JPH0429522Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to the improvement of insulator type arresters used in high-voltage distribution lines. This product relates to an insulator arrester that has a fuse built into the insulator body to allow AC (commercial frequency) follow-on current to escape to the ground and at the same time cut off the follow-on current.

[Conventional technology]

In high-voltage distribution lines, it has the function of supporting insulated wires in the same way as high-voltage pin insulators, and the function of an arrester to safely release abnormal high voltages such as lightning surges propagating through distribution lines to the ground. Insulator arresters have recently come into use.

As mentioned above, this insulator-type arrester is intended to be used in the same way as a high-voltage pin insulator, so it cannot be made particularly large in shape compared to a pin insulator. Therefore, the voltage non-linear resistance element (zn0 element) built into the insulator naturally has its shape (cross-sectional area and length) limited, and the discharge withstand capacity of the resistance element tends to be reduced.

[The problem that the idea attempts to solve]

In the conventional technology described above, when an excessive surge current exceeding the discharge withstand capacity of the non-linear resistance element flows, an external short circuit (external flash short) is likely to occur in the non-linear resistance element, and the follow-up arc at that time This resulted in an explosion accident in which the insulator was destroyed, leading to problems such as damage to the insulation function of the line and the spread of unexpected damage to the surrounding area due to follow-up arcs.

In view of the above, an object of the present invention is to provide an insulator type arrester that can prevent the insulator from being destroyed even if an excessive lightning surge current flows.

[Means for Solving the Problem] In order to achieve the above object, the insulator type arrester of the present invention has a fuse wire 19 and a voltage nonlinear resistance element 2 connected in series in the insulator body 1. Stack the fuse wire 19
A fuse tube 16 is placed on the outside of the insulator body 1, and an adhesive material 3 having insulation properties and elasticity is placed between the outer peripheral surface and the inner wall surface of the insulator body 1.
1, and an insulating material 14 having insulation properties and elasticity is also filled between the outer circumferential surface of the resistor element 2 and the inner wall surface of the insulator body 1.

[Effect]

If the lightning surge current is less than the discharge withstand capacity of the nonlinear resistance element 2, the current
The fuse wire 19 will not be blown out because the flow is caused to escape to the ground and the follow-on current is instantly cut off.

If the lightning surge current is a large current that exceeds the discharge withstand capacity of the nonlinear resistance element 2, an external circuit (flash short) occurs in the nonlinear resistance element, and this causes AC (commercial frequency)
However, the fuse wire 19 is fused and the current is cut off, and the impact when the fuse is blown is alleviated by the fuse tube, reducing the risk of explosion of the insulator 1. It disappears.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

Reference numeral 1 denotes an insulator body having double deep grooves 1a formed on the outer circumferential surface and a through-hole storage portion 1b formed in the center.The storage portion 1b is located on the upper side and forms a fuse storage portion 1c. A resistive element housing portion 1d is formed at the lower side.

2 is a donut-shaped voltage nonlinear resistance element made of a zinc oxide (ZN0) element provided with a discharge hole 2a, and is stored vertically in three stages in the element 2 and the above-mentioned resistance element storage part 1b. ing. 3 indicates an insulating member such as a rubber band.

Reference numeral 4 denotes a cap-shaped upper sealing plate made of a thin phosphor bronze plate, copper plate, stainless steel plate, etc., which is metallized on the upper step portion 1e of the resistance element housing portion 1d and further hermetically bonded with a wax material. 4 is in contact with the upper end surface 2a of the resistive element 2. Reference numeral 5 designates a lower sealing plate which is metallized and soldered to the inner circumferential surface 1g of the opening end 1f on the lower side of the resistive element housing portion 1d to form a hermetically sealed seal in the same manner as the upper sealing plate 4. A stretchable bending portion 5a is formed in a part of the shaped copper plate. It should be noted that the resistive element housing portion 1d is safely isolated from the outside air by this lower sealing plate 5 and the above-mentioned upper sealing plate 4.
Reference numeral 6 denotes a cap-shaped contact fitting that comes into contact with the outer surface 5b of the lower sealing plate 5, and is bonded to the lower sealing plate 5 with a silicone resin adhesive 7. Reference numeral 8 denotes a cap-shaped base metal fitting fixed to the outer circumference 1h of the lower end of the insulator body 1 via an adhesive 39 such as cement, which further covers the lower sealing plate 5 from the outside and further covers the bottom surface of the metal fitting. 8a
At the center thereof, a mounting bolt 9 is provided which protrudes downward and perpendicularly, with a head 9a protruding from the inner surface and fixed integrally by welding. 10 is a buffer gasket made of rubber or cork that is interposed between the lower end 1i of the insulator and the protrusion 8b on the inner surface of the base metal fitting 8;
1 and 12 are the contact fitting 6 and the head 9 of the mounting bolt 9
a, the conductive piece and the coil spring interposed between the upper surface 9a', and the lower end surface 2 of the resistance element 2 in the storage section.
c is electrically connected via the base metal fitting 8 or the mounting bolt 9 to the arm 13 which is the ground side during installation. Reference numeral 14 indicates an insulating member having insulation and elasticity filled in the gap between the inner wall surface 1d' of the housing portion 1d and the resistance element 2, and 15 indicates a nut provided on the threaded portion 9b of the mounting bolt 9.

Reference numeral 16 denotes a discharge type fuse tube housed in the fuse storage section 1c, which has a smaller diameter than the resistance element storage section 1d. It is composed of an inner layer 16a made of generated melamine resin, etc., and an outer layer 16b made of FRP etc. that is closely attached and reinforced from the outside. It is threadedly connected to the threaded part 17b of the arc emitting part 17a, and the threaded part 16b at the lower end is threadedly connected to a threaded member 18 fixed to the outer periphery 4a side of the upper sealing plate 4. 19 is a fuse wire stretched inside the fuse tube 16;
One end 19a on the upper side is screwed into the threaded portion 17d of the arc emitting portion 17a during the screw connection.
Further, the other end 19b of the lower side is press-connected to the upper sealing plate 4 which connects to the upper end surface 2b of the resistor element 2 in the same manner when screwed together.

The above-mentioned electric wire connection terminal 17 is attached to one side of the cap-shaped fixed part 17b and the small-diameter cap-shaped arc emitting part 17a and the fixed part 17b, which are formed in the upper center of the fixed part 17d. It consists of a protruding electric wire connecting part 17c, and the above-mentioned fixing part 17b is placed over the upper outer periphery of the insulator body 1, and is fixed by an adhesive 20 such as cement.
Reference numeral 17a' denotes an arc discharge port provided in the arc discharge portion 17a, which is provided adjacently above the open end 16e on the upper side of the fuse tube 16, and the discharge port is provided in the arc discharge portion 17a that protrudes downward. It is located in the center of the top surface. 21 is a pressure relief lid made of a thin plate placed on the locking step 17a'' of the discharge port 17a' from the outside, and 22 is an injection valve that covers the pressure relief lid 21 from the outside to make it watertight. 17c' shows the silicone resin sealing material used at the wire connection part 1.
7c is a wire holder protruding to the side; 23 is a washer made of aluminum or the like fitted into the recess 17c'' of the wire holder; 24 is a support portion 17b' provided on the fixed portion 17b; The electric wire press part 24a at the other end is rotatably pivoted and the electric wire holder 1
7c', and the horizontal part 26a of the metal fitting 24 is engaged with an engaging groove _17c1 formed on the lower surface side of the wire holder on the side surface of the metal fitting 24. A notch 24b is formed into which the vertical portion 26b of the matched ⊥-shaped tightening bolt 26 is inserted.

Reference numeral 24d indicates a recess formed opposite to the recess 17c'' of the wire receiver 17c', 27 a U-shaped washer, and 28 a tightening nut provided on the threaded portion 26b' of the vertical portion 26b.

Note that the insulated wire 29 remains in the recess 17 even when the core wire is stripped and the insulation coating is removed.
The electric wire is sandwiched and supported between c'' and 24d, and the electric wire and the electric wire connection terminal are electrically connected. 30 is a packing made of rubber or cork, and 31 is the outer peripheral surface of the fuse cylinder 16 and the fuse housing part 1c. This shows, for example, a silicone-based adhesive having insulation and elasticity that fills the gap formed by the inner peripheral surface of the 33.
indicates an insulating cover.

