Patent Application
20130270228
The present invention relates to a switchgear such as a disconnecting switch and/or a circuit breaker which opens or closes an electrical path in an electric power system, and, more particularly, relates to an improvement in arc extinguishing performance.
For example, in a disconnecting switch and/or a circuit breaker which interrupts current in insulating gas such as SF6 gas and dry air, as a technique which interrupts an arc generated between electrodes during current interruption, there is a method in which arc extinguishing gas is made to generate from an arc extinction member and the arc is made to cool by the arc extinguishing gas; and accordingly, the arc is interrupted. This is a method in which the arc extinction member is disposed near an arc generation portion of a fixed electrode or a movable electrode and the arc comes into contact with the arc extinction member; and accordingly, the arc is cooled by the arc extinguishing gas generated from the arc extinction member.
As such a known switchgear, an arc is made to generate between a fixed contact and a movable contact and between a current-carrying contact and the movable contact to interrupt the arc by decoupling, and the arc generated between the current-carrying contact and the movable contact is brought into contact with a fluorine resin tube; and accordingly, arc extinguishing gas is made to generate and to improve interruption performance (see, for example, Patent Document 1).
In the above-described known switchgear, the arc extinction member generates the arc extinguishing gas by being melted by the heat of the arc. However, the amount of generation of arc extinguishing gas changes depending on the melting temperature of the arc extinction member and the coefficient of thermal conductivity of insulation gas. In order to surely generate arc extinguishing gas, what is important is to bring the arc into contact with the arc extinction member.
In the known art such as Patent Document 1, no means exists to control the extending direction of the arc toward the arc extinguishing member side; and therefore, there is no certainty that the arc comes into contact with the arc extinction member, the arc extinguishing gas is likely not to be generated, and the generation of the arc extinguishing gas is unstable.
The present invention has been made to solve the above described problem, and an object of the present invention is to provide a switchgear in which the extending direction of an arc is controlled in the direction of the surface of an arc extinction member by a pressure gradient in connection with the generation of the heat of the arc and arc extinguishing gas, and interruption performance is improved by the stable generation of the arc extinguishing gas.
According to the present invention, there is provided a switchgear including: a fixed contactor provided in a tank filled with insulating gas; and a movable contactor provided in the tank, the movable contactor being connected to and disconnected from the fixed contactor so as to move forward and backward. The switchgear includes an arc extinction member including a surrounding portion which is slidably connected to the outer circumferential surface of the movable contactor halfway in a movement range from a close contact state to an open contact state, and is formed so as to surround an arc space portion in a sealed manner, the surrounding portion being formed with a through hole through which the arc space communicates with the outside of the arc space.
Furthermore, according to the present invention, there is provided a switchgear including: a fixed contactor provided in a tank filled with insulating gas; and a movable contactor provided in the tank, the movable contactor being connected to and disconnected from the fixed contactor so as to move forward and backward. The switchgear includes: an arc extinction member having a surrounding portion which is slidably connected to the outer circumferential surface of the movable contactor halfway in a movement range from a close contact state to an open contact state, and is formed so as to surround an arc space portion in a sealed manner; and an arc extinguishing member provided in a central portion of the movable contactor, the arc extinguishing member being formed with a center hole axially formed in a central portion of the arc extinguishing member.
According to the present invention, an arc space communicates with the outside of the arc space by a through hole formed in a surrounding portion of an arc extinction member, thereby being capable of controlling the extending direction of an arc so as to be surely brought into contact with the arc extinction member, whereby arc extinguishing gas is stably generated and arc extinguishing performance of a switchgear can be improved.
Hereinafter, a switchgear according to Embodiment 1 of the present invention will be described with reference to
A movable contactor 2 is connected to and disconnected from the fixed contactor 1 by moving forward and backward in the horizontal direction of the drawing by a driving device (not shown in the drawing). A plurality of tubular shaped current collectors 21 are disposed around the movable contactor 2 and are always slidably connected to the outer circumferential surface 2a thereof with respect to axial movement of the movable contactor 2. An outer circumferential portion of the current collector 21 is surrounded by a movable side shield 22 for electric field relaxation. A leading end portion of the movable contactor 2 on the fixed contactor 1 side constitutes a contact portion 2b formed in a tubular shape; and the contact portion 2b goes into between the fixed arc contact 11 and the fixed main contact 12 of the fixed contactor 1 in a close contact state of the switchgear and is electrically connected with a predetermined contact pressure by the fixed main contact 12.
