JPH036981Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention A-1. Field of Industrial Application The present invention relates to a disconnection prevention device that is used by being directly attached to an insulated wire of a high-voltage distribution line.

A-2 Prior Art Recent high-voltage distribution lines use insulated wires. As shown in FIG.
It is supported and fixed to the head 5 of the head 5 by a support fitting 6 such as a binding wire or a wrapping grip. by the way,
In the support device in which the insulated wire is supported and fixed to the head of the insulator using the support metal fittings, when a lightning surge h enters the line and an abnormal overvoltage is applied, most of the overvoltage is transferred to the line. Since voltage is applied between the supporting metal fitting 6 and the pin 7 or the cross arm 8 due to the voltage shared by the capacitance, a flash short occurs between the two. When this flash fault occurs, creeping streamers g rapidly develop from the ends of both sides of the support metal fitting 6 along the insulation coatings of the left and right electric wires, centering on the insulator body, and reach a weak point 2a' somewhere in the insulation coating. Dielectric breakdown of the electric wire 2 occurs, and at the dielectric breakdown point, a fixed follow-on current flows, and the electric wire 2 is disconnected or the insulator body 4 is broken due to uneven heat due to the arc heat.

As mentioned above, once a disconnection occurs, it takes a long time to discover the faulty section and restore it, resulting in a prolonged power outage, and if the disconnected wire is discharged while still being charged, it may lead to a public disaster. Therefore, measures to prevent disconnection due to lightning surges are extremely important issues, and some high-voltage power distribution lines are currently using arcing horns for high-voltage pin insulators, or current limiting devices that are connected in series to the arcing horns. Countermeasures such as installing horns have been taken and have had some success.

A-3 Problems to be Solved by the Present Invention However, the above-mentioned arcing horn (including current limiting horn) method still has major problems. In other words, in the above-mentioned arcing horn method, the incoming lightning surge is discharged to the earth (ground) by the arcing horn provided on the charging side or the ground side of the high-voltage pin insulator, or even on both the charging side and the ground side. In this case, in order to ensure that the discharge occurs in advance at the horn (side), the discharge starting voltage of the arcing horn is set to the flash voltage of the high-voltage pin insulator (side) to which the horn is attached (between the live part of the insulator and the ground). Since the voltage is set much lower than the discharge starting voltage, this poses a fatal problem if the insulation of the high-voltage distribution line inevitably deteriorates. In addition, by attaching a current limiting element unit to an insulated wire and electrically connecting one charging side electrode to the insulated wire, and facing the other discharge electrode with an air gap 1 in between, a high voltage distribution line (high voltage Although devices that prevent the insulation from deteriorating (pin insulators) have been proposed, such devices lack installation stability as they are cantilevered and attach only the live electrode side to the insulated wire, and they also have problems with protrusions. There was a problem in that the size was large and aesthetically undesirable. This proposal proposes a disconnection prevention device that solves the problem of deterioration in line insulation, and at the same time, accurately captures incoming lightning surges without delaying discharge and guides them quickly and safely to the ground. In particular, the present invention relates to a configuration that allows stable attachment to insulated wires and smartness after attachment.

B. Structure of the device B.1 Means for solving the problem To this end, in this proposal, an insulated wire is supported and fixed to the head of the insulator body of a high-voltage pin insulator using a support fitting such as a binding wire or a wrapping grip, and the insulator is For supporting devices for insulated wires in high-voltage power distribution lines, which are attached and fixed to the earth-side bracket using pins fixed to the body, the insulated wires near the ends of the support brackets are made of insulators with voltage nonlinearity. Attach a current-limiting element whose outer periphery is covered, and directly connect the non-current-charging side electrode provided along the outer periphery of the insulation coating of the insulated wire to one end face of the element, and directly connect it to the support metal fitting or at a predetermined insulation distance. In a device for preventing disconnection of an insulated wire, the wire breakage prevention device is configured such that the wires are closely opposed to each other while maintaining the same, and a charging side electrode that is in close contact with the other end face of the insulated wire is directly electrically connected to the core wire of the insulated wire. proposed a disconnection prevention device characterized in that a current limiting element having a horseshoe-shaped cross-section, a divisible circle, or an arc shape is placed over an insulated wire from the outer periphery of the sheath and placed concentrically with respect to the wire. It is something to do.

