CN110993431B

CN110993431B - Novel arc extinguishing contact structure of high-voltage switch SF6 gas arc extinguishing chamber

Info

Publication number: CN110993431B
Application number: CN201911050863.9A
Authority: CN
Inventors: 杨震; 万媛媛; 蒋昌虎; 胡飞
Original assignee: Teba Shanghai Zonfa Power Ehv Equipment Co ltd
Current assignee: Tbea Yunji High Voltage Switch Co ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2022-06-28
Anticipated expiration: 2039-10-31
Also published as: CN110993431A

Abstract

The invention discloses a novel arc extinguishing contact structure of a high-voltage switch SF6 gas arc extinguishing chamber, which comprises a static arc contact and a movable end contact. The invention adopts the static arc contact with variable radius to block the main nozzle in the pre-compression stage, so that the pressure of the cylinder is quickly established, and the nozzle is immediately unobstructed when the electric arc begins to appear. The cylinder is additionally provided with the holes, so that high-heat electric ions are cooled by using a siphon principle, gas circulation flow is realized, long arc extinguishing of electric arcs is accelerated, and better arc extinguishing performance is achieved. The flow guide cone and the flow dispersing cover added in the invention can prevent the thermal ions from rebounding to a high potential area to cause breakdown discharge of the shell or the basin, and have better safety performance.

Description

Novel arc extinguishing contact structure of high-voltage switch SF6 gas arc extinguishing chamber

Technical Field

The invention relates to a novel arc extinguishing contact structure of a high-voltage switch SF6 gas arc extinguishing chamber.

Background

The circuit breaker is a core component which is used for controlling and protecting a high-voltage power system, the SF6 gas arc-extinguishing chamber is a key module of the high-voltage switch circuit breaker, and the main function of the circuit breaker is to rapidly reduce the temperature of an electric arc and accelerate the extinguishing of the electric arc by utilizing the flowing of SF6 gas through the contact and relative movement of a movable contact and a fixed contact in SF6 gas so as to achieve the purpose of opening the high-voltage switch.

The traditional arc extinguish chamber in the market at present adopts the static contact and the moving contact part to cooperate to realize the on-off current, the contradiction of the nozzle throat diameter when different fault currents are switched off is caused by the on-off mode, different fault currents must be switched off by adopting different nozzle throat diameters, the cost is high, the universality is poor, and the universality cannot be realized for different fault currents. In order to enhance the arc quenching capability of some products, the commonly adopted method is to increase the opening distance, increase the opening speed in unit time and the like, so that the stability of the products is reduced, and the product cost is increased.

Disclosure of Invention

The purpose of the invention is: the arc extinguishing problem in the high-voltage switch is solved by adopting a simple arc extinguishing contact structure with low cost.

In order to achieve the above object, the technical scheme of the present invention is to provide a novel arc extinguishing contact structure for an SF6 gas arc extinguishing chamber of a high-voltage switch, which comprises a static arc contact and a dynamic end contact, wherein the dynamic end contact is sleeved outside a pipe, the pipe is arranged on a piston of a cylinder, a small nozzle arranged at the end of the piston presses the dynamic end contact in the piston through a pressing ring, the end of the piston is further provided with a main nozzle, the small nozzle is located in the main nozzle, an operating mechanism drives a rod of the cylinder through an intermediate transmission structure, so that the dynamic end contact in the piston is driven by the rod to contact or be away from the static arc contact to realize the closing and opening movements of the circuit breaker, and the novel arc extinguishing contact structure is characterized in that the static arc contact is sequentially divided into a thin section with a diameter phi 1, a transition section with a diameter phi 2 and a thick section with a diameter phi 3 from the direction away from the dynamic end contact to the direction close to the dynamic end contact, the phi 1< 3< phi 2, and the phi 2 is adapted to the throat diameter of the main nozzle, the static arc contact is arranged on the bracket, the bracket is arranged in the static support, the end part of the static support is provided with a contact ring matched with the main nozzle, the transition section, the thick section and part of the thin section of the static arc contact are positioned in the contact ring, and a cylinder is arranged in a space enclosed by the bracket and the static support.

