JPH05135669A - Puffer type gas circuit breaker - Google Patents

Abstract

PURPOSE:To make effective use of high-pressure gas that a puffer chamber generates so as to enhance the arc-extinguishing performance of a puffer type gas circuit breaker by restraining blowing out of gas at the initial stage of the period of breaking action. CONSTITUTION:A nozzle 25 for concentrating on an arc high-pressure gas flowing out of a puffer chamber is connected via a spring 27 so that the position of the nozzle 25 is variable relative to a movable-side arc contact portion 24. In the first stage of the period of breaking action, the spring is held in an expanded state as long as pressure within the puffer chamber 30 is low, and then the nozzle makes contact with the end of the arc contact portion, thus restraining flowing out of the gas while preventing flowing out of gas that does not serve to extinguish the arc. When the gas pressure exceeds a predetermined value, the spring is contracted by forces exerted on the nozzle and the nozzle is separated from the arc contact portion so that a gas circulating passage is formed and the high-pressure gas is blown out, whereby the high-pressure gas that the puffer chamber generates is effectively utilized in the extinction of the arc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for electric power used for making and breaking a circuit in a power system, and more particularly to a high pressure gas generated by a puffer chamber for generating a high pressure gas at the time of interruption in an arc. The present invention relates to a puffer type gas circuit breaker having improved arc extinguishing performance by being sprayed.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a structure of an arc extinguishing chamber of a puffer type gas circuit breaker and its surroundings. In this figure,
The main contact 11, the arc contact 12, and the electrostatic shield 1 on the fixed side are placed in a cylindrical container 100 in which an insulating gas is sealed.
3 is arranged in the upper part of the figure, and the movable main contact 21, the arc contact 22 and the flow guide 2 made of an insulator are arranged in the lower part of the figure.
3, a nozzle 25A, which is also made of an insulator, a puffer chamber 30,
The side wall 31, the inner diameter wall 32, and the outer diameter wall 3 of the puffer chamber 30.
3. Outflow hole 34 for outflowing gas from the puffer chamber to the outside
Are arranged respectively. The puffer piston 42 constituting one side wall of the puffer chamber and the contactor 41 in contact with the puffer chamber belong to the fixed side connected to the container 100 at a lower portion (not shown) and flow to the main contactor 21 and the arc contactor 22. The electric current is collected by the contactor 41 through the inner diameter wall 32. The side wall 31, the inner diameter wall 32, and the outer diameter wall 33 forming the puffer chamber are also called puffer cylinders.

FIG. 3 shows a midway of the breaking operation in which the circuit breaker shifts from the "closed" state to the "open" state. The arc 20 bridging the arc contacts 12 and 22 on the fixed side and the movable side, respectively.
0 indicates that the movable side is moving downward without being extinguished. When the circuit breaker is in the "closed" state, the fixed-side main contact 11 and the movable-side main contact 21 are in contact with each other, and the steady-state current mainly flows through these main contacts 11 and 21. .. At this time, the arc contacts 12 and 22 are also in contact. The gas flow passage 26 is composed of a space sandwiched between the nozzle 25A and the flow guide 23, and both of them are attached to the arc contactor 22 or the side wall 31 by bolts (not shown). The shape is fixed and does not change.

The interrupting operation will be described in more detail below. As the operation shaft (not shown) moves downward, the movable side interlocking with the operation shaft moves downward and the main contacts 11 and 21 separate. At this time, the arc contacts 12, 2
2 is in contact with the main contactor 1
No commutation occurs between the main contacts 11 and 12 due to the commutation from the 1, 21 to the arc contacts 12 and 22.

The arc contacts 12, 22 are separated. At this time, the state electrically bridged by the arc 200 is maintained. This state is similar to FIG. 1 described later. In the above process, the side wall 31, the inner and outer diameter walls 32, 33 constituting the puffer cylinder are moved downward to move the puffer chamber 3
Since 0 is compressed in the vertical direction in the figure, the internal pressure of the puffer chamber 30 rises. As a result, the gas flow 20 through the gas holes 34
1. A gas flow 202 is generated through the gas flow passage 26A. As the moving distance on the movable side increases, the gas flow 20
The flow velocity of 1,202 increases, and the gas flow ejected from the nozzle 25A blows on the arc 200 to make the arc unstable. The current is extinguished once the current crosses the zero point, and then the current interruption is completed without re-ignition.

