JPH0574291A - Puffer-type gas-blast circuit breaker - Google Patents

Abstract

PURPOSE:To provide a small-sized, lightweight, and highly reliable puffer-type gas-blast circuit breaker having a buffer cylinder with excellent current-carrying and heat resistance performances. CONSTITUTION:Contactible/separable contactor sections 1, 2 are provided within a vessel in which an arc-extinguishing gas is filled. A buffer chamber 1 composed of a puffer piston 10 and a puffer cylinder 21 is compressed and the compressed gas is guided to a nozzle portion 8 to thereby extinguish an arc 15 generated between arc contactors 3 and 7. Holes 5d are provided in an operation rod 5 for driving the puffer cylinder, which holes permit communication between a hollow portion 5c and the puffer chamber at the initial stage of the breaking operation and communication between the hollow portion and the vessel at the ending stage of the breaking operation. The puffer cylinder is constructed of a structural gradient alloy so that the proportion may change radially from the inner surface to the outer surface thereof. The inner surface of the puffer cylinder is constructed of a material having an excellent heat resistance while the outer surface thereof is constructed of a material having an excellent electrical conductivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc extinguishing chamber of a puffer type gas circuit breaker, and more particularly to an improvement of the arc extinguishing chamber of a circuit breaker for increasing the pressure of arc extinguishing gas by utilizing thermal energy generated by a current interrupting arc. ..

[0002]

2. Description of the Related Art With the increase in capacity of power generation systems, the breaking capacity required for circuit breakers used in substations and switching stations has increased, and high reliability has been required. In order to increase the reliability of the circuit breaker, it is important to reduce the number of parts and simplify the structure. From this point of view, the number of breaking points of the circuit breaker has been reduced, and for that purpose, the breaking performance of the circuit breaker must be improved and the breaking capacity per point must be increased.

In the conventional general puffer type gas circuit breaker, in order to improve the breaking performance, it is necessary to increase the gas pressure in the puffer chamber to form a strong blowing gas flow. A simple method that can be considered to achieve such a high gas pressure in the puffer chamber is to move a large puffer cylinder at a high opening speed. However, when such a method is adopted, not only the size of the arc-extinguishing chamber becomes large, but also a large drive device is required, and the economical efficiency of manufacturing and operating the circuit breaker is lost. ..

On the other hand, as a method of increasing the gas pressure in the puffer chamber without using a large puffer cylinder, a method of utilizing the thermal energy of the arc has been conventionally proposed. In this method, the thermal energy of the generated arc is effectively used, the gas pressure in the puffer chamber is efficiently increased, and a strong blowing gas flow is formed, thereby improving the breaking performance.

An example of a conventional puffer type gas circuit breaker based on such a principle is shown in FIGS. 4 to 6, and the operation principle thereof will be described below. 4 to 6 are cross-sectional views showing only the vicinity of the shutoff portion in the arc extinguishing chamber.
Shows the closing state, FIG. 5 shows the initial state of the breaking operation, and FIG. 6 shows the latter state of the breaking operation.

First, as shown in FIG. 4, a fixed contact portion 1 and a movable contact portion 2 are provided in a non-illustrated arc extinguishing chamber filled with an arc extinguishing gas so as to be able to come into contact with and separate from each other. .. The fixed contactor portion 1 is composed of a fixed arc contactor 3 and a fixed current-carrying contactor 4 which is arranged so as to surround the fixed arc contactor 3 and is fixed integrally. Further, in the movable contactor portion 2, the puffer cylinder 6 is arranged around the hollow operation rod 5, and is operated by the flange portion 5a provided at the tip of the operation rod 5 (end portion on the fixed contactor portion 1 side). It is fixed to the rod 5. On the fixed contact portion 1 side of the flange portion 5a of the operation rod 5, a movable arc contact element 7, an insulating nozzle 8, and a movable energizing contact element 9 are sequentially arranged inside and outside, and are integrally fixed to the flange portion 5a.