An arc extinction member 3 constituting the arc extinction chamber is fixed to the fixed side shield 13 and has a surrounding portion 31 which is slidably connected to the outer circumferential surface 2a of the movable contactor 2 halfway in a movement range from a close contact state to an open contact state, the surrounding portion 31 being formed so as to surround an arc space portion S in a sealed manner. Then, the surrounding portion 31 of the arc extinction member 3 is formed with a plurality of through holes 31a (in this example, two vertically symmetric positions of the drawing) at predetermined portions, the through holes 31 being provided for deflecting the extending direction of a generated arc A by a pressure gradient.
Incidentally, the shape of the arc extinction member 3 may be formed in a cylindrical shape as shown in
Incidentally, the number of the through holes 31a and their circumferential placing positions are not particularly limited, but it is permissible if the arc A can be extended in the direction of the wall surface of the surrounding portion 31 by the pressure gradient which is generated in connection with the generation of the arc A and lowers from the center side of the arc space portion S toward the wall surface side of the surrounding portion 31, at least one place; and the through holes 31a do not also need to be arranged in a line-symmetric manner.
Incidentally, the arc space portion S includes spaces formed inside the surrounding portion 31 of the arc extinction member 3 and the tubular shaped contact portion 2b of the movable contactor 2.
Furthermore, the through hole 31a may be formed such that the diameter of the outer circumferential surface side of the surrounding portion 31 of the arc extinction member 3 is larger than the diameter of the inner circumferential surface side of the surrounding portion 31 of the arc extinction member 3, as shown in
Further, a columnar arc extinguishing member 4 is provided in the inside of the fixed arc contact 11 so as to protrude from an opening end portion of the fixed arc contact 11 toward the separating direction of the movable contactor 2. Incidentally, the arc extinguishing member 4 may be located at the same surface position as the opening end of the fixed arc contact 11; but preferably, the arc extinguishing member 4 is protruded toward the separating direction of the movable contactor 2, that is, toward the arc space portion 5, as shown in
As a material that can be preferably used for the arc extinction member 3 and the arc extinguishing member 4, there can be included those combined with any one or a plurality of kinds of, for example, polytetrafluoroethylene, polyacetal, acrylic acid ester copolymer, aliphatic hydrocarbon resin, polyvinyl alcohol, polybutadiene, polyvinyl acetate, polyvinyl acetal, isoprene resin, ethylene-propylene rubber, ethylene-vinyl acetate copolymer, and polyamide resin.
Incidentally, the same material may be used for the arc extinction member 3 and the arc extinguishing member 4, or the materials of these members may be different from each other. In addition, for example, in the case of a three phase alternating current, the similarly configured switchgears, each shown in
Next, the operation of the thus configured Embodiment 1 will be described with reference to
First, as shown in
The separation of the movable contactor 2 proceeds and the movable contactor 2 passes by the through holes 31a. Then, as shown in
Accordingly, arc extinguishing gas is further stably generated in a great amount from the arc extinction member 3; and therefore, the arc A is decomposed or cooled by the arc extinguishing gas and interruption performance is improved. Furthermore, when the arc A comes into contact with the arc extinguishing member 4 provided in the central portion of the fixed arc contact 11, arc extinguishing gas is also generated from the arc extinguishing member 4; and accordingly, a pressure gradient is generated to form the flow of gas and the arc extinguishing gas acts so as to be blown to the arc A. Thus, a cooling effect on the arc A increases and the interruption performance is further improved. Finally, the leading end of the movable contactor 2 goes to the inside of the movable side shield 22 as shown in
As described above, according to Embodiment 1, the configuration is made such that the arc extinction member 3 includes the surrounding portion 31 which is slidably connected to the outer circumferential surface 2a of the movable contactor 2 halfway in the movement range from the close contact state to the open contact state, and the surrounding portion 31 is formed with the through hole 31a for deflecting the direction of the generated arc in the direction of the inner circumferential surface of the surrounding portion 31 by the pressure gradient; and therefore, the extending direction of the arc A is controlled by the pressure gradient generated inside the surrounding portion 31 and the arc can be surely brought into contact with the arc extinction member 3. Thus, the arc extinguishing gas is stably generated and arc extinguishing performance of the switchgear can be improved. Furthermore, it also becomes possible to achieve a reduction in size of the device and to reduce environmental load by the improvement of the arc extinguishing performance.
Further, the arc is brought into contact with the arc extinction member 3 and is cooled by utilizing the pressure rise due to the heat of the arc; and therefore, time in which the arc is controlled depends on the pressure. That is, even in the case of reaching near a current zero point, the arc continues to come into contact with the arc extinguishing member and the stable generation of the arc extinguishing gas can be expected. Whereas, in the case of controlling the extending direction of the arc by utilizing electromagnetic force, the time in which the arc is controlled is determined by current. Thus, the electromagnetic force reduces near the current zero point and accordingly the arc is likely not to come into contact with the arc extinction member; and therefore, the stable generation of the arc extinguishing gas cannot be expected.
