Switch-disconnectors for clean dry air insulated metal enclosed switchgear

Abstract

The load switch for clean dry air insulated metal enclosed switchgear belongs to the technical field of power switches, and overcomes the problems of poor arc extinguishing ability, complex structure, high cost, many components and large volume of clean dry air insulated switchgear in the prior art. The invention is characterized in that a locking pin is installed on the upper static contact, an arc extinguishing chamber driving plate is fixedly connected to the main knife, an auxiliary knife is fixedly installed on the upper part of the vacuum arc extinguishing chamber assembly, the vacuum arc extinguishing chamber assembly is installed in parallel between two main knives and can rotate relative to the two main knives, and a sliding pin is installed on the lower part of the vacuum arc extinguishing chamber assembly. The beneficial effects are simple structure, low cost and small volume. Moreover, since the vacuum arc extinguishing chamber only completes the breaking of load current, the carrying of load current and the closing of short-circuit current are completed by the main knife, thereby eliminating the internal shielding tube and the internal magnetic field system for breaking short-circuit current, and the external size of the vacuum arc extinguishing chamber is reduced by 70% compared with the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of power switches, and in particular relates to a load switch for clean dry air insulated metal enclosed switch equipment. Background Art

[0002] The load switch is an important electrical component on the gas-filled ring network switch cabinet. Its functions include opening and closing the load current and closing the short-circuit current, and it plays a very important role in the entire power supply system. In the prior art, there are three types of load switches used for gas-insulated metal-enclosed switchgear. The first type is a knife-type load switch that uses SF6 gas as an insulating and arc-extinguishing medium. The arc generated during the opening and closing of the switch is extinguished by SF6 gas, thereby completing the opening and closing of the circuit. However, since SF6 is a greenhouse gas and a gas for emission reduction stipulated in the Kyoto Protocol, this type of load switch product has the problem of causing pollution and damage to the environment, and at the same time has an adverse effect on the normal operation of electrical equipment and people's health. The second type is a compressed air load switch. During the opening and closing process of the switch, the high-pressure gas generated by the movement of its own piston blows out the arc. It has a complex structure and high cost. In addition, the sