WO2015146518A1

WO2015146518A1 - Gas circuit-breaker

Info

Publication number: WO2015146518A1
Application number: PCT/JP2015/056368
Authority: WO
Inventors: 内井　敏之; 崇文飯島; 嵩人石井
Original assignee: 株式会社東芝
Priority date: 2014-03-24
Filing date: 2015-03-04
Publication date: 2015-10-01
Also published as: JP6382543B2; JP2015185381A

Abstract

Provided is a gas circuit-breaker that is compact and highly reliable even when an alternative gas having a low environmental impact is used. In the gas circuit-breaker provided with a pair of fixed arc electrodes (30a, 30b) disposed so as to be opposite from one another inside a sealed container and constituted in such a manner that an arc discharge (7) may be generated therebetween when a current is interrupted, a pressurization chamber (35) for generating a pressurized gas for the purpose of blasting an arc-quenching gas onto the arc discharge (7), and an accumulation chamber (36) for accumulating the pressurized gas, an opening-closing portion (41) is provided, for bringing the accumulation chamber (36) into a closed state or an open state. In addition, the pressurized chamber (35) is constituted so as to have a cylinder (39) and a mobile piston (33), and generate the pressurized gas by adiabatic compression of the arc-quenching gas inside the cylinder (39) via the movement of the mobile piston (33). The arc-quenching gas has a lower global warming potential than SF₆ gas and a specific heat ratio of at 20°C of greater than 1.1.

Description

Gas circuit breaker

Embodiment of this invention is related with the gas circuit breaker which switches an electric current interruption | blocking and injection | throwing-in in an electric power grid | system.

In the power system, a gas circuit breaker is used to switch the current including an excessive accident current. The gas circuit breaker mechanically disconnects the contactor during the disconnection process, and extinguishes the arc generated by the disconnection by blowing an insulating medium and an arc-extinguishing medium.

The type of gas circuit breaker as described above is now widely used as a puffer type (see, for example, Patent Document 1). In the puffer-type gas circuit breaker, a fixed arc contact and a fixed energizing contact, and a movable arc contact and a movable energizing contact are respectively arranged in an airtight container filled with an arc extinguishing gas. . The electric current is conducted or cut off by bringing both arc contacts and both energizing contacts into contact with or separated from each other by a mechanical driving force.

In this gas circuit breaker, the volume decreases with the separation of the contacts, and the pressure-accumulating space in which the arc-extinguishing gas is accumulated and the arc-contacting properties of the pressure-accumulating space are arranged so as to surround both arc contacts. An insulating nozzle is provided to guide the gas to arc discharge. In the interruption process, the fixed arc contact and the movable arc contact are separated to generate an arc between the arc contacts. The arc is extinguished by strongly blowing the arc-extinguishing gas that has been sufficiently accumulated in the pressure accumulating space with the separation of the contact through the insulating nozzle, thereby restoring the insulation performance of both arc contacts. Complete the current interruption.

As the arc extinguishing gas, SF ₆ gas (sulfur hexafluoride gas) is widely used. This is because SF ₆ gas is chemically stable and non-toxic, and has excellent arc interruption performance (arc extinguishing performance) and electrical insulation performance. In particular, it is very suitable for high voltage gas circuit breakers. On the other hand, it is known to have a high global warming effect, and in recent years, reduction of the amount of use is desired.

The magnitude of global warming action is generally expressed by the global warming potential (GWP), that is, the relative value when CO ₂ gas is 1, and it is known that the global warming potential of SF ₆ gas reaches 23,900. It has been. Against this background, alternative gases such as carbon dioxide (CO ₂ ) gas, nitrogen (N ₂ ) gas, oxygen (O ₂ ) gas, and methane (CH ₄ ) gas are applied as arc extinguishing gas in the gas circuit breaker. (See Patent Documents 2 and 3). These alternative gases have no global warming effect or are very small compared to SF ₆ gas, so by applying these alternative gases to gas circuit breakers instead of SF ₆ gas, The influence can be greatly suppressed.

Japanese Patent Publication No. 7-109744 Japanese Patent No. 4660407 Japanese Patent No. 5127469

However, it is known that any of the above-described alternative gases is greatly inferior in arc extinguishing performance than SF ₆ gas. Therefore, the arc extinguishing performance is inevitably lowered only by following the structure of the conventional gas circuit breaker and changing the arc extinguishing gas to be filled from SF ₆ gas to alternative gas.

On the other hand, in general, if the pressure in the pressure accumulating space is increased even with the same arc extinguishing gas, the arc discharge can be more powerful and the arc extinguishing performance can be improved. Since the compressibility of the arc extinguishing gas depends on the volume change rate of the pressure accumulating space, it is desirable that the pressure accumulating space is large.

However, if the cylinder that defines the accumulator space or the fixed piston inserted in the cylinder is made larger and its volume is increased, the weight of the movable part and the driving reaction force for compression will increase as a result. End up. In other words, using an alternative gas to obtain an arc extinguishing performance equivalent to the currently popular SF ₆ gas circuit breaker necessitates an increase in the size of the device and an increase in the size of the drive unit. This has led to a decline in the reliability of the machine.

The gas circuit breaker according to the present embodiment is made in order to solve the above-described problems, and is a compact and highly reliable gas circuit breaker even in the case of using an alternative gas that has little environmental impact. The purpose is to provide a vessel.

In order to achieve the above object, the gas circuit breaker according to the present embodiment includes a sealed container filled with an arc extinguishing gas, and is disposed oppositely in the sealed container and can be electrically energized. A pair of arc electrodes configured to be capable of generating arc discharge, and a booster that pressurizes the arc-extinguishing gas to generate boosting gas in order to blow the arc-extinguishing gas against the arc discharge. In the gas circuit breaker, the pressure accumulating space is closed or opened in a gas circuit breaker provided with a pressure accumulating space for storing the pressure increasing gas and a rectifying means for guiding the pressure increasing gas from the pressure accumulating space toward the arc discharge. An openable and closable opening / closing part for making a state is provided, and the pressure increasing part has a cylinder and a piston, and adiabatically compresses the arc-extinguishing gas inside the cylinder by moving at least one of them, Configured serial to generate a boosted gas, the arc extinguishing gas, global warming potential SF ₆ smaller than the gas, and wherein the specific heat ratio is greater than 1.1 at 20 ° C..

