RU2498439C1 - Vacuum dead-tank circuit breaker - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: vacuum dead-tank circuit-breaker contains at least one gas-filled tank with a hollow insulator inside thus forming a sealed chamber and vacuum arc-quenching chamber (VAQC) consisting of insulator with two flanges, at that one flange is connected hermetically to the first flange of the hollow insulator. Inside VAQC insulator there are moving and fixed contacts and bellows connected hermetically to the flange of VAQC insulator; insulation traction is connected to the moving contact; it passes through VAQC bellows and moving unit of the hollow insulator. At that the second flange of the hollow insulator is connected hermetically to gas-filled tank of the circuit-breaker.

EFFECT: increasing reliability of the circuit-breaker, its environmental safety, expanding application scope to areas with severe climatic conditions.

5 cl, 2 dwg

Description

The invention relates to electrical engineering, namely to switching devices of high voltage.

SF6 gas has excellent electrical insulating and quenching properties, due to which compact switchgears were created, significantly reducing the size of substations.

Gas-insulated gas circuit breakers are known, including gas-insulated switchgear complete circuit breakers (GIS), containing a grounded sealed enclosure with a gas-insulated arcing device, which is mounted on the supporting insulation inside this enclosure, electrical inputs to the housing and a drive with a transmission mechanism to the arcing device.

However, SF6 has its drawbacks. When the switch is operated, toxic products are formed in it, and special technology for their disposal is required. The increasing use of SF6 equipment leads to an increase in the production of SF6 gas, which ultimately ends up in the atmosphere, which is fraught with environmental problems. In addition, its use in areas with harsh climates is difficult due to condensation of SF6 gas at low temperatures.

Known tank switch with gas insulation, in which a vacuum arcing chamber (WDC) is used as a switching element (patent WO No.2011052010, class H02B 13/02 publ. 05/05/2011), located in a gas environment.

The vacuum interrupter chamber consists of an insulating body (glass, ceramics), inside of which are movable and fixed contacts, a bellows to ensure the movement of the movable contact, and an insulating rod.

Due to the insufficient mechanical strength of the insulating casing of the VDK and the bellows, the gas pressure in such a tank switch must be very low and close to atmospheric pressure. It is also necessary to reduce the effort while ensuring the required speed of the movable contact of the VDK and, accordingly, the use of a drive with lower energy.

Low gas pressure leads to a loss of electrical strength of the gas insulation, which leads to a significant increase in the size of the tank switch.

Closest to the proposed solution is a tank vacuum switch (hereinafter referred to as the switch), which also uses a vacuum arcing chamber (US Patent No. 4,458,119, class H01H 33/04 publ. 07/03/1984), containing at least one gas-filled a tank with a hollow insulator forming an airtight chamber inside it, a vacuum arcing chamber (VDK) consisting of an insulator with two flanges, one of the flanges being hermetically sealed with the first flange of the hollow insulator, with the VDK insulators located odvizhnogo and a stationary contact and a bellows sealingly connected to the flange VAQC insulator, insulating traction, integrated with the movable contact and extending through the bellows and the movable seal VAQC hollow insulator assembly.

The circuit breaker tank is filled with SF6 gas at pressures up to 0.5 MPa. In order to protect the VDK from the effects of the pressure of the gas, it is placed in the specified pressurized chamber. The disadvantage of this solution is the lack of reliability of the switch. The VDK case and the sealed chamber are structurally completely autonomous and do not have a connection with the switch tank. Over time, there will be leakage of SF6 gas through the movable seal into the sealed chamber, which will increase the pressure inside it and create a threat to the functioning of the VDK (mechanical load on the bellows and the VDK case, reducing the speed of the moving contact). Since the sealed chamber is not connected to the circuit breaker tank, protection against increasing pressure inside it is possible only with a significant complication of the design, leading to a decrease in the reliability of the circuit breaker.

It is known that the use of SF6 gas in circuit breakers at the pressure necessary to turn off short-circuit currents limits the use of the latter in areas with low ambient temperatures. For these purposes, use a mixture of gas with other gases. However, in this case, the total pressure of the mixture is usually significantly higher than that which occurs in purely SF6 circuit breakers. In this case, the application of the considered solution further reduces the reliability of the circuit breaker.

The technical result of the invention is to increase the reliability of the tank vacuum circuit breaker, its environmental safety and environmental safety, as well as expanding the scope of application of circuit breakers in areas with severe climatic conditions.

The specified technical result is achieved in that in a tank vacuum circuit breaker containing at least one gas-filled tank, with a hollow insulator forming an airtight chamber inside it, a vacuum arcing chamber (VDC), consisting of an insulator with two flanges, one of flanges are hermetically fastened to the first flange of the hollow insulator, with movable and fixed contacts and a bellows located inside the VDK insulator, hermetically connected to the VDK insulator flange, the insulating rod is fastened th to the movable contact, and extending through the bellows and the movable seal VAQC hollow insulator assembly, new is that the second flange of the hollow insulator and hermetically bonded to gas-filled switch tank.

A vacuum interrupter chamber is located inside the hollow insulator, while its first flange is hermetically fastened to the flange of the insulator VDK from the side of its fixed contact.

