JP2015011911A - Gas circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas circuit breaker which is small-sized and has an excellent current interruption performance in a low current region even with a small driving force.SOLUTION: Within a sealed container filled with arc-extinguishing gas, a fixed arc contact 4 and a fixed electrification contact 2 are disposed while coaxially opposing a movable arc contact 3 and a movable electrification contact 1. An insulation nozzle 5 is provided which blows the arc-extinguishing gas to arc discharge that occurs between the fixed arc contact 4 and the movable arc contact 3 when both the arc contacts are separated. Pressure storage means is provided for blowing the arc-extinguishing gas into the insulation nozzle 5. A capturing or discharging part is provided for a decomposition product generated by the arc discharge. The capturing or discharging part for the decomposition product is a recessed capturing part 16 provided e.g., in a portion where a blow channel is converted from an axial direction to a radial direction on an inner surface of the insulation nozzle 5.

Description

  Embodiments of the present invention relate to a gas circuit breaker having pressure accumulating means for blowing arc-extinguishing gas.

  As a gas circuit breaker that performs current switching in a power system, a type called a puffer type is widely used. This puffer-type gas circuit breaker has a pressure accumulating means for blowing arc-extinguishing gas against arc discharge generated in the interruption process. For example, as shown in Patent Document 1, the pressure accumulating means includes a puffer cylinder, a puffer piston disposed inside the puffer cylinder, and a puffer chamber (arcing chamber) surrounded by the puffer cylinder and the puffer piston. Yes.

  Generally, the cutoff performance tends to increase as the gas pressure in the puffer chamber increases. At the time of shut-off, the puffer chamber moves with respect to the puffer piston in a fixed state, so that the puffer chamber becomes high pressure. Further, since the hot gas generated by the arc discharge generated between the fixed arc contact and the movable arc contact also flows into the puffer chamber, the puffer chamber has a higher pressure. This high pressure gas is strongly blown against the arc discharge from the puffer chamber through the insulating nozzle, the arc is extinguished, and the current interruption is completed.

  When a small current is interrupted in the gas circuit breaker, the current is interrupted when the distance between the fixed arc contact and the movable arc contact is narrow, and at the same time, a large recovery voltage is applied between the contacts. For this reason, the electric field distribution and the opening speed of the circuit breaker are designed so that there is no flashing between the separated contacts.

JP 2012-216362 A

  In the gas circuit breaker as described above, when a large current is interrupted, the insulating nozzle, the fixed arc contact, and the movable arc contact evaporate to generate decomposition products. At present, it is designed to ensure the performance of the gas circuit breaker even in the presence of decomposition products between the fixed arc contact and the movable arc contact. However, if the amount of decomposition products in the region where the electric field between the fixed arc contact and the movable arc contact is extremely high can be reduced, the insulation performance of the circuit breaker can be greatly improved.

  An object of an embodiment of the present invention is to have a structure in which a large amount of decomposition products do not exist between arc contacts even after a gas circuit breaker performs a large current interruption, and is small in size and small in driving force. An object of the present invention is to provide a gas circuit breaker having excellent current interruption performance in the region.

  In the gas circuit breaker of the present embodiment, the fixed arc contact and the fixed energized contact are arranged concentrically with the movable arc contact and the movable energized contact in a sealed container filled with an arc extinguishing gas. And an insulating nozzle that blows the arc-extinguishing gas against an arc discharge generated between the arc contacts when the fixed arc contactor and the movable arc contactor are separated from each other. The pressure accumulating means for feeding the arc extinguishing gas is provided, and a capture or discharge part for the decomposition product generated by the arc discharge is provided.

It is sectional drawing which shows the gas circuit breaker of 1st Embodiment, The left half shows the interruption | blocking state and the right half shows the state in the middle of the interruption | blocking process. It is sectional drawing which shows the gas circuit breaker of 2nd Embodiment, A left half shows the interruption | blocking state and a right half shows the state in the middle of the interruption | blocking process. It is sectional drawing which shows the gas circuit breaker of 3rd Embodiment, A left half shows the interruption | blocking state and a right half shows the state in the middle of the interruption | blocking process. It is sectional drawing which shows the gas circuit breaker of 4th Embodiment, A left half shows the interruption | blocking state and a right half shows the state in the middle of the interruption | blocking process. It is sectional drawing which shows the gas circuit breaker of 5th Embodiment, The left half shows the interruption | blocking state and the right half shows the state in the middle of the interruption | blocking process.

(1) First Embodiment (1-1) Configuration FIG. 1 shows the configuration of a puffer-type gas circuit breaker according to this embodiment. The right side of the center line in FIG. 1 shows a state in the middle of the interruption process when the small current is interrupted, and the left side of the center line shows the interruption state.

  The gas circuit breaker of this embodiment includes a movable energizing contact 1, a movable arc contact 3, a fixed energizing contact 2, and a fixed arc contact 4 disposed in a gas tank (not shown) filled with an arc extinguishing gas. Have The movable energizing contact 1, the movable arc contact 3, and the insulating nozzle 5 installed on the outer periphery thereof are fixed to a puffer cylinder 6. The puffer cylinder 6 and the operating rod 7 are connected to the operating mechanism via an insulating rod (not shown).

In the puffer-type gas circuit breaker, SF ₆ gas (sulfur hexafluoride gas) is mainly used as the insulating medium and arc-extinguishing medium, and gas other than SF ₆ gas can be used as the insulating medium and arc-extinguishing medium, and various gases can be used. Sometimes mixed.

  The puffer piston 10 is fixed to a piston support 12 that is a fixed portion. The operating rod 7 includes a hollow portion 7a and a solid portion 7b. An exhaust hole 11 is provided in the hollow portion 7a, and the hollow portion 7a and the inside of the piston support 12 communicate with each other. The fixed energizing contact 2, the fixed arc contact 4, and the cooling cylinder 13 are coupled by an electrode support 14, and are indirectly fixed to the gas tank via an insulating cylinder (not shown).

  A concave capturing section 16 is provided in a portion where the spray passage on the inner surface of the insulating nozzle 5 is converted from the axial direction to the radial direction. The shape of the capturing part 16 is formed so that the angle α (angle of the groove with respect to the axis) described in FIG. 1 is 90 ° or less. That is, in the prior art, the angle α is larger than 90 °, and the inner surface of the insulating nozzle 5 gently moves from the vicinity of the tip of the movable arc contactor 3 toward the small diameter portion of the insulating nozzle 5. It is a narrowed shape. On the other hand, in the present embodiment, the capture portion 16 that is recessed in an inverted V shape toward the distal end side of the insulating nozzle 5 is formed on the inner surface of the narrow diameter portion on the movable arc contact 3 side.

(1-2) Operation When the circuit breaker according to the present embodiment starts the opening operation from the closed state, the movable portion moves to the operation mechanism (not shown) (downward in FIG. 1). During the interruption process shown in the right half of FIG. 1, arc discharge occurs between the fixed arc contact 4 and the movable arc contact 3. Since this arc discharge is very high temperature, high-temperature gas is generated from the arc discharge, and the heated arc extinguishing gas also becomes high temperature.

  The high-temperature gas generated in this way flows into the puffer chamber 9, and after flowing through the movable arc contact 3 and the hollow portion 7a, flows out into the tank space (not shown) through the piston support 12 through the exhaust hole 11. The gas pressure in the puffer chamber 9 is increased by the flowing high temperature gas, and the volume of the puffer chamber 9 is reduced by the movement of the movable part, so that the gas in the puffer chamber 9 is compressed and the gas pressure is increased. This high pressure gas is strongly blown against the arc discharge from the puffer chamber 9 through the insulating nozzle 5, and as a result, the arc discharge is extinguished and the current interruption is completed.

  At the time of interrupting a large current, the insulating nozzle 5, the fixed arc contact 4 and the movable arc contact 3 exposed to the high temperature gas evaporate to generate a decomposition product 15 along with such arc discharge. When the small current is interrupted, the decomposition product 15 in the vicinity of the movable-side puffer chamber 9 and the movable arc contact 3 is charged to a polarity opposite to the polarity on the fixed side. In the configuration in which the capture unit 16 does not exist, the charged decomposition product 15 moves toward the fixed arc contact 4 and reaches an extremely high electric field region, so that a severely insulating state is formed. On the other hand, in the present embodiment, by providing the capture portion 16 on the inner surface of the insulating nozzle 5, the amount of the charged decomposition product 15 flowing from the inside of the puffer chamber 9 into the arc contacts 3, 4 can be greatly reduced. it can.

  In particular, since the angle α of the concave capture portion 16 is configured to be 90 ° or less, even if the decomposition product 15 flows out from the capture portion 16 between the arc contacts 3 and 4, Since it can move to the hollow part 7a side, the improvement of the insulation performance at the time of a small electric current interruption | blocking is anticipated.

(1-3) Effect According to the present embodiment, the decomposition product 15 existing in the vicinity of the puffer chamber 9 and the movable arc contact 3 when a small current is interrupted flows into a position where the electric field between the arc contacts 3 and 4 is high. Therefore, it is possible to provide a gas circuit breaker having a small current interruption performance even with a small driving force.

(2) Second Embodiment (2-1) Configuration A second embodiment will be described with reference to FIG. In FIG. 2, the right side of the center line shows a state in the middle of the interruption process when a small current is interrupted, and the left side of the center line shows the interruption state.

  In the present embodiment, a capture taper portion 17 is provided in the downstream region of the inner surface of the insulating nozzle 5. The shape of the trapping taper portion 17 is formed so that the angle β described in FIG. 2 (the angle of the trapping taper portion 17 with respect to the central axis of the insulating nozzle 5) is 8 ° or more. That is, for example, as shown in FIG. 1, the shape of the inner peripheral surface of the insulating nozzle 5 is normally formed at the same angle from the tip of the insulating nozzle 5 to the movable arc contact 3 side, and the tip side is widened. It has a trumpet shape. In the present embodiment, a trapping taper portion 17 is formed on the inner surface of the insulating nozzle 5 such that the inner diameter of the insulating nozzle 5 is abruptly narrowed toward the movable arc contact 3 side.

(2-2) Action In the gas circuit breaker according to the present embodiment, the decomposition product 15 in the vicinity of the movable puffer chamber 9 and the movable arc contactor 3 is charged to a polarity opposite to the polarity on the fixed side when a small current is interrupted. .

  In the conventional insulating nozzle, since the charged decomposition product 15 moves toward the fixed arc contact 4 and reaches a region where a high electric field is applied, a severely insulating state is formed. In the present embodiment, by providing the capture taper portion 17 on the inner periphery of the insulating nozzle 5, as shown in the right half of FIG. As shown in the left half of FIG. 2, the trapped taper portion 17 traps the amount of the decomposition product 15 returning to the vicinity of the movable puffer chamber 9 and the movable arc contact 3.

(2-3) Effect According to the present embodiment, the amount of the charged decomposition product 15 existing in the vicinity of the puffer chamber 9 and the movable arc contact 3 when a small current is interrupted can be reduced. Improvement of insulation performance is expected. As a result, it is possible to provide a gas circuit breaker having an excellent small current interruption performance even with a small driving force.

(3) Third Embodiment (3-1) Configuration A third embodiment will be described with reference to FIG. In FIG. 3, the right side of the center line shows a state in the middle of the interruption process when the small current is interrupted, and the left side of the center line shows the interruption state.

  In the present embodiment, an exhaust taper portion 18 for moving the decomposition product 15 in the radial direction is provided at the base of the fixed arc contact 4. In general, the fixed arc contact 4 is formed with the same thickness from the tip to the base, but in this embodiment, the fixed arc contact 4 spreads in a conical shape from the tip to the base at the root of the fixed arc contact 4. An exhaust taper portion 18 is provided.

(3-2) Operation In the present embodiment, the decomposition product 15 in the vicinity of the movable puffer chamber 9 and the movable arc contactor 3 is charged to a polarity opposite to the polarity on the fixed side when a small current is interrupted. In the conventional shape, the charged decomposition product 15 moves toward the fixed arc contact 4 and reaches a high electric field region, so that a severe situation is formed in an insulating manner. In the present embodiment, in the process in which the decomposition product 15 moves from the upstream side to the fixed side downstream during the shut-off operation, the decomposition product 15 is guided by the exhaust taper portion 18 so that most of the decomposition product 15 is radially outside the inner diameter of the insulating nozzle 5. Move to. Therefore, the amount of the decomposition product 15 that returns to the vicinity of the movable-side puffer chamber 9 and the movable arc contact 3 can be greatly reduced.

(3-3) Effect Also in this embodiment, the amount of the charged decomposition product 15 existing in the vicinity of the puffer chamber 9 and the movable arc contact 3 when a small current is interrupted can be reduced as in the above embodiments. It can be expected to improve the insulation performance when a small current is interrupted.

(4) Fourth Embodiment (4-1) Configuration A fourth embodiment will be described with reference to FIG. In FIG. 4, the right side of the center line shows a state in the middle of the interruption process when the small current is interrupted, and the left side of the center line shows the interruption state. In the present embodiment, a diffusion plate 19 having an inner diameter approximately equal to the outer diameter of the insulating nozzle 5 is installed on the outer periphery of the fixed arc contact 4, and the exhaust hole 20 that guides the decomposition product 15 to the diffusion plate 19 in the radial direction. Is provided. As shown in the right half of FIG. 4, the diffusion plate 19 has an inner diameter such that the exhaust hole 20 is closed by the outer periphery of the insulating nozzle 5 when the circuit breaker is turned on and in the middle of the shut-off process. As the insulating nozzle 5 enters and exits from the diffusion plate 19, the exhaust hole 20 opens, and the gas inside the diffusion plate 19 is discharged together with the decomposition products 15 to the outside of the diffusion plate 19.

(4-2) Action According to the present embodiment, the provision of the diffusion plate 19 and the exhaust hole 20 makes most of the insulating nozzle 5 in the process in which the decomposition product 15 moves from the upstream side to the fixed side downstream during the shut-off operation. Since it moves outward in the radial direction from the inner diameter, the amount of the decomposition product 15 returning to the vicinity of the movable puffer chamber 9 and the movable arc contact 3 can be greatly reduced.

(4-3) Effect Also in this embodiment, the amount of the charged decomposition product 15 existing in the vicinity of the puffer chamber 9 and the movable arc contact 3 when a small current is interrupted can be reduced as in the above embodiments. It can be expected to improve the insulation performance when a small current is interrupted.

(5) Fifth Embodiment (5-1) Configuration A fifth embodiment will be described with reference to FIG. In FIG. 5, the right side of the center line indicates a state in the middle of the interruption process when the small current is interrupted, and the left side of the center line indicates the interruption state. In this embodiment, it has the structure which provided the exhaust hole 20 which guides the decomposition product 15 to radial direction at the electricity supply part and the fixed electricity supply contact 2 of a fixed side downstream. As a modification of the present embodiment, it is possible to provide the exhaust hole 20 in either or both of the fixed energizing contact 2 and the cooling cylinder 13 that supports it.

(5-2) Action According to the present embodiment, by disposing the exhaust hole 20 in either or both of the fixed energizing contact 2 and the cooling cylinder 13 that supports the contact, it is disassembled from upstream to fixed side downstream during the shut-off operation. Since the product 15 is easily moved in the radial direction in the process of moving, the amount of the decomposition product 15 returning to the vicinity of the movable puffer chamber 9 and the movable arc contact 3 can be greatly reduced.

(5-3) Effects Also in this embodiment, the amount of charged decomposition products 15 existing in the vicinity of the puffer chamber 9 and the movable arc contact 3 when a small current is interrupted can be reduced as in the above embodiments. It is possible to improve the insulation performance when a small current is interrupted.

