RU2517688C2 - Hybrid gas-blast circuit breaker for switchgear with sf6 gas insulation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: circuit breaker comprises fixed part with arc contact part, and moving part with cylinder. It incorporates piston fitted in cylinder, blow chamber and heat expansion chamber composed by separation wall. Besides, it includes working electrode extending through piston inner part and cylinder. Besides, moving part comprises arc contact part of moving part to be displaced right up to fixed part arc part. One side surface of separation wall is equipped with moving valve including tight-contact part and moving part. Tight-contact part is displaced by pressure difference and tightly pressed against the separation wall. Moving part extending from tight-contact part allows working electrode passage there through and expansion chamber opening/closure.

EFFECT: reliable arc quench with no gas pressure drop.

3 cl, 5 dwg

Description

FIELD OF THE INVENTION

The invention relates to an extinguishing type gas hybrid switch for a gas-insulated switchgear. In particular, the gas switch must be able to reliably eliminate the arc when the fault current is interrupted without any loss of pressure extinguishing the arc gas.

State of the art

In general, a gas-insulated switchgear includes a circuit breaker, a current transformer, a line disconnector / earthing switch, a bus disconnector / earthing switch, and the like. The gas switch installed in the power line opens and closes during normal operation to check the units and lines, and in the event of an accident in the power line interrupts the fault current for safe protection of the lines and units of consumers.

Further, in the gas circuit breaker, which is a device for interrupting the fault current, the extinction of the arc arising in the gas medium between two points of contact is made by gas.

Such gas switches according to the type of arc extinction are divided into blow, rotary, thermal expansion, hybrid extinguishing, etc. In the gas circuit breaker in general use as an arc extinguishing gas is used sulfur hexafluoride (SF _6).

Of these types of switches, blasting is the type in which, when the fault current is interrupted, the arc-extinguishing gas is compressed in the compression chamber inside the switch using an external driving force, and the compressed gas is blown into the gap to extinguish the arc. A thermal expansion switch is a type of switch in which the heat of an arc that occurs when the fault current is interrupted is accumulated in the thermal expansion chamber (at this time the pressure rises) and the gas is blown into the gap under pressure increased by the accumulated heat. The switch obtained by combining the two types described above is a quenching type hybrid switch.

Gas switches with hydraulic and pneumatic drives (which are mostly blast type) require a drive unit and a high interruption rate, which leads to mechanical damage to the gas switch, increase its size and increase manufacturing cost.

Accordingly, a damping-type hybrid gas switch has been developed that can break ultra-high voltage and high current circuits at a lower speed using a small driving force (the driving force created by the motor and spring). As shown in FIG. 1, a quench-type hybrid gas switch includes a fixed part 10 and a movable part 20. The fixed part 10 includes a screen 11, a main contact part 12 of the fixed part mounted inside the screen 11, and an arc contact part 13 of the fixed part located in the center of the main contact part 12 of the fixed part.

The movable part 20 includes a cylinder 21, a piston 22 mounted so that it is fixed in the cylinder 21, a blow chamber 24 and a thermal expansion chamber 25, which are formed by a partition wall 23 placed between them, and are filled with a gas extinguishing arc.

The movable part 20 of a gas circuit breaker of this type is equipped with a working electrode 26, which passes through the piston 22 and goes to the end of the cylinder 21. The nozzle 27 goes to the end of the cylinder 21 and is connected to it in the area of the end of the working electrode 26.

The arc contact portion 26a of the movable portion is formed at an end portion of the working electrode 26 of the movable portion 20.

An outlet 22a is formed in the end surface of the piston 22, and this outlet 22a is equipped with a safety valve 22b. Further, an outlet 23a is formed in the partition wall 23, and this outlet 23a is equipped with a check valve 23b.

As another structure, as shown in FIG. 2, a known structure is used in which, instead of forming a partition wall 23 inside the cylinder 21, a sleeve 28 is formed separately from the structure of the moving part 20, so that the blow chamber 24 and the thermal expansion chamber 25 are connected to each other with a friend.

In the extinguishing type of hybrid gas switch described, having such a design in which the movable part 20 is separated from the fixed part 10 during the start of interruption or during the flow of a small current, the blast chamber 24 inside the cylinder 21 is compressed by a fixed piston 22, so that the pressure increases. Then, when the check valve 23b installed in the outlet 23a of the separation wall 23 is opened, the compressed arc extinguishing gas contained in the blowing chamber 24 passes through the thermal expansion chamber 25, and the arc arising between the arc contact portion 26a of the movable part of the working electrode 26 and the arc contact part 13 of the fixed part is eliminated (action extinguishing the arc).

Since the arc arising in the gap when a large current is interrupted is large, a large amount of heat is accumulated in the thermal expansion chamber 25, so that the pressure increases. Accordingly, the arc can be eliminated by a quenching gas under high pressure.