It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on 1st Embodiment. (A) is a cross-sectional view showing the state at the time of charging, (b) is the first half of the blocking process, and (c) is the second half of the blocking process. An example with these global warming potential of SF ₆ gas and substitute gas (GWP) and a table showing the specific heat ratio. It is sectional drawing which shows the rod of 1st Embodiment. It is sectional drawing which shows the structure around the movable piston of 1st Embodiment. It is a graph which shows the comparison of the pressure | voltage rise characteristic of blowing gas pressure. It is a graph which shows the stroke change of the compression reaction force and the movable part acceleration force in the case of a flat drive output characteristic. It is a graph which shows the stroke change of the compression reaction force and the movable part acceleration force in the case of a monotonously decreasing drive output characteristic. It is sectional drawing which shows the whole structure of the gas circuit breaker which concerns on other embodiment. (A) is a cross-sectional view showing the state at the time of charging, (b) is the first half of the blocking process, and (c) is the second half of the blocking process.

[First Embodiment]
(Constitution)
Hereinafter, the overall configuration of the gas circuit breaker of the present embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a cross-sectional view showing the overall configuration of the gas circuit breaker according to the present embodiment. FIG.

The gas circuit breaker connects and separates the electrodes that make up the electric circuit, and switches between current interruption and on state. In the current interruption process, the electrodes are bridged by arc discharge. In the current interruption process, a gas flow of arc extinguishing gas is generated, and the gas flow is guided and blown to the arc discharge to cool the arc discharge and extinguish the arc at the current zero point.

The gas circuit breaker has a sealed container (not shown) made of grounded metal or insulator, and the inside thereof is filled with an arc extinguishing gas. The arc extinguishing gas is a gas having arc extinguishing performance and insulation performance.

As the arc extinguishing gas, in the present embodiment, a gas having a global warming potential smaller than that of SF ₆ gas and a specific heat ratio at room temperature (here, 20 degrees Celsius) is larger than 1.1 of SF ₆ gas. Is used.

For example, as shown in FIG. 2, any one of noble gases such as nitrogen (N ₂ ), carbon dioxide (CO ₂ ), oxygen (O ₂ ), methane (CH ₄ ), helium (He), argon (Ar), etc. One kind of single gas can be used. Alternatively, even if a mixed gas is used, the global warming potential does not increase or the specific heat ratio does not decrease compared to the single gas before mixing. Therefore, a mixed gas containing at least one of the above single gases is also available. Can be used. Note that “-” in the item “GWP” in FIG. 2 indicates zero or almost zero.

The electrode of the gas circuit breaker is roughly divided into a fixed electrode part A and a movable electrode part B, and is arranged facing the sealed container. Each of the fixed electrode portion A and the movable electrode portion B is mainly composed of a plurality of members having a basic shape of an internal hollow cylinder or an internal solid column, and has a concentric arrangement having a common central axis. By matching the diameters, the related members face each other and function cooperatively.

The fixed electrode part A has fixed

arc electrodes

30 a and 30 b and a fixed energizing electrode 3. The movable electrode part B has a movable energizing electrode 5 and a trigger electrode 31.

The fixed

arc electrodes

30a and 30b are not members included in the movable portion having the movable energizing electrode 5 and the trigger electrode 31, but are members which are fixedly disposed opposite to each other in a sealed container (not shown). On the other hand, the movable part having the movable energizing electrode 5 and the trigger electrode 31 which are movable elements of the movable electrode part B is directly or indirectly connected to a driving device (not shown), and is fixed according to the operating force of the driving device. It approaches and separates from the part A along the center line.

Thereby, the movable electrode part B comes in contact with and separates from the fixed electrode part A, and the arc discharge 7 is generated and extinguished in the process of turning on and off the current and interrupting the current. Further, the pressure in the sealed container is a single pressure, for example, the charging pressure of the arc extinguishing gas, at any part during normal operation.

Each member of the fixed electrode part A and the movable electrode part B will be described in more detail. The fixed energizing electrode 3 is larger in diameter than the fixed arc electrode 30a, and is arranged concentrically with the fixed arc electrode 30a with a common central axis. The movable energizing electrode 5 has a cylindrical shape whose outer diameter is the same as the inner diameter of the fixed energizing electrode 3, and has a common central axis with the fixed energizing electrode 3, so that the movable energizing electrode 3 can be contacted and separated from the fixed energizing electrode 3. Has been placed. These constitute part of the electric circuit by the contact between the fixed energizing electrode 3 and the movable energizing electrode 5.

The pair of fixed

arc electrodes

30a and 30b has a cylindrical shape having substantially the same diameter, and is fixedly disposed in the sealed container with the central axis being common and the openings being opposed to and spaced from each other. The opening edges of the fixed

arc electrodes

30a and 30b facing each other bulge out inside. The trigger electrode 31 has a solid rod shape, and is disposed on the central axis so as to connect the fixed arc electrodes 30a and 3b inside the fixed

arc electrodes

30a and 30b. For example, one end of the trigger electrode 31 is directly or indirectly connected to a driving device (not shown), and the driving force moves the inside of the fixed

arc electrodes

30a and 30b along the central axis so as to advance and retreat.

The outer diameter of the trigger electrode 31 coincides with the inner diameter of the opening edge portion of the fixed

arc electrodes

30a, 30b that bulges toward the inside. When the trigger electrode 31 is inserted into the fixed arc electrode 30a, the inner surface of the fixed arc electrode 30a and the outer surface of the trigger electrode 31 come into contact with each other, and a state is established in which electrical conduction is possible. Similarly, the inner surface of the fixed arc electrode 30b and the outer surface of the trigger electrode 31 are in contact with each other and are electrically connected. The trigger electrode 31 accepts the arc discharge 7 by freely moving between an energizing position for energizing the

fixed arc electrodes

30a and 30b and a blocking position away from the fixed arc electrode 30a.

When the trigger electrode 31 is located at the energization position, it contacts the fixed

arc electrodes

30a and 30b. That is, the fixed

arc electrodes

30a and 30b are short-circuited by the trigger electrode 31 to realize an energized state. When moving from the energized position to the cutoff position, the trigger electrode 31 is separated from the fixed arc electrode 30a, and an arc discharge 7 is generated between the trigger electrode 31 and the fixed arc electrode 30a. When the trigger electrode 31 is further away from the fixed arc electrode 30a and the distance between the fixed arc electrode 30a and the trigger electrode 31 is larger than the distance between the fixed arc electrode 30a and the fixed arc electrode 30b, the arc discharge 7 is eventually triggered. Transition from the electrode 31 to the arc electrode 30b. Thus, the trigger electrode 31 serves as a switch unit that switches between energization and interruption.

An insulating nozzle 32 is fixedly arranged in a sealed container around the rod-shaped trigger electrode 31. The insulating nozzle 32 is provided in a sealed container so as to surround a space between the fixed

arc electrodes

30a and 30b. Therefore, the trigger electrode 31 moves inside the insulating nozzle 32 during the interruption operation, and the arc discharge 7 is generated inside the insulating nozzle 32. The shape of the insulating nozzle 32 has a constriction in a partial section, and the diameters of the openings at both ends are enlarged. Therefore, the end portion of the insulating nozzle 32 surrounds the opening edge portions of the fixed

arc electrodes

30a and 30b facing each other, and the opening at one end portion of the insulating nozzle 32 is directed to the movable piston 33 described later. Yes.

The gas flow blown to the arc discharge 7 is generated by the pressure increasing chamber 35 and the pressure accumulating chamber 36. The pressure accumulating chamber 36 and the pressure increasing chamber 35 are provided in the movable electrode portion B and are provided so as to surround the trigger electrode 31. The pressure accumulating chamber 36 stores the arc extinguishing gas boosted by the boosting chamber 35 and blows the stored arc extinguishing gas to the arc discharge 7. The pressure accumulating chamber 36 is formed as a space surrounded by the trigger electrode 31, the cylindrical member 40, and the fixed arc electrode 30b.

That is, the cylindrical member 40 is disposed so as to surround the trigger electrode 31 with the same diameter as the outer diameter of the fixed arc electrode 30b and the central axis. The opening edge of the cylindrical member 40 is connected to the opening edge opposite to the opening end that bulges inside the fixed arc electrode 30b so that the cylinder continues. Since the cylindrical member 40 has a larger diameter than the trigger electrode 31, the outer peripheral surface of the trigger electrode 31 is separated from the inner peripheral surface of the cylindrical member 40, and is surrounded by the trigger electrode 31, the cylindrical member 40, and the fixed arc electrode 30b. A pressure accumulating chamber 36 is formed.

The pressure accumulating chamber 36 is provided with an openable / closable opening / closing portion 41 for closing or opening the internal space of the pressure accumulating chamber 36. In the present embodiment, the opening / closing portion 41 is formed by a contact (sliding) portion between the portion that bulges toward the center of the tip of the fixed arc electrode 30 b and the outer peripheral surface of the trigger electrode 31. That is, this contact portion has a certain airtightness, and the opening / closing part 41 closes the accumulator chamber 36 by the contact between the fixed arc electrode 30b and the trigger electrode 31 in the first half of the current interruption process, and the arc discharge. The thermal exhaust gas 20 generated by the heat of No. 7 is restricted from flowing into the pressure accumulating chamber 36, and the pressurized gas in the pressure accumulating chamber 36 is restricted from flowing out. On the other hand, in the second half of the current interruption process, the trigger electrode 31 is separated from both the fixed

arc electrodes

30a and 30b, thereby opening the pressure accumulating chamber 36. In the present embodiment, the trigger electrode 31 also serves as an opening / closing means for switching between the closed state and the open state of the pressure accumulating chamber 36 in addition to the energization or cutoff switch means.

In the pressurizing chamber 35, the arc extinguishing gas inside is pressurized. The pressurizing chamber 35 is a space provided on the outer peripheral side of the pressure accumulating chamber 36 and surrounded by the cylinder 39, the cylindrical member 40, and the movable piston 33. As shown in FIG. 1, the cylinder 39 has a cylindrical shape with a bottom end, and has an opening at the front end side of the fixed arc electrode 30b and an end surface at the rear end side of the fixed arc electrode 30b. It is fixedly placed inside. That is, the cylinder 39 is provided so as to surround the cylindrical member 40 and the fixed arc electrode 30b which are a continuous cylinder.

The movable piston 33 is inserted into the cylinder 39 so as to close the opening of the cylinder 39. For this reason, the thermal exhaust gas between the fixed

arc electrodes

30 a and 30 b generated by the generation of the arc discharge 7 does not flow into the boosting chamber 35.

The movable piston 33 has a sliding inner peripheral surface 33a and a sliding outer peripheral surface 33b, and is configured to be movable along the center line. As shown in FIG. 1, in the present embodiment, the movable piston 33 has a disk whose center is an open disk and a cylinder protruding from the opening edge. The sliding inner peripheral surface 33 a is a cylindrical inner peripheral surface and a disk inner peripheral surface, and is slidable with the fixed arc electrode 30 b and the cylindrical member 40. The sliding outer peripheral surface 33 b is a disk outer peripheral surface and is slidable with the inner peripheral surface of the cylinder 39.

A seal member 47 is provided on the sliding inner peripheral surface 33a and the sliding outer peripheral surface 33b to make the inside of the pressurizing chamber 35 airtight. The sliding inner peripheral surface 33 a is wide along the center line, and the seal member 47 of the sliding inner peripheral surface 33 a that slides with the cylindrical member 40 is a communication hole provided at the proximal end portion of the cylindrical member 40. 34 apart from the width of 34. The movable piston 33 moves away from the arc discharge 7 by the operating force of a driving device (not shown), whereby the volume of the boosting chamber 35 decreases and the pressure in the boosting chamber 35 increases. That is, the movable piston 33 serves as a pressure increasing means.

The movable piston 33 and the trigger electrode 31 may be moved by separate drive devices or may be moved by a common drive device. When the movable piston 33 is moved by a common driving device, the movable piston 33 is driven by being connected to a rod 43 coupled by a trigger electrode 31 and a link 42, for example. In order to prevent axial misalignment and prevent excessive mechanical force from being concentrated in one place, the rod 43 is separated by a predetermined angle around the center line as shown in FIG. 3 which is a cross-sectional view orthogonal to the center line. It is desirable to provide a plurality of them. In order to prevent the pressure in the pressure increasing chamber 35 from leaking out from the sliding portion of the rod 43 and the cylinder 39, the same portion is sealed by the seal member 47.

An intake hole 17 is provided in the bottom surface of the cylinder 39, and an intake valve 19 is provided in the intake hole 17. The intake valve 19 is configured to replenish the arc-extinguishing gas into the booster chamber 35 only when the pressure in the booster chamber 35 is lower than the filling pressure in the sealed container.

(Energized state)
In the energized state, the fixed energizing electrode 2 and the movable energizing electrode 5 are electrically connected, and these members become one of the electric paths. Although not particularly illustrated, two conductors are fixed to the fixed electrode portion A side and the movable electrode portion B side by spacers in the sealed container, respectively. The spacer insulates the sealed container from the conductor and supports the conductor. In the energized state, the current flows into the gas circuit breaker via a bushing (not shown), and the member that becomes the above-mentioned electric path from the conductor on the fixed electrode portion A side, and the conductor and the bushing on the movable electrode portion B side (not shown). To the outside of the gas circuit breaker.

