JPH0451483A - Lightning arrester of self arc suppressing extinction type - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for protecting power distribution equipment from overvoltages caused by lightning.

[Prior art] Lightning arresters limit the overvoltage by dividing current when the peak value of overvoltage caused by lightning strikes, etc. exceeds a certain value, and quickly interrupts the follow-on current to restore the current state. It has the function of self-recovery.

Conventional lightning arresters commonly used include:
One example is a combination of a current limiting element with a built-in current limiting element and a series gap. Usually, a zinc oxide element having excellent nonlinear voltage-current characteristics is used as a current limiting element. In this device, when a lightning surge enters the live terminal, the series gap flashes and discharges current through the current limiting element. After discharge, the arc is extinguished and subsequent current is cut off due to the non-linear voltage-current characteristics of the current-limiting element.

[Problem to be solved by the invention] Conventional devices of this type have a hole-machined F for pressure relief.
Zinc oxide elements are stacked in several layers on a RP tube, and then E
The structure was complex, as it was molded with an organic insulating abrasive material such as P-rubber. In addition, in the above device, if a fault current flows and an arc current is generated inside the device, there is a risk that the device will explode and scatter as the internal pressure increases, so it is necessary to provide an additional arcing horn (or arcing ring) on the outside to prevent this. was there. Furthermore, when stacking several stages of heavy zinc oxide elements in the above-mentioned apparatus, a problem arose in that the weight of the apparatus increased and its workability deteriorated.

An object of the present invention is to provide a lightning arrester that has a simpler structure, requires fewer parts, and is easier to construct than the conventional lightning arresters described above.

[Means for Solving the Problems] The arc self-extinguishing lightning arrester according to the present invention includes a cylindrical body made of an insulating material and having a lower dielectric strength on the inside than the outside, and a space inside the cylindrical body that is provided to partition a space inside the cylinder. , a partition that is slidable along the inner surface of the cylinder from a predetermined position within the cylinder; a first electrode that is provided on the partition and is movable together with the partition;
A sealing wall provided to seal one space partitioned by a partition wall in the cylinder, and a second electrode provided on the sealing wall to face the first electrode, the first electrode and the second electrode When an arc is generated between the two electrodes, the gas in the one space expands due to the energy of the arc, and at least the partition wall moves to widen the distance between the two electrodes.

Further, in the arc self-extinguishing lightning arrester according to the present invention, in the space partitioned by the partition wall in the cylinder, the partition wall slides from a predetermined position to transfer the compressed gas to the other space separated by the partition wall. An exhaust port for blowing into the space can further be provided in the partition wall.

Note that the partition wall and the first electrode and the sealing wall and the second electrode according to the present invention may be integrally formed of the same material.

Further, the sealing wall according to the present invention does not necessarily have to be fixed, but may be provided so as to be slidable.

[Function] The arc self-extinguishing lightning arrester configured as described above has the following features:
One electrode is connected to the ground side and the other electrode is connected directly to the energized side or arranged with a gap provided.

When a lightning surge enters the power supply side, a flash short circuit is created between both electrodes, and the lightning current is discharged through the ground.

The cylindrical body that forms the device has a lower dielectric strength on the inside than on the outside, so when a lightning surge enters the energized side, flashover will not occur on the outside of the cylindrical body, and it will always be inside the cylindrical body. A flashover occurs between the electrodes and an arc occurs.

The energy of the generated arc increases the pressure of the gas between the electrodes, that is, the gas existing between the partition wall where the first electrode is provided and the sealing wall where the second electrode is provided. This increase in pressure causes the partition, which is slidable along the inner surface of the cylinder, to move in the direction of gas expansion.

At this time, the first electrode moves together with the partition wall and the distance between the electrodes increases, so that the arc is extinguished.

Further, the gas existing in the space partitioned by the partition wall inside the cylinder is compressed by the sliding movement of the partition wall, and is blown into the space between the electrodes through the exhaust port.

In this way, the arc generated between the two electrodes is blown off and extinguished.

[Example] Next, an arc self-extinguishing type lightning arrester according to the present invention will be described based on the drawings.

(Example 1) An example of the arc self-extinguishing type lightning arrester shown in FIG. 1 will be described.