As described above, the arc 200 is actually extinguished and the extinction of arc is completed only after the arc contacts 12 and 22 are separated from each other to some extent and the arc 200 is extended. , Both arc contacts 12,
The arc will not extinguish immediately after 22 leaves.

[0007]

As described above, since the fixed side and the movable side are separated to some extent at the time of extinguishing the arc, the nozzle 25A passes through the gas flow passage 26A by that time.
Since the gas blown out from it does not work effectively for extinguishing the arc, there is a problem in the effective use of the high pressure gas generated in the puffer chamber. An object of the present invention is to solve such a problem and to effectively utilize the high-pressure gas generated in the puffer chamber to improve the blocking performance.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a movable side arc contactor portion is provided outside the arc contactor portion and interlocks with the arc contactor portion. In a puffer type gas circuit breaker comprising a nozzle forming a gas flow passage between them and a puffer chamber for generating a high pressure gas in conjunction with the movement of the movable part at the time of interruption and for flowing the high pressure gas into the gas flow passage, The nozzle is connected to the arc contactor portion via a spring movable in the moving direction of the arc contactor portion, and when the gas pressure of the puffer chamber is equal to or less than a predetermined value, the nozzle causes the arc contactor portion to move. The gas flow passage is maintained in a closed state by contacting the tip of the arc contact portion, and when the gas pressure exceeds a predetermined value, the nozzle separates from the tip of the arc contact portion and the gas flow passage opens. Also, arcing contact terminal part is composed of a flow guide made of insulating material provided on the outer side of the movable arcing contact, and to form a gas flow path between the flow guide and the nozzle.

[0009]

In the structure of the present invention, the nozzle is connected to the arc contactor through the spring movable in the moving direction of the arc contactor so that the relative position of the nozzle to the arc contactor can be changed. When the gas pressure in the puffer chamber is below a predetermined value, this spring is in an extended state and the nozzle contacts the tip of the arc contactor to keep the gas flow passage closed and suppress the outflow of high pressure gas. Then, when the movable part moves further and the gas pressure exceeds a predetermined value, the spring contracts and the nozzle separates from the tip of the arc contact part to form the same gas flow path as before and blow out high pressure gas from the nozzle. Let Until then, the outflow of gas was suppressed as described above, so higher-pressure gas was blown out and the arc extinguishing effect was improved. Further, the arc contactor portion is provided with an arc contactor and a flow guide made of an insulating material for controlling the flow of high-pressure gas together with the nozzle provided on the outer side of the arc contactor. When forming, the outflow of gas is suppressed by the contact between this flow guide and the nozzle, and if the arc contactor consists of only the arc contactor and there is no flow guide, the tip of the arc contactor and the nozzle The contact suppresses the outflow of gas.

[0010]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is a cross-sectional view showing a structure of an arc extinguishing chamber and its surroundings of a puffer type gas circuit breaker according to an embodiment of the present invention. The same components as those in FIG. To do. The difference from FIG. 3 of FIG. 1 is that the nozzle 25 has a side wall 34.
It is not attached by bolting to the above, but is attached so as to be movable in the vertical direction in the figure via the spring 27. This figure also shows the initial state during the breaking operation, immediately after the arc contacts 12 and 22 are mechanically separated from each other. Therefore, since the moving amount of the movable part is still small, the puffer chamber 30 still has a large volume, and the pressure rise inside the puffer chamber 30 is small, so that the spring 27
Is in an extended state, the lower flange portion of the nozzle 25 hits the side wall 31 of the puffer chamber 30 and is in a stopped position, the tip of the flow guide 23 is in contact with the nozzle 25, and the gas flow passage 26 is closed. Is in a closed state. Since the gas flow passage 26 is in the closed state, even if the gas pressure in the puffer chamber 30 rises, the gas does not flow out or is sufficiently small. Therefore, the volume of the puffer chamber due to the downward movement of the movable part in the figure. The reduction of will directly contribute to the increase of pressure.