The vacuum interrupter chamber is located outside the hollow insulator, while its first flange is hermetically fastened to the flange of the insulator VDK from the side of its movable contact.

Hollow insulator consists of several parts

The sealed chamber is equipped with a safety device.

The use of the specified hollow insulator, fastened to the switch tank by a second flange, forms a sealed chamber isolated from the rest of the gas-filled tank (hereinafter referred to as the tank), inside which the air-tight compressor can be located. In this case, inside it, the gas pressure is kept constantly low, which ensures the normal functioning of the air-gas compressor. For the same purpose, the sealed chamber may be filled with insulating liquid. In the remaining volume of the tank, gas insulation under increased pressure can be used to reduce its dimensions. Prevention of increased gas pressure inside the sealed chamber is provided by a safety device. Since the second flange of the sealed chamber is connected to the tank, the safety device has an outlet through the wall of the tank into the environment.

A variant with the arrangement of the airborne insulator outside the hollow insulator is also possible if the material of the insulator insulator can withstand increased gas pressure. In this case, a sealed chamber with a lower pressure ensures the reliable operation of the bellows, the movable seal and the drive of the airborne collar.

The sealant chamber insulator may be made of several parts. In this case, it is simplified to carry out current collection from the flange of the VDK associated with the movable contact.

Figure 1 presents an example of a tank vacuum circuit breaker with a VDK located inside a hollow insulator.

Figure 2 shows an example of a tank vacuum circuit breaker with a VDK located outside the hollow insulator.

The tank vacuum switch contains a metal gas-filled tank 1. If the tank switch consists of several arcing breaks, then it can consist of several tanks. Inside the tank are placed: a hollow insulator 2 (Fig. 2), which may consist of several parts 2a and 2b (Fig. 1), with two flanges 3, 4; vacuum interrupter chamber 5; insulation rod 6 associated with the drive of the switch. In the tank of the switch are insulators of high-voltage bushings 7. The hollow insulator (Fig. 1) forms a sealed chamber, inside of which there is a VDK consisting of an insulator 8 with two flanges 8a, 8b, a movable 9 and a fixed 10 contacts, a bellows 11. The bellows is hermetically connected to flange 86 of the insulator VDK. The insulating rod 6 is bonded to the movable contact of the VDK and passes through the VDK bellows and the movable seal assembly 12 of the hollow insulator. The sealed chamber has a safety device 13 that maintains the required pressure inside the hollow insulator, for example, a safety valve.

The hermetic chamber is formed due to the fact that the first flange 3 of the hollow insulator 2 is hermetically fastened to the flange 8a of the VDK insulator from the side of its fixed contact 10, and its second flange 4 is connected to the switch tank. Here, the VDK is located inside the sealed chamber (figure 1). But it can be located outside the sealed chamber (figure 2). Then the first flange 3 of the hollow insulator is hermetically fastened to the flange 86 of the insulator VDK from the side of its movable contact 9, and its second flange 4 is connected to the switch tank.

Outside the hollow insulator, the gas pressure can be any in accordance with the specific technical requirements for the circuit breaker in terms of ambient temperature and size. Inside this insulator in a sealed chamber, the pressure is selected from the condition of the permissible pressure for reliable operation of the air-breathing apparatus.

The operation of switching the switch on and off is performed by transmitting, through the insulating rod 6, passing through the bellows 11 and the movable seal assembly 12, a movement impulse from the drive to the movable contact of the VDK 9. The bellows also ensures the tightness of the vacuum interrupter chamber itself and does not experience dangerous mechanical loads, since inside it, as well as inside a hollow insulator, the gas pressure is low or the gas is replaced by an insulating liquid. The same can be said about the rolling seal assembly.

In the proposed solution, gas mixtures with a higher pressure can be used as the main insulation. And the use of compressed air as an insulating gas will provide an unlimited climatic zone of operation of the circuit breaker and guarantee its full environmental cleanliness.

At the same time, the use of a safety device will ensure the protection of the airborne complex against dangerous high pressure.

Claims (5)

1. Tank vacuum circuit breaker containing at least one gas-filled tank, with a hollow insulator forming an airtight chamber placed inside it, a vacuum arcing chamber (VDK), consisting of an insulator with two flanges, one of the flanges being hermetically fastened to the first flange hollow insulator, with movable and fixed contacts and a bellows located inside the VDK insulator, hermetically connected to the flange of the VDK insulator, an insulating rod fastened with a movable contact and passing through the VD bellows K and the assembly of the movable seal of the hollow insulator, characterized in that the second flange of the hollow insulator is also hermetically fastened to the gas-filled switch tank. 2. Tank vacuum circuit breaker according to claim 1, characterized in that the vacuum arcing chamber is located inside the hollow insulator, while its first flange is hermetically fastened to the flange of the insulator VDK from the side of its fixed contact. 3. Tank vacuum circuit breaker according to claim 1, characterized in that the vacuum arcing chamber is located outside the hollow insulator, while its first flange is sealed to the flange of the insulator VDK from the side of its movable contact. 4. Tank vacuum circuit breaker according to claim 1, characterized in that the hollow insulator consists of several parts. 5. Tank vacuum circuit breaker according to claim 1, characterized in that the sealed chamber is equipped with a safety device.

Images