The puffer cylinder 6 forms a puffer chamber 11 together with the puffer piston 10 fixed to a fixing portion (not shown) and the outer surfaces of the operating rod 5. Further, between the movable arc contactor 7 and the insulating nozzle 8 in the flange portion 5a of the operation rod 5, there is provided an opening 5b for ejecting the gas in the puffer chamber 11 and blowing the gas through the insulating nozzle 8 to the arc. It is provided. Operating rod 5
Is provided with a communication hole 5d for communicating the hollow portion 5c with the outside. The gas flow in the hollow portion 5c is connected to the base end side of the communication hole 5d (the side opposite to the fixed contact portion 1). A protrusion 5e is provided to guide the outside from 5d. Reference numeral 12 in the figure is a sliding contactor that is fixed together with the puffer piston 10 to a fixed portion (not shown) and slides with respect to the puffer cylinder 6, and reference numeral 13 in the figure is a first one connected to the fixed contactor portion 1. 1 is a conductor, 14 is a movable contactor 2 (sliding contactor 1)
2) a second conductor connected to.

The energization path of the puffer type gas circuit breaker having the above-described structure in the closed state shown in FIG. 4 extends from the bushing (not shown) to the arc extinguishing chamber through the first conductor 13 to reach the arc extinguishing chamber. In (1), there is a first path from the fixed energizing contact 4 to the movable energizing contact 9 and a second path from the fixed arc contact 3 to the moving arc contact 7. Then, the first and second paths merge at the flange portion 5a of the operation rod 5 to form a single path, and reach the second conductor 14 via the puffer cylinder 6 and the sliding contact 12, From bushings not shown to external circuits.

Further, each contactor 3, of both contactor portions 1, 2.
At the initial stage of the breaking operation as shown in FIG. 5, the fixed energizing contactor 4 and the movable energizing contactor 9 are separated first, and subsequently, the fixed arc contactor 3 and the movable arc contactor. 7 are separated from each other, and as a result, an arc 15 is generated between the fixed arc contact 3 and the movable arc contact 7. On the other hand, the communication hole 5 of the operating rod 5
d is configured to connect the hollow portion 5c of the operating rod 5 and the puffer chamber 11 at the initial stage of the shutoff operation as shown in FIG. Further, the communication hole 5d of the operation rod 5
As shown in FIG. 6, after passing through the inner diameter end portion 10a of the puffer piston 10 in the latter half of the shutoff operation, the hollow portion 5c of the operating rod 5 communicates with the surrounding gas space.

Next, the operation of the puffer type gas circuit breaker will be described with reference to FIGS. 5 and 6. First, as shown in FIG. 5, in the initial stage of the breaking operation, the arc 15 generates a large amount of heat, but the nozzle 8 has not been sufficiently opened, and therefore has no breaking ability. Further, at the initial stage of the shut-off operation, the communication hole 5d of the operation rod 5 has not passed the end 10a of the puffer piston 10 yet, so the hollow portion 5c of the operation rod 5 is connected to the inside of the puffer chamber 11 via the communication hole 5d. It is in communication.

On the other hand, since the pressure inside the puffer chamber 11 does not rise so much at the initial stage of the shutoff operation, the thermal expansion flow of the gas from the arc 15 is the hot gas flow 16a ejected from the opening of the nozzle 8. In addition to the above, a hot gas flow 16b flowing through the hollow portion 5c of the operation rod 5 and a hot gas flow 16c flowing into the inside of the nozzle 8 are formed. this house,
The hot gas flow 16b passing through the hollow portion 5c of the rod 5 suddenly passes through the communication hole 5d of the operating rod 5 and suddenly flows into the puffer chamber 11
Flow into. In this case, the hot gas flow 16 from the arc 15
Since the heat energy of b is very large, this hot gas flow 1
6b gives large heat energy to the gas in the puffer chamber 11. This thermal energy is the puffer piston 10
Since it is added to the physical compression energy of the puffer cylinder 6, the pressure in the puffer chamber 11 becomes extremely high.

Thereafter, as shown in FIG. 6, in the latter half of the shut-off operation, the communication hole 5d of the operating rod 5 passes through the end 10a of the puffer piston 10 and the hollow portion 5c of the operating rod 5 and the surrounding gas space. Communicate with. Therefore, the heat generated by the arc in the hollow portion 5c of the operating rod 5 is not communicated with the communication hole 5d.
Is discharged to the surrounding gas space via. In such a state, the nozzle 8 has already been sufficiently opened, so that the current can be interrupted. Puffer room 1
Since the heat taken in 1 is dispersed almost uniformly in the puffer cylinder 6, the high pressure rising state in the puffer chamber 11 continues until the shutoff operation is completed. Therefore,
High-speed gas flow 1 from inside the puffer chamber 11 through the nozzle 8.
Since 6d is blown onto the arc 15 for a long time, a high breaking performance can be obtained.

