orthogonal thereto, and has a large diameter suspension type lightning arrestor 6 having a lightning protection function and a small diameter lightning protection lightning function having no lightning protection function. It is configured by alternately connecting a plurality of suspension insulators 7.

The lower horn mounting member 8 is connected to the lower end of the insulator string 5 via a socket clevis 9, and the lower horn mounting member 8 is connected to the transmission line 1 via a connecting link 10.
An electric wire clamp 12 for supporting 1 is attached. The pair of arcing horns 13 and 14 are attached to the upper and lower horn mounting brackets 4 and 8, respectively.
3 and 14 reduce damage to the surface flashover of the insulator string 5 during abnormal lightning strikes.

Next, the structure of the suspension type lightning protection insulator 6 will be described in detail. As shown in FIG. 2, the insulator main body 15 is integrally formed of porcelain and has a cylindrical head 15a with a bottom and its head. A cap portion 15b formed on the outer periphery of 15a and a plurality of folds 15 concentrically formed on the inner surface of the cap portion 15b.
and c. The cap metal fitting 16 is fitted and fixed to the head portion 15a of the insulator body 15 by cement, and a fitting concave portion 16a is formed on the top thereof. The pin fitting 17 is fixed in the head portion 15a of the insulator body 15 by cement,
A fitting portion 17a is formed at the lower end thereof.

The pair of accommodating cylinders 18 are formed integrally with the cap portion 15b of the insulator body 15. Multiple current limiting elements 1
9 is accommodated and arranged in the accommodating cylinder 18, and is formed of a resistor whose main component is zinc oxide having a non-linear voltage-current characteristic. A pair of upper and lower cap electrodes 20 and 21 are capped and fixed to the upper and lower end portions of the housing cylinder 18, respectively.
The current limiting element 19 is joined to the inner surfaces of 0 and 21 by the urging force of a spring (not shown).

The upper discharge electrode 22 is the upper cap electrode 20.
Is fixed to the upper surface of the insulator by welding and extends obliquely upward toward the outer peripheral side of the insulator body 15. The lower discharge electrode 23 is welded and fixed to the lower surface of the lower cap electrode 21, and extends obliquely downward toward the outer peripheral side of the insulator body 15. Then, as shown in FIG. 1, the tip of the upper discharge electrode 22 and the tip of the lower discharge electrode 23 between the adjacent suspension type lightning protection insulators 6 are the outer periphery of the suspension type lightning protection insulator 6 and the outer periphery of the suspension insulator 7. At the intermediate position, they are opposed to each other with a predetermined discharge gap G.
The pair of arc guides 26 are fixed to the outer circumference of the cap fitting 16 and horizontally extend outward along the upper surface of the upper cap electrode 20. Then, should the current limiting element 19 fall into the conductive state, the arc guide 26 guides the arc outwardly, thereby preventing the insulator body 15 from being broken.

Next, the structure of the suspension insulator 7 will be described in detail. As shown in FIG. 1, the insulator main body 27 is integrally formed of porcelain, and has a bottomed cylindrical head portion 27a and its head portion 27a. The cap portion 27b formed on the outer periphery and the cap portion 27
The inner surface of b is provided with a plurality of concentric pleats 27c. The cap metal fitting 28 is fitted and fixed to the head portion 27a of the insulator main body 27 by cement, and a fitting concave portion 28a is formed at the top thereof. The pin fitting 29 is fixed in the head portion 27a of the insulator body 27 by cement, and a fitting portion 29a is formed at the lower end thereof. Then, the fitting portion 17a of the pin fitting 17 of the suspension type lightning protection insulator 6 is engaged with the fitting concave portion 28a of the cap fitting 28 of the suspension insulator 7, and the fitting portion 29a of the pin fitting 29 of the suspension insulator 7 is suspended. By engaging with the fitting recess 16a of the cap fitting 16 of the type lightning protection insulator 6, a plurality of suspension type lightning protection insulators 6 and suspension insulators 7 are alternately connected in series in the vertical direction.