B-2 Embodiment An embodiment of the present invention will be specifically explained below with reference to FIGS. 2 to 6. Reference numeral 1 in FIG. 2 shows a well-known insulated wire support device, in which the insulated wire 2 is supported and fixed to the head 5 of the insulator body 4 of the high-voltage pin insulator 3 by a support fitting 6 such as a binding wire or a wrapping grip. The insulator body is attached to a grounded bracket 8 with a nut 9 via a pin 7 fixed to the insulator body. Reference numeral 10 shows the disconnection prevention device of the present invention, which is attached to the insulated wire 2 near the end 6a of the support fitting 6, which has a large potential gradient. The current limiting element 11, which is the main part of the prevention device, has a substantially horseshoe-shaped cross section. The current limiting element 11 is made of a material such as silicon carbide (SiC) or zinc oxide (ZnO), and has the function of blocking (blocking) the follow-on current of the commercial frequency due to discharge due to its excellent voltage nonlinearity.
Reference numeral 12 denotes a non-charging side (ground) electrode that is electrically in close contact with one end surface 11a of the current limiting element which is sprayed with a metal such as aluminum, and an auxiliary electrode piece that is connected to the same electrode by a screw 14. 13 is provided along the coated outer circumference 2a of the insulated wire 2, and its tip is kept at a predetermined insulation distance l (in the embodiment of the present invention, the distance from the end of the support metal fitting 6 is within 20 mm) from the end 6a of the support metal fitting 6. They are facing each other closely. In this case, instead of the auxiliary electrode piece, a part of the non-charging side electrode may be formed to protrude forward and be opposed to the support metal fitting as described above. Reference numeral 15 denotes a charging side electrode that is electrically in close contact with the other end surface 11b of the current limiting element 11, which is also sprayed with metal, and when attached to a part of it, it pierces the insulation coating 2a of the insulated wire and the core wire 2b.
A needle-shaped contact portion 15a is formed to protrude inward. Reference numeral 16 denotes an insulating material such as epoxy resin which integrally covers the outer peripheral surfaces of the auxiliary electrode piece 13 connected to the non-charging side electrode 12, the charging and non-charging side electrodes 15 and 12, and the current limiting element 11. This insulator has a connection hole 16b formed in the same area as the connection part 16a that protrudes downward, and a wire contact part 16c that is in close contact with the wire along the outer periphery of the wire coating. on the other end. 1
Reference numeral 5a indicates a contact portion of the charging side electrode which is located at the center of the wire contact portion 16c and protrudes inward from the insulator 16 in a needle shape, and 17 indicates a nut inserted into the tightening portion.

Further, 18 has one end connected to the connecting portion 16b of the insulator.
It is a pressed body with a substantially rectangular cross section made of enexy resin or the like, which is pivoted by a support pin 19, and has a recessed wire contact portion 18a at a position opposite to the wire contact portion 16c of the insulator. In addition to forming
A nut 20 is inserted into the other end. 21
22 is an insulating cover made of rubber or synthetic resin that is attached to the outside of the insulator 16 and can be opened and closed at one end; 23 is a silicone-based filler injected into the void inside the cover; This is to prevent rainwater from entering and flashing on the outer surface of the insulator.

In addition, when attaching the disconnection prevention device with the above configuration to an existing or newly installed insulated wire support device, both wire contact portions 16c, 1 of the insulator 16 and the pressing body 18
8a to the outer periphery 2a of the insulated wire 2, and tighten the tightening screw 21 provided on the tightening part side with the nut 2.
0 and tightened, the insulating cover 22 is attached, and finally, the filler 23 is injected into the cover through a small hole (not particularly shown) provided in the cover to complete the installation.

