JP6363038B2 - Gas circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker, and more particularly to a gas circuit breaker that blows an insulating gas at the time of current interruption to extinguish an arc.

  In recent years, the power system has been increased in voltage and current, and the capacity of gas circuit breakers has been increased in order to obtain the required breaking performance. On the other hand, in order to reduce costs, miniaturization is being promoted by optimizing the blocking portion structure and the exhaust / shield structure.

  The general structure and operation of the gas circuit breaker during the breaking operation will be described with reference to FIG. The gas circuit breaker is housed in a gas tank 1 filled with an insulating gas. Normally, the fixed arc contact 3 on the opposite side of the movable arc contact 2 on the operating device side, and the movable main contact 4 and the fixed main contact 5 are electrically connected. Is transmitted through the hollow rod 6 by an operating device (not shown), the fixed arc contact 3 on the fixed side, the movable arc contact 2 on the movable side, the main contact 5 on the fixed side, and the main movable side on the movable side. The contact 4 moves to a state where each contact 4 is physically separated.

  Even after the contact is released, an electric current flows between the fixed arc contact 3 and the movable arc contact 2 to generate an arc. Since the gas circuit breaker blows and extinguishes high-pressure insulating gas to the arc, the insulating piston in the puffer chamber 9 is compressed by the fixed piston 7 during the movable side operation, and the gas is blown to the arc. Disappearance is performed.

  The hot gas generated at the time of gas spraying has a low density at a high temperature and has a low dielectric strength. In order to prevent the insulation performance between the electrodes from deteriorating, it is necessary to quickly exhaust the hot gas from the internal exhaust tube 13 through the external exhaust tube 14 through the exhaust hole 15 in the external exhaust tube part after successful arc extinction.

  The role of the exhaust tube is to quickly discharge the generated hot gas without staying between the electrodes, and to efficiently cool the hot gas.

  With reference to FIG. 8, the mechanism of dielectric breakdown between the external exhaust cylinder 14 and the gas tank 1 will be described. When hot gas with insufficient gas cooling and low density and low dielectric strength reaches a high electric field at the end of the exhaust hole 15, the dielectric strength between the external exhaust cylinder 14 and the gas tank 1 decreases, and the external An accident (ground fault) occurs that causes dielectric breakdown between the exhaust pipe 14 and the tank 1.

  For ground faults, measures are taken such as increasing the gas tank diameter to obtain ground insulation performance by relaxing the electric field between the exhaust stack and the tank, and improving the cooling capacity of the hot gas by expanding the exhaust stack. ing.

  As an exhaust structure for cooling the generated hot gas, there is an invention described in Patent Document 1. According to the present invention, the exhaust structure is composed of a first exhaust pipe and a second exhaust pipe having an inner diameter larger than the outer shape of the first exhaust pipe, and the hot gas generated when a large current is interrupted is generated inside the first exhaust pipe. The exhaust flow path to the tank is lengthened without leading the exhaust structure linearly by guiding it to the flow path leading to the gap between the first and second exhaust cylinders.

JP 2007-35518

  In the invention described in Patent Document 1, when hot gas that cannot be processed due to the downsizing of the circuit breaker is exhausted into the gas tank from the exhaust hole of the exhaust pipe having the conventional structure, the high electric field portion at the end of the exhaust hole There is a problem that the insulation performance is reduced by reaching the above.

  In order to solve the above-described problems, a gas circuit breaker according to the present invention includes a pair of arc contacts arranged in a gas tank so as to be capable of opening and closing operations, and one of the pair of arc contacts coaxially. A connected hollow rod (6), a puffer cylinder (8) coaxially provided on the outer periphery of the hollow rod (6), an insulating nozzle (10) fixed to the blocking portion side of the puffer cylinder, An internal exhaust pipe (13) provided on the other outer periphery of the pair of arc contacts, an external exhaust pipe (14) provided on the outer periphery of the internal exhaust pipe (13), and an external exhaust pipe (14). And a gas circuit breaker that allows hot gas generated by the shut-off operation to flow from the internal exhaust pipe (13) to the exhaust hole (15) via the external exhaust pipe (14). The hot gas flows through the exhaust hole (15). Characterized in that the mounting member (17, 18) for rectifying the hot gas to flow and downstream.