In the thus configured Embodiment 2, when an arc A is generated, a pressure gradient is generated by the heat of the arc A, the pressure gradient being lowered from the center side of an arc space portion S to the direction of the through hole 4a in the central portion of the arc extinguishing member 4 and two directions toward through holes 31a of a surrounding portion 31; and the flow of gas is formed in the direction of dashed line arrow D in
A part of the arc A, which exists on the fixed arc contact 11 side, extends to the outer circumferential surface side of the arc extinguishing member 4 in response to the flow of gas and comes into contact with the arc extinguishing member 4. Whereas, a part of the arc A, which exists on the movable contactor 2 side, comes into contact with the inner circumferential surface of the arc extinction member 3 in response to the flow of gas, as in Embodiment 1. Therefore, the arc A can be brought into contact with both the arc extinguishing member 4 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased; and thus, interruption performance is further improved.
In the thus configured Embodiment 3, an arc A performs rotational motion in response to circumferential force due to a magnetic field by the permanent magnets 5. That is, the arc A is driven in the rotational direction on an electrode, that is, a fixed arc contact 11; and therefore, interruption performance is improved by the temperature suppression of the electrode and the cooling effect of forced-convection. At the same time, the arc A is characterized by extending so as to conform with a longitudinal magnetic field of the permanent magnets 5, that is, a magnetic field in the separating direction of the movable contactor 2; and the arc A is pulled by the permanent magnets 5.
In the case of Embodiment 3, the permanent magnets 5 is covered around by the arc extinguishing member 4 for protection; and therefore, the arc A pulled by the permanent magnets 5 stably comes into contact with the arc extinguishing member 4. That is, a part of the arc A, which exists on the fixed arc contact 11 side, remains in a state where the part of the arc A comes into contact with the arc extinguishing member 4; whereas a part of the arc A, which exists on the movable contactor 2 side, remains in a state where the latter part of the arc A comes into contact with the arc extinction member 3. Therefore, the arc A can be brought into contact with both the arc extinguishing member 4 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased; and thus, interruption performance can be further improved.
In the thus configured Embodiment 4, when an arc A is generated, a pressure gradient is generated by the heat of the arc A, the pressure gradient being lowered from the center side of an arc space portion S to the direction of the through hole 4a in the central portion of the arc extinguishing member 4 and two directions toward through holes 31a of a surrounding portion 31; and the flow of gas is formed in the direction of dashed line arrow G in
A part of the arc A, which exists on the fixed arc contact 11 side, extends to the outer circumferential surface side of the arc extinguishing member 4 in response to the flow of gas and comes into contact with the arc extinguishing member 4. Further, the part of the arc A comes into contact with the arc extinguishing member 4 more surely by characteristics in which the arc A extends so as to conform with a longitudinal magnetic field of the permanent magnets 5. Whereas, a part of the arc A, which exists on the movable contactor 2 side, comes into contact with the inner circumferential surface of the arc extinction member 3 in response to the flow of gas, as in Embodiment 1. Therefore, the arc A can be brought into contact with both the arc extinguishing member 4 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased; and thus, interruption performance is further improved.
In the thus configured Embodiment 5, when an arc A is generated, a pressure gradient is generated by the heat of the arc A, the pressure gradient being lowered from the center side of an arc space portion S to the direction of the through hole 41a in the central portion of the arc extinguishing member 41 and two directions toward through holes 31a of a surrounding portion 31; and the flow of gas is formed in the direction of dashed line arrow H in
A part of the arc A, which exists on the fixed arc contact 11 side, comes into contact with the outer circumferential surface of the arc extinguishing member 41 and the inner circumferential surface of the arc extinction member 3 in response to the flow of gas. Therefore, the arc A can be brought into contact with both the arc extinguishing member 41 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased, as in the above Embodiment 2; and thus, interruption performance is further improved.
In the thus configured Embodiment 6, an arc A performs rotational motion in response to circumferential force due to a magnetic field by the permanent magnets 51. That is, the arc A is driven in the rotational direction on an electrode, that is, the movable contactor 2; and therefore, interruption performance is improved by the temperature suppression of the electrode and the cooling effect of forced-convection. At the same time, the arc A is characterized by extending so as to conform with a longitudinal magnetic field of the permanent magnets 51, that is, a magnetic field in the separating direction of the movable contactor 2; and the arc A is pulled by the permanent magnets 51.
The permanent magnets 51 is covered around by the arc extinguishing member 41 for protection; and therefore, the arc A pulled by the permanent magnets 51 stably comes into contact with the arc extinguishing member 41. Therefore, the arc A can be brought into contact with both the arc extinguishing member 41 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased, as in the above Embodiment 3; and thus, interruption performance is further improved.
In the thus configured Embodiment 7, when an arc A is generated between the fixed main contact 12 and a movable contactor 2, a pressure gradient is generated by the heat of the arc A, the pressure gradient being lowered from the center side of an arc space portion S to two directions toward through holes 31a of a surrounding portion 31; and the flow of gas is formed in the direction of dashed line arrow I in
The arc A comes into contact with the inner circumferential surface of the arc extinction member 3 in response to the flow of gas, as in Embodiment 1. Therefore, the arc A can be surely brought into contact with the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased, as in the above Embodiment 1; and thus, interruption performance is further improved.
In the thus configured Embodiment 8, an arc A is generated between the fixed main contact 12 and the movable contactor 2. The arc A performs rotational motion in response to circumferential force due to a magnetic field by the permanent magnets 51. That is, the arc A is driven in the rotational direction on an electrode, that is, the movable contactor 2; and therefore, interruption performance is improved by the temperature suppression of the electrode and the cooling effect of forced-convection.
At the same time, the arc A is characterized by extending so as to conform with a longitudinal magnetic field of the permanent magnets 51, that is, a magnetic field in the separating direction of the movable contactor 2; and the arc A is pulled by the permanent magnets 51. The permanent magnets 51 is covered around by the arc extinguishing member 41 for protection; and therefore, the arc A pulled by the permanent magnets 51 stably comes into contact with the arc extinguishing member 41. Therefore, the arc A can be brought into contact with both the arc extinguishing member 41 and the arc extinction member 3 and the amount of generation of arc extinguishing gas can be increased, as in Embodiment 3; and thus, interruption performance is further improved.
Furthermore, the fixed arc contact 11 does not exist; and therefore, the arc extinguishing member 41 and the permanent magnets 51 can be increased in size. Thus, the contact probability of the arc extinguishing member 41 can be raised, it becomes possible to enhance the magnetic flux density of the permanent magnets 51, and the amount of generation of arc extinguishing gas can be increased; and therefore, interruption performance can be further improved.
In the thus configured Embodiment 9, when an arc A is generated, a pressure gradient is generated by the heat of the arc A, the pressure gradient being lowered from the center side of the arc space portion S to the directions toward through holes 310a of the surrounding portion 310; and the flow of gas is formed in the direction of dashed line arrow J in
Furthermore, an arc extinction member 3 constituting the arc extinction chamber is fixed to the fixed side shield 13 side and has a surrounding portion 31 which is slidably connected to the outer circumferential surface 2a of the movable contactor 2 halfway in a movement range from a close contact state to an open contact state, the surrounding portion 31 being formed so as to surround an arc space portion S in a sealed manner. The through hole 31a exists at a predetermined portion of the surrounding portion 31 of the arc extinction member 3 in Embodiment 1 to Embodiment 9; however, the through hole 31a does not exist in this Embodiment 10. The other configuration is similar to that of Embodiment 1.
Hereinafter, the operation of the switchgear according to Embodiment 10 of the present invention will be described with reference to
In the thus configured Embodiment 10, first, in the case where the switchgear is in the close contact state as shown in
The separation of the movable contactor 2 proceeds and the movable contactor 2 passes by the through holes 410b. Then, in a state where the movable contactor 2 is in the surrounding portion 31 of the arc extinction member 3 as shown in
Accordingly, arc extinguishing gas is stably generated in a great amount from the arc extinguishing member 410; and therefore, the arc A is decomposed or cooled by the arc extinguishing gas and interruption performance is improved. Furthermore, when the arc A comes into contact with the arc extinguishing member 410 provided in the central portion of the fixed arc contact 11, arc extinguishing gas is also generated from the arc extinguishing member 410; and accordingly, a pressure gradient is generated to form the flow of gas and the arc extinguishing gas acts so as to be blown to the arc A. Thus, a cooling effect on the arc A increases and the interruption performance is further improved.
Incidentally, the number of the through holes 410b and their circumferential placing positions are not particularly limited, but it is permissible if the arc A can be extended to the outer circumferential surface of the arc extinguishing member 410 by the pressure gradient which is generated in connection with the generation of the arc A and lowers from the center side of the arc space portion S toward the through hole 410b, at least one place; and the through holes 410b do not also need to be arranged in a line-symmetric manner.
The present invention is suitable for achieving a highly reliable switchgear in which an arc space communicates with the outside of the arc space by a through hole formed in a surrounding portion of an arc extinction member, thereby being capable of controlling the extending direction of an arc so as to be surely brought into contact with the arc extinction member.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011 001572 | Jan 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/069283 | 8/26/2011 | WO | 00 | 4/5/2013 |
