JPH0982187A - Arc self-extinguishing type gas-blast circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of interrupting performance due to the entrance of a high-temperature arc into a compression chamber made of aluminum and enclosing an arc-extinguishing gas by providing the compression chamber with a heat-resistant insulating material on its inner surface, and making the compression chamber serve also as one of main contacts. SOLUTION: While a circuit is closed, a current flows through a lead conductor 9, a compression chamber 3 serving also as a fixed main contact, a movable main contact 6, a movable support 7, and a lead conductor 10 in that order. When an operating rod 8 is moved toward an open position, first the contacts 3, 6 separate from each other, and the current is commutated to arc contacts 2, 5; when the contacts 2, 5 finally separate from each other, they produce an arc, and a gas heated by the energy of the arc is stored in the chamber 3. Then the inner surface of the chamber 3 is covered with a cover 4 made from Teflon to prevent aluminum from being converted to metallic vapor by the high-temperature gas. An alternating current approaches zero, and the high- temperature gas in the chamber 3 is strongly sprayed to the arc through a nozzle 1 to extinguish an arc current.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a self-extinguishing type gas circuit breaker.

[0002]

2. Description of the Related Art A puffer-type gas circuit breaker, which is currently the mainstream of gas circuit breakers, drives a cylinder forming a puffer chamber to the blocking side to rapidly blow SF6 gas in the puffer chamber from a nozzle. The current is cut off by. Although this puffer-type gas circuit breaker has excellent breaking performance, it requires a high-power and high-speed drive device to compress and spray SF6 gas, which has a large viscosity. In addition, the structure of each part tends to increase in size in order to withstand the large output of the drive device.

As a countermeasure against this, a self-extinguishing arc type gas circuit breaker has been proposed. As shown in FIG. 5, this self-extinguishing type gas circuit breaker does not have a puffer chamber on the movable side, but has a compression chamber 3 near the fixed-side arc contactor 2, and the fixed-side arc contactor 2 is movable. The arc contactor 5 of FIG. A nozzle 1 is attached around the fixed-side arc contactor 2 so that SF6 gas blown out from the compression chamber 3 is guided and effectively blown onto the arc. A main contactor 6 is attached to the arc contactor 5 on the movable side, and these can be collectively turned on / off by an operating rod 8. The movable side main contactor 6 in the ON state
Is in contact with the outer surface of the compression chamber 3 which also serves as the main contact on the fixed side. The fixed side and the movable side are fixed by the interelectrode support insulator 13 to form one arc extinguishing chamber.

When the current is cut off, the pressure inside the compression chamber 3 rises due to the hot gas 12 of the arc 11 generated between the movable side arc contactor 5 and the fixed side arc contactor 2. The diameter of the arc becomes smaller as the current approaches the zero point, the nozzle 1 is no longer blocked, and the high-pressure gas in the compression chamber 3 is blown through the nozzle 1 to the arc to interrupt the current. In addition, 9 is a fixed-side lead conductor, 10 is a movable-side lead conductor, and 17 is aluminum metal vapor.

In this system, the driving device only needs to output the movable electrode to open the electrode, and the structure of the arc extinguishing chamber can be greatly simplified. Further, the self-extinguishing type gas circuit breaker is generally excellent in breaking performance at a rated breaking current with large arc energy.

[0006]

However, when the breaking current becomes a large current such as 80 kA to 100 kA, the hot gas flowing into the compression chamber becomes higher in temperature, and in some cases, the arc itself reaches the inside of the compression chamber. There is a possibility of intrusion. The compression chamber usually serves as a current-carrying path for the load current when the circuit is normally closed, and is made of aluminum having good conductivity. When aluminum has a low melting point and is exposed to a high temperature arc, it easily supplies metal vapor into the arc. When aluminum metal vapor is mixed in the arc, heavy particles are added, the efficiency of heat exchange of high-temperature gas is deteriorated, and the cooling of the arc by gas spraying does not work effectively.

Further, since aluminum has a low ionization energy, it is easily ionized and supplies electrons together with ion particles. When a large amount of ions and electrons are supplied, the electron density and electric conductivity of the high temperature gas (plasma) forming the arc increase, which also has a disadvantageous effect on arc interruption. If the volume of the compression chamber is increased, it is possible to prevent the temperature of the hot gas from rising excessively, but it becomes impossible to obtain sufficient blowing force at the time of interruption of a low current level, for example, a load current of about several thousand amperes. I will end up.