Preferably, the smooth part of the cylinder is provided with an opening, when the main nozzle is fully opened, the pressure difference between the gas between the cylinder and the static support and the gas flowing at high speed in the cylinder enables the fresh cooled SF6 gas between the cylinder and the static support to enter the cylinder through the opening, so as to cool down high-heat electric ions, realize the circular flow of the gas and accelerate the long arcing extinguishing of the electric arc.

Preferably, a flow dispersing cover is further arranged in the space enclosed by the bracket and the static support, the flow dispersing cover is sleeved outside the cylinder, and the flow dispersing cover is used for dispersing the thermal ions out and preventing the thermal ions from rebounding to a high potential area to cause breakdown discharge of the shell or the basin.

Preferably, a guide cone for guiding hot air to smoothly flow out of the arc extinguish chamber is further arranged in the space surrounded by the bracket and the static support, the flow of SF6 gas is accelerated by the guide cone, the temperature of hot ions is rapidly reduced, gas flow rebounding is prevented, and gas flow hedging is formed.

The invention adopts the static arc contact with variable radius to block the main nozzle in the pre-compression stage, so that the pressure of the cylinder is quickly established, and the nozzle is immediately unobstructed when the electric arc begins to appear. The cylinder is additionally provided with the holes, so that high-heat electric ions are cooled by using a siphon principle, gas circulation flow is realized, long arc extinguishing of electric arcs is accelerated, and better arc extinguishing performance is achieved. The flow guide cone and the flow dispersing cover added in the invention can prevent the thermal ions from rebounding to a high potential area to cause breakdown discharge of the shell or the basin, and have better safety performance.

The invention overcomes the defects of the prior art and can effectively improve the defects of the traditional arc extinguish chamber when different fault currents are cut off. The diameter of the throat of the main nozzle is in conflict when different fault currents are switched on and switched off, and the main nozzle can be used universally under different fault currents. The radius-variable static arc contact is simple to manufacture, and compared with a countermeasure for realizing the on-off of different fault currents on the market, the radius-variable static arc contact is convenient and simple and has lower cost. Compared with the contact structure of an arc extinguish chamber on the market, the contact structure has better arc extinguishing performance.

Drawings

FIG. 1 is a general structure of the present invention;

FIG. 2 is an enlarged partial view of part I of FIG. 1;

FIG. 3 is an enlarged view of a portion of the second section of FIG. 1;

FIG. 4 shows the closing position of the present invention;

FIG. 5 illustrates the point just-off position of the present invention;

FIG. 6 is a 10ms position just after dotting in the present invention;

FIG. 7 is a 20ms position just after dotting in the present invention;

FIG. 8 illustrates the open position of the present invention;

fig. 9 is a cartridge of the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

As shown in fig. 1 to fig. 3, the novel arc extinguishing contact structure for a gas arc extinguishing chamber of a high-voltage switch SF6 provided by the invention comprises a fixed contact part and a movable contact part.

The stationary contact portion includes a stationary seat 50 that fits over the insulating basin. The stationary support 50 is made of cast aluminum alloy, and the bracket 30 and the barrel 40 are assembled in the stationary support 50. The barrel 40 is an aluminum alloy product and is located in a space formed by the bracket 30 and the stationary base 50. The stationary arc contact 20 is mounted on the carrier 30. The static arc contact 20 is made of copper-tungsten alloy to ensure that the static arc contact has anti-arc burning capability when having reliable through-current capability, the static arc contact 20 is sequentially divided into a thin section with the diameter phi 1, a transition section with the diameter phi 2 and a thick section with the diameter phi 3 from the direction far away from the movable end contact 140 to the direction close to the movable end contact 140, the diameter phi 1 is less than phi 3 and less than phi 2, and the phi 2 is matched with the throat diameter of the main nozzle 70. In this example, Φ 1 is 25mm, and Φ 3 is 29 mm. The stationary support 50 is also fitted with a contact ring 10.