In the apparatus shown in FIG. 1, one end of a cylindrical insulating cylinder 1 made of ceramic is covered with a metal lid 10, and the other end is a lower electrode in which an electrode part 4a extending from the center into the cylinder is formed. The body 4 is sealed.

Further, the outer periphery of the insulating tube 1 is covered with an insulating sleeve 2 having umbrella-shaped pleats formed with an organic insulating material. Therefore, the outside of the insulating tube 1 has a higher dielectric strength than the inside.

On the other hand, an upper electrode body 3 is provided inside the insulating cylinder 7 and is slidable along its inner surface. The upper electrode body 3 is
The electrode portion 3a extends from the center thereof to face the electrode portion 4a of the lower electrode body 4. The upper electrode body 3 is electrically connected to the lid body 10 by a lead wire 9, and is normally supported by insulating stoppers 7a and 7b fixed to the cylindrical body of the insulating cylinder 1 so as to face each other.

The arc self-extinguishing lightning arrester configured as above is
Either the lid body 10 or the lower electrode body 4 is connected to the ground, and the other is directly connected to the energized side, or they are arranged with a gap provided therebetween. In the device installed in this manner, when a lightning surge enters the power supply side, an arc is generated between the electrode portions 3a and 4a of the upper electrode body 3 and the lower electrode body 4, respectively. The energy of this arc increases the pressure of the gas between the electrodes, pushing up the slidable upper electrode body 3. As a result, the upper electrode body 3 moves in the direction of the arrow shown in the figure, and the gap between the electrodes widens, so that the arc is extinguished. Note that after the arc is extinguished, the upper electrode body 3 returns to its original position due to its own weight.

(Example 2) An example of the arc self-extinguishing type lightning arrester shown in FIG. 2 will be described.

In the apparatus shown in FIG. 2, both ends of a cylindrical insulating tube 1 made of ceramic are covered with metal lids 10a and 10b. Further, the outer periphery of the insulating cylinder 1 is covered with an insulating sleeve 2 formed with umbrella-shaped pleats made of an organic insulating material.

An upper electrode body 3 and a lower electrode body 4 that are slidable along the inner surface of the insulating cylinder 1 are provided inside the cylinder. The upper electrode body 3 has an electrode portion 3a at its center extending in the direction of the lower electrode body 4, and is electrically connected to the lid body 1-Oa through a lead wire 9a. Further, the upper electrode body 3 is usually
It is supported by insulating stoppers 7a and 7b fixed to the cylindrical body of the insulating cylinder 1 so as to face each other. On the other hand, the lower electrode body 4 is supported by a spring 6 within the cylindrical body at an appropriate distance from the upper electrode body 3. The lower electrode body 4 has an electrode portion 4a formed at its center extending in the direction of the upper electrode body 3, and is electrically connected to the lid body 10b by a lead wire 9b.

The device configured as described above includes the lid body 10a or 10
Either one of b is connected to the ground, and the other is connected directly to the power supply side or arranged with a gap provided. In the device installed in this way, when a lightning surge enters the power supply side, an arc is generated between the electrode parts 3a and 4a,
The energy increases the pressure of the gas between the electrodes. As a result, the upper electrode body 3 and the lower electrode body 4 are both pushed together, and the gap between the electrodes increases, so that the arc is extinguished.

After the arc is extinguished, the upper electrode body 3 returns to its original state due to its own weight, and the lower electrode body 4 returns to its original state due to the elastic force of the spring 6.

(Embodiment 3) An embodiment of the arc self-extinguishing type lightning arrester shown in FIG. 3 will be described.

The structure of the device shown in FIG. 3 is the same as that of Example 1, except for the slidable upper electrode body 3.

On the other hand, in the upper electrode body 3, a plurality of exhaust ports 3b and 3c are formed in the vicinity of an electrode portion 3a formed at the center thereof. These exhaust ports are formed obliquely so that when the gas between the upper electrode body 3 and the lid body 10 exits, it is concentrated in the direction of the electrode portion 3a.

The apparatus configured as described above is the same as that of the first embodiment. Similarly, when a lightning surge enters the power supply side by setting it between the ground and the power supply side, an arc is generated between the electrode parts 3a and 4a. The energy of this arc increases the gas pressure between the electrodes, pushing up the slidable upper electrode body 3. As a result, the gap between the electrodes becomes wider and the arc is extinguished, but the sliding of the upper electrode body 3 compresses the air between the upper electrode body 3 and the lid body 10, and the air between the upper electrode body 3 and the lid body 10 is compressed. 3b and 3
It is discharged from C. The arc is extinguished more quickly because of this air evacuation.