(6) Sixth Embodiment (6-1) Configuration In this embodiment, in addition to the configurations shown in the first to fifth embodiments, the global warming is higher than the SF ₆ gas as an arc extinguishing gas. A gas having a small coefficient is used.

(6-2) Action Conventionally, as the arc extinguishing gas, SF ₆ gas having excellent arc extinguishing performance and electrical insulation performance is used. However, SF ₆ gas is said to have a global warming effect 23,900 times that of carbon dioxide gas, and a circuit breaker using an alternative gas is desired. However, if gas, which has a smaller impact on the environment, specifically air, nitrogen, carbon dioxide, etc., which have a lower global warming potential than SF ₆ gas, is used as an alternative, arc extinguishing performance and electrical insulation performance are better than SF ₆ gas. Therefore, there is a concern that the blocking performance is deteriorated.

In order to obtain a cutoff performance equivalent to that of conventional equipment using a gas other than SF ₆ gas, it is necessary to increase the size of components such as the puffer cylinder 6 and the puffer piston 10 and to drive the movable part with a large driving force. Comes out. In the present embodiment, since the configuration described in the first to fifth embodiments can be used to prevent the degradation of the shielding performance due to the decomposition product 15, the arc extinguishing performance and the electrical insulation performance are SF ₆ gas. Even when an inferior insulating gas is used, sufficient insulation performance can be secured when a small current is interrupted.

(6-3) Effect According to the present embodiment, the use of a gas having a global warming potential smaller than that of SF ₆ gas as the arc extinguishing gas can prevent the apparatus from becoming large and the driving force from being increased. it can.

(7) Other Embodiments The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined. For example, the present invention can be applied to gas circuit breakers other than the puffer type. Moreover, what combined suitably two or more of each said embodiment is also included by this invention.

DESCRIPTION OF SYMBOLS 1 ... Movable energizing contact 2 ... Fixed energizing contact 3 ... Movable arc contact 4 ... Fixed arc contact 5 ... Insulating nozzle 6 ... Puffer cylinder 7 ... Operation rod 7a ... Hollow part 7b ... Solid part 9 ... Puffer chamber 10 ...... Puffer piston 11 ... exhaust hole 12 ... piston support 13 ... cooling cylinder 14 ... electrode support 15 ... decomposition product 16 ... capturing part 17 ... capturing taper part 18 ... exhaust taper part 19 ... diffusing plate 20 ... exhaust hole

Claims (6)

In a hermetically sealed container filled with arc-extinguishing gas, a fixed arc contact and a fixed energizing contact are arranged concentrically with the movable arc contact and the movable energizing contact,
An insulating nozzle that blows the arc-extinguishing gas is provided for arc discharge generated between the arc contacts when the fixed arc contact and the movable arc contact are separated.
A pressure accumulating means for feeding the arc extinguishing gas to the insulating nozzle is provided;
A gas circuit breaker characterized by being provided with a capture or discharge part for decomposition products generated by arc discharge.   The capture or discharge part of the decomposition product is a recessed capture part provided in a part where the spray channel on the inner surface of the insulating nozzle is converted from the axial direction to the radial direction. The gas circuit breaker described.   2. The gas circuit breaker according to claim 1, wherein the decomposition product capture or discharge portion is a capture taper portion that prevents the decomposition product from flowing into the movable side on the inner surface downstream of the insulating nozzle.   2. The gas cutoff according to claim 1, wherein the decomposition product capture or discharge portion is an exhaust taper portion that converts a gas flow path during operation in a radial direction in the vicinity of a base of a fixed arc contact. vessel.   The capture or discharge part of the decomposition product includes a cylindrical diffusion plate provided on the fixed side of the arc extinguishing chamber and an exhaust hole formed in the diffusion plate. The gas circuit breaker described. The capture or discharge part of the decomposition product is a fixed energizing contact provided on the fixed side of the arc extinguishing chamber and / or an exhaust hole provided in a cooling cylinder supporting the contact. The gas circuit breaker described in 1.