A conventional extinguishing-type hybrid gas switch has a structure in which a compressed arc-extinguishing gas, leaving the blowing chamber 24, necessarily passes through the thermal expansion chamber 25. Sometimes, the relatively high pressure of the blasting chamber 24 becomes equal to the pressure of the thermal expansion chamber 25 when gas passes through it, which causes the problem of reducing the pressure of the gas extinguishing the arc, as a result of which the efficiency of breaking the fault current is reduced.

Further, as shown in FIG. 2, even in the design of a parallel quenching hybrid gas circuit breaker, the compressed arc quenching gas exits the blast chamber 24 through the sleeve 28 and passes separately to the thermal expansion chamber 25 and to the nozzle 27. Accordingly, the compressed arc quenching gas can injection is not effective, so that the removal of the arc that has arisen in the nozzle 27 may not be effective.

Disclosure of invention

Technical challenge

An object of the present invention is to provide an apparatus for discharging gas separating a blast chamber and a thermal expansion chamber from one another by a movable valve according to the conditions for breaking the fault current.

Technical solution

According to the invention, a quenching type hybrid gas switch for a gas-insulated switchgear is provided, comprising a fixed portion including an arc contact portion; a movable part including a cylinder, a piston mounted inside the cylinder, a blow chamber and a thermal expansion chamber formed by a dividing wall, and a working electrode passing through the inside of the piston and cylinder and including an arc contact part, which can be brought close to the fixed arc contact part parts, and one side surface of the separation wall is equipped with a movable valve, including an adhering part, moved by the differential pressure and adjacent to the separation wall ke, and a movable part extending from the adhering portion which permit the passage therethrough of the working electrode, and the opening and closing of the thermal expansion chamber.

The adhering part forming the movable valve may be equipped with one or more outlets through which the arc-extinguishing gas is discharged into the blow chamber, and each outlet may be connected to a check valve, and a passage opening may be formed in the moving part.

The thermal expansion chamber can be equipped with an outlet that exhausts the arc-extinguishing gas to the fixed part as one surface of the thermal expansion chamber, and the outlet can be equipped with a check valve, and the support tube can be made so that the movable part of the movable valve is sliding, and the support tube may be equipped with an outlet opening and closing the movable part of the movable valve.

Advantages of the Invention

According to the invention, when conditions associated with the fault current, i.e. whether a weak current, medium current or high current is interrupted, the movable valve is automatically biased by the pressure drop, as a result, the arc-extinguishing gas is blown out, eliminating the arc. Accordingly, when the fault current is interrupted, the compressed gas extinguishing the arc is blown into the nozzle gap without any pressure loss, thereby reliably eliminating the arc.

Brief Description of the Drawings

1 is a diagram illustrating an example of a (sequential) quenching type gas hybrid switch according to the prior art.

2 is a diagram illustrating an example of a (parallel) quenching type gas hybrid switch according to the prior art.

FIG. 3 is a diagram illustrating an example of an extinguishing type gas hybrid switch according to the present invention.

4 is a diagram illustrating a state in which a quench-type hybrid gas circuit breaker according to the present invention is activated when the fault current is small.

5 is a diagram illustrating a state in which a quench-type hybrid gas circuit breaker according to the present invention is triggered when a fault current is large.

The implementation of the invention

Below, examples of embodiments of the present invention are described in detail with reference to the accompanying drawings.

Elements repeating the known are indicated by the same reference numbers, and their detailed description is omitted. New items received new numbers and are described in detail.

FIG. 3 is a diagram illustrating an example of an extinguishing type gas hybrid switch according to the invention. As shown in the drawings, one side surface of the partition wall 23 is equipped with a movable valve 30.

The movable valve 30 includes an adhering part 31 that is adjacent to the partition wall 23 and a movable part 32 having a tubular shape (or sleeve shape) extending from the adhering part 31 and allowing the working electrode 26 to pass. In the adhering part 31 there is one or more outlet openings 31a formed parallel to the periphery, and check valves 31b are connected to these outlets 31a.

The movable part 32 is equipped with a passage hole 32a and is formed in the form of a cylindrical pipe, so that the movable part is connected to the working electrode 26 so as to be able to move along its outer peripheral surface.

One side surface of the thermal expansion chamber 25 is equipped with an outlet 25a and a check valve 25b facing the stationary part 10.

The thermal expansion chamber 25 is equipped with a support tube 25c that allows the movable part 32 of the movable valve 30 to slide along it, and an outlet 25a that opens and closes with the movable part 32 formed on the front side of the support tube 25c (in the direction of the fixed part 10). According to an embodiment providing such a structure for interrupting the load current or weak fault current as shown in FIG. 4, the movable part 20 is separated from the fixed part 10 by a drive unit (not shown), and an arc arises in the gap between the arc contact part 13 of the fixed part and an arc contact portion 26a of the movable portion. Since the pressure inside the blasting chamber 24 formed in the cylinder 21 exceeds the pressure inside the thermal expansion chamber 25, the movable valve 30, mounted on one side surface of the dividing wall 23, is shifted to the right along the outer surface of the working electrode 26 in its longitudinal direction. Due to movement of the movable valve 30, the outlet 25d formed in the support tube 25c of the thermal expansion chamber 25 is blocked, and the check valve 31b located in the adherent portion 31 of the movable valve 30 is opened.