[0013]

By the way, in the puffer type gas circuit breaker as described above, the puffer cylinder is required to be light in weight because it is a part of the movable portion. Also, as explained as the energizing path,
The puffer cylinder must be composed of a good conductor in order for current to flow in the wall of the puffer cylinder. If the puffer cylinder is made of a good conductor, the cross-sectional area of the current-carrying portion can be made small, and therefore the effect of weight reduction is also great. For this reason, puffer cylinders have traditionally been
Often composed of aluminum. However, in such a puffer cylinder made of aluminum, when the arc energy is positively taken into the puffer cylinder as described above, the gas heated to a high temperature by the arc is absorbed in the puffer cylinder. Moreover, the inner surface of the puffer cylinder may be damaged by heat.

In order to avoid such damage of the puffer cylinder, for example, an inner surface of the puffer cylinder made of aluminum is made of a polymer material such as polytetrafluoroethylene (PTFE) or an insulator having excellent heat resistance such as ceramics. It is considered to provide an inner wall for protection. However, when the puffer cylinder has a two-layer structure composed of an insulator and a metal as described above, if there is a small gap at the interface between these substances, three layers of metal, solid insulator, and insulating gas will be generated. A point contact part is formed. At such a three-point contact portion, the electric field becomes extremely high, which may cause a problem such as a spark discharge when energized to damage the cylinder.

On the other hand, instead of the inner wall made of an insulator, it is possible to provide an inner wall made of a heat-resistant metal such as a copper-tungsten alloy. In this case, although the three-point contact portion is not formed, since the electric resistances of the materials of the inner cylinder and the outer cylinder are different, the voltage drop in the axial direction is different, and the potential difference occurs at the boundary surface between the two layers, and the spark is generated. There is a risk of generating a discharge and eventually damaging the puffer cylinder.

The present invention has been proposed in order to solve the problems of the prior art as described above, and an object thereof is to effectively use the arc energy at the time of the breaking operation and to achieve a high breaking with a small driving energy. (EN) Provided is a compact, lightweight, and highly reliable puffer type gas circuit breaker having a puffer cylinder that has excellent performance, and has excellent energization performance and heat resistance performance.

[0017]

A puffer-type gas circuit breaker according to the present invention has a movable contactor and a fixed contactor and a movable contactor capable of contacting and separating in a container filled with an arc-extinguishing gas. A puffer type that compresses the gas by compressing a puffer chamber consisting of a puffer piston and a puffer cylinder provided at the nozzle part and guides it to the nozzle part to cool and extinguish the arc generated between the fixed and movable arc contacts. In the gas circuit breaker, the operating rod that drives the puffer cylinder is provided with a hole that communicates the hollow portion with the outside, and the hollow portion of the operating rod and the puffer chamber are connected to each other in the initial stage of the shutoff operation. In a puffer type gas circuit breaker that communicates through a hole, and communicates the hollow portion of the operating rod and the container through the hole of the operating rod in the latter half of the blocking operation,
In particular, it has the following features. That is,
The puffer cylinder is configured such that the composition of the structurally graded alloy having a continuously varying positional composition causes the composition of the structurally graded alloy to change in the radial direction between the inner surface of the puffer cylinder and the outer surface of the puffer cylinder. In addition, the inner surface of the puffer cylinder is made of a material having excellent heat resistance, and the outer surface of the puffer cylinder is made of a material having excellent electrical conductivity.

Further, the material having excellent heat resistance which constitutes the inner surface of the puffer cylinder is made of at least one component of tungsten, copper-tungsten alloy, boron nitride and alumina, so that the outer surface of the puffer cylinder is excellent in electrical conductivity. It is desirable that the material comprises at least one of aluminum, copper and silver.

[0019]

In the puffer-type gas circuit breaker of the present invention having the above-mentioned structure, the arc energy is positively taken into the puffer chamber through the hollow portion of the operating rod at the initial stage of the breaking operation. The pressure can be thermally and efficiently increased, and as a result, it is possible to contribute to labor saving of drive energy. Further, in the latter half of the shutoff operation, the heat of the hollow portion of the operating rod is released to the surrounding gas space. Then, since a high-speed gas flow is blown to the arc from the puffer chamber having a high pressure, a high interruption performance can be obtained.