(Embodiment 4) An embodiment of the arc self-extinguishing type lightning arrester shown in FIG. 4 will be described.

In the apparatus shown in FIG. 4, one end of a cylindrical insulating cylinder 1 made of ceramics is covered with a metal lid 10, and the other end is covered with a lower electrode portion 4a extending from the center into the cylinder. It is sealed with body 4.

Further, the outer periphery of the insulating tube 1- is covered with an insulating sleeve 2 in which umbrella-shaped pleats are formed with an organic insulating material.

Inside the insulating tube 1, a cylindrical insulating guide pipe 5 is further provided above. Note that the insulating guide pipe 5 is attached to the inner wall of the insulating tube 1 via a support portion (not shown). Further, one end of the insulated guide pipe 5 close to the lower electrode body 4 is tapered into a conical shape. An upper electrode body 3 is provided inside the insulated guide pipe 5 and is slidable along its inner wall. The upper electrode body 3 has an electrode portion 3 a formed at its center that extends so as to face the lower electrode body 4 , and is electrically connected to the lid body 10 by a lead wire 9 . Further, normally, the upper electrode body 3 is secured within the insulated guide pipe 5 at a narrowed portion.

On the other hand, a conical exhaust wall 8 is provided around the tapered tip 5a of the insulating guide pipe 5, and is attached to the inner wall of the insulating tube. This exhaust wall 8 is closely attached to the inner wall of the insulating cylinder 1, and forms an exhaust port 11- for guiding the gas passing between the insulating guide pipe 5 and the insulating cylinder 1 to the center of the cylinder.

As in the first embodiment, the device configured as described above has a cell L-L between the ground and the power supply side, and when a lightning surge enters the power supply side, an arc is generated between the electrode parts 3a and 4a. do. At this time, the gas between the electrodes expands, and the upper electrode body 3 slides within the insulated guide pipe 5 in the direction of the arrow. As a result, the distance between the electrodes increases and the arc is extinguished.
Furthermore, air compressed by this sliding passes between the insulating guide pipe 5 and the insulating cylinder 1 and is blown out from the exhaust port 1, thereby blowing out the arc.

1.2 [Effects of the Invention] As explained above, the arc self-extinguishing lightning arrester according to the present invention effectively utilizes the energy of the arc generated between the electrodes to quickly interrupt the following current. , its structure is very simple. Therefore, the present invention provides an unprecedented lightning arrester that has a simple structure, a small number of parts, is low cost, and is easy to install, in place of the conventional lightning arrester that uses current limiting elements. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment according to the present invention. FIG. 2 is a sectional view showing a second embodiment according to the invention. FIG. 3 is a sectional view showing a third embodiment according to the invention. FIG. 4 is a sectional view showing a fourth embodiment according to the present invention. In the figure, 1 is an insulating tube, 2 is an insulating sleeve, 3 is an upper electrode body, 3a and 4a are electrode parts, 3b and 3c are exhaust ports, 4 is a lower electrode body, 5 is an insulated guide pipe, 6 is a spring,
7a and 7b are insulating stoppers, 8 is an exhaust wall, 9 is a lead wire, 10 is a lid, and 11 is an exhaust port. 1.3 Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A cylindrical body made of an insulating material and having a lower dielectric strength on the inside than on the outside; and a cylindrical body provided to partition a space inside the cylindrical body, and a cylindrical body that extends from a predetermined position within the cylindrical body along the inner surface of the cylindrical body. a slidable partition wall; and a first member provided on the partition wall and movable together with the partition wall.
an electrode, a sealing wall provided to seal one space partitioned by the partition wall in the cylindrical body, and a second electrode provided on the sealing wall so as to face the first electrode. , When an arc is generated between the first electrode and the second electrode, the energy of the arc expands the gas in the one space, and at least the partition wall moves to widen the distance between the two electrodes. An arc self-extinguishing lightning arrester characterized by being configured as follows. (2) In the other space partitioned by the partition wall in the cylinder, an exhaust port is provided in the partition wall to blow compressed gas into the one space when the partition wall slides from a predetermined position. The arc self-extinguishing type lightning arrester according to claim 1, characterized in that: