JPH077627B2 - Puffer type gas breaker - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a puffer type gas circuit breaker, and more particularly to a puffer type gas circuit breaker provided with a shock absorber in an opposing arc electrode portion to improve reliability.

[Technical Background of the Invention] With the increase in demand for electric power, the power plant and substation are steadily increasing in capacity. Moreover, due to the difficulty in constructing a power plant in an urban area, which is a region where a large amount of electricity is consumed, the transmission lines are lengthened, and there is a trend toward higher voltages in order to improve this transmission efficiency. With the increase in the capacity of the power transmission system, the breaking capacity required for circuit breakers used in substations and switchyards has been increasing, and the breaking current is 63K in the current 550KV system.
The one up to A has been put to practical use. This 550KV-63KA is composed of 4 points, and if this is applied to the 1000KV system as it is, it will correspond to 8 points. In order to improve the reliability of the circuit breaker, it is important to reduce the number of breaking points and the number of parts as much as possible. For this purpose, it is necessary to increase the breaking capacity per breaking point. At transmission voltages of 168 KV and above, puffer-type SF ₆ gas circuit breakers are mainly used. This is due to the excellent blocking and insulating properties of SF ₆ gas, but especially 2
Since the puffer type structure is simpler than the pressure type, it is the mainstream of high voltage circuit breakers. Further, in a closed gas switchgear where the entire equipment of the substation is insulated with SF ₆ gas, it is particularly often used because it has great advantages in coordination of insulation with external equipment or arrangement of equipment.

One way to improve the blocking performance of such a puffer type gas circuit breaker is to speed up the contact opening speed between the electrodes. This can be achieved by increasing the driving force, but as a result, the driving device becomes large and the cost increases. Further, it is possible to increase the speed by reducing the weight of the movable part, but there is a limit. Increasing the contact opening speed causes new problems such as reliability of the seal sliding part between SF ₆ and the air, or impact strength of each member. Considering these points, a configuration as shown in FIG. 4 is conceivable as a method of making the driving force almost the same as that of the conventional one and obtaining the opening speed faster than the conventional one to improve the insulation recovery characteristic between the tracks.

FIG. 4 shows an arc extinguishing chamber of a puffer type gas circuit breaker, and this arc extinguishing chamber is housed in a container (not shown) filled with an arc extinguishing gas such as SF ₆ . The figure shows the closed state of the circuit breaker. In FIG. 4, the movable electrode 1
A puffer piston 3 is slidably inserted in the puffer cylinder 2 integrally mounted with the puffer cylinder 2. An insulating nozzle 4 is arranged around the movable electrode 1, and a space surrounded by the puffer cylinder 2 and the puffer piston 3 communicates with a passage formed by the insulating nozzle 4 and the movable electrode 1. The movable electrode 1 of the operating rod 5 to which the movable electrode 1, the puffer cylinder 2, and the insulating nozzle 4 are fixed.
An operation mechanism (not shown) is connected to the end portion on the opposite side, and the movable electrode 1 is opened and closed with the opening and closing operation of the insulating rod 5 by this operation mechanism. On the other hand, the opposing arc electrode 6 facing the movable electrode is connected to a plurality of link devices 7 arranged around the operation rod 5 via a plate 8 and an insulating rod 9 and a puffer piston 3.
It is integrally connected with. The link device 7 includes a lever 7a, links 7b and 7c, and a link support portion 7d.
The lever 7a is divided and supported by a fulcrum 7e of the link support portion 7d at a predetermined link ratio, one end of the lever 7a is connected to the operation rod 5 by a link 7b, and the other end of the lever 7a is a link 7c. Is connected to the plate 8 at a connecting point 7f. The connecting portion between the lever 7a and the links 7b and 7c is rotatably engaged with a pin or the like.
7d is attached and fixed to an insulating cylinder 10 that is insulated and fixed to the container. On the opposite side of the opposing plate 11a connecting the opposing arc electrode 6 and the insulating rod 9 to the opposing arc electrode, the energizing cylinder 1
1, the energizing cylinder 11 is slidably operated with the energizing portion 13 of the energizing rod 12 which is supported and fixed in the direction opposite to the operation mechanism.

