JP2682180B2 - Puffer type gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a puffer type gas circuit breaker used as a large capacity power circuit breaker, and more particularly to the structure of an arc extinguishing chamber thereof.

[Conventional technology]

The puffer type gas circuit breaker compresses arc extinguishing gas and blows this compressed gas to the open gap of the interrupting part to extinguish the generated arc and interrupt the large current. As the gas, SF ₆ gas is extremely excellent and is used even for ultra-high pressure, large capacity class circuit breakers.

FIG. 3 is a vertical cross-sectional view showing a main part configuration of a conventional puffer type gas circuit breaker. A metal container is provided in a cylindrical metal container 1 filled with SF ₆ gas of several atmospheres as an arc extinguishing gas. Fixed contactor 3 supported from the left side of 1 via an insulator 2.
A movable contactor 4 capable of coming into contact with and separated from the movable contactor 4; a puffer cylinder 5 interlocking with the movable contactor 4; and a main puffer chamber 6 formed in the puffer cylinder 5, and a right side surface of the metal container 1 via an insulator 7. Fixed piston 8 and movable contact 4 supported
And the movable contactor 4 moves in the X direction when the current is cut off to guide the gas compressed in the main puffer chamber 6 to the separation gap 9 between the fixed contactor 3 and the movable contactor 4. It is heated by the insulating nozzle 10A and the second insulating nozzle 10B, and the arc 15 between the fixed and movable contactors which is provided so as to penetrate in the central axis direction of the main puffer chamber 6 on the side opposite to the fixed contactor of the movable contactor 4. A cylindrical drive rod 12 having an exhaust passage 12A for exhausting the gas to the free space 11 in the metal container 1 is housed as a main component of the current cutoff portion.

When the driving force in the X direction is transmitted from a driving device (not shown) through the insulating rod 13 when the current is cut off, the movable contactor 4 which is a movable portion integrated with the first insulating nozzle 10A,
When the second insulating nozzle 10B, the drive rod 12, and the puffer cylinder 5 move in the X direction and the fixed contactor 3 does not escape from the throat portion 10 of the first insulating nozzle 10A, as shown in the figure, the main puffer The first insulating nozzle 10 is compressed by the fixed piston 8 in the chamber 6 and is blown from the plurality of spray holes 5A.
Gas flow that flows through the gap between A and the second insulating nozzle 10B and blows the gap 9 between the fixed contact 3 and the movable contact 4
14A cools the arc 15 generated in the open gap portion 9,
The gas heated by the arc 15 is discharged into the free space 11 as gas flows 14B and 14C in the exhaust passage 12A. As the breaking current increases, the arc 15 increases and tries to close the inlet of the exhaust passage 12A, so the main puffer chamber 6
The gas flow 14A from tends to be difficult to flow. Therefore, the gas pressure in the main puffer chamber 6 rises as the breaking current increases.

Such an arc extinguishing method, that is, a method of extinguishing the inlet side of the exhaust passage 12A with the arc 15 so as to close the inlet side of the exhaust passage 12A and increasing the pressure increase in the puffer chamber 6 to extinguish the puff is from the intention of "blowing out". It is called a puffer type, and is used as a large-current breaker because the fixed contactor 3 can take a large amount of gas to blow to the arc 15 when the fixed contactor 3 escapes from the throat portion 10 of the first insulating nozzle 10A. .

[Problems to be solved by the invention]

However, as described above, in the conventional device, the breaking current increases and the arc heat heats the main puffer chamber 6
Since the pressure in the main puffer chamber 6 rises against this,
Rod for compressing the gas inside by a fixed piston 8
There was a drawback that the operating force of 12 had to be increased as the breaking current increased.

When this operating force is small, the reaction force against the gas pressure is insufficient, the separation speed between the fixed contact 3 and the movable contact 4 decreases, and in extreme cases, the movable contact 4 is pushed back in the X direction. The reverse phenomenon occurs and it becomes impossible to shut off. Therefore,
The drive device in the conventional device is provided so as to generate an operating force determined by the rated breaking current of the circuit breaker.