The present invention has been made in view of the above circumstances, and its purpose is to prevent the breaking performance of aluminum even if an excessively high temperature gas or arc enters the compression chamber of the self-powered arc-extinguishing chamber. An object of the present invention is to provide a self-extinguishing arc type gas circuit breaker in which metal vapor is prevented from being mixed in high temperature gas.

[0009]

In order to achieve the above object, a self-extinguishing type gas circuit breaker according to claim 1 of the present invention is provided with a pair of main contactors and a delay later than the pair of main contactors. A pair of dissociating arc contacts, an aluminum compression chamber containing an arc extinguishing gas whose opening is connected to one of the pair of arc contacts, and a nozzle mounted around the arc contacts. And a heat-resistant insulator attached to the inner surface of the compression chamber, and the compression chamber doubles as one contactor of the main contactor.

According to a second aspect of the present invention, in the self-extinguishing type gas circuit breaker according to the first aspect, a cover made of a material having a melting point and an ionization energy higher than that of aluminum is attached to the inner surface of the compression chamber. And

A third aspect of the present invention includes a pair of main contacts,
A pair of arc contacts that dissociate later than the pair of main contacts, a nozzle mounted around the pair of arc contacts, and a melting point and ionization energy independent of the main contacts are higher than those of aluminum. It is characterized in that the opening of the compression chamber containing the arc-extinguishing gas made of high material is connected to the arc contactor, and the insulating layer is provided between the main contactor and the compression chamber.

According to a fourth aspect of the present invention, in the self-extinguishing type gas circuit breaker according to the first aspect, a first check is provided in which an auxiliary puffer chamber is connected to the compression chamber and is closed when the pressure of the compression pressure rises. A valve is provided between the puffer chamber and the compression chamber,
It is characterized in that a second check valve, which is adjusted to open in association with the closing of the first check valve, is provided between the puffer chamber and the outside of the arc extinguishing chamber.

According to a fifth aspect of the present invention, in the self-extinguishing type gas circuit breaker according to the second or third aspect, the material having a melting point and an ionization energy higher than that of aluminum is iron or steel. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a closed state of a self-extinguishing type gas circuit breaker according to a first embodiment (corresponding to claim 1, claim 2 and claim 5) of the present invention. FIG.

As shown in FIGS. 1 and 2, a compression chamber 3 made of aluminum is provided on the fixed side, and a heat resistant insulator 4 made of Teflon is attached to the inner surface. The stationary side arc contactor 2 is attached to the outlet of the compression chamber 3 so that the movable side arc contactor 5 can come into contact with and separate from the movable side arc contactor 5. A nozzle 1 is attached around the stationary side arc contactor 2, and the compression chamber 3
The SF6 gas blown out from is guided so as to be effectively blown to the arc. A main contactor 6 is attached to the arc contactor 5 on the movable side, and the main contactor 6 can be collectively turned on / off by an operating rod 8. In the inserted state, the movable side main contactor 6 contacts the outer surface of the compression chamber 3 which also serves as the fixed side main contactor. The fixed side and the movable side are fixed by the interelectrode support insulator 13 to form one arc extinguishing chamber.

Next, the operation of this embodiment will be described.
In the closed state of FIG. 1, the current is output conductor 9-fixed side main contactor (compression chamber) 3-movable side main contactor 6-movable support 7-.
It flows in the order of the lead conductor 10. When the operation rod 8 starts to move toward the open circuit side by the opening / closing operation mechanism (not shown), the main contacts 3 and 6 are first separated, and the current is commutated to the arc contacts 2 and 5. When the operating rod 8 further moves to the open side,
As shown in FIG. 2, the movable side arc contactor 5 and the fixed side arc contactor 2 are separated from each other, and an arc 11 is generated therebetween. In the vicinity of the peak value of the electric current, the diameter of the arc 11 is thick enough to close the inner diameter of the nozzle 1, and the gas heated by the arc energy is stored in the compression chamber 3 and its pressure and temperature increase. At this time, since the Teflon cover 4 is attached to the inner surface of the compression chamber 3, the aluminum in the compression chamber 3 is prevented from being ejected as a metal vapor by the high temperature gas. Therefore, the energy of the electric current is effectively used for increasing the pressure and is not adversely affected by the metal vapor.