Next, the operation of the insulator arrester having the above configuration will be explained.

Under normal conditions, only the normal voltage to ground (approximately 4kV on a 6kV class power distribution line) is applied to resistive element 2, so no current flows through resistive element 2 (in reality, it is very small). leakage current flows, but this can be ignored in practice).

When an abnormal voltage such as a lightning surge propagates from the above-mentioned normal state, the surge is transmitted to the insulated wire 29.
- Wire connection part 17c of electric wire connection terminal 17, arc discharge part 17a - Fuse wire 19 - Upper sealing plate 4 -
Resistance element 2 - lower sealing plate 5 - contact fitting 6 - conductive piece 11/coil spring 12 - head 9a of mounting bolt 9
- It is released from the base metal fitting 8 and arm metal fitting 13 to the earth via the ground wire.

Furthermore, when the above-mentioned abnormal voltage enters, if it is a large current that exceeds the discharge withstand capacity of the resistor element 2, an external circuit (flash short) occurs in the discharge hole 2a of the resistor element, which causes AC ( (commercial frequency) superimposes and a follow-on arc flows, but at this time,
The upper sealing plate 4 is destroyed by the follow-on arc, and the fuse wire 19 is also cut off, but in this case, the increased internal pressure of the fuse tube 16 causes the pressure relief cover 21 of the arc outlet 17a' to close. Since the arc scatters, the arc is immediately emitted outside the main body, and explosion of the insulator body 1 is prevented. Note that the above voltage nonlinear resistance element 2
As can be seen from the drawing, since a donut-shaped element is used, flashover occurs even in the central discharge hole 2a as described above, but when a solid element 2' is used as shown in Figure 2. Since flashover occurs on the outer peripheral surface of the element, the gap G between the insulating cylinder 32 and the outer peripheral surface of the element becomes an arc discharge hole.

[Effect of idea]

Since the present invention is constructed as described above, the nonlinear resistance element and the fuse work together against lightning surge current over a wide area, thereby reliably preventing destruction of the arrester. In particular, even if an AC (commercial frequency) follow-on arc flows, this follow-on current can be quickly interrupted by a fuse in series with a voltage nonlinear resistance element, which is provided within the insulator. Accidents of explosion of the insulator due to arc can be reliably prevented. Furthermore, since the resistor element and the fuse are stacked vertically in two layers and stored in the storage portion formed in the insulator body so that they are connected in series, the whole can be made compact.

Furthermore, in this invention, an insulating and elastic adhesive 31 is filled between the fuse tube and the insulator, so the adhesive blocks arc heat, buffers and absorbs pressure, and absorbs shock. It is possible to protect the fuse tube from the arc heat and excessive pressure generated when the circuit is cut off, and also to protect the insulator from explosion. Since it is filled with an insulating material that has properties of
This protects the inner wall surface of the insulator and, in turn, protects the insulator body from explosion accidents.

[Brief explanation of drawings]

Fig. 1 is a longitudinal half-sectional view of an insulator arrester showing an embodiment of the present invention, Fig. 2 is a sectional view of the main part of another embodiment, and Fig. 3 is a side view of the wire connection terminal section of Fig. 1. , FIG. 4 also shows a plan view. DESCRIPTION OF SYMBOLS 1...Insulator, 2...Voltage nonlinearity resistance element, 1
6...Fuse tube, 19...Fuse wire.

Claims (1)

[Scope of utility model registration request] A fuse wire 19 and a voltage nonlinear resistance element 2 are stacked in two layers, upper and lower, and stored in the insulator 1 so that they are connected in series, and a fuse tube 16 is placed on the outside of the fuse wire 19 with its outer peripheral surface. An adhesive material 31 having insulation and elasticity is filled and disposed between the inner wall surface of the insulator body 1, and an insulating material is also provided between the outer circumferential surface of the resistance element 2 and the inner wall surface of the insulator body 1. An insulator-shaped arrester characterized by being filled with an insulating material 14 having strength and elasticity.