An object of the present invention is to provide a device in which the interior of the puffer cylinder is divided into two chambers so that even if the breaking current increases, the operating force of the drive rod need not be increased accordingly.

[Means for solving the problem]

In order to solve the above problems, according to the present invention, a fixed contact, a movable contact that can be brought into contact with and separated from the fixed contact, and a puffer that interlocks with the movable contact are provided in a metal container filled with an arc extinguishing gas. A cylinder, a fixed piston that forms a main puffer chamber in the puffer cylinder, and a gas that surrounds the movable contact and compresses the gas compressed in the main puffer chamber on the side opposite to the fixed piston of the puffer cylinder. From the fixed / movable contact to the opening of the fixed / movable contact, the auxiliary puffer chamber and the blowing passage are arranged in the puffer cylinder adjacent to the side opposite to the fixed piston of the main puffer chamber. However, the auxiliary puffer chamber is partitioned so as not to communicate with the main puffer chamber and has a communication hole communicating with the opening gap portion, and the blowing passage has the auxiliary puffer chamber. It is arranged on the inner diameter side of the chamber and communicates only with the main puffer chamber at its end on the fixed piston side so as to pass the gas flow from the main puffer chamber toward the open gap part. It is assumed that the end portion of is connected to the spray hole.

[Action]

According to the configuration of the present invention, an auxiliary puffer chamber that is separated from the main puffer chamber in the puffer cylinder adjacent to the side opposite to the fixed piston of the main puffer chamber, and a blower that guides the gas in the main puffer chamber to the blowing holes. With the structure that the connecting passage is provided, the gas in the opening gap expanded by the arc heat has a large flow resistance in the blowing passage, so it is difficult to flow to the main puffer chamber side, and most of the gas is connected. It flows into the auxiliary puffer chamber side through the mouth. Therefore, since the pressure increase due to the arc heat is almost eliminated in the main puffer chamber, it is not necessary to increase the operating force of the drive rod so much even if the breaking current increases. On the other hand, since the gas pressure in the auxiliary puffer chamber increases due to the arc heat as the breaking current increases, a large amount of gas stored in the auxiliary puffer chamber when the fixed contact escapes from the throat portion of the first insulating nozzle communicates with the communication hole. It flows out through and blows out the arc.

〔Example〕

 The present invention will be described below based on reference examples.

FIG. 1 is a cross-sectional view showing a main part configuration of a puffer type gas circuit breaker according to an embodiment of the present invention.
In addition to the main puffer chamber 60, an auxiliary puffer chamber 16 provided with a plurality of communication holes 16A communicating with the open gap 9 is provided inside the main puffer chamber 60, and the first insulating nozzle 10A and the second insulating nozzle 10A are provided. An intermediate insulating nozzle 10C that guides the gas flows 14D and 14E from the puffer cylinder 50 is provided between the insulating nozzle 10B and the insulating nozzle 10B. A check valve 17 including a valve body 17A made of a conical piece, a spring 17B, a spring support 17C, and a nozzle portion 17D into which the valve body 17 is fitted so as to pass only the gas flow 14D directed to 9 ing. The same parts as those of the conventional device are denoted by the same reference numerals, and the detailed description is omitted.

In FIG. 1, the gas in the opening gap portion 9 expanded by the heat of the arc 15 passes through the gap between the first insulating nozzle 10A and the intermediate insulating nozzle 10C and enters the auxiliary puffer chamber 16 through the communication hole 16A. , The gas pressure in the auxiliary puffer chamber 16 rises with an increase in the breaking current, but the gas does not enter the main puffer chamber 60 due to the check valve 17, and the increase in gas pressure in the main puffer chamber 60 due to arc heat is Absent. Therefore, even if the breaking current increases, the reaction force of the drive rod 12 is not much affected. When the fixed contactor 3 escapes from the throat portion 10 of the first insulating nozzle 10A, a large amount of gas flow 14E is generated from the auxiliary puffer chamber 16 to blow out the arc 15.

FIG. 4 is a characteristic diagram showing the pressure characteristics in the puffer chamber when the current is cut off. The horizontal axis indicates time, and the drive start time t ₀ of the drive rod 12 to the contact opening start time t of the separation gap 9 is indicated. _It shows up to the drive end time t ₂ of the drive rod 12 via ₁ ,
The vertical axis shows the pressure in the puffer chamber. In the figure, the broken line
18 is the main puffer chamber 6 in the conventional apparatus shown in FIG.
Shows the pressure characteristic curve of the
Corresponding to the pressure characteristics in the device of the reference example shown in the figure, the alternate long and short dash line 19 indicates the pressure characteristic curve of the main puffer chamber 60, and the solid line 20 indicates the pressure characteristic curve 20 of the auxiliary puffer chamber 16.

In FIG. 4, the main puffer chambers 6 and 60 have the same pressure rising characteristics because they are only mechanically compressed by the fixed piston 8 before the opening of the separation gap portion 9, but the opening start time is the same. After t _1, the pressure in the main puffer chamber 6 in the conventional apparatus rises sharply as shown by the pressure characteristic curve 18 due to the inflow of gas expanded by the arc 15, and after the pressure is increased to P ₂ , the fixed contactor 3 has the first insulation. The pressure drops to escape the throat portion 10 of the nozzle 10A. On the other hand, the pressure of the main puffer chamber 60 in the apparatus of the reference example of FIG. As pressure
After the pressure is increased to P ₁ , the pressure decreases because the fixed contactor 3 escapes from the throat portion 10 of the first insulating nozzle 10A, but the pressure in the auxiliary puffer chamber 16 becomes as shown by the pressure characteristic curve 20 due to the gas inflow. After a sharp rise and pressure increase to a pressure approximately equal to P ₂ ,
A gas stream 14E can be generated which blows off the arc 15. The maximum pressure P ₂ of the pressure characteristic curves 18 and 20 increases as the breaking current increases, but the maximum pressure P ₁ of the pressure characteristic curve 19 is smaller than P ₂ because it does not participate in the breaking current, and P ₂ increases as the breaking current increases. And the difference between P ₁ and P ₁ becomes large.

As can be seen from FIG. 4, the maximum gas pressure in the auxiliary puffer chamber 16 rises as much as the conventional device, so that the breaking speed and the current breaking ability are not reduced at all. Furthermore, even if the breaking current increases, it is no longer necessary to increase the operating force of the drive rod 12 accordingly, so in the conventional device, the driving device was provided in accordance with the rated breaking current of, for example, several tens of kA. The operating force of the drive rod 12 is less than half that of the conventional device, and the drive device can be made smaller, and the operating force is reduced, and the impact force generated at the gas circuit breaker itself at the time of disconnection is also reduced. The components of the container are also more compact.

FIG. 2 is a cross-sectional view showing the essential structure of a puffer type gas circuit breaker according to an embodiment of the present invention.
An auxiliary puffer chamber 161 formed by partitioning the main puffer chamber 61 so as not to communicate with the main puffer chamber 61, and a blowing passage 21 communicating with the main puffer chamber 61 and the blowing holes 51A are arranged. Has a plurality of communication holes 161A communicating with the separation gap portion 9, and the same parts as those of the conventional device are denoted by the same reference numerals and detailed description thereof will be omitted.

In FIG. 2, the gas in the opening gap portion 9 expanded by the heat of the arc 15 passes through the communication hole 161A and the auxiliary puffer chamber 16
1, the gas pressure in the auxiliary puffer chamber 161 rises with an increase in the breaking current, but to the main puffer chamber 61 side, a blowing passage is provided.
Since 21 is narrow and long, the flow resistance is large, gas cannot enter the main puffer chamber 61 in a short time, and the gas pressure in the main puffer chamber 61 due to arc heat hardly increases.
Therefore, even if the breaking current increases, the reaction force of the drive rod 12 is not much affected. When the fixed contactor 3 escapes from the throat portion 10 of the first insulating nozzle 10A, a large amount of gas flow 14F is generated from the auxiliary puffer chamber 161, and the arc 15 is blown out.