Next, the disconnection prevention device 10 shown in FIGS. 4 to 6 will be explained. This shows another embodiment of the present invention in which the attachment to the insulated wire is slightly different.
After the insulated wire 2 is completely fitted into the wire contact portion 16c of the insulator 16, the wire contact portion 24a of the tightening band 24 is inserted into the contact portion 16c from the outside to press the wire. Then, when the band wound around the outer circumference of the insulator 16 is tightened, the charging side electrode 1
The contact portion 15a of the electric wire 5 pierces the insulating coating 2a of the electric wire and connects with the core wire 2b, and the attachment is fixed at the same time by this connection. In addition, in the drawings, the same numbers are added to the same members as in the embodiment described above, and the description thereof will be omitted.

Next, the operation will be explained.

Now, if a lightning surge invades and the impact overvoltage is at least greater than the flash voltage of the high voltage pin insulator, a flash will occur between the pin 7 or arm 8 on the ground side and the support 6. As a result of this flashing, a creeping streamer rapidly develops from the end 6a of the support fitting along the outer periphery _2a1 of the insulated wire 2, but the streamer is a disconnection prevention device attached to the insulated wire near the end of the support fitting. is guided to the non-charging side electrode 12 of. In other words, the streamer is connected to the outer circumference 2 of the insulated wire so as to be grounded and opposite to the end 6a of the support fitting.
It is accurately captured by the non-charging side electrode 12 (more specifically, the auxiliary electrode piece 13) provided along the _a1 .
Then, the same surge is caused by the core wire 2b of the insulated wire, the charging side electrode 15, the current limiting element 11, the non-charging side electrode 12, the insulation gap (insulation distance), the support fitting 6, the creeping surface 4a of the insulator body 4, and the pin 7 or arm. It quickly escapes to the earth (earth) through the discharge path of gold 8. At the same time, the current-limiting element 11 and the creeping gap 4a of the insulator 4, which are interposed in series in this discharge path, prevent (block) the follow-on current of the commercial frequency, and the insulated wire is cut off by the follow-on current arc that occurs in the past. Reliably prevent disconnection accidents.

The disconnection prevention device of the present invention has the following embodiments: (1) A sheet-like or pipe-like insulation reinforcing body made of rubber or synthetic resin is attached closely to the outer periphery of the insulated wire near the attachment part of the insulator; Therefore, the insulation coating of the wire should not be damaged by a lightning surge before the protection device does.
However, in this case, the insulating reinforcement must be long enough to extend beyond the end of the support fitting.

(b) Install a disconnection prevention device on the insulated wire near both ends of the support bracket, not just one end.

(c) When a flash short circuit occurs between the support bracket 6 and the pin 7 or the cross arm 8 due to a lightning surge, the surge can be accurately captured by the non-current electrode 12 of the disconnection prevention device. Electrode 12 and support fitting 6
A direct electrical connection between the two using lead wires, etc.

(d) The cross-sectional shape of the current limiting element should be a horseshoe shape or a divisible circle or arc shape so as to surround the outer periphery of the insulated wire.

(e) When connecting the charging side electrode that is in close contact with the current limiting element to the core wire 2b of the insulated wire, remove part of the insulation coating near the attachment part beforehand.

F. It can be used not only for 6KV high-voltage distribution lines but also for extra-high-voltage electric lines.

However, insulated wires must be used.

It is of course understandable that the technical idea of the present proposal can be realized by such methods.

