JPH021777Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a lightning-resistant tension insulator that suppresses and interrupts follow-on arcs during lightning flash faults in power transmission and distribution lines, thereby preventing wire breakage and insulator separation. It is.

(Prior art) In general, tension insulators and lightning arresters are
As shown in Japanese Patent No. 43529, the lightning arrester is mounted separately, and the arcing horns provided at both ends of the lightning arrester are opposed to the charging fitting or the grounding fitting with an air gap in between. In such a lightning-resistant tension device, flying objects may adhere to the air gap, or soiled snow may freeze and stick to the electrical connection to the charging fitting or grounding fitting. In this state, the line voltage is constantly applied to the current limiting element, so there is a problem that the current limiting element is easily deteriorated.

On the other hand, as a tension insulator with built-in lightning arrester,
-167430 and Utility Model Application Publication No. 57-6114 have been proposed, but these tension-resistant insulators have cap electrodes fitted and fixed at both ends of the insulator, and a current limiting element is built inside the insulator. However, if the current limiting element receives an excessive lightning surge, that is, a lightning surge that exceeds the discharge capacity, it may explode, and in such a case, the tension-resistant insulator may be damaged and separated. There is a problem that the wires may fall to the ground or break.

(Problems to be Solved by the Invention) This invention solves the problem that the current limiting element installed in the conventional tension insulator is easily deteriorated, and the current limiting element in the tension insulator with built-in lightning arrester is subject to deterioration or excessive lightning surge. The aim is to solve the problem of the tension insulators breaking off due to explosions caused by electrical wires falling to the ground or breaking.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention attaches cap electrodes to both ends of the tension insulation rod, and similarly, the voltage and current characteristics are different from the outer periphery of the tension insulation rod. A cylindrical current limiting element made of linear material is fitted,
A cylindrical insulator is fitted around the outer periphery of the current limiting element, and the gap formed by the tension-resistant insulating rod, cap electrode, current limiting element, cylindrical insulator, etc. is filled with a closed foam insulator and sealed. This configuration is adopted.

(Function) By adopting the above-mentioned means, the current limiting element quickly changes its resistance value when excessive voltage due to lightning surge is applied to the power transmission/distribution line and is applied to both cap electrodes due to the non-linearity of the voltage-current characteristics. In addition to discharging the large current of the lightning surge, the line voltage is low in response to the follow-on current, so the resistance value is immediately restored and the insulation is restored, so the follow-on discharge is suppressed and cut off, and the line is discharged. will return to normal. In addition, the current limiting element is hermetically encapsulated by the closed foam insulating material to improve airtightness, thereby suppressing deterioration. In the unlikely event that the current limiting element deteriorates or explodes due to excessive lightning surge, etc.
Even if the cylindrical insulator breaks and falls off, the tension insulator itself will not be separated because the two cap electrodes are connected by a tension insulating rod, thus preventing the wire from falling to the ground or breaking. be done.

(Example) Below, an example embodying the present invention is shown in Figure 1~
This will be explained based on FIG.

FIG. 1 shows the entire lightning-resistant tension device in which a normal tension-resistant insulator 9 and a lightning-resistant tension insulator 11 of the present invention are connected in series, and 1 is a jumper wire support insulator that is fixed upright on a cross arm 2. , there is a binding line 3 at its upper end.
The hem portion 4a of the insulated wire 4 is tied down. Reference numerals 5 and 6 indicate ground side retaining devices that are fastened to the arm 2; 7 and 8 indicate electric wire gripping devices such as crank fittings that grip the insulated wire 4 from both ends of the selvage portion 4a; and 9
are the ground side retaining tools 5, 6 and the wire gripping tools 7, 8.
The tension insulators 11 are connected by connecting pins 10 between them, and the tension insulators 11 are lightning-resistant tension insulators of the present invention, which are connected by connecting pins 10 between the ground side retaining devices 5 and 6 and the tension insulators 9.