(First half of the blocking process)
When it is necessary to interrupt an excessive accident current, a small advance current, a delayed load current such as a reactor cutoff, or an extremely small accident current, the trigger electrode 31 is separated from the fixed arc electrode 30a upon receiving the operating force of the driving device. The arc discharge 7 is generated between the trigger electrode 31 and the fixed arc electrode 30a. The thermal exhaust gas 20 generated from the arc discharge 7 flows in a direction away from the arc discharge 7 without delay by the insulating nozzle 32 at the same time as the generation. That is, the gas is discharged through the exhaust hole (not shown) provided in the fixed arc electrode 30a and the exhaust hole 37 provided in the movable energizing electrode 5 into the sealed container.

In the first half of the shut-off process, the trigger electrode 31 is in contact with the fixed arc electrode 30b, so the opening / closing part 41 is closed and the pressure accumulating chamber 36 is closed. In other words, the heat exhaust gas 20 is prevented from entering the pressure accumulating chamber 36 by closing the opening / closing part 41. On the other hand, the pressure increasing chamber 35 and the pressure accumulating chamber 36 are defined by the cylindrical member 40, and are formed as an integral space by the communication hole 34 provided in the proximal end portion of the cylindrical member 40. Therefore, the arc extinguishing gas existing in the sealed space composed of the pressurizing chamber 35 and the pressure accumulating chamber 36 is adiabatically compressed and boosted as the movable piston 33 moves backward. Further, since the opening / closing part 41 is closed, the outflow of the pressurized gas in the pressure accumulating chamber 36 is restricted.

As described above, most of the heat exhaust gas 20 that has become high temperature due to the heat of the arc discharge 7 is discharged into the sealed container and the pressure accumulation chamber 36 is closed, so that the inflow to the pressure accumulation chamber 36 side is limited, If there is, it is a very small amount. Therefore, in a very short time during the shut-off operation, the arc extinguishing gas is almost not affected by the arc heat and is almost brought about by the adiabatic compression action by the movable piston 33.

(Second half of the blocking process)
In the latter half of the shut-off process, the volume of the pressurizing chamber 35 becomes relatively small, and most of the arc extinguishing gas compressed by the movable piston 33 is stored in the pressure accumulating chamber 36 through the communication hole 34. At the same time, the pressure increasing chamber 35 and the pressure accumulating chamber 36 are separated in pressure by the sealing member 47 provided on the movable piston 33 closing the communication hole 34. That is, the pressure increasing chamber 35 and the pressure accumulating chamber 36 are not an integral space. Furthermore, as shown in FIG. 4, the pressure in the pressurizing chamber 35 is quickly released to the sealed container as the released compressed gas 49 by the pressure release mechanism 48 thereafter. The pressure release mechanism 48 may be provided with a groove 43a in a part of the rod 43, but may have various other structures.

On the other hand, since the trigger electrode 31 passes through the fixed arc electrode 30b and the opening / closing part 41 is released, the compressed gas in the pressure accumulating chamber 36 travels along the trigger electrode 31 and is powerfully applied to the arc discharge 7 as the blowing gas 21. Be sprayed. The gas flow is appropriately rectified so that the blowing gas 21 is effectively blown to the arc discharge 7 by the insulating nozzle 32 and the thermal exhaust gas 20 is smoothly discharged.

At this stage, the arc discharge 7 is transferred to the fixed arc electrode 30b. Therefore, the period during which the arc discharge 7 is ignited on the trigger electrode 31 is only a limited period in the first half of the interruption process until the arc discharge 7 is transferred to the fixed arc electrode 30b.

(After the shutdown process is complete)
The booster chamber 35 is provided with an intake hole 17 and an intake valve 19. The intake valve 19 is configured to replenish the arc-extinguishing gas into the booster chamber 35 only when the pressure in the booster chamber 35 is lower than the filling pressure in the sealed container.

Therefore, when the charging operation is performed again after the shut-off process is completed, fresh arc-extinguishing gas is supplied to the booster chamber 35 through the intake hole 17 from the sealed container.

(Function)
(A) Lowering of blowing gas In the gas circuit breaker of the present embodiment, the arc-extinguishing gas is boosted by using a mechanical boosting action that compresses the arc-extinguishing gas inside the boosting unit 35 by the movable piston 33 and boosts the pressure. However, the self-pressurizing action of the arc extinguishing gas by the heat of the arc discharge 7 is not used. The gas 21 blown to the arc discharge 7 is an arc extinguishing gas whose pressure is increased by mechanical compression by the movable piston 33 without being thermally boosted by the heat of the arc discharge 7. Therefore, the temperature of the pressurizing gas 21 sprayed to the arc discharge 7 is much lower than the temperature of the conventional spraying gas using the self-pressurizing action. As a result, the cooling effect of the arc discharge 7 by blowing the pressurizing gas 21 can be remarkably enhanced. Therefore, even in alternative gas than SF ₆ gas extinguishing performance is poor, it is possible to have equivalent extinguishing performance and conventional SF ₆ gas circuit breakers.

In particular, in the present embodiment, the arc-extinguishing gas that has a global warming potential smaller than that of SF ₆ gas and a specific heat ratio at 20 ° C. larger than 1.1 of SF ₆ gas is used as the arc-extinguishing gas. As a result, the following effects are exhibited.

First, since the global warming potential is smaller than that of SF ₆ gas, it is possible to reduce the influence on the environment in the production and use stages of the gas circuit breaker.

On the other hand, in the present embodiment, since the pressure is increased mainly by adiabatic compression by the movement of the movable piston 33, a remarkable pressure increasing action can be obtained by using an alternative gas having a larger specific heat ratio than the SF ₆ gas. In general, when a gas having an initial volume V0 and an initial pressure P0 is adiabatically compressed to a compressed volume V1 (<V0), the compressed pressure P1 is given by Equation 1.
P1 = P0 × (V0 / V1) ^γ (Expression 1)
Here, γ is the specific heat ratio of the gas.

That is, when gas is adiabatically compressed at the same compression ratio (V0 / V1), it can be seen that the pressure increase after compression works as a power of the specific heat ratio of the gas. FIG. 5 shows a result of comparing the arc spray pressure in the arc extinguishing structure between SF ₆ gas (specific heat ratio 1.1) and alternative gas (specific heat ratio 1.4). As shown in FIG. 5, a stronger arc spray pressure can be obtained in the arc extinguishing structure mainly using adiabatic compression when an alternative gas having a specific heat ratio larger than 1.1 is used.

