Patent Application
20130168357
The present application claims priority from Japanese Patent application serial No. 2011-290056, filed on Dec. 28, 2011, the content of which is hereby incorporated by reference into this application.
The present invention relates to a puffer-type gas circuit-breaker, and more particularly to the exhaust structure of a puffer-type gas circuit-breaker.
A gas circuit-breaker practically used in a high-voltage electric power transmission network uses both a gas circuit-breaker of mechanical puffer chamber type, which compresses a dielectric gas in an enclosure tank with a mechanical force and blasts arcs generated between contacts with the compressed dielectric gas to interrupt the arcs, and a gas circuit-breaker of thermal puffer chamber type (self-blast chamber type), which uses arc energy generated between contacts to blast arcs with a dielectric gas.
In the puffer-type gas circuit-breaker, it is important to improve interruption performance and dielectric performance. A technique related to a puffer-type gas circuit-breaker aimed at improving interruption performance is disclosed in PTL 1 (Japanese Patent Laid-open No. Hei 1 (1989)-313827). In this technique, as shown in
The circuit-breaker according to this technique is structured so that a high-temperature and high-pressure gas including conductive materials generated through arc quenching is not easily inhaled from the inlet holes 280. Accordingly, it is possible to supply a dielectric gas with a low impurity density into the puffer chamber 90, enabling interruption performance to be favorably maintained. In this structure, however, the high-temperature and high-pressure gas including conductive materials generated through arc quenching may flow toward an insulating support member (not shown), by which a moving-side conductor is fixed on the right side on the drawing sheet. Therefore, there has been a risk that if the insulating support member is blasted with the high-temperature and high-pressure gas including conductive materials, the dielectric performance of the breaker may be adversely affected.
An object of the present invention is to provide a gas circuit-breaker that not only solves the above problem with the dielectric performance but also improves the interruption performance. Specifically, an object of the present invention is to improve the dielectric performance by preventing the insulating support member from being directly blasted with a high-temperature and high-pressure gas including conductive materials generated through arc quenching, the insulating support member being a weak point in terms of insulation of the circuit breaker, and to improve the interruption performance by supplying a dielectric gas with a low impurity density into a puffer chamber.
The puffer-type gas circuit-breaker according to the present invention includes an enclosure tank filled with a dielectric gas; a stationary cylinder, on a moving side, that is held in the enclosure tank by an insulating support tube and is connected to a current conductor; a puffer shaft, in a hollow shape, that is provided in the stationary cylinder so as to be coaxial with the stationary cylinder, one end of the puffer shaft being linked to an insulating rod linked to an operating device, the puffer shaft having a puffer shaft flow hole through which a high-temperature and high-pressure gas generated at the time of arc generation is exhausted; a moving puffer piston that is connected to the other end of the puffer shaft so as to be coaxial with the puffer shaft, the moving puffer piston being movable in the stationary cylinder in an axial direction thereof; a moving arc contact, an insulating nozzle, and a moving main contact that are provided at an end of the moving puffer piston so as to be mutually concentric from an inner side; a partition wall secured to the inner circumference of the stationary cylinder, the partition wall having a guide member through which the puffer shaft slidably passes; and a stationary-side stationary cylinder having a stationary arc contact and a stationary main contact at one end, the stationary arc contact and stationary main contact being disposed opposite to the moving arc contact and moving main contact. In this structure, the partition wall has flanges at both ends, the flanges being secured to the stationary cylinder so as to form a space in the stationary cylinder, one flange of the partition wall has an inlet hole and an outlet hole, the one flange of the partition wall forms a mechanical puffer chamber together with the moving puffer piston, the stationary cylinder, and the puffer shaft, the other flange of the partition wall forms a hot gas exhaust chamber together with the stationary cylinder, the stationary cylinder has a hole used for gas inhaling and a hole used for gas expelling, the holes communicating with the space in the stationary cylinder, and also has a hot gas exhaust opening that communicates with the hot gas exhaust chamber, the hot gas exhaust opening is formed in radial direction of the stationary cylinder and communicates with the puffer shaft flow hole after an arc is generated, the hole used for gas inhaling is formed on one side relative to a virtual plane that bisects the stationary cylinder in a radial direction, and the hot gas exhaust opening is formed on the other side relative to the virtual plane.
The partition wall preferably has a dividing member that divides the space in the stationary cylinder into two parts to divide the space in the stationary cylinder into an inhaling space that communicates with the hole used for gas inhaling and an expelling space that communicates the hole used for gas expelling; the hole used for gas inhaling is preferably formed on the same side as the inhaling space and the hole used for gas expelling is preferably formed on the same side as the expelling space.
When the stationary cylinder is divided into two parts with the virtual plane that is orthogonal to the current conductor and bisects the stationary cylinder in a radial direction, the hot gas exhaust opening is preferably disposed opposite to a side on which the current conductor is disposed.
Because a high-temperature and high-pressure gas generated from an arc space at the time of arc generation is exhausted to a place distant from an insulating support tube and a moving-side current conductor, it becomes possible to prevent a ground fault and improve dielectric performance. In addition, since the high-temperature and high-pressure gas generated at the time of arc generation is prevented from entering a thermal puffer chamber, a dielectric gas with a low impurity density can be supplied to arcs and thereby interruption performance can also be improved.
A puffer-type gas circuit-breaker in the present invention will be described below with reference to the drawing.
The stationary main contact 2 and the stationary arc contact 4 are electrically connected to a stationary-side current conductor 14. The moving main contact 3 and the moving arc contact 5 are electrically connected to a moving-side current conductor 15 through a moving puffer piston 10 and a stationary cylinder 11 on a moving side (moving-side stationary cylinder).
A thermal puffer chamber (self-blast chamber) S1 is formed with a space enclosed by the moving puffer piston 10 and a puffer shaft 12, which is hollow. An inlet hole 10a, which communicates with a mechanical puffer chamber S2 in the puffer piston 10, is provided with a check valve 10c. The check valve 10c restricts a gas flow from the thermal puffer chamber S1 into the mechanical puffer chamber S2 but does not restrict a gas flow from the mechanical puffer chamber S2 to the thermal puffer chamber S1.
An insulating nozzle 6 is provided between the moving main contact 3 and moving arc contact 5 so as to be concentric with them. The insulating nozzle 6 is structured so that the dielectric gas in the thermal puffer chamber S1, which is exhausted through an outlet hole 10b, is blown to arcs generated in a space formed between the stationary arc contact 4 and the moving arc contact 5 (the space will be referred to below as the arc space).
The moving arc contact 5 is disposed at one end of the puffer piston 10. A space enclosed by the other end of the puffer piston 10, the moving-side stationary cylinder 11, the puffer shaft 12, and a partition wall 13 forms the mechanical puffer chamber S2. The puffer piston 10 can reciprocate in the mechanical puffer chamber S2 in the axial direction, by which an opening operation and a closing operation can be carried out.
One end of the puffer shaft 12 is secured to the one end of the puffer piston 10 so as to be concentrically disposed inside the puffer piston 10. The other end of the puffer shaft 12 is linked to an insulating operating rod 16. The insulating operating rod 16 is linked to an operating device (not shown). Due to this structure, the driving force of the operating device (not shown) is transmitted to the puffer piston 10.
The moving-side stationary cylinder 11 is secured to the interior of the enclosure tank 20 by an insulating support tube 7. The moving-side stationary cylinder 11 has gas inlet holes 11a, gas outlet holes 11b, and hot gas exhaust openings 11c. The partition wall 13 is provided on the inner circumference of the moving-side stationary cylinder 11 so as to slidably hold the puffer shaft 12.
The partition wall 13, which is cylindrical, has flanges at both ends. The flanges are fitted to the inner circumference of the moving-side stationary cylinder 11 and are attached to the moving-side stationary cylinder 11 with screws or the like. A sliding member (not shown) such as a piston ring is provided at an arbitrary position on the inner surface of the partition wall 13 thereby the puffer shaft 12 slides on the inner surface of the partition wall 13 while maintaining a hermetic seal in the mechanical puffer chamber S2.
The puffer shaft 12, which is hollow, has a shaft outlet hole 12a. The shaft outlet hole 12a is formed as shown in
The shield 17 is configured to minimize the clearance between the puffer shaft 12 and the shield 17 within a range in which the puffer shaft 12, which moves in the axial direction, does not come into contact with the shield 17, minimizing an amount of the high-temperature and high-pressure gas, which is exhausted through the shaft outlet hole 12a into the hot gas exhaust chamber S4, flowing into the insulating support tube 7. Thus, the high-temperature and high-pressure gas generated in the arc space can be exhausted through the hot gas exhaust openings 11c of the hot gas exhaust chamber S4. To prevent the exhausted high-temperature and high-pressure gas from flowing toward the insulating support tube 7 as much as possible, the hot gas exhaust openings 11c are formed so that the gas is exhausted in radial directions.
The partition wall 13 has inlet holes 13a and outlet holes 13b, each of which has a check valve 8 and a release valve 9. The release valve 9 is a check valve for outgoing chamber gas. The release valve 9 is formed with, for example, a spring support member 9a, a spring biased valve 9b, and a release pressure spring 9c having a prescribed elastic coefficient. The release valve 9 is configured to release the pressure from the mechanical puffer chamber S2 when the pressure reaches a threshold level, thereby coordinating the exhaust of the gas in the mechanical puffer chamber S2.
As shown in
The number of gas inlet holes 11a, gas outlet holes 11b, and hot gas exhaust openings 11c, which are disposed in the moving-side stationary cylinder 11, their shapes, and their positions can be appropriately changed. To reduce the risk of the high-temperature and high-pressure gas exhausted through the hot gas exhaust openings 11c from flowing into the gas inlet holes 11a, the gas inlet holes 11a are preferably formed on one side relative to the virtual plane that bisects the moving-side stationary cylinder 11 in a radial direction, and the hot gas exhaust openings 11c are preferably formed on the other side relative to the virtual plane. In this structure, the gas inlet holes 11a and the hot gas exhaust openings 11c are configured so that the gas inlet holes 11a and the hot gas exhaust openings 11c are separated from each other as much as possible. Thus, a dielectric gas with a low impurity density is always supplied into the thermal puffer chamber S1, so the interruption performance of the circuit breaker can be improved.
As described above, the present invention can improve the dielectric performance of the circuit breaker by exhausting the high-temperature and high-pressure gas, generated at the time of arc generation, from the arc space to a place distant from the insulating support tube 7 and moving-side current conductor 15. The present invention can also improve the interruption performance of the circuit breaker by preventing the high-temperature and high-pressure gas generated at the time of arc generation from flowing into the mechanical puffer chamber S2 and thermal puffer chamber S1 and by supplying a dielectric gas with a low impurity density to arcs. These improvements can be achieved with the structures shown in
The opening operation of the puffer-type gas circuit-breaker according to the present invention will be described with reference to
In this state, the shaft outlet hole 12a communicates with the hot gas exhaust chamber S4 as described above. The high-temperature and high-pressure gas, in which conductive materials generated in the arc space have been melted, passes through the hollow interior of the puffer shaft 12 and is exhausted through the shaft outlet hole 12a into the hot gas exhaust chamber S4. The high-temperature and high-pressure gas is further exhausted through the hot gas exhaust openings 11c into the interior of the enclosure tank in radial directions of the moving-side stationary cylinder 11. Since the hot gas exhaust openings 11c are formed at positions distant from the gas inlet holes 11a as far as possible as described above, the high-temperature, high-pressure gas generated in the arc space are exhausted to a place distant from the gas inlet holes 11a as far as possible.
When the opening operation proceeds from the state in
By contrast, in case of interrupting low current, even if the moving puffer piston 10 is moved to the right on the drawing sheet, the pressure in the arc space is not so increased by the arc 1 when compared with the case of interrupting high current, so the pressure in the thermal puffer chamber S1 is not so high when compared with the case of interrupting high current. Accordingly, the release valve 9 is not positively opened and the check valve 10c is opened instead. Then, the dielectric gas in the mechanical puffer chamber S2 is blown to the arc 1 through the thermal puffer chamber S1 and the arc 1 is thereby quenched.
When the opening operation further proceeds, the puffer-type gas circuit-breaker enters a completely open state shown in
In the state in which a closing operation is in progress shown in
With the structure (see
The partition wall 13 may be structured as shown in
In the structure shown in
A second embodiment of the present invention will be described with reference to
At one end of the partitioning members 13d, a guide 13c is provided so that the hollow puffer shaft 12 slides in the axial direction. The gas inlet holes 11a and inlet holes 13a are formed on the upper side (inlet-side space S3a), on the drawing sheet, of the partitioning member 13d. The gas outlet holes 11b and the outlet holes 13b are formed on the lower side (outlet-side space S3b), on the drawing sheet, of the partitioning member 13d.
Although, in the embodiment shown in
In this embodiment, the moving-side current conductor 15 is drawn upward on the drawing sheet. In view of the positions of the gas inlet holes 11a and the hot gas exhaust openings 11c, therefore, the partitioning members 13d are structured so as to divide the intra-stationary cylinder space S3 into an upper part and a lower part. However, this is not a limitation; if the moving-side current conductor 15 is drawn in the horizontal direction on the drawing sheet, the partitioning members 13d may be structured so as to divide the intra-stationary cylinder space S3 into a right part and a left part. That is, the structure of the partitioning member 13d can be appropriately changed according to the direction in which the moving-side current conductor 15 is drawn.
With the structure described above, even if the high-temperature and high-pressure gas exhausted through the hot gas exhaust openings 11c flows through the gas outlet holes 11b into the outlet-side space S3b, the partitioning members 13d blocks the flow of the gas. Accordingly, it becomes possible to prevent the gas from flowing into the inlet-side space S3a, in which the inlet holes 13a are formed. This prevents the high-temperature and high-pressure gas from flowing into the thermal puffer chamber S1, so interruption performance can be further improved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-290056 | Dec 2011 | JP | national |