  The present invention changes the gas flow by arranging a structure that changes the gas flow in the exhaust hole portion of the external exhaust pipe that discharges the hot gas generated when the current is interrupted into the gas tank, thereby increasing the height of the end of the exhaust hole. It is possible to prevent the hot gas having a lowered insulation performance from reaching the electric field portion, and the insulation performance is improved.

  Also, by changing the hot gas flow, the arrival of the hot gas to the gas tank can be delayed, and the hot gas path that becomes the starting point of the ground fault can be eliminated between the high-pressure side exhaust pipe and the grounded side tank, Time for cooling the hot gas can also be obtained, and the ground insulation performance can be improved.

It is sectional drawing of the gas circuit breaker concerning Example 1. FIG. It is an enlarged view of the exhaust pipe part concerning Example 1, and explanatory drawing of a gas flow. It is an expanded sectional view of straightening members A17 and B18 concerning Example 1. FIG. It is a perspective view of rectification members A17 and B18 concerning Example 1. FIG. It is the figure seen from the X direction in FIG. It is the schematic at the time of applying this invention to the gas circuit breaker of a double drive system. It is a schematic diagram at the time of applying the present invention to a heat puffer type gas circuit breaker. It is an enlarged view in the high electric field part of the exhaust hole part of the exhaust pipe in the conventional gas circuit breaker, and explanatory drawing of a gas flow.

  Embodiments of the present invention will be described below with reference to the drawings. The following are merely examples of implementation, and are not intended to limit the content of the invention to the following specific embodiments. The invention itself can be carried out in various modes as long as it conforms to the contents described in the claims.

Although omitted in FIG. 1, the circuit breaker has a hollow rod 6 connected to an operating device via an insulating rod, and the entire circuit breaker is disposed in a gas tank 1 filled with SF ₆ gas.

  As shown in FIG. 1, the circuit breaker in this embodiment includes a fixed arc contact 3, a movable arc contact 2, a puffer cylinder 8, a puffer cylinder 8, a puffer piston 7, a hollow rod 6, and a mover cover 11. A puffer chamber 9 constituted by a space surrounded by the insulating nozzle 10, a movable-side main contact 4, a fixed-side main contact 5, an internal exhaust cylinder 13, and an external exhaust cylinder 14 are schematically configured.

  The fixed-side conductor 12 and the external exhaust cylinder 14 are electrically connected to the internal exhaust cylinder 13 and the fixed arc contact 3 through the support structure 16, and the electrically connected movable-side arc contact 2 and the hollow rod 6 are connected. The puffer piston 7, the puffer cylinder 8, and the movable main contact 4 are electrically connected to the fixed side in the energized state (closed state), respectively.

  The puffer chamber 9 is coaxially disposed on the inner periphery of the puffer cylinder 8 and the puffer cylinder 8 and has a hollow inside, and a hollow rod 6 into which the insulating gas flows into the hollow, and the puffer cylinder 8. And a puffer piston 7 that slides in a space formed between the hollow rod 6 and the hollow rod 6.

  The puffer piston 7 is fixed to a mounting seat provided on the inner peripheral surface of the gas tank 1. The pressure formation of the insulating gas blown to the arc in the puffer chamber is performed by moving the movable puffer cylinder 8 relative to the fixed puffer piston 7. More specifically, the driving force of the operating device is transmitted from the insulating rod connected to the operating device (not shown) to the puffer cylinder 8 through the hollow rod 6, and the puffer cylinder 8 moves to the right side of the drawing surface to move the inside of the puffer chamber 9. The insulating gas is compressed.

  The high-pressure insulating gas compressed in the puffer chamber 9 is sprayed between the fixed arc contact 3 and the movable arc contact 2 against the arc generated during the interruption operation. The hot hot gas generated after being blown by the arc passes through the insulating nozzle 10, passes through the inside of the internal exhaust pipe 13, passes through the space between the internal exhaust pipe 13 and the external exhaust pipe 14, and is cooled from the exhaust hole 15 to the gas tank. 1 is discharged.