Accordingly, the arc extinguishing gas contained in the blowing chamber 24 passes through the open outlet 23a of the separation wall 23 and through the check valve 31b installed in the outlet 31a of the adherent portion 31 of the movable valve 30. Then, the arc extinguishing gas passes between the movable part 32 of the movable valve 30 and a working electrode 26; By injecting gas between these elements, an action is taken to eliminate the arc in the gap between the nozzle 27 and the arc contact part 13 of the fixed part.

In other words, the arc-quenching gas from the blasting chamber 24 enters directly into the gap between the nozzle 27 and the arc contact part 13 of the fixed part without passing through the thermal expansion chamber 25, thereby reliably acting on the arc-quenching action without any pressure loss.

On the other hand, when a large current is interrupted, a large arc arises in the gap, as shown in FIG. 5, and as the amount of heat of the arc accumulated in the thermal expansion chamber 25 increases, the pressure increases. At this time, since the pressure inside the thermal expansion chamber 25 becomes higher than the pressure inside the blowing chamber 24, the movable valve 30 is shifted to the left, pressing against the partition wall 23. Accordingly, the outlet 25d of the thermal expansion chamber 25 is opened, so that the compressed arc quenching gas quickly discharged and blown into the gap. At the same time, a check valve 25b mounted on one side of the thermal expansion chamber 25 also opens, and the arc quenching gas is discharged so as to eliminate the arc arising in the gap.

Although at this time the pressure inside the blasting chamber 24 is less than in the chamber 25 of thermal expansion, but thanks to the operation of the drive unit, the pressure is constantly increasing. And when the pressure reaches or exceeds a predetermined value, the safety valve 22b installed in the piston 22 is opened, so that the arc quenching gas passes through the outlet 22a, and the pressure decreases.

Further, when the arc occurs at a high pressure that is maintained at the moment of breaking the medium current circuit (this is the current at which the pressure in the blasting chamber 24 exceeds the pressure in the thermal expansion chamber 25 when the current becomes zero when the short circuit current is interrupted), the movable valve 30 is shifted towards the blast chamber 24, so that the outlet 25d of the thermal expansion chamber 25 opens and the pressure inside the thermal expansion chamber 25 rises. When the average current becomes zero, the movable valve 30 is biased towards the thermal expansion chamber 25, so that the outlet 25d of the thermal expansion chamber 25 is blocked. Accordingly, the arc extinguishing gas that is compressed inside the thermal expansion chamber 25 opens the check valve 25b located in the thermal expansion chamber 25, so that the arc extinguishing gas compressed inside the thermal expansion chamber 25 is blown into the nozzle 27 to eliminate the arc in the gap.

Although exemplary embodiments of the present invention have been shown and described, it will be understood by one skilled in the art that numerous modifications of its form and details may be proposed without departing from the spirit of the present invention and its scope limited by the appended claims.

According to the invention, when conditions associated with the fault current, i.e. whether a low current, medium current or high current is interrupted, the movable valve is automatically biased by the pressure drop, as a result of which the gas extinguishing the arc is blown, thereby extinguishing the arc. Accordingly, when the fault current is interrupted, the compressed gas extinguishing the arc is blown into the nozzle gap without any pressure loss, thereby reliably eliminating the arc.

Claims (3)

1. An extinguishing-type hybrid gas switch for a gas-insulated switchgear, comprising a fixed part (10) including an arc contact part (13); a movable part (20) including a cylinder (21), a piston (22) mounted inside the cylinder (21), a blow chamber (24) and a thermal expansion chamber (25) formed by a partition wall (23), and a working electrode (26) passing through the inner part of the piston (22) and cylinder (21), as well as including the arc contact part (26a), which can be brought close to the arc contact part (13) of the fixed part, and one side surface of the separation wall (23) is equipped a movable valve (30) including an adhering part (31) to be moved ohm pressure and adjacent to the dividing wall (23) and a movable part (32) extending from the adhering portion (31) and permit the passage therethrough of the working electrode (26) and opening and closing the chamber (25) of thermal expansion. 2. The switch according to claim 1, characterized in that the adhering part (31) forming the movable valve (30) is equipped with one or more outlet openings (31a), releasing the arc-quenching gas from the blast chamber (24), each outlet (31a) is connected to a check valve (31b), and a through hole (32a) is formed in the movable part (32). 3. The switch according to claim 1, characterized in that the thermal expansion chamber (25) is equipped with an outlet (25a), which releases the arc-quenching gas to the fixed part (10) as one surface of the thermal expansion chamber (25), and the outlet (25a) is equipped with a check valve (25b), and a support tube (25c) is provided that slides the movable part (32) of the movable valve (30), while the support tube (25c) is equipped with an outlet (25d) that can be opened and closed the movable part (32) of the movable valve (30).

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