In the above configuration, when the operating rod 5 is driven rightward in the figure at a constant speed by the driving force of the operating mechanism,
The driving force is transmitted to one end of the lever 7a via the link 7b. At this time, the lever 7a rotates by receiving a rotation moment about the fulcrum 7e, and the link 7c connected to the other end of the lever 7a and the plate 8 connected to the link 7c, the insulating rod 9, and the puffer piston 3 are Move from right to left. Along with this, the opposing arc electrode 6 also moves from the right to the left, and performs the cutting operation. Near the end of the operation, the operation rod 5 is decelerated and stopped by the action of the shock absorber inside the operation mechanism, and the operation is completed. In addition, as for the closing operation, the operation which is completely opposite to the above-mentioned interruption operation is performed.

As described above, in the puffer type gas circuit breaker as shown in FIG. 4, the moving direction of the movable electrode and the opposing arc electrode are always opposite to each other during the cutting / closing operation. The speed can be increased relatively. Further, since the puffer piston 3 operates in the direction opposite to the moving direction of the puffer cylinder 2, the gas compression efficiency of the space formed by the both increases, and a large gas pressure increase can be obtained even if the diameter of the puffer cylinder 2 is small. There is also.

[Problems of Background Art] However, the puffer type gas circuit breaker as described above has the following problems.

That is, as described above, the operating rod 5 is rapidly decelerated by the shock absorber at the end of the cutting operation. On the other hand, the opposing arc electrode 6 continues to move in the left-right direction due to its inertial force. Therefore, a large pulling force is applied to the member connecting them, for example, the insulating rod 9. 3 (A) and 3 (B) respectively show the displacement of the operating rod 5 and the opposing arc electrode 6 and the insulating rod 9 at the time of such a cutting operation.
(Solid line), the tensile stress generated in the insulating rod 9 during deceleration may reach several times the compressive stress generated during acceleration. When a large load is repeatedly applied to an insulator that is weaker than metal in this way, the insulating rod 9 is easily broken or the joint portion with the metal such as the plate 8 is easily damaged, and the insulation reliability is deteriorated. I will end up.
Further, since the elastic modulus of the insulator is small, large free vibration is likely to occur even after the operation, resulting in a decrease in strength, which aggravates the problem. Although a compressive force is applied to the insulating rod 9 at the end of the closing operation, the operating speed is slower than that at the time of interruption, and therefore the deceleration force is much smaller, so there is no strength problem in this case.

As described above, the conventional puffer type gas circuit breaker has a serious problem in insulation reliability due to damage at the end of the blocking operation due to insufficient strength of the insulating rod.

[Object of the Invention] The present invention has been proposed in order to eliminate the above-mentioned drawbacks of the prior art. An object of the present invention is to provide an insulating rod that connects the operating rod and the opposing arc electrode at the end of the cutting operation. Provides a puffer-type gas circuit breaker that eliminates the problem of strength of the insulating rod and improves the insulation reliability by preventing a large tensile force from acting and causing a large free vibration even after operation. It is to be.

[Summary of the Invention] A puffer-type gas circuit breaker of the present invention is a buffer composed of a damper cylinder and a damper piston between a current-carrying cylinder attached to an opposing arc electrode and a current-carrying portion of a current-carrying conductor on which the cylinder slides. A device is provided, and the damper piston and the damper cylinder are fitted to each other during the opening operation of the electrodes to form a buffer chamber, and the gas in the buffer chamber is compressed as the opening operation progresses. It is characterized by having done.

With such a configuration, when the operating rod is decelerated at the end of the cutting operation, the opposing arc electrode portion is similarly decelerated by the shock absorber, so that the operating rod and the opposing arc electrode are connected. No large tensile force is applied to the insulating rod.

[Embodiment of the Invention] Next, an embodiment of the puffer type gas circuit breaker according to the present invention will be described with reference to FIGS. 1 and 2. It should be noted that the same parts as those of the above-described conventional technique are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1, a damper piston 14 is attached to the inner peripheral portion of the energizing cylinder 11 on the opposite side of the opposing plate 11a to which the opposing arc electrode 6 facing the movable electrode 1 is attached. On the other hand, a damper cylinder 15 is formed in the inner peripheral portion of the current-carrying portion 13 of the current-carrying conductor 12 which is supported and fixed in the direction opposite to the operation mechanism, and which forms a buffer chamber 16 by fitting with the damper piston 14 during the cutting operation. Has been done. The damper cylinder 15 is provided with a small hole 15a that connects the buffer chamber 16 and the inside of the container.