As the alternating current approaches the current zero point, the diameter of the arc gradually becomes smaller and the nozzle is closed. Then, the high-pressure gas in the compression chamber 3 is guided by the nozzle 1 and strongly blows on the arc, and the arc current is extinguished at the current zero point.

A heat-resistant insulator attached to the inner surface of the compression chamber 3,
For example, Teflon 4 can prevent the metal vapor of aluminum from being mixed into the high temperature gas even when a large current of 80 kA to 100 kA is cut off. Therefore, the energy of a large current of 80 kA to 100 kA can be effectively used for increasing the gas pressure of the compression chamber without increasing the volume of the compression chamber and lowering the cutoff property of the load current and the small current, and blocking the large current. Is possible.

Even if the Teflon-made insulator is decomposed into a vapor by the high temperature gas, the atoms constituting the Teflon are the carbon atom C and the fluorine F, and there is no particular problem. F is an atom that constitutes SF6 gas, and even if mixed, it does not deteriorate the blocking performance. On the contrary, the F atom attaches an electron and becomes an F ⁻ ion to reduce the electron density.
Increasing the number of atoms has an advantageous effect on blocking. Since C atoms have a higher ionization energy than aluminum and are less likely to be ionized, they are not a problem as much as aluminum vapor is mixed.

Further, it becomes possible to eliminate the factors which adversely affect the current interruption such as the increase of aluminum ions and electrons due to the mixing of the metal vapor and the decrease of the heat exchange efficiency, and the energy of the large current increases the pressure of the compression chamber 3. Can be used effectively.

In this embodiment, a heat-resistant insulator such as Teflon is used to prevent aluminum vapor from mixing in the high temperature gas in the compression chamber. Instead of this insulator, ionization energy is used. Even if a cover made of a material having a high temperature and being hard to be ionized is attached to the inner surface of the compression chamber, the same effect as that of the present embodiment can be obtained. Iron is one of the most industrially applicable materials.

FIG. 3 is a block diagram of a self-extinguishing type gas circuit breaker (in the middle of opening) which is a second embodiment (corresponding to claim 3 and claim 5) of the present invention. In this figure, the present embodiment is different from the embodiment of FIG. 1 in that the main contact on the fixed side and the compression chamber are composed of completely different parts, and the compression chamber 15 itself is made of a material such as iron that is difficult to ionize. To manufacture. The main contactor 14 for energization is made of a material having good conductivity such as aluminum, and the thin insulator 16 is sandwiched between the main contactor 14 and the compression chamber 15. Since the other configurations are the same, the same portions are denoted by the same reference numerals, and the duplicate description will be omitted.

According to this embodiment, the main contact 14 for energization is
Since a thin insulator 16 is sandwiched between the compression chamber 15 and the compression chamber 15, it is possible to prevent an abnormally high temperature from being caused by a load current flowing through the iron compression chamber 15. Other effects are the same as those in FIG.

FIG. 4 is a block diagram of a self-extinguishing type gas circuit breaker (state in the middle of opening) which is a third embodiment (corresponding to claim 4) of the present invention. As shown in the figure, in the present embodiment, both the auxiliary puffer chamber 26 and the compression chamber 24 are provided on the movable side so that the pressure increase of the compression chamber due to the arc energy can be sufficiently obtained even when the small current is cut off. It is configured. A movable-side arc contactor 23 is provided at the tip of the operation rod 29, a movable-side main contactor 22 having a nozzle 21 attached thereto is arranged outside the movable-side arc contactor 23, and heat-resistant inside the movable-side main contactor 22. The insulator 25 is attached to form the compression chamber 24. An auxiliary puffer chamber 26 is provided behind the compression chamber 24 via a first check valve 27. 28 is a second check valve, 30 is a fixed-side main contactor, and 31 is a fixed-side arc contactor.