(B) Improvement of durability and reduction of maintenance In the gas circuit breaker of the present embodiment, the arc extinguishing gas to be blown is at a low temperature. Therefore, the temperature around the arc discharge 7 is lowered. Therefore, the deterioration of the fixed

arc electrodes

30a and 30b and the insulating nozzle 32 due to the current interruption can be remarkably reduced, and the durability is improved. As a result, the maintenance frequency of the fixed

arc electrodes

30a and 30b and the insulating nozzle 32 can be reduced, and the maintenance burden can be reduced.

Further, the period in which the arc discharge 7 is ignited on the trigger electrode 31 is only a limited period in the first half of the interruption process until the arc discharge 7 is transferred to the fixed arc electrode 30b. Therefore, the diameter of the trigger electrode 31 may be the minimum necessary as long as the durability that can withstand this period is satisfied. That is, since it is not necessary to increase the diameter of the trigger electrode 31 more than necessary, the weight of the movable part can be reduced. On the other hand, since the fixed

arc electrodes

30a and 30b fixed in the hermetic container do not affect the weight of the movable part, the fixed

arc electrodes

30a and 30b can be made thick without worrying about an increase in weight. For this reason, the durability of the fixed

arc electrodes

30a and 30b against a large current arc is remarkably improved. Furthermore, when the fixed

arc electrodes

30a and 30b are made thick, it is possible to greatly reduce the electric field concentration at the tips of the fixed

arc electrodes

30a and 30b when a high voltage is applied between the electrode gaps.

Therefore, the required electrode gap interval can be shortened compared to the conventional gas circuit breaker. As a result, the length of the arc discharge 7 is shortened, and the electric input power to the arc discharge 7 when the current is interrupted is reduced.

(C) Achieving a reduction in current interruption time According to the present embodiment, the pressure and flow rate of the compressed gas sprayed to the arc discharge 7 is determined according to the current conditions because the self-pressure boosting action by the arc heat is not used. It is always constant regardless. Also, the timing for starting the spraying to the arc discharge 7 is determined at the timing at which the tip of the trigger electrode 31 passes through the fixed arc electrode 30b and the two are separated from each other. Therefore, the current interruption completion time is not prolonged, and the request for shortening the current interruption completion time can be met.

(D) A reduction in driving operation force As the driving stroke of the trigger electrode 31 and the like approaches the complete cutoff position, the pressure of the compressed gas in the boosting chamber 35 and the pressure accumulating chamber 36 increases, and at the same time, compression that acts on the movable piston 33. Reaction force increases. In order to overcome this, a driving device having a corresponding driving force is required.

In the complete shut-off position, the pressure increasing chamber 35 and the pressure accumulating chamber 36 are separated in pressure by the seal member 47 provided on the movable piston 33 closing the communication hole 34. At the same time, as shown in FIG. 4, the pressure in the pressure increasing chamber 35 is released by the pressure release mechanism 48. For this reason, as long as there is at least driving energy capable of pulling the movable part to the complete shut-off position, no force that reverses the stroke is applied to the movable piston 33 thereafter, so there is no fear that the stroke will reverse.

Further, the trigger electrode 31 has a smaller diameter than the fixed

arc electrodes

30a and 30b, and can be lighter than conventional movable arc electrodes and drive rods. Further, since the insulating nozzle 32 is not included in the movable part in addition to the two fixed

arc electrodes

30a and 30b, the weight of the movable part can be significantly reduced. In this embodiment in which the weight of the movable part is advanced as described above, the driving operation force can be greatly reduced in terms of obtaining the opening speed of the movable part necessary for interrupting the current.

Furthermore, if the spraying pressure itself necessary to cut off the current can be reduced along with the weight reduction, the driving operation force necessary for compression can be reduced. In this embodiment, since the temperature of the blowing gas 21 is much lower than that of the prior art, the cooling effect of the arc discharge 7 is remarkably increased, and the arc discharge 7 can be interrupted at a lower pressure.

Also, the thermal exhaust gas 20 generated from the arc discharge 7 flows in the direction away from the arc discharge 7 without delay at the same time as the generation, and is quickly discharged into the space in the sealed container. Therefore, the blowing gas 21 to the arc discharge 7 flows due to the difference between the pressure on the upstream side, that is, the pressure in the pressure accumulating chamber 36, and the pressure on the downstream side, that is, in the vicinity of the fixed arc electrode 30a. That is, if the pressure on the downstream side is high, a sufficient blowing force cannot be obtained no matter how much the pressure in the pressure accumulating chamber 36 is increased.

According to the present embodiment, simultaneously with the occurrence of the arc discharge 7, the pressure of the thermal exhaust gas 20 is quickly discharged to the sealed container, so that the pressure on the downstream side, that is, in the vicinity of the fixed arc electrode 30a is always equal to the filling pressure of the sealed container. A nearly equivalent value is maintained. Therefore, it is possible to reduce the spray pressure necessary for interrupting the current, and to reduce the driving operation force.

In this embodiment, the low-temperature pressurization gas 35 ejected from the inside of the fixed arc electrode 30b is concentrated on the root portion of the arc discharge 7 located in the vicinity of the fixed arc electrode 30b and blown across from the inside to the outside. It will be attached. Therefore, the arc can be interrupted at a lower pressure, and the driving operation force can be reduced while maintaining an excellent interrupting performance.

The pressure of the thermal exhaust gas 20 generated from the arc discharge 7 is quickly discharged into the space in the sealed container as described above, but the opening at one end of the insulating nozzle 32 is directed to the movable piston 33. Therefore, there is a possibility that a part of the left side surface of the movable piston 33 shown in FIG. However, even when the pressure of the thermal exhaust gas 20 is applied, the pressure becomes a force that supports the compressive force of the movable piston 33 and does not act at least as a reaction force of the driving operation force of the movable piston 33. . Also from this point, the driving operation force can be reduced.

(E) Stabilization of gas flow Further, in the present embodiment, complicated valve control is not required when adjusting the pressure in the pressure accumulating chamber 36, and the arc heat is increased in increasing the blowing pressure of the arc-extinguishing gas. It does not use the self-pressurization effect by. Therefore, the same blowing gas pressure and gas flow can always be stably obtained regardless of the breaking current condition. For this reason, performance instability due to the magnitude of the cutoff current does not occur at all.

In this embodiment, the insulating nozzle 32 and the fixed

arc electrodes

30a and 30b are all fixed in a sealed container. Therefore, the relative position of each member does not change, and since the self-pressure boosting action by the arc heat is not used at all, the pressure and the flow rate of the pressurizing gas 21 sprayed to the arc discharge 7 are also current. Regardless of conditions, it is always constant. Therefore, it is possible to optimally design the flow path in the insulating nozzle 32 so as to be ideal for arc interruption.