In particular, in the present invention, the inner surface of the puffer cylinder is made of a material having excellent heat resistance, so that when the arc energy (hot gas flow) at the initial stage of the breaking operation is introduced into the puffer chamber, the puffer cylinder is heated by heat. No damage to the inner surface. Moreover, since the puffer cylinder does not have a two-layer structure and a structurally graded alloy with no boundary surface is used, there is no problem of spark discharge due to the potential difference at the boundary surface, and the puffer cylinder is reliably damaged. It can be prevented. In addition, the outer surface of the puffer cylinder, which has no problem of heat, is made of a material having excellent electrical conductivity, so that the function as an energization path is good. First, in the present invention, a puffer cylinder having excellent current-carrying performance and heat-resisting performance in terms of materials and structure can be realized. Therefore, since it is not necessary to make the puffer cylinder thick or large, from this point, there is an advantage that the circuit breaker can be made smaller and lighter.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the puffer type gas circuit breaker according to the present invention will be described below with reference to FIGS. In this case, FIG. 1 and FIG. 3 are cross-sectional views showing only the vicinity of the shutoff portion in the arc extinguishing chamber, FIG. 1 being the closing state and FIG. 3 being the shutoff operation initial state. Further, FIG. 2 is a graph showing the composition with respect to the radial position of the puffer cylinder. The same members as those in FIGS. 4 to 6 are designated by the same reference numerals and the description thereof will be omitted. First, as shown in FIG. 1, the puffer cylinder 21 in the present embodiment is made of a so-called structurally graded alloy whose positional composition continuously changes. The composition of this gradient structure alloy is configured to change in the radial direction between the inner surface and the outer surface of the puffer cylinder 21. The inner surface of the puffer cylinder 21 is made of a material having excellent heat resistance, that is, tungsten,
The puffer cylinder 21 is made of at least one component of copper-tungsten alloy, boron nitride, and alumina.
The outer surface of is composed of a material having excellent electrical conductivity, that is, at least one component of aluminum, copper, and silver. In this case, the composition of the puffer cylinder 21 in the radial direction specifically changes with an inclination as shown in FIG.

Next, the operation of the puffer type gas circuit breaker of this embodiment will be described with reference to FIGS. 1 and 3. That is,
In the closed state shown in FIG. 1, current flows through the puffer cylinder 21 as described above, but the outer surface of the puffer cylinder 21 is made of a material having excellent electrical conductivity, which is favorable. The current-carrying characteristics are shown.

As shown in FIG. 3, in the initial stage of the shutoff operation, the hollow portion 5c of the operating rod 5 communicates with the puffer chamber 11 through the communication hole 5d of the operating rod 5. At the initial stage of this shut-off operation, the pressure inside the puffer chamber 11 has not risen so much, so the thermal expansion flow of the gas from the arc 15 is added to the hot gas flow 16a ejected from the opening of the nozzle 8 and the operating rod 5 The hot gas flow 16b flows through the hollow portion 5c and the hot gas flow 16c flows into the inside of the nozzle 8. Of these, the hot gas flow 16b passing through the hollow portion 5c of the rod 5 suddenly flows into the puffer chamber 11 via the communication hole 5d of the operation rod 5.

In this case, the hot gas stream 16 from the arc 15
Since the heat energy of b is very large, this hot gas flow 1
6b gives large heat energy to the gas in the puffer chamber 11. This thermal energy is the puffer piston 10
Since it is added to the physical compression energy of the puffer cylinder 6, the pressure in the puffer chamber 11 becomes extremely high. Further, a large amount of heat energy is applied to the inner surface of the puffer cylinder 21, but in the present embodiment, the inner surface of the puffer cylinder 21 is made of a heat-resistant material, and thus the inner surface of the puffer cylinder 21 is formed. The heat damage of can be prevented. Further, as shown in FIG. 2, since the composition of the puffer cylinder 21 is configured to continuously change in the radial direction between the inner surface and the outer surface, there is no boundary surface such as a two-layer structure, and thus the boundary is not formed. There is no problem of generating spark discharge due to the potential difference on the surface.