C. Effect of the present invention As described above, the disconnection prevention device of the present invention supports and fixes an insulated wire to the head of the insulator body of a high-voltage pin insulator using a support fitting such as a bind wire or a wrapping grip, and then attaches the insulator body to the insulator body. In a support fitting for an insulated wire in a high-voltage distribution line, which is attached and fixed to a ground arm by a fixed pin, a current limiting element having voltage nonlinearity is attached to the insulated wire near the end of the support fitting, and the same is applied. The non-current electrode, which is in close contact with one end face of the element and is provided along the outer periphery of the insulation coating of the insulated wire, is directly connected to the support metal fitting or is placed close to and opposite to the support metal fitting while maintaining a predetermined insulation distance, and further The charging side electrode, which is in close contact with the other end face, is electrically connected directly to the core wire of the insulated wire, so even if a lightning surge intrudes, it can be quickly discharged to the earth (earth) through the current limiting element. At the same time, the following current is blocked (cut off) by the same element, so it goes without saying that it is possible to reliably prevent disconnection of insulated wires caused by follow-on arcs, which was seen in the past. There is no need to move the high-voltage pin insulator, electric wire, or wire support fitting on the support device side, and it can be attached to the insulated wire near the end of the support fitting as is, so it can insulate a wide range of areas, regardless of whether it is existing or newly installed. It has the advantage of being applicable to wire support devices. Furthermore, since it is directly attached to the electric wire, it does not require a special installation location, and it also has the advantage that the installation does not spoil the aesthetic appearance. In addition, since the prevention device of this invention is directly attached to the electric wire as described above, the horn system is equipped with a high-voltage pin insulator, which lowers the inherent voltage withstand performance (between the live part and the ground) of the high-voltage pin insulator and distributes power. It also has excellent insulation properties, such as not substantially lowering the insulation class of the line. Furthermore, in the wire breakage prevention device of the present invention, the non-current-charging side electrode, which is provided in close contact with one end face of the current-limiting element and along the outer periphery of the coating of the insulated wire, is directly connected to the support metal fitting or at a predetermined insulation distance. The surge can be directly captured by the non-charging side electrode, or the creeping streamer that rapidly develops along the outer periphery of the insulation coating of the insulated wire can be captured. Surges are captured more reliably than in the case of an air gap (air discharge), and an air gap is formed between the support fitting on the wire support device side and the non-charging side electrode on the prevention device side. Compared to the disconnection prevention device described above, the spark delay during discharge and the variation in discharge starting voltage are eliminated or reduced, resulting in stable discharge characteristics. In addition, when installing the disconnection prevention device, there is no need to make fine adjustments to the air gap, and the installation can be done easily (roughly). Since the element is attached over the outer periphery of the insulated wire, stable attachment can be maintained, and even after installation, it gives a clean impression and is aesthetically pleasing.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the installation of a conventionally well-known insulated wire support device, Fig. 2 shows an embodiment of the present invention, and Fig. 3 is a cross-sectional view of the proposed wire breakage prevention device attached to an insulated wire. A sectional view taken along the line A-A in Fig. 2 and Fig. 4 show other embodiments of the present invention.
A longitudinal sectional view of the disconnection prevention device attached to the insulated wire, Figure 5 is a BB sectional view in Figure 4, and Figure 6
The figure is a plan view of FIG. 4 with the insulating cover, filler, and tightening band removed. 1 ...Wire support device, 2...Insulated wire, 2a...
...Insulation coating, 2a ₁ ...Insulation coating outer periphery, 2b ... Core wire, 4 ... Insulator body, 5 ... Head, 6 ... Supporting metal fitting, 6a ... End, 7 ... Pin, 8 ... Bracelet , 1
0... Disconnection prevention device, 11... Current limiting element, 11
a, 11b... end face, 12... non-charging side electrode, 1
3... Auxiliary electrode piece, 15... Charging side electrode, l...
insulation distance.

Claims (1)

[Scope of utility model registration request] In a high-voltage distribution line in which an insulated wire is supported and fixed to the head of the insulator body of a high-voltage pin insulator using a support fitting such as a binding wire or a wrapping grip, and is attached and fixed to a cross arm on the ground side using a pin fixed to the insulator body. For an insulated wire support device, a current-limiting element whose outer periphery is covered with an insulator having voltage non-linearity is attached to the insulated wire near the end of the support fitting, and the current-limiting element is closely attached to one end face of the element. Also, the non-carrying side electrode provided along the outer periphery of the insulation coating of the insulated wire is directly connected to the support metal fitting or is closely opposed to it while maintaining a predetermined insulation distance, and the charging side electrode is placed in close contact with the other end face of the same element. In the disconnection prevention device for an insulated wire that is electrically directly connected to the core wire of the insulated wire, the disconnection prevention device includes a current limiting element whose cross section is formed into a horseshoe shape, a divisible circle, or an arc shape. A disconnection prevention device characterized by being placed over an insulated wire from the outer periphery of the sheath and placed concentrically with respect to the wire.