(F) Improvement of shut-off performance during high-speed reclosing operation Further, the pressure increasing chamber 35 is provided with an intake hole 17 and an intake valve 19, and when the pressure in each chamber becomes lower than the filling pressure in the sealed container, the arc extinguishing is performed. Sexual gas can be automatically inhaled. For this reason, the low temperature arc extinguishing gas is quickly replenished into the pressure increasing chamber 35 during the charging operation. Therefore, there is no concern at all about the deterioration of the interruption performance even in the second interruption process in the high-speed reclosing duty.

(effect)
(1) The gas circuit breaker according to the present embodiment is arranged in a sealed container filled with an arc-extinguishing gas and is opposed to the sealed container so that it can be electrically energized. A pair of fixed

arc electrodes

30a, 30b configured to be capable of being generated, and a pressurizing chamber 35 that pressurizes the arc extinguishing gas to generate the pressurizing gas in order to blow the arc extinguishing gas to the arc discharge 7; In a gas circuit breaker provided with a pressure accumulating chamber 36 for accumulating pressurized gas and an insulating nozzle 32 for guiding the pressurized gas from the pressure accumulating chamber 36 toward the arc discharge 7, the accumulating chamber 36 is closed or opened. An openable / closable opening / closing part 41 is provided. The pressurizing chamber 35 has a cylinder 39 and a movable piston 33, and the movable piston 33 is configured to adiabatically compress the arc extinguishing gas inside the cylinder 39 to generate the boosted gas. . The arc extinguishing gas was an arc extinguishing gas having a global warming potential smaller than that of SF ₆ gas and a specific heat ratio at 20 ° C. larger than 1.1.

Thereby, the pressure is increased mainly by adiabatic compression by the movement of the movable piston 33, and the adiabatic compression works as a power of the specific heat ratio, so that a remarkable pressure increasing action can be obtained. Furthermore, since it is adiabatic compression, the heat generated by the arc discharge 7 does not flow into the booster 35, and the temperature of the arc extinguishing gas is reduced as compared with the conventional gas circuit breaker into which the heat from the arc discharge 7 flows. While the temperature can be lowered, and the pressurizing gas can be stored in the pressure accumulating chamber 36 until immediately before the arc discharge 7 is sprayed by the opening / closing part 41, a sufficient spraying pressure can be secured. Therefore, it is not necessary to increase the drive energy and the device size of the drive device.

According to the present embodiment, there is little influence on the environment, an arc extinguishing gas cooling effect and a boosting effect can be obtained, and an increase in equipment size and drive device can be avoided, which is compact and reliable. High gas circuit breaker can be obtained.

(2) The opening / closing part 41 closes the pressure accumulating chamber 36 in the first half of the current interruption process, restricts the flow of the thermal exhaust gas 20 generated by the heat of the arc discharge 7 into the pressure accumulating chamber 36, or accumulates pressure. The flow of the pressurization gas in the chamber 36 is limited, the pressure accumulation chamber 36 is opened in the latter half of the current interruption process, and the pressure increase gas in the pressure accumulation chamber 36 is guided to the arc discharge 7. As a result, it is possible to increase the cooling effect of the pressurizing gas or to spray the pressurizing gas to the arc discharge 7 in a state in which a sufficient blowing pressure is ensured. A highly reliable gas circuit breaker can be obtained.

(3) In the latter half of the current interruption process, the internal space of the boosting chamber 35 and the internal space of the pressure accumulating chamber 36 are configured to be separated in pressure, and the pressure in the internal space of the boosting chamber 35 is released. The pressurizing chamber 35 was configured as described above. As a result, it is possible to blow the boosted gas from the pressure accumulating chamber 36 to the arc discharge 7 without being affected by the boosting chamber 35 and to release the pressure in the internal space of the boosting chamber 35 independently of the blowing. Since the reverse stroke of the stroke of the movable piston 33 due to the compression reaction force can be suppressed and excessive driving energy is not required, it is possible to avoid an increase in equipment size and driving device.

(4) The arc extinguishing gas is a single gas of nitrogen (N ₂ ), carbon dioxide (CO ₂ ), oxygen (O ₂ ), methane (CH ₄ ), or a rare gas, or at least 1 A mixed gas containing seeds was used. Thus, it is possible to reduce the effects of global warming than the prior art using SF ₆ gas.

(5) The configuration is such that the pressure of the thermal exhaust gas 20 generated from the arc discharge 7 does not act as a compression reaction force of the arc extinguishing gas by the movable piston 33. Since the temperature of the arc extinguishing gas blown to the arc discharge 7 can be made much lower than that of the prior art using the self-pressure boosting action, the cooling effect of the arc discharge 7 can be remarkably improved, and the movable piston Since the drive energy of 33 can be reduced, it is possible to avoid an increase in equipment size and drive device as a result.

(6) The pair of fixed

arc electrodes

30a and 30b are fixed in a sealed container, and a trigger electrode 31 having a smaller diameter than the fixed

arc electrodes

30a and 30b is fixed inside the pair of fixed

arc electrodes

30a and 30b. 30a, 30b is movably disposed, and the trigger electrode 31 is brought into contact with the pair of fixed

arc electrodes

30a, 30b to short-circuit both the fixed

arc electrodes

30a, 30b. An arc discharge 7 is generated between the trigger electrode 31 and one fixed arc electrode 30a, and the arc discharge 7 is finally transferred from the trigger electrode 31 to the other fixed arc electrode 30b.

In general, the arc electrode is required to have durability against the arc discharge 7. However, in a gas circuit breaker having a structure in which a solid cylindrical electrode is subtracted from a conventional movable arc electrode having a cylindrical shape, more durability is required. In this case, it is necessary to make the fixed arc electrode thicker. As a result, the diameter of the movable arc electrode is increased, leading to an increase in the weight of the movable part. On the other hand, in the present embodiment, the period during which the arc discharge 7 is ignited on the trigger electrode 31 is only a limited period until the arc discharge 7 is transferred to the fixed arc electrode 30b. This can reduce the weight of moving parts. Further, since the fixed

arc electrodes

30a and 30b are fixed in the sealed container, the fixed

arc electrodes

30a and 30b can be thickened and the durability can be improved without worrying about an increase in the weight of the movable part. Thus, it is possible to achieve both improvement in durability and weight reduction of the movable part.

(7) The thermal exhaust gas 20 generated from the arc discharge 7 flows in a direction away from the arc discharge 7 without delay at the same time as the generation of the thermal exhaust gas 20, and is quickly discharged into the space in the sealed container. As a result, the pressure between the fixed

arc electrodes

30a and 30b is always maintained at a value substantially equal to the filling pressure of the sealed container, so that the spraying pressure necessary for interrupting the current can be reduced and the driving operation force can be reduced. . As a result, it is possible to avoid an increase in equipment size and drive device.