FIG. 2 is a cross-sectional view showing a state in which the movable part of the circuit breaker of FIG. 1 is moved to the lower part of the figure and near the end of the breaking operation. The position of the movable part is that in FIG. It is at the same position as the end of the breaking operation in a state of being far away from the fixed side of the contactor 12. However, the arc 200 shows a state where it has not been erased yet. When the gas pressure in the puffer chamber 30 exceeds a predetermined pressure, the force for moving the nozzle 25 upward in the figure exceeds the force of the spring 27 and the spring 27
And the nozzle 25 moves upward to move the flow guide 23
The relative position to the gas flow passage 26 is as shown in this figure.
The high-speed gas blows out from the nozzle 25 to accelerate the extinction of the arc.

Since the outflow of gas is suppressed until the pressure in the puffer chamber 30 reaches a predetermined value, there is no loss in the pressure increase in the puffer chamber 30 due to the moving amount of the movable part, and it is effectively utilized. If the structure and size of the arc extinguishing chamber are the same, the allowable breaking current is large, and the size of the arc extinguishing chamber can be reduced in order to secure the same breaking current. In the circuit breaker described above, the arc contactor portion 24 has a composite structure including the arc contactor 22 and the flow guide 23. However, such a structure makes the allowable breaking current larger or the arc extinguishing chamber This structure is adopted to improve the breaking performance for downsizing, etc. Rather, the arc contactor portion 24 is composed of only the arc contactor 22 without providing a flow guide, and the structure is simplified, A configuration with a small number of points is more common. Even in such a case, the present invention can be applied to bring the tip of the arc contactor 22 into contact with the nozzle 25 when the pressure in the puffer chamber 30 is low, so that the same effect as described above can be produced.

[0013]

As described above, according to the present invention, the nozzle is connected to the arc contactor through the spring movable in the moving direction of the arc contactor, and the relative position of the nozzle relative to the arc contactor is movable. When the gas pressure in the puffer chamber is less than a predetermined value, the nozzle keeps the gas flow passage closed by the nozzle contacting the tip of the arc contactor. In the period when it is practically impossible to extinguish the arc, the outflow of high-pressure gas from the puffer chamber is suppressed, and when the moving part moves further and the gas pressure exceeds a predetermined value, the nozzle contacts the tip of the arc contact part. A high-pressure gas is ejected from the nozzle by forming the same gas flow passage as in the conventional case away from the. Up to this point, the outflow of gas was suppressed as described above, so higher-pressure gas was ejected to improve the arc extinguishing effect, and the effect of improving arc extinguishing performance was obtained. It is expected that the size of the arc extinguishing chamber can increase the allowable breaking current, and the size of the arc extinguishing chamber can be reduced in order to secure the same allowable breaking current. Further, when the arc contactor portion is composed of the arc contactor and the flow guide and the flow guide forms the tip of the arc contactor portion, the outflow of gas is suppressed by the contact between the flow guide and the nozzle. When there is no flow guide, the outflow of gas is suppressed by the contact between the tip of the arc contactor and the nozzle, and the same effect as described above can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a puffer type gas circuit breaker according to an embodiment of the present invention immediately after a breaking operation of an arc extinguishing chamber and its surroundings.

FIG. 2 is a cross-sectional view showing a state of the arc breaker chamber of the circuit breaker of FIG.

FIG. 3 is a cross-sectional view showing a structure of an arc extinguishing chamber of a conventional puffer type gas circuit breaker and its surroundings.

[Explanation of symbols]

 11 main contactor 12 arc contactor 13 electrostatic shield 21 main contactor 22 arc contactor 23 flow guide 24 arc contactor part 25 nozzle 26 gas flow passage 27 spring 30 puffer chamber

Claims (2)

[Claims] 1. A movable arc contactor, a nozzle provided outside the arc contactor and forming a gas flow path between the nozzle and the arc contactor, and for moving the movable part during interruption. In a puffer type gas circuit breaker comprising a puffer chamber for generating high pressure gas in an interlocking manner and for causing the high pressure gas to flow out to the gas flow passage, the nozzle is arced via a spring movable in the moving direction of the arc contact portion. When the gas pressure in the puffer chamber is equal to or lower than a predetermined value, the nozzle contacts the tip of the arc contact portion and maintains the gas flow passage closed. A puffer-type gas circuit breaker characterized in that when the gas pressure exceeds a predetermined value, the nozzle separates from the tip of the arc contact portion to open the gas flow passage. 2. The arc contactor portion comprises a movable arc contactor and a flow guide made of an insulator provided on the outer side of the movable arc contactor, and a gas flow passage is formed between the flow guide and the nozzle. The puffer type gas circuit breaker according to claim 1.