Next, the lightning-resistant tension insulator 11 will be explained with reference to FIGS. 2 to 4. Reference numeral 12 denotes a tension-resistant insulating rod made of a material with excellent mechanical strength such as reinforced plastic, and a cap electrode 13 on the power supply side having a screw hole 13a is screwed into one of screws 12a formed at both ends of the rod. A ground side cap electrode 14 having a screw hole 14a is screwed into the other end. The cap electrode 13 is divided into two parts, a cap part 13b and a terminal part 13c, and a conductive ring 15 is interposed between them. The cap electrode 1
3 and 14 are the retaining tools 5 and 6 by the connecting pin 10.
and a tension insulator 9.
16 is a cap portion 13b of the cap electrode 13;
A cylindrical insulator made of porcelain is interposed between the cylindrical insulator 16 and the cap part 14b of the cap electrode 14, and is fastened and fixed by both the electrodes 13 and 14. Rubber between the
An elastic cushion ring 17 made of resin or the like is interposed.

Reference numeral 18 denotes an annular power supply side electrode fitted around the outer periphery of the tension-resistant insulating rod 12, and 19 also represents the insulating rod 1.
a ring-shaped ground side electrode fitted around the outer periphery of 2;
Reference numeral 20 denotes a cylindrical current-limiting element interposed between the electrodes 18 and 19 via doughnut-shaped electrode plates 21 and 22, such as disc springs, and is made of zinc oxide or the like with non-linear voltage-current characteristics. It is made of material. 23 is the cap portion 1 of the cap electrode 13;
A plurality of bodies made of an insulating sound-absorbing material such as porous ceramic are interposed between the electrode 3b and the electrode 18, and are designed to absorb acoustic energy and alleviate discharge shock. Reference numeral 24 denotes a discharge electrode on the energized side screwed to the inner surface of the cap portion 13b of the cap electrode 13, and 25 denotes a discharge electrode on the ground side screwed to the electrode 18. They are disposed facing each other within the cylinder 23 with a predetermined discharge interval L between them. In this embodiment, the discharge gap L is set large so that the operation start voltage against lightning surges becomes high.

26 is an elastic insulating material such as ethylene propylene rubber molded on the outer peripheral surfaces of the electrodes 18, 19, the current limiting element 20, and the electrode plates 21, 22, and is transparent to both the electrodes 18, 19 during molding. A coating layer is also formed in the cylindrical gap between the outer circumferential surface of the tension-resistant insulating rod 12 and the inner circumferential surfaces of both electrodes 18, 19, current limiting element 20, and both electrode plates 21, 22 via passages 18a, 19a. are doing. Reference numeral 27 denotes an injection hole 13 formed through the cap portion 13b of the cap electrode 13.
A closed foam insulator such as nitrile rubber or polyurethane is press-fitted into the cylindrical insulator 16 from d to strengthen the insulation inside the insulator 16 and improve airtightness.

By the way, when the cap electrodes 13 and 14 are screwed into the screw 12a of the tension-resistant insulating rod 12, an adhesive is applied to the screwed portion to strengthen the insulation of the gap and increase the fixing force. Further, the contact surface between the cap part 14b of the cap electrode 14 and the electrode 19,
Alternatively, it is desirable to eliminate gaps between the contact surfaces of the electrodes 18, 19, current limiting element 20, and electrode plates 21, 22 to improve conductivity and adhesion.

Alternatively, the elastic insulator 26 may be omitted and the closed foam insulator 27 may be filled here as well.

Next, the operation of the lightning-resistant tension device constructed as described above will be explained.

Now, when an impact voltage such as a lightning surge occurs in the insulated wire 4, this voltage flashes over the tension insulator 9 from the insulated wire 4 or the wire gripper 7 and is applied to the lightning tension insulator 11. is the terminal part 13c of the cap electrode 13 → the conductive ring 15 →
It is discharged from the discharge electrode 24 to the discharge electrode 25 via the cap part 13b, and flows to the cap electrode 14 via the electrode 18→electrode plate 21→current limiting element 20→electrode plate 22→electrode 19. Then, the current-limiting element 20 built into the lightning-resistant tension insulator 11 quickly discharges the large current of the lightning surge due to the non-linearity of the voltage-current characteristics, and the line voltage is low against the following current. Therefore, the resistance value is immediately restored and the insulation is restored, so the follow-on discharge is suppressed and interrupted, and the electric line returns to normal.