Next, the operation of the suspension type lightning arrester device for a power transmission line configured as described above will be described. Now, in this suspension type lightning arrester device, when a lightning surge current enters the power transmission line 11, the current is located at the bottom through the wire clamp 12, the connecting link 10, the lower horn mounting bracket 8 and the socket clevis 9. It flows to the lower discharge electrode 23 of the suspended lightning arrester 6. Furthermore, the lower cap electrode 2
1 to the upper cap electrode 20 through the current limiting element 19, flashover from the upper discharge electrode 22 in the discharge gap G, and then flow to the lower discharge electrode 23 of the suspended type lightning protection insulator 6 facing. Then, in each suspension type lightning arrester 6, after repeating this operation in sequence, the current flows from the upper cap electrode 20 of the suspension type lightning arrester 6 located at the uppermost part to the cap metal fitting 16, the upper horn mounting metal fitting 4, the U clevis 3. And it flows to the support arm 1 through the hanging metal fitting 2, and is discharged from the steel tower to the ground.

Further, the subsequent flow generated thereafter is the discharge gap G between the discharge electrodes 22 and 23 in each of the suspension type lightning protection insulators 6.
Then, the resistance value of the current limiting element 19 is restored to suppress and cut off, thereby preventing a short circuit accident.

In the suspension type lightning arrester device of this embodiment, a plurality of suspension type lightning arresters 6 and suspension insulators 7 are alternately connected to form an insulator series 5, and the lowermost end closest to the power transmission line 11 is formed. The insulator is the lightning protection insulator 6. Therefore,
The capacitance can be averaged over the entire length of the insulator string 5, and the corona characteristics can be improved. In addition, the voltage distribution can be equalized over the entire length of the insulator string 5, and the failure of each insulator 6, 7 can be easily detected.

Further, the discharge electrodes 22 and 23 are provided on the cap electrodes 20 and 21 of the current limiting element 19 in each suspension type lightning protection insulator 6.
And the tips of the discharge electrodes 22 and 23 are arranged to face each other with a predetermined discharge gap G at an intermediate position between the outer circumference of the suspended lightning arrester 6 and the outer circumference of the suspended insulator 7. It is possible to prevent bird damage, such as birds stopping on the electrodes 22 and 23, and to prevent the damage of the birds by wind pressure.
Even if a horizontal shake occurs, the discharge electrodes 22 and 23 can maintain the balance.

The present invention is not limited to the structure of the above-described embodiment. For example, the discharge electrodes 22 and 23 are fixed to the cap electrodes 20 and 21 with bolts, and the like without departing from the spirit of the present invention. Then, it is possible to embody by arbitrarily changing the configuration of each unit.

[0020]

Since the present invention is configured as described above, it is possible to average the electrostatic capacitance over the entire length of an insulator series including a plurality of suspension type lightning arresters and suspension insulators. In addition, the corona characteristics can be improved, the voltage distribution can be equalized over the entire length of the insulator string, and the failure detection of each insulator can be easily performed.

Further, according to the present invention, in particular, the tip of the discharge electrode projecting on the electrodes at both ends of the current limiting element is provided at a predetermined position at the intermediate position between the outer circumference of the suspension type lightning arrestor and the outer circumference of the suspension insulator. Since the discharge electrodes are arranged to face each other with a discharge gap, it is possible to prevent bird damage such as birds stopping on the discharge electrode, and to prevent lateral vibration from occurring in the insulator string due to wind pressure or the like.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a suspended lightning arrester device embodying the present invention.

FIG. 2 is a partially cutaway front view showing the suspension type lightning protection insulator in an enlarged manner.

[Explanation of symbols]

5 Insulator series, 6 Suspension type lightning protection insulator, 7 Suspension insulator, 15
Insulator body, 19 Current limiting device, 20 Upper cap electrode, 21 Lower cap electrode, 22 Upper discharge electrode, 2
3 Lower discharge electrode, G discharge gap.

Claims (1)

[Claims] 1. A large diameter suspension type lightning arrestor with a built-in current limiting element and a plurality of small diameter suspension insulators having no lightning protection function are alternately connected, and both ends of the current limiting element in each suspension type lightning arrestor are connected. Discharge electrodes are respectively projected on the electrodes, and the tips of the discharge electrodes are opposed to each other with a predetermined discharge gap at an intermediate position between the outer periphery of the suspension type lightning arrestor and the outer periphery of the suspension insulator. Type lightning arrester device.