Next, the operation of this embodiment will be described.
In the case of a small current interruption, the gas sent out from the puffer chamber 26 is blown between the arc contacts 31 through the compression chamber 24 and the nozzle 21 provided ahead of the compression chamber 24 to interrupt the current. In case of large current interruption, arc 32
When the pressure in the compression chamber 24 rises due to the hot gas 33 generated by, the first check valve 27 is closed and the puffer chamber 26
The second check valve 28 is opened at the same time when the gas inflow from is stopped to release the pressure in the puffer chamber 26. The subsequent operation is similar to the case without the auxiliary puffer chamber 26,
Also in this case, since the heat-resistant insulator 25 is attached to the inner surface of the compression chamber 24, it is possible to prevent aluminum vapor from being mixed into the high-temperature gas, and there is no adverse effect on shutoff.

[0026]

As described above, according to the first aspect of the present invention.
According to claim 5, it is possible to prevent aluminum vapor from being mixed in the high temperature gas by adopting a structure in which a heat resistant insulator such as Teflon is attached to the inner surface of the compression chamber of the self-powered arc-extinguishing chamber. It will be possible.

Further, according to the second, third and fifth aspects of the present invention, it is possible to suppress the mixing of aluminum vapor, which has a disadvantageous effect on the current interruption as in the prior art, and to effectively use the energy of the arc current. Moreover, it can be used for increasing the pressure in the compression chamber, and can contribute to the improvement of the blocking performance. As described above, according to the present invention, the large current breaking performance of the self-extinguishing type gas circuit breaker can be improved without lowering the breaking performance of small current and load current.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a self-extinguishing type gas circuit breaker (closed state) according to a first embodiment of the present invention.

FIG. 2 is a view showing a state in which the self-extinguishing arc type gas circuit breaker of FIG. 1 is in the middle of opening.

FIG. 3 is a configuration diagram of a self-extinguishing type gas circuit breaker (a state in the middle of opening a pole) according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a self-extinguishing arc type gas circuit breaker (a state in the middle of opening a pole) according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional self-extinguishing type gas circuit breaker.

[Explanation of symbols]

1, 21 ... Nozzle, 2 ... Fixed-side arc contactor, 3 ... Compression chamber / fixed-side main contactor, 4, 25 ... Heat-resistant insulator, 5 ... Movable-side arc contactor, 6, 22 ... Movable-side main contact Child, 7 ... Movable support, 8, 29 ... Operation rod, 9, 10 ... Output conductor, 11, 32 ... Arc, 12, 33 ... Hot gas, 13 ...
Inter-electrode support insulator, 14, 30 ... Main contact on fixed side, 15 ...
Iron compression chamber, 16 ... Insulator, 17 ... Aluminum vapor jet, 23 ... Movable side arc contactor, 24 ... Compression chamber, 26
... auxiliary puffer chamber, 27 ... first check valve, 28 ... second check valve, 31 ... fixed side arc contactor.

Claims (5)

[Claims] 1. A pair of main contacts, a pair of arc contacts that dissociate later than the pair of main contacts, and an extinguishing arc whose opening is connected to either one of the pair of arc contacts. A compression chamber made of aluminum containing a gas, a nozzle mounted around the arc contactor, and a heat-resistant insulator mounted on the inner surface of the compression chamber, wherein the compression chamber is one of the main contacts. A self-extinguishing type gas circuit breaker characterized by also functioning as a contactor. 2. The self-extinguishing type gas circuit breaker according to claim 1, wherein a cover made of a material having a melting point and an ionization energy higher than that of aluminum is attached to the inner surface of the compression chamber. Gas circuit breaker. 3. A pair of main contacts, a pair of arc contacts that dissociate later than the pair of main contacts, a nozzle mounted around the pair of arc contacts, and the main contacts. And an insulating layer between the main contact and the compression chamber, the opening of the compression chamber containing the arc extinguishing gas made of a material having a melting point and ionization energy higher than that of aluminum is connected to the arc contactor. A self-extinguishing type gas circuit breaker characterized by being provided with. 4. The self-extinguishing type gas circuit breaker according to claim 1, wherein an auxiliary puffer chamber is provided so as to be connected to the compression chamber, and a first check valve that closes when the pressure of the compression pressure rises is compressed with the puffer chamber. A self-extinguishing system characterized in that a second check valve provided between the chambers and adjusted so as to open in association with the closing of the first check valve is provided between the puffer chamber and the outside of the arc extinguishing chamber. Arc type gas circuit breaker. 5. The self-extinguishing type gas circuit breaker according to claim 2 or 3, wherein the material having a higher melting point and ionizing energy than aluminum is iron or steel. vessel.