The blowing passage 161A is the check valve 17 in the reference example of FIG.
And serves as a passage for mechanically compressed gas from the main puffer chamber 61 by the fixed piston 8 and prevents the expanded gas from the opening gap portion 9 from flowing back to the main puffer chamber 61. Therefore, the pressure characteristic in the puffer chamber when the current is cut off in the embodiment of FIG. 2 is almost the same as the characteristic of the reference example of FIG. 1 in FIG. 4, and it is necessary to use a check valve having a complicated mechanism. There is no. The width and length of the blowing passage 161A differ depending on the magnitude of the circuit breaker's rated breaking current.For example, in the case of a few 10 kA breaking rating, the blowing passage 161A has a radial width of about 5 mm and a long length. An effective flow resistance occurs when the distance is several 10 mm.

〔The invention's effect〕

As described above, according to the present invention, the auxiliary puffer chamber and the blowing passage are arranged adjacent to the anti-fixing piston side of the main puffer chamber in the puffer cylinder, so that the gas flow expanded by the thermal arc is blown by the main puffer chamber. Since it is possible to prevent it from flowing into the chamber, the conventional device had the drawback that the operating force of the drive rod had to be increased as the breaking current increased. It is possible to provide a device having an arc extinguishing ability.

Therefore, even if the puffer cylinder of the size of the conventional device is divided into halves to form the main puffer chamber and the auxiliary puffer chamber according to the present invention, the same arc extinguishing ability can be obtained with an operating force of half or less of that of the conventional device. Therefore, the drive device can be downsized, and the weight of the gas circuit breaker can be reduced by making the components in the gas circuit breaker compact.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part structure of a puffer type gas circuit breaker according to a reference example of the present invention, and FIG. 2 is a sectional view showing a main part structure of a puffer type gas circuit breaker according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing the structure of the main part of a conventional puffer type gas circuit breaker, and FIG. 4 is a characteristic diagram showing the pressure characteristic in the puffer chamber. 1: Metal container, 2: Insulator, 3: Fixed contact, 4: Movable contact, 5,50,51: Puffer cylinder, 6,60,61: Main puffer chamber, 5A, 50A, 51A: Spray hole , 7: Insulator pipe, 8: Fixed piston, 9: Opening gap part, 10: Throat part, 10A: First insulating nozzle, 10B: Second insulating nozzle, 10C: Intermediate insulating nozzle,
11: Free space, 12: Drive rod, 12A: Exhaust passage, 13: Insulation rod, 14A, 14B, 14C, 14D, 14E, 14F: Gas flow, 15: Arc, 16,161: Auxiliary puffer chamber, 16A, 161A: Communication Hole, 17: Check valve, 17A: Valve body, 17B: Spring, 17C: Spring support, 17D: Nozzle part, 18: Pressure characteristic curve of main puffer chamber 6, 19: Pressure characteristic curve of main puffer chamber 60, 20 : Pressure characteristic curve of the auxiliary puffer chamber 16, 21: Spray passage.

Claims (1)

(57) [Claims] 1. A metal container filled with an arc-extinguishing gas, a fixed contact, a movable contact that can be brought into contact with and separated from the fixed contact, a puffer cylinder that interlocks with the movable contact, and a main inside the puffer cylinder. The fixed piston forming the puffer chamber and the gas compressed in the main puffer chamber, which surrounds the movable contactor, are opened from the spray holes provided on the side opposite to the fixed piston of the puffer cylinder to open the fixed / movable contactor. In a device provided with an insulating nozzle leading to a clearance, an auxiliary puffer chamber and a blowing passage are arranged in the puffer cylinder adjacent to an opposite fixed piston side of the main puffer chamber. A partition hole is formed so as not to communicate with the puffer chamber, and a communication hole communicating with the opening gap portion is provided, and the spray passage is disposed on the inner diameter side of the auxiliary puffer chamber. At the end on the fixed piston side, only the main puffer chamber communicates with the main puffer chamber so that the gas flow from the main puffer chamber to the open gap passes. A puffer type gas circuit breaker characterized by being formed.