JPH07312154A - Puffer type gas circuit breaker - Google Patents

Abstract

PURPOSE:To provide a puffer type gas circuit breaker, applying improvement in a gas puffering time width capable of breaking an arc, and improving withstanding voltage performance after breaking a large current. CONSTITUTION:In a peripheral side of a puffer cylinder 17, the second fixed cylinder 20, brought into slide contact with this peripheral surface, is provided. This second fixed cylinder 20 is secured to the first fixed cylinder 19 set up in a peripheral side of this second fixed cylinder. On the other hand, a movable piston 18, secured in a peripheral side to the puffer cylinder 17 to come into slide contact with an internal peripheral surface of the first fixed cylinder 19, is provided, to form an auxiliary puffer chamber 21 as shown in the drawing. A groove 22 is formed in an internal peripheral surface of the first fixed cylinder 19, and by sliding a piston part 24 of the movable piston 18 in the groove 22, gas in the sealed puffer chamber 21 flows out through the groove 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear, and more particularly to a puffer type gas circuit breaker.

[0002]

2. Description of the Related Art Regarding a conventional puffer type gas circuit breaker,
This will be described with reference to FIGS. 6 and 7. FIG. 6 shows a case where the blocking unit is in the closed state. Further, the shutoff portion is housed in a container (not shown) filled with arc extinguishing gas.

Reference numeral 1 is a fixed contact portion, and 4 is a movable contact portion. The fixed contactor portion 1 is composed of a rod-shaped fixed arc contactor 3 and a fixed main contactor 2 located on the outer periphery thereof. Further, the movable contactor portion 4 is composed of a movable arc contactor 6, an insulating nozzle 7 located on the outer periphery of the movable arc contactor 6, a movable main contactor 5 located outside the insulating nozzle 7, and the like. The movable arc contactor 6 and the movable main contactor 5 that form the movable contactor 4 are the fixed arc contactor 3 of the fixed contactor 1.
Also, it has a so-called sliding structure that can move while the fixed main contactor 2 and a part thereof are in contact with each other. In the closed state, the movable arc contact 6 is in contact with the fixed arc contact 3 and the movable main contact 5 is in contact with the fixed main contact 2.

The movable contact portion 4 is constructed integrally with the operating rod 9 and a puffer cylinder 8 provided on the outer peripheral side thereof, and the operating rod 9 is connected to an operating mechanism portion (not shown). . A puffer piston 10 is provided inside the puffer cylinder 8. The puffer piston 10 forms a puffer chamber 11 together with the puffer cylinder 8 and the operation rod 9. In addition, an opening 13 that communicates between the movable arc contact 6 and the insulating nozzle 7 is formed in the upper part of the puffer chamber 11. In the circuit breaker configured as described above, the contact opening operation when a disconnection command is issued will be described with reference to FIG. Note that the same parts as those in FIG.

When a cutoff command is issued, an operation mechanism section (not shown) is operated to move the operation rod 9 downward in the figure.
When the operation rod 9 moves, the movable contactor portion 4 moves in a direction away from the fixed contactor portion 1, and the opening operation starts. When the movable contactor section 4 moves, the fixed main contactor 2 and the movable main contactor 5 first separate from each other. In this state, the fixed arc contactor 3 and the movable arc contactor 6 are in a connected state, and a current flows between them. When the movable contact portion 4 moves further downward, the fixed arc contact 3 and the movable arc contact 6 separate. At this time, if, for example, an arc 12 is generated between the arc contacts 3 and 6, the state in which the current is not interrupted continues even if the arc contacts 3 and 6 are separated from each other.

By the way, even if the movable contact portion 4 moves due to the opening operation, the puffer piston 10 is fixed. Therefore, the puffer cylinder 8 and the operating rod 9,
Then, the volume of the puffer chamber 11 surrounded by each surface of the puffer piston 10 gradually decreases. As a result, the arc extinguishing gas contained in the puffer chamber 11 is compressed. The pressure of the arc-extinguishing gas increases due to compression, and the arc-extinguishing gas flows out from the opening 13 as a gas flow 14 as indicated by an arrow. The outflowing gas rises along the insulating nozzle 7 and is blown to the arc 12 to extinguish it. The gas is extinguished and then discharged into the surrounding space as indicated by arrow 15.

[0007]

The conventional puffer type gas circuit breaker described above operates well in the range defined by the normal standard. It also has the ability to cut off current within the breaking time specified in the standard. However, since the arc-extinguishing gas is blown to the arc for a short period of time, it may not be possible to perform sufficient interruption under special conditions not specified in the standard. For example, (1) when the transient component of the direct current immediately after the accident temporarily becomes larger than the amplitude of the alternating current component and a current zero point does not occur over several cycles of the alternating current, a so-called current zero miss phenomenon occurs, (2) This is the case when an accident such as a lightning strike occurs, that is, when a so-called multiple lightning phenomenon occurs immediately after the accident current is interrupted for the maximum arc time.

In such a case, in order to cut off the arc current, it is required to blow the gas for a longer time than usual. Therefore, if the spraying time is short, the current may be insufficiently interrupted. Further, when the large current is cut off, the free carbon generated by the partial decomposition of the material of the insulating nozzle is not sufficiently removed, and the insulation of the insulating nozzle may be destroyed.

The present invention solves the above-mentioned drawbacks, and an object of the present invention is to provide a puffer-type gas circuit breaker capable of lengthening the blowing time of gas for cutting off an arc.

[0010]

The invention according to claim 1 of the present invention has a fixed contact portion, a state in which the fixed contact portion is connected to the fixed contact portion, and a state in which the connection is released. A movable contact portion that moves in a contact state to perform an opening operation, an insulating nozzle that surrounds the tip of the movable contact portion, and a state in which the movable contact portion is coupled to the fixed contact portion. From the operation rod to be moved to a state where the connection is released, a surface that moves together with the movement of the movable contactor portion or a surface that is in a stationary state independently of the movement of the movable contactor portion, and A puffer chamber having an opening connected between the tip of the movable contact portion and the insulating nozzle, a surface that moves together with the movement of the movable contact portion, and a movement independent of the movement of the movable contact portion. It is surrounded by a state surface, and
The movable contactor portion is provided with a sub-puffer chamber in which a passage communicating with the puffer chamber is formed in a state where the movable contactor portion is disengaged from the fixed contactor portion.

According to a second aspect of the present invention, the passage that connects the puffer chamber and the auxiliary puffer chamber is
At the temperature and pressure of the arc-quenching gas in the auxiliary puffer chamber when the puffer chamber and the sub-puffer chamber communicate with each other, the density of the arc-quenching gas, the number of moles, the molecular weight, and the speed of sound are respectively ρ,
When n, m, and a, the effective cross-sectional area is (90 × m × n) / (ρ × a) or less.

According to a third aspect of the present invention, the puffer chamber and the sub-puffer chamber are communicated with each other when the movable contact portion moves by ½ or more of the moving distance by the opening operation. Is configured.

[0013]

According to the above construction, when a certain time has passed after the opening operation was started, the compressed gas flows out of the puffer chamber and the arc generated between the fixed arc contact and the movable arc contact is generated. Be sprayed on. However, even if the gas flows out from the puffer chamber, the sub-puffer chamber is in a sealed state until the puffer chamber and the sub-puffer chamber communicate with each other, and the gas in the sub-puffer chamber does not flow out. During this time, the gas in the auxiliary puffer chamber is compressed by the movement of the movable piston. Then, when the gas outflow from the puffer chamber ends, the puffer chamber and the sub-puffer chamber communicate with each other, and the gas flows out from the sub-puffer chamber. Then, the arc is sprayed. As a result, the gas flowing out of the puffer chamber and the gas flowing out of the sub-puffer chamber are continuously blown to the arc, and the blowing time of the gas to the arc becomes long.

According to the second aspect of the present invention, the effective cross-sectional area of the passage that connects the puffer chamber and the sub-puffer chamber has a value such that the outflow time of the gas from the sub-puffer chamber becomes long, and The spraying time can be maintained for a long time.

According to the third aspect of the present invention, the gas outflow time from the puffer chamber and the gas outflow time from the sub-puffer chamber can be set to continue, and the effective gas blowing time can be lengthened. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The same parts as those in FIGS. 6 and 7 are designated by the same reference numerals.

FIG. 1 shows the case where the shutoff unit is in the closed state. Further, the shutoff portion is housed in a container (not shown) filled with arc extinguishing gas.

Reference numeral 1 is a fixed contact portion, and 4 is a movable contact portion. The fixed contactor portion 1 is composed of a rod-shaped fixed arc contactor 3 and a fixed main contactor 2 arranged on the outer periphery thereof. In addition, the movable contactor portion 4 includes a movable arc contactor 6
And an insulating nozzle 7 located on the outer periphery thereof, a movable main contact 5 located outside the insulating nozzle 7, and the like.
The movable arc contactor 6 and the movable main contactor 5 that make up the movable contactor 4 move in a state where the fixed arc contactor 3 and the fixed main contactor 2 of the fixed contactor 1 partially contact with each other. It has a so-called sliding structure. In the closed state, the movable arc contact 6 is in contact with the fixed arc contact 3 and the movable main contact 5 is in contact with the fixed main contact 2.

The movable contact portion 4 is integrally formed with the operation rod 9 and a puffer cylinder 17 surrounding the outside thereof. The operating rod 9 is an operating mechanism (not shown).
And a puffer piston 10 is provided inside the puffer cylinder 17. Each surface of the puffer piston 10, the puffer cylinder 17, and the operation rod 9 forms a puffer chamber 11. And puffer room 1
An opening 13 communicating with the movable arc contact 6 and the insulating nozzle 7 is formed in the upper part of the device 1.

Further, on the outer periphery of the puffer cylinder 17,
A second fixed cylinder 20 whose one end slides on the outer surface thereof is provided. The other end of the second fixed cylinder 20 is connected to the first fixed cylinder 19 located on the outer circumference thereof.
The first fixed cylinder 19 and the second fixed cylinder 20
Is fixed to a container (not shown) that accommodates the blocking unit regardless of the movement of the movable contactor 4. Further, one end of a movable piston 18 is connected to the puffer cylinder 17. The other end of the movable piston 18 is bent into a brim to form a piston portion 24. The piston part 24 is
The space formed by the first fixed cylinder 19 and the second fixed cylinder 20 moves vertically in the drawing, and the tip of the piston portion 24 slides on the inner surface of the first fixed cylinder 19. The puffer cylinder 17 and the movable piston 1
8, each surface of the first fixed cylinder 19 and the second fixed cylinder 20 forms an auxiliary puffer chamber 21.

The movable piston 18 and the movable cylinder 23 located on the outer periphery of the movable piston 18 form a gas flow passage 25, and the gas flow passage 25 is formed in the puffer cylinder 17 through the flow hole 2.
7 to the puffer chamber 11. Also, the first
A groove 22 that forms a gas passage is formed in the lower end of the inner surface of the fixed cylinder 19 in the moving direction of the movable contact portion 4. As will be described later, the groove 22 has such a shape that the tip of the piston portion 24 passes through the groove 22 when the movable contact portion 4 moves by ½ or more of the moving distance by the opening operation. Formed in position.

With the above-mentioned configuration, when in the closed state,
The fixed arc contactor 3 and the movable arc contactor 6 come into contact with each other, and the fixed main contactor 2 and the movable main contactor 5 come into contact with each other.
Electricity flows between the movable contact portion 4 and the movable contact portion 4.

Next, regarding the opening operation of the gas circuit breaker, FIG.
Will be described with reference to. FIG. 2 shows an initial state in which the opening operation has started. When a cutoff command is issued, an operation mechanism section (not shown) operates to lower the operation rod 9 downward in the figure. Then, the operation rod 9 moves the movable contactor portion 4 in a direction away from the fixed contactor portion 1. When the movable contactor section 4 starts moving, the fixed main contactor 2 and the movable main contactor 5 first separate from each other. Next, the fixed arc contactor 3 and the movable arc contactor 6 separate. When the movable arc contactor 6 is separated from the fixed arc contactor 3, the arc 1 is placed between the arc contactors 6 and 3.
When 2 occurs, even if both arc contacts 6 and 3 are mechanically separated, the state in which the current is not interrupted continues.

By the way, during the opening operation, the puffer cylinder 17 also moves downward together with the operating rod 9. At this time, the puffer piston 10 is stationary because it is fixed to the container (not shown). Therefore, the volume of the puffer chamber 11 surrounded by the surfaces of the operation rod 9, the puffer cylinder 17, and the puffer piston 10 becomes small. As a result, the gas pressure in the puffer chamber 11 increases and the puffer chamber 1
The gas of No. 1 flows out from the opening 13 and is blown to the arc 12. Although the puffer chamber 11 communicates with the gas flow passage 25 through the flow hole 27, the space forming the gas flow passage 25 is closed, so that the gas in the puffer chamber 11 flows into the gas flow passage 25. There is no such thing. FIG. 3 shows a state in which the opening operation is advanced as compared with the case of FIG.
Is further down. At this time, the puffer chamber 11 becomes small, and the outflow of gas from the puffer chamber 11 is almost completed. At this time, the movable piston 18 is lowered by the movement of the movable contactor portion 4, and the volume of the auxiliary puffer chamber 21 is reduced. Therefore, the gas in the auxiliary puffer chamber 21 is in a high pressure state, and in this state, the piston portion 2
When 4 reaches the portion of the groove 22, a gap is created at the tip of the piston portion 24, and the auxiliary puffer chamber 21 communicates with the gas flow passage 25. As a result, the gas in the sub-puffer chamber 21 enters the puffer chamber 11 through the gas flow path 25 and the flow hole 27,
It flows out from the opening 13. And it is sprayed on the arc.

Here, the time change of the gas pressure blown to the arc will be described with reference to FIG. The vertical axis of FIG. 4 is the effective blowing gas pressure, and the horizontal axis is time.

A curve A shows the time change of the gas pressure in the puffer chamber 11, and a curve B shows the time change of the gas pressure in the auxiliary puffer chamber 21. At the time when the gas pressure in the puffer chamber 11 decreases and the blowing from the puffer chamber 11 decreases, the gas pressure in the sub-puffer chamber 21 rises and the blowing starts. Therefore, the effective gas blowing time for the arc becomes longer as indicated by the solid line C.

Further, in the above-described embodiment, the tip of the piston portion 24 reaches the groove 22 and the auxiliary puffer chamber 21
At the temperature and pressure of the arc extinguishing gas in the sub-puffer chamber when communicating with the puffer chamber 11, the gas density, the number of moles, the molecular weight, and the speed of sound are ρ, n, m, and a, respectively, and Is S, and after 10 msec has passed since both puffer chambers communicate with each other, the difference between the gas pressure in the sub-puffer chamber 21 and the gas pressure in the container and the gas pressure in the container is The ratio (H) and {(ρ × a
The relationship with the value of (× S) / (m × n)} is obtained by calculation as shown in FIG.

By the way, if the above ratio (H) is 10% or more, the spraying of the auxiliary puffer chamber 21 is effective.
From the relationship shown in FIG. 5, when the spraying is extended for 10 msec or more after the puffer chambers are communicated with each other, the following expression (1) should be satisfied, and this has been experimentally confirmed.

(Ρ × a × S) <(90 × m × n) (1) According to the above embodiment, the auxiliary puffer chamber is provided in addition to the puffer chamber, and the arc-quenching gas is emitted from the puffer chamber. The arc extinguishing gas is blown from the auxiliary puffer chamber after a certain time has passed after being blown. Therefore, the effective spraying time of the arc extinguishing gas becomes long. Therefore, the current can be cut off even under severe conditions that are out of specification, such as the current zero-miss phenomenon and the multiple lightning phenomenon. Further, it is also possible to blow away the free carbon generated when the insulating nozzle material is partially decomposed when the large current is cut off, and the withstand voltage performance after the large current is cut off can be improved.

[0030]

According to the present invention, it is possible to realize a puffer type gas circuit breaker in which the arc extinguishing gas is blown for a long time.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing an initial contact opening state of the puffer type gas circuit breaker shown in FIG.

FIG. 3 is a cross-sectional view showing a latter state of opening of the puffer type gas circuit breaker shown in FIG.

FIG. 4 is a view showing a time change with respect to an effective blowing gas pressure.

FIG. 5 is a diagram relating to gas spraying characteristics immediately after opening and after 10 msec.

FIG. 6 is a cross-sectional view showing a closed state of a conventional puffer type gas circuit breaker.

FIG. 7 is a cross-sectional view showing a state where the puffer type gas circuit breaker shown in FIG. 6 is in the process of opening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixed contactor part, 2 ... Fixed main contactor, 3 ... Fixed arc contactor, 4 ... Movable contactor part, 5 ... Movable main contactor, 6 ... Movable arc contactor, 7 ... Insulation nozzle, 9 ... Operation Rod, 10 ... Puffer piston, 11 ... Puffer chamber, 13 ... Opening part, 17 ... Puffer cylinder, 18 ... Movable piston, 19 ... First fixed cylinder, 20 ... Second fixed cylinder, 21 ... Secondary puffer chamber, 22 ... Communication Part, 23 ... Movable cylinder, 24 ... Piston part, 25 ... Gas flow path, 27 ... Flow hole.

Front page continued (72) Inventor Hitoshi Mizoguchi 2-1, Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa Stock company Toshiba Hamakawasaki Factory

Claims (3)

[Claims] 1. A movable contact having a fixed contact portion and a state in which the fixed contact portion is connected and a state in which the fixed contact portion is released from the fixed contact portion, the movable contact performing a contact opening operation by moving with the tip in contact with the fixed contact portion. A child part, an insulating nozzle that surrounds the periphery of the tip of the movable contact part, and an operating rod that moves the movable contact part from a state in which the movable contact part is coupled to a state in which the coupling is released. Surrounded by a surface that moves together with the movement of the movable contact portion and a surface that is in a stationary state independently of the movement of the movable contact portion, and between the tip of the movable contact portion and the insulating nozzle. The movable contactor is surrounded by a puffer chamber having an opening for connection, a surface that moves together with the movement of the movable contactor portion, and a surface that is in a stationary state independent of the movement of the movable contactor portion, and Part is uncoupled from the fixed contact part A puffer-type gas circuit breaker having a sub-puffer chamber in which a passage communicating with the puffer chamber is formed. 2. The arc for extinguishing the passage connecting the puffer chamber and the sub-puffer chamber at the temperature and pressure of the arc-extinguishing gas in the sub-puffer chamber when the puffer chamber and the sub-puffer chamber communicate with each other. When the density, the number of moles, the molecular weight, and the speed of sound of the volatile gas are ρ, n, m, and a, respectively, the effective area is (90 × m × n) / (ρ × a) or less. The puffer type gas circuit breaker according to claim 1. 3. The puffer chamber and the auxiliary puffer chamber,
One half of the distance that the movable contact portion moves by the opening operation.
The puffer type gas circuit breaker according to claim 1, wherein the puffer type gas circuit breaker is configured to communicate with each other when moved.