  Hot gas is discharged into the exhaust hole 15 through the internal exhaust cylinder 13 and a space formed between the internal exhaust cylinder 13 and the external exhaust cylinder 14. At this time, there is a possibility that the hot gas reaches the high electric field part B at the end of the exhaust hole 15, or may wrap around and reach the high electric field part A.

  As illustrated in the explanatory view of the fixing method to the exhaust pipe of FIG. 3, the rectifying member A17 that changes the flow of hot gas to the fixed side of the exhaust hole 15 of the external exhaust pipe 14 and the rectifying member B18 to the movable side of the exhaust hole 15 are explained. Is installed. FIG. 5 is a view seen from the X direction in FIG.

  The rectifying member A17 uses a rectifying member A fixing hole 14a provided in the external exhaust cylinder 14 in the vicinity of the high electric field portion A inside the external exhaust cylinder 14 and a rectifying member A fixing bolt hole 17c provided in the rectifying member A17. It is fixed by an A fixing bolt 17a and a rectifying member A fixing nut 17b, and is arranged so as to be inclined so that one end on the exhaust hole 15 side faces the exhaust hole 15 side.

  The rectifying member B18 uses a rectifying member B fixing hole 14b provided in the external exhaust cylinder 14 so as to cover the high electric field portion B inside the external exhaust cylinder 14, and a rectifying member B fixing bolt hole 18c provided in the rectifying member B18. The rectifying member B fixing bolt 18a and the rectifying member B fixing nut 18b are fixed, and one end of the exhaust hole 15 side is inclined so as to face the exhaust hole 15 side.

  First, the flow of the hot gas is changed along the inclined portion of the rectifying member A. Accordingly, the hot gas does not directly reach the high electric field portion A (see FIG. 2) and flows toward the rectifying member B18.

FIG. 4 is a perspective view of the rectifying member A17 and the rectifying member B18. In FIG. 4, the angle θ ₁ inclined toward the exhaust hole 15 side of the rectifying member A17 is larger than the angle θ ₂ inclined toward the exhaust hole 15 side of the rectifying member B18. The angle θ ₁ and the angle θ ₂ are not particularly limited as long as the flow of the hot gas can be changed toward the exhaust hole 15 by the inclined portion of the angle θ ₂ of the flow straightening member B 18. By doing so, the hot gas can be discharged into the gas tank 1 without reaching the high electric field portions A and B which are the weak points of the exhaust hole 15.

The hot gas whose discharge direction is changed by the rectifying member B is discharged at an angle θ ₂ along the rectifying member B, not in the vertical direction with respect to the gas tank. By doing so, it is possible to increase the distance that the hot gas reaches the inner wall of the gas tank 1. Thereby, the time until the hot gas reaches the inner wall of the gas tank 1 is extended, and the insulation performance can be improved.

  In the present embodiment, PTFE, which is often used as the material of the insulating nozzle 10 and the mover cover 11, is described as an example of the material of the rectifying member A17 and the rectifying member B18. In the present invention, since the rectifying member A17 and the rectifying member B18 are required to change the flow of the hot gas, a resin material excellent in strength, heat resistance, and insulation performance other than PTFE may be used. Further, when the rectifying member A17 and the rectifying member B18 are formed of a resin material, ablation of the structure occurs due to the hot gas. The hot gas can be cooled by the heat of vaporization at this time.

  Moreover, since the present invention aims to improve the insulation performance with the gas tank 1 due to the arrival of the hot gas by changing the flow of the hot gas, the deterioration of the insulation performance due to the arrival of the hot gas exceeds the improvement of the insulation performance due to the effect of the rectifying member. In this case, the material of the rectifying member A17 and the rectifying member B18 may be a metal.

  When a metal is used as the material of the rectifying member, a screw hole may be cut in place of the fixing bolt hole provided in the rectifying member A17 and the rectifying member B18 and fixed without using a nut. It should be noted that the hot gas can be cooled more effectively by using a metal material or a resin material having high thermal conductivity for the rectifying members A17 and B18 of the present invention.

  In the above embodiment, the fixed arc contact 3 is fixed, but the present invention is applied to a so-called dual drive circuit breaker in which the arc contact facing the movable arc contact 2 on the movable side is relatively movable. Is also possible.

  Hereinafter, an embodiment applied to a double drive type circuit breaker will be described with reference to FIG. The tip of the insulating nozzle 10 is fixed to one end of the connecting rod 21, and the other end of the connecting rod 21 and one end of the connecting lever 22 are rotatably connected. The substantially center of the connecting lever 22 is fixed to the inner peripheral surface of the internal exhaust cylinder 13 by a support shaft 23 so as to be rotatable, and the other end of the connecting lever 22 and the terminal end of the fixed arc contact 3 are rotatably connected. With such a configuration, when the movable side starts an interruption operation, the fixed arc contact 3 moves in a direction away from the movable side.

  By arranging the rectifying members A17 and B18 described in the above embodiments in the exhaust hole 15 of the external exhaust cylinder 14 of such a double drive circuit breaker, the same effects as in the above embodiments can be obtained.

  In the above embodiment, an example of a puffer type circuit breaker that obtains a blowing gas pressure by mechanical compression of the puffer piston 7 is used. However, a heat puffer type that obtains a blowing gas pressure by taking in arc heat into a fixed heat puffer chamber 26. The present invention can also be applied to a circuit breaker. The said circuit breaker is demonstrated with reference to FIG. A check valve 24 is provided between the heat puffer chamber 26 and the mechanical puffer chamber 27. Further, the mechanical puffer chamber 27 is provided with a pressure release valve 25, which has a structure in which the pressure does not increase more than necessary and an increase in operating force can be suppressed.

In this embodiment, SF ₆ is used as the insulating gas, but the type of insulating gas is not limited to SF _6, and other insulating gases such as dry air and nitrogen gas can be used.

  DESCRIPTION OF SYMBOLS 1 ... Gas tank, 2 ... Movable arc contact, 3 ... Fixed arc contact, 4 ... Movable side main contact, 5 ... Fixed side main contact, 6 ... Hollow rod 7 ... Puffer piston, 8 ... Puffer cylinder, 9 ... Puffer chamber, 10 ... Insulating nozzle, 11 ... Mover cover, 12 ... Fixed conductor, 13 ... Inside Exhaust tube, 14 ... external exhaust tube, 14a ... rectifying member A fixing hole, 14b ... rectifying member B fixing hole, 15 ... exhaust hole, 16 ... support structure, 17 ... Rectifier member A, 17a ... Rectifier member A fixing bolt, 17b ... Rectifier member A fixing nut, 17c ... Rectifier member A fixing bolt hole, 18 ... Rectifier member B, 18a ... Bolt for fixing the rectifying member B, 18b... Nut for fixing the rectifying member B, 18c. Bolt hole, 21 ... connecting rod, 22 ... connecting lever, 23 ... support shaft, 24 ... check valve, 25 ... pressure relief valve, 26 ... heat puffer chamber, 27 ..Machine puffer room

Claims (3)

A pair of arc contacts arranged opposite to each other to enable opening and closing operations in the gas tank;
A hollow rod coaxially connected to one of the pair of arc contacts;
A puffer cylinder provided coaxially on the outer periphery of the hollow rod;
A fixed piston provided in a space between the puffer cylinder and the hollow rod;
An insulating nozzle fixed to the blocking portion side of the puffer cylinder;
An internal exhaust pipe provided on the other outer periphery of the pair of arc contacts;
An external exhaust pipe provided on the outer periphery of the internal exhaust pipe;
An exhaust hole provided in the external exhaust cylinder,
A gas circuit breaker that causes the hot gas generated in the shut-off operation to flow from the internal exhaust pipe to the exhaust hole via the external exhaust pipe,
A gas circuit breaker, wherein a rectifying member for rectifying the hot gas is attached to the upstream side and the downstream side of the hot gas in the exhaust hole. The gas circuit breaker according to claim 1,
The gas circuit breaker characterized in that the hot gas rectified toward the rectifying member provided on the downstream side by the rectifying member provided on the upstream side is discharged from the exhaust hole. The gas circuit breaker according to claim 2,
A gas circuit breaker characterized in that the exhaust hole side end of each of the rectifying members extends toward the exhaust hole.