(8) As the rectifying means, an insulating nozzle 32 fixed in the sealed container is provided. Thereby, unlike the gas circuit breaker in which the conventional insulating nozzle moves along with the compression of the arc extinguishing gas, the insulating nozzle 32 does not affect the weight of the movable part, so that the driving energy can be reduced. An increase in size can be avoided.

[Second Embodiment]
(Constitution)
A second embodiment will be described with reference to FIGS. The second embodiment has the same basic structure as that of the first embodiment, but is characterized by a drive device that drives a movable part, which is not shown in FIGS.

6 and 7, the compression reaction force (a), that is, the force that the movable piston 33 receives from the pressure of the pressure-increasing chamber 35 is indicated by a solid line, the driving force (a) of the driving device is indicated by a dotted line, and the force that accelerates the movable part ( The effective acceleration force ((ear)) is indicated by a one-dot chain line. The horizontal axis is the drive stroke, and the complete closing position is 0 pu and the complete opening position is 1.0 pu. Here, if the influence of friction or the like is ignored, the effective acceleration force is expressed as “driving force (A) -compression reaction force (A)”. As for the effective acceleration force, a positive value means acceleration force, and a negative value means deceleration force.

Since the gas circuit breaker of the present embodiment mainly performs adiabatic compression by the movable piston 33, the curve of the compression reaction force ((a), solid line) is known as adiabatic compression characteristics in FIG. Monotonically increasing characteristics as shown in FIG. In addition, since the thermal energy from the arc discharge 7 is not used to increase the pressure of the blowing gas, the curve of the compression reaction force (solid line) is always a constant curve regardless of the magnitude of the cutoff current or the phase of the alternating current. .

FIG. 6 shows a case where the driving force ((A), dotted line) of the driving device is flat with respect to the stroke. On the other hand, FIG. 7 shows a case where the driving force ((A), dotted line) of the driving device attenuates with respect to the stroke. In FIG. 6, as the most extreme example, the driving force is constant at 0.5 pu over the entire stroke position. On the other hand, FIG. 7 shows a case where the driving force linearly attenuates from 0.8 pu to 0.2 pu as an example.

Further, the drive energy stored in the drive device for the shut-off operation is given as an area obtained by integrating the drive force ((A), dotted line) with a stroke. That is, in the case of the driving force characteristic of FIG.
0.5 pu × full stroke 1 pu = 0.5 (Expression 2)
The amount of energy.

On the other hand, in the case of the driving force characteristics of FIG. 7, the driving energy has a trapezoidal area surrounded by the vertical axis 0 pu line and the driving force (b) dotted line,
(0.8 pu + 0.2 pu) ÷ 2 × full stroke 1 pu = 0.5 (Expression 3)
The amount of energy.

That is, FIG. 6 and FIG. 7 have the same driving energy although the stroke characteristics of the driving force are different. The second embodiment is characterized in that a drive device having an output attenuation type characteristic as shown in FIG. 7 is employed. That is, as the driving device, one that is configured such that the driving force decreases in the shut-off process is used.

(Function)
In general, the size and cost of a drive device tend to increase monotonically with respect to drive energy. That is, although the driving devices in FIGS. 6 and 7 have different driving force characteristics, the driving energy is the same, and therefore, it can be said that there is no great difference in the size and cost of the driving devices.

On the other hand, even if the driving energy is the same, the driving device having the characteristics shown in FIG. 7 that produces a large driving force in the first half of the stroke and attenuates toward the second half has a larger effective acceleration force (ear) than that in FIG. It turns out that it is a value. Since the compression reaction force characteristics (A) are the same in FIGS. 6 and 7, and the drive energy is also the same, the speed at the fully open position (stroke 1pu) is the same, but the speed during the stroke is Unlike in both cases, the top speed of the movable portion is higher in FIG. 7 where the acceleration force in the first half of the opening is larger.

This is because when the operation drive energy is the same, the drive device having the output attenuation type drive characteristics as shown in FIG. 7 increases the drive speed of the movable portion compared to the drive device having the drive characteristics shown in FIG. It shows that you can. This means that the gap between the electrodes opens faster for the gas circuit breaker, which is a great merit in terms of quick recovery of electrical insulation between the electrodes. Further, if the driving speed of the movable portion is increased, the arc discharge 7 is transferred from the trigger electrode 31 to the fixed arc electrode 30b, and the time until the low-temperature compressed gas is strongly blown from the accumulator 36 to the arc discharge 7 is increased. This shortens the time required for completing the shut-off and further improves durability.

The effects described above can be obtained because the gas circuit breaker mainly performs the adiabatic compression by the movable piston 33 to increase the pressure of the blowing gas, so that the compression reaction force is very small in the initial stage and toward the latter half. This is due to the rapidly increasing properties. In addition, it is an indispensable condition for obtaining the function and effect that the compression reaction force always has a constant curve regardless of the magnitude of the breaking current, the alternating current phase, or the like. Both are features that cannot be achieved with a conventional gas circuit breaker structure that utilizes the self-pressurizing action. This is because in the conventional circuit breaker, the compression reaction force applied to the fixed piston is greatly influenced by the heat generated by the arc, so it does not have a monotonically increasing curve, and the aspect varies greatly depending on the condition of the breaking current.

A specific policy for changing the drive output from a flat characteristic as shown in FIG. 6 to an attenuating characteristic as shown in FIG. 7 under the same driving energy will be described. This can be easily realized by using a stored spring as a drive energy source. In principle, the output characteristic of the spring mechanism is given by the following equation, and becomes a monotonically decreasing straight line as shown in FIG.
F = k · (L + 1−x) (Formula 4)
Here, F: drive output, k: spring constant, x: stroke (pu), L: compression length (pu) of the spring at the complete opening position (stroke x = 1 pu).

In particular, if the spring is configured to be close to the free length at the fully open position (L≈0 pu), the value of the spring constant k for obtaining the same driving energy increases, and the driving force is reduced as the spring is released. It becomes the characteristic which attenuates greatly with respect to the stroke.

Alternatively, when using a drive device that has a relatively flat output characteristic with respect to the stroke, such as a hydraulic operation mechanism, the output characteristic is attenuated without changing the operation drive energy by connecting an appropriate link structure. It is also possible to change to a type.

Various measures other than the above can be considered for the output characteristics to be damped, but the important thing is that the structure shown in the first embodiment is combined with a driving device whose driving force is damped with respect to the stroke. Thus, even with the same operation drive energy, the dissociation rate of the electrode can be effectively increased, such as quick insulation recovery of the circuit breaker, reduction of time required for completion of interruption, improvement of durability, This means that a unique merit can be obtained.