Now, in the embodiment of the present invention, the current limiting element 20 is built into the cylindrical insulator 16, and the elastic insulator 26
Since the element is hermetically encapsulated with the closed foam insulator 27, insulation and airtightness can be improved and deterioration of the current limiting element 20 can be suppressed.

In addition, in the embodiment of the present invention, the tensile insulation rod 12
Since the insulating rod 12 is protected by the elastic insulator 26 and the closed foam insulator 27, in the unlikely event that the current limiting element 20 deteriorates or explodes due to excessive lightning surge, the cylindrical insulator 16 Even if the wires are scattered, the tension-resistant insulating rods 12 are not severed and retain their ability to hold the wires, thereby preventing the wires from falling to the ground or breaking.

Furthermore, in the embodiment of the present invention, a tension insulator device can be constructed by connecting nine tension insulators in series or by connecting one lightning insulator 11 alone. In comparison, it has the advantage of not having space constraints and not becoming an obstacle during track repair.

By the way, in the above embodiment, the discharge interval 〓L of the discharge electrodes 24 and 25 is set higher than that of a normal lightning arrester, and the operation start voltage against a lightning surge is set higher. No abnormal voltage is applied, and there is no constant voltage burden on the current limiting element 20. Incidentally, in the case of 6KV, the operation start voltage of this lightning-proof tensile insulator 11 can be set to 1.5 to 3 times the operation start voltage according to JEC203 regulations for lightning arresters to achieve the intended purpose. For this reason, as mentioned above, since it does not operate at low-level abnormal voltages on the line, there is no need to deal with sustained low-level abnormal voltages at commercial frequencies like lightning arresters do, such as increases in line voltage due to intermittent arc discharge. The height of the current-limiting element 20 can be set smaller than that of the lightning arrester, and the current-limiting element 20 can be made smaller.
Deterioration can be prevented by reducing the constant voltage burden.

Note that the present invention can also be embodied in the following embodiments.

As shown in FIG.
An electrode 18,
19. The electrode plates 21 and 22 and the current-limiting element 20 are configured to be held in a pinched manner. In this case, a conductive adhesive is also used between the cap portion 13b and the electrode 18.

(Effects of the invention) As detailed above, the present invention can suppress deterioration of the current limiting element, and in the unlikely event that the current limiting element deteriorates or explodes due to excessive lightning surge, the cylindrical insulator is scattered. It also prevents tension-resistant insulating rods from breaking off, thereby preventing wires from falling to the ground or breaking, and eliminates space constraints compared to when a current-limiting element is installed externally, reducing obstacles during line repair. It has the effect of eliminating the

[Brief explanation of the drawing]

Figure 1 is a front view showing a lightning tension device incorporating the lightning tension insulator of the present invention, Figure 2 is an enlarged sectional view of only the lightning tension insulator, and Figure 3 is taken along line A-A in Figure 2. FIG. 4 is an end view taken along line BB in FIG. 2, and FIG. 5 is a sectional view showing another example of the present invention. 11...Lightning resistant tension insulator, 12...Tension resistant insulation rod,
13, 14... Cap electrode, 16... Cylindrical insulator, 18, 19... Electrode, 20... Current limiting element, 2
1, 22... Electrode plate, 26... Elastic insulator, 27
...Closed foam insulation.

Claims (1)

[Claims for Utility Model Registration] 1. Cap electrodes 1 at both ends of the tension insulating rod 12.
Similarly, a cylindrical current-limiting element 20 made of a material with non-linear voltage-current characteristics is fitted on the outer periphery of the tension-resistant insulating rod 12, and the current-limiting element 20 is The cylindrical insulator 16 was fitted, and the gap formed by the tension insulating rod 12, cap electrodes 13, 14, current limiting element 20, cylindrical insulator 16, etc. was filled with closed foam insulator 27 and sealed. A lightning-resistant tension insulator characterized by: 2 The current limiting element 20 has electrode plates 21 on both ends thereof,
The lightning-resistant tensile insulator according to claim 1, wherein both the outer peripheral surface and the inner peripheral surface are covered with an elastic insulator 26 together with the electrodes 18 and 19 which are brought into contact with each other via the electrodes 22.