In the present embodiment having the above-mentioned configuration, the operating rod 5 is operated by operating the operating mechanism from the closed state shown in FIG.
Is driven to the right in the figure, the puffer piston 3, the insulating rod 9, and the opposed arc electrode 6 connected by the link device 7 move from the right to the left to perform the cutting operation.
In this case, the operating rod 5 is rapidly decelerated by the shock absorbing device (not shown) as described above, but at the same time, the damper piston 14 and the damper cylinder 15 provided on the opposing arc electrode 6 side are fitted together. Starting, the buffer chamber 16 is formed and the gas inside is compressed. As a result, the opposing arc electrode 6 and the opposing plate 11a are also rapidly decelerated in the direction opposite to the operation rod 5 to complete the blocking operation, and the gas compressed in the buffer chamber 16 flows out from the small hole 15a. FIG. 2 is an enlarged view showing the vicinity of the opposed arc electrode 6 in such a cutoff state.

In this way, since the shock absorber provided on the side of the opposed arc electrode 6 effectively acts, the stress generated in the insulating rod 9 at the end of the cutting operation can be suppressed as much as possible, and the opposed arc electrode 6 after the operation can be suppressed. Because vibration of the part can be suppressed,
As shown by the dotted lines in FIGS. 3A and 3B, the strength of the insulating rod 9 can be sufficiently maintained, and as a result, the insulation reliability of the puffer type gas circuit breaker can be improved.

The present invention is not limited to the above embodiment,
For example, the arrangement of the damper piston and the damper cylinder can be reversed.

[Effects of the Invention] As described above, according to the present invention, by providing a simple shock absorber composed of a damper cylinder and a damper piston on the side of the opposing arc electrode, the opposing arc electrode is operated at the operation rod at the end of the cutting operation. The stress applied to the insulating rod, which is the connecting portion between the operating rod and the opposing arc electrode, was drastically reduced in the same manner as in (1), so that the insulating rod was prevented from damage and the insulation reliability was improved. A puffer type gas circuit breaker can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing a closed state of a puffer type gas circuit breaker which is an embodiment of the present invention, FIG. 2 is an enlarged sectional view showing a cutting state of the embodiment of FIG. 1, and FIG. 3 (A). (B) is a displacement diagram of the operating rod and the opposing arc electrode and a displacement diagram of stress of the insulating rod during the cutting operation. FIG. 4 is a sectional view showing an arc extinguishing chamber of a conventional puffer type gas circuit breaker. DESCRIPTION OF SYMBOLS 1 ... Movable electrode, 2 ... Puffer cylinder, 3 ... Puffer piston, 4 ... Insulation nozzle, 5 ... Operation rod, 6 ... Opposed arc electrode, 7 ... Link device, 8 ... Plate, 9 ... Insulation rod, 10 ... Insulation cylinder, 11 ... energizing cylinder, 11a ... opposed plate, 12 ... energizing conductor, 13 ... energizing part, 14 ... damper piston, 15 ... damper cylinder, 15a ... small hole.

Claims (1)

[Claims] 1. An electrode which opposes each other so as to come in contact with and separate from each other in a container in which an arc extinguishing gas such as SF ₆ gas is sealed, and the electrode is attached to one end of an operating rod connected to an operating mechanism via an insulating rod. A movable electrode and a puffer cylinder, which are one of the above, and a puffer piston and a plurality of insulating rods that slide in the puffer cylinder through a link device are fixed to the other end of the operating rod. An opposing arc electrode facing the movable electrode is fixed to the insulating rod of the book, and further, an energizing cylinder that slides with the energizing portion of the energizing conductor fixed to the opposite arc electrode on the side opposite to the operating mechanism. By installing, the puffer piston and the opposing arc electrode always move in the opposite direction to the movable electrode and the puffer cylinder, and the puffer cylinder and puffer piston move the arc-extinguishing gas in the puffer cylinder. In a puffer type gas circuit breaker that compresses and guides an arc generated between opposing electrodes by an insulating nozzle fixed to the puffer cylinder to extinguish the arc, a current-carrying cylinder attached to the opposing arc electrode, A shock absorber composed of a damper cylinder and a damper piston is provided between the cylinder and the current-carrying portion of the current-carrying conductor, and the damper piston and the damper cylinder are fitted to each other in the middle of the opening and closing operation of the electrodes to absorb the shock. A puffer-type gas circuit breaker characterized by forming a chamber and compressing the gas in the buffer chamber as the opening operation progresses.