Further, the high gas pressure in the boosting chamber 35 described in the first embodiment is disconnected from the movable piston 33, and the pressure in the boosting chamber 35 is released by the release mechanism 48, so that the driving force is greatly increased in the latter half of the opening. Even if it drops, there will be no inconvenience such as the moving part going backwards.

As one guideline for the output-decreasing type driving force characteristic, the driving force at the complete cutoff position (stroke 1 pu) is, for example, approximately 80% or less with respect to the driving force at the closing position (stroke 0 pu). suggest. If the output reduction rate at the fully open position is set to be 80% or less, the above-described action can be substantially obtained.

(effect)
As described above, in the present embodiment, the driving device for mechanically compressing the arc extinguishing gas of the booster 35 is provided, and the driving device is configured such that the driving force decreases with the driving stroke. Thereby, since the acceleration force in the first half of the opening increases, the effect of promptly restoring the electrical insulation between the electrodes is obtained. Further, if the driving speed of the movable portion is increased, the arc discharge 7 is transferred from the trigger electrode 31 to the fixed arc electrode 30b, and the time until the low-temperature compressed gas is strongly blown from the accumulator 36 to the arc discharge 7 is increased. The effect of shortening and shortening the time required to complete the shutoff and improving the durability can be obtained.

[Other Embodiments]
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof, as long as they are included in the scope and gist of the invention.

For example, in the first and second embodiments, the movable piston 33 can be moved in the direction of the center line by the driving device and is used as the boosting means, but is not limited thereto. For example, as shown in FIG. 8, the piston may be fixed, and the movable cylinder 39 'connected directly or indirectly to the driving device may be moved with respect to the fixed piston 33'. Thus, even if the movable cylinder 39 ′ is used as a pressure increasing means, the volume of the pressure increasing portion 35 is variable, so that the arc extinguishing gas inside the pressure increasing portion 35 can be compressed and pressure increased.

The movable cylinder 39 ′ has a sliding surface that can slide with the fixed arc electrode 30b and the cylindrical member 40 in the same manner as the movable piston 33, and the communication hole 34 can be closed by the movement of the movable cylinder 39 ′. Configure as follows.

In the first and second embodiments, the fixed electrode portion A is fixed in the sealed container and only the movable electrode portion B is moved in the axial direction, but the movable electrode portion B is moved with respect to the fixed electrode portion A. The fixed electrode portion A may also be moved in the axial direction so as to move relatively, so that a so-called dual motion mechanism that improves the relative opening speed may be used.

A ... Fixed electrode part B ... Movable electrode part 1 ... Gas circuit breaker 2 ... Opposite energizing electrode 3 ... Movable energizing electrode 7 ... Arc discharge 17 ... Intake hole 19 ... Intake valve 20 ... Thermal exhaust gas 21 ... Blowing gas (pressurized gas)
30a, 30b ... fixed arc electrode 31 ... trigger electrode 33 ... movable piston 33a ... sliding inner peripheral surface 33b ... sliding outer peripheral surface 33 '... fixed piston 34 ... communication hole 35 ... pressure increasing chamber 36 ... pressure accumulating chamber 37 ... exhaust hole 39 ... Cylinder 39 '... Moving cylinder 40 ... Cylinder member 41 ... Opening / closing part 42 ... Link 43 ... Rod 43a ... Groove 47 ... Seal member 48 ... Pressure release mechanism 49 ... Release compressed gas

Claims

A sealed container filled with arc-extinguishing gas;
A pair of arc electrodes arranged oppositely in the sealed container, electrically energized, and configured to generate arc discharge between each other when the current is interrupted,
In order to blow the arc-extinguishing gas against the arc discharge, a pressure-increasing unit that pressurizes the arc-extinguishing gas to generate a pressure-increasing gas;
A pressure accumulating space for storing the pressurizing gas;
In the gas circuit breaker provided with rectifying means for guiding the boosted gas from the pressure accumulation space toward the arc discharge,
An openable and closable opening / closing part for making the pressure accumulation space closed or open is provided,
The pressurizing unit has a cylinder and a piston, and is configured to adiabatically compress the arc extinguishing gas inside the cylinder by moving at least one of the cylinder and generate the pressurizing gas.
A gas circuit breaker characterized in that the arc-extinguishing gas has a global warming potential smaller than SF 6 gas and a specific heat ratio at 20 ° C. is larger than 1.1.
The opening / closing part closes the pressure accumulating space in the first half of the current interruption process, restricts the flow of thermal exhaust gas generated by the heat of the arc discharge into the pressure accumulating space, or Limiting outflow of the pressurizing gas,
2. The gas circuit breaker according to claim 1, wherein, in the second half of the current interruption process, the pressure accumulating space is opened, and the boosted gas in the pressure accumulating space is guided to the arc discharge.
In the latter half of the current interruption process, the internal space of the booster and the pressure accumulation space are configured to be separated in pressure, and the internal space of the booster is configured to release pressure. The gas circuit breaker according to claim 1 or 2, characterized by the above.
The arc extinguishing gas is nitrogen (N 2 ), carbon dioxide (CO 2 ), oxygen (O 2 ), methane (CH 4 ), or any one kind of rare gas, or at least one kind. The gas circuit breaker according to any one of claims 1 to 3, wherein the gas breaker is a mixed gas.
A driving device for mechanically compressing the arc-extinguishing gas of the boosting unit is provided;
The gas circuit breaker according to any one of claims 1 to 4, wherein the driving device is configured such that a driving force thereof decreases with a driving stroke.
The pressure of the thermal exhaust gas generated from the arc discharge is configured not to act as a compression reaction force of the arc extinguishing gas by the piston or the cylinder. Gas circuit breaker.
The pair of arc electrodes are fixed in the sealed container,
Inside the pair of arc electrodes, a trigger electrode having a smaller diameter than the arc electrodes is disposed so as to be movable between the arc electrodes,
The trigger electrode is brought into an energized state by short-circuiting both arc electrodes in contact with the pair of arc electrodes, and when the current is interrupted, the arc discharge occurs between the trigger electrode and the one arc electrode, 7. The gas circuit breaker according to claim 1, wherein the arc discharge is finally transferred from the trigger electrode to the other arc electrode.
The thermal exhaust gas generated from the arc discharge is configured to flow in a direction away from the arc discharge without delay at the same time as the generation of the thermal exhaust gas, and to be quickly discharged into the space in the sealed container. The gas circuit breaker according to any one of claims 1 to 7.
The gas circuit breaker according to any one of claims 1 to 8, wherein the rectifying means is an insulating nozzle fixed in the sealed container.