The moving arc contact part comprises a cylinder 110 and a moving end contact 140. The cylinder 110 is made of an aluminum alloy and includes a piston 130 and a rod 100, and the piston 130 is mounted on the rod 100. The tube 120 is fitted into the piston 130 of the cylinder 110. The movable end contact 140, the circular ring 170 and the small nozzle 150 are screwed on the piston 130. The moving end contact 140 is made of copper-tungsten alloy, so as to ensure that the moving end contact has arc burning resistance while having reliable through-current capacity. The piston 130 has a main nozzle 70 at an end thereof, and a small nozzle 150 is located in the main nozzle 70. The main nozzle 70 is made of polytetrafluoroethylene material, and in order to improve the arc ablation resistance of the main nozzle, additives such as boron nitride or molybdenum disulfide can be added into the polytetrafluoroethylene material. A small nozzle 150 provided at the end of the piston 130 presses the movable end contact 140 into the piston 130 by a pressing ring 160. The piston 130 is fitted over the tube 120. The rod 100 is assembled with the insulated pull rod 80 through the shaft pin 90 so that the insulated pull rod 80 can drive the movable end contact 140 to move. The operating mechanism drives the moving end contact 140 to contact or be away from the static arc contact 20 through the insulating pull rod 80 through an intermediate transmission mechanism consisting of the connecting rod 180, the crank arm 190 and the rotating shaft 200 so as to realize the closing and opening movement of the circuit breaker.

The static arc contact 20 is of a variable radius configuration in order to block the main orifice 70 during the pre-compression phase, allowing the cylinder 110 pressure to build rapidly, and the main orifice 70 to become immediately clear when the arc begins to appear. The thick section of the static arc contact 20 from the closing position (see fig. 4) to the just opened position is positioned at the throat of the main nozzle 70, so that the pre-compression is more sufficient, the pressure of the cylinder 110 is conveniently and quickly established, and the low-current short-arcing is favorably switched on and off. When the moving end contact 140 moves to the just-split position (see fig. 5), the thick section of the static arc contact 20 leaves the throat of the main nozzle 70, the thin section begins to locate at the throat of the main nozzle 70, and the arc begins to ignite. The main nozzle 70 throat flow gap begins to increase. When the moving end contact 140 moves to the position 10ms immediately after the tapping point (see fig. 6), the main port 70 is opened step by step, and the air flow starts to be ejected efficiently. When the movable end contact 140 moves to the position 20ms after the point of separation (see fig. 7), the main nozzle 70 is fully opened, the air flow starts to be efficiently sprayed out, a large amount of high-temperature electric ions are taken away, and the long arcing of the electric arc is finished and extinguished. The spring operating mechanism enters a buffering stage. After the long-time arcing of the electric arc is finished and extinguished, the spring operating mechanism enters a buffering stage, and the arc gap can maintain effective air blowing for a period of time until the brake opening is finished, which is shown in figure 9. The contradiction of the diameter of the throat of the main nozzle 70 when different fault currents are cut off is solved, and the cut-off of the different fault currents is realized.

A preferred embodiment is: as shown in fig. 9, an aperture 210 is added to the smooth portion of the barrel 40. After the opening 210 is added, when the moving end contact 140 moves to fully open the main nozzle 70 and the airflow starts to be ejected efficiently, the air flows at high speed in the cylinder 40. At this time, a pressure difference is formed between the gas in the cylinder 40 and the stationary holder 50 and the gas flowing at a high speed in the cylinder 40. After the opening 210 is added on the cylinder 40, according to the siphon principle, the pressure difference enables the fresh cooled SF6 gas between the cylinder 40 and the static support 50 to enter the cylinder 40 through the opening, so as to cool down the high-heat electric ions, and meanwhile, the gas circulation flow is realized, so that the long-time arc extinguishing of the electric arc is accelerated, and the arc extinguishing performance is better.

A preferred embodiment is: a guide cone T and a diffuser 60 are also arranged in the space formed by the bracket 30 and the static support 50. The deflector cone T is an aluminum stamping or may be cast with the stationary support 50. The diversion cone T can guide hot air to smoothly flow out of the arc extinguish chamber, and rebound is prevented. The diffuser 60 is a stainless steel stamping or is made of a rolled section. The diffuser 60 disperses the thermionic ions. The flow guide cone T and the flow dispersing cover 60 can play a role in preventing thermoelectric ions from rebounding to a high potential area to cause breakdown discharge of a shell or a basin.

Claims

1. A novel arc extinguishing contact structure of a high-voltage switch SF6 gas arc extinguishing chamber comprises a static arc contact (20) and a dynamic end contact (140), wherein the dynamic end contact (140) is sleeved outside a tube (120), the tube (120) is arranged on a piston (130) of a cylinder (110), a small nozzle (150) arranged at the end part of the piston (130) presses the dynamic end contact (140) in the piston (130) through a pressing ring (160), the end part of the piston (130) is also provided with a main nozzle (70), the small nozzle (150) is positioned in the main nozzle (70), an operating mechanism drives a rod (100) of the cylinder (110) through an intermediate transmission structure, so that the dynamic end contact (140) in the piston (130) is driven by the rod (100) to be in contact with or be far away from the static arc contact (20) to realize the closing and opening movements of a circuit breaker, and the opening movements of the circuit breaker, and is characterized in that the static arc contact (20) is sequentially divided into thin sections with the diameter phi 1 from the direction far away from the dynamic end contact (140) to the dynamic end contact (140), The diameter of the transition section is phi 2 and the diameter of the thick section is phi 3, phi 1 is less than phi 3 and is less than phi 2, phi 2 is adaptive to the throat diameter of the main nozzle (70), the static arc contact (20) is arranged on the bracket (30), the bracket (30) is arranged in the static support (50), the end part of the static support (50) is provided with a contact ring (10) matched with the main nozzle (70), the transition section, the thick section and part of the thin section of the static arc contact (20) are positioned in the contact ring (10), and a cylinder (40) is arranged in a space enclosed by the bracket (30) and the static support (50);

And an opening (210) is formed in the smooth part of the cylinder (40), when the main nozzle (70) is completely opened, the pressure difference formed by the gas between the cylinder (40) and the static support (50) and the gas flowing at high speed in the cylinder (40) enables the fresh cooled SF6 gas between the cylinder (40) and the static support (50) to enter the cylinder (40) through the opening (210), so that high-heat electric ions are cooled, the circulating flow of the gas is realized at the same time, and the long arcing extinguishment of the electric arc is accelerated.

2. The novel arcing contact structure for the gas extinguishing chamber of the high-voltage switch SF6 according to claim 1, wherein a current-dissipating cover (60) is further disposed in the space enclosed by the bracket (30) and the static support (50), the current-dissipating cover (60) is sleeved outside the barrel (40), and the current-dissipating cover (60) dissipates thermal ions to prevent the thermal ions from rebounding to a high potential area to cause breakdown discharge of the housing or the basin.

3. The novel arcing contact structure for the high-voltage switch SF6 gas extinguishing chamber according to claim 1, wherein a guiding cone (T) for guiding the hot gas flow to smoothly flow out of the extinguishing chamber is further disposed in the space surrounded by the bracket (30) and the static support (50), the guiding cone (T) accelerates the flow of SF6 gas, the temperature of the hot ions is rapidly reduced, the gas flow is prevented from rebounding, and the opposite impact of the gas flow is formed.