By the way, the operation in the latter half of the interruption operation is not shown, but is exactly the same as the above-mentioned prior art. That is, in the latter half of the shut-off operation, the communication hole 5d of the operating rod 5 connects the hollow portion 5c of the operation rod 5 to the surrounding gas space, and the heat generated by the arc in the hollow portion 5c of the operating rod 5 communicates with the communication hole. It is released into the surrounding gas space via 5d. Then, since a high-speed gas flow is blown onto the arc for a long time from the inside of the puffer chamber 11 which has been increased in pressure by the arc energy through the nozzle 8, a high interruption performance can be obtained.

The present invention is not limited to the above embodiment, and the material forming the puffer cylinder can be appropriately selected. Further, the present invention relates to a puffer type gas circuit breaker of a type in which arc energy is positively taken into the puffer chamber through the hollow portion of the operating rod, and in particular, as a puffer cylinder, a structural gradient alloy whose composition changes in the radial direction. Since it is characterized by using, the structure and arrangement of each of the other parts can be changed as appropriate as long as it has this characteristic, and similar excellent effects can be obtained.

[0027]

As described above, according to the present invention, the puffer cylinder is constructed by using a structurally graded alloy so that its composition changes in the radial direction from the inner surface to the outer surface, and The inner surface of the puffer cylinder is made of a material with excellent heat resistance, and the outer surface of the puffer cylinder is made of a material with excellent electrical conductivity, so that the thermal energy of the arc during the breaking operation can be effectively used and a small driving energy is required. It is possible to provide a small, lightweight, and highly reliable puffer-type gas circuit breaker having a puffer cylinder having excellent current-carrying performance and heat-resisting performance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a closed state of an embodiment of a puffer type gas circuit breaker according to the present invention.

FIG. 2 is a graph showing the composition of the puffer type gas circuit breaker of FIG. 1 with respect to the radial position of the puffer cylinder.

FIG. 3 is a sectional view showing an initial state of a breaking operation of the puffer type gas circuit breaker of FIG.

FIG. 4 is a cross-sectional view showing a closed state of an example of a conventional puffer type gas circuit breaker.

5 is a sectional view showing an initial state of a breaking operation of the puffer type gas circuit breaker of FIG.

6 is a cross-sectional view showing the latter state of the shutoff operation of the puffer type gas circuit breaker of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed contact part 2 ... Movable contact part 3 ... Fixed arc contact device 4 ... Fixed energization contact device 5 ... Operation rod 5a ... Flange part 5b ... Opening part 5c ... Hollow part 5d ... Communication hole 5e ... Convex part 6 ... Conventional puffer cylinder 7 ... Movable arc contactor 8 ... Insulating nozzle 9 ... Movable energizing contactor 10 ... Puffer piston 10a ... Puffer piston end 11 ... Puffer chamber 12 ... Sliding contactor 13, 14 ... Conductor 15 ... Arc 16a ... 16c ... Hot gas flow 16d ... Gas flow 21 ... Puffer cylinder according to the present invention

Front page continuation (72) Inventor Eiichi Hagimori 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Head Office

Claims (2)

[Claims] 1. A puffer including a puffer piston and a puffer cylinder provided in a movable contact part, having a fixed contact part and a movable contact part which can be contacted and separated, in a container filled with an arc-extinguishing gas. A puffer-type gas circuit breaker for compressing gas by guiding the chamber to guide it to the nozzle part to cool and extinguish the arc generated between the fixed and movable arc contacts. The rod is provided with a hole for communicating the hollow portion with the outside, and the hollow portion of the operating rod and the puffer chamber are communicated with each other through the hole of the operating rod in the initial stage of the blocking operation, and the operating rod is in the latter stage of the blocking operation. In a puffer-type gas circuit breaker for communicating the hollow part of the pouch with the container through the hole of the operation rod, the puffer cylinder having a structural gradient joint whose positional composition continuously changes. The composition of this graded alloy is designed to change in the radial direction between the inner surface of the puffer cylinder and the outer surface of the puffer cylinder, and the inner surface of the puffer cylinder is made of a material with excellent heat resistance. A puffer type gas circuit breaker characterized by being made of a material with excellent conductivity. 2. A material having excellent heat resistance which constitutes the inner surface of the puffer cylinder is made of at least one of tungsten, copper-tungsten alloy, boron nitride and alumina, and has excellent electrical conductivity which constitutes the outer surface of the puffer cylinder. The puffer type gas circuit breaker according to claim 1, wherein the material is made of at least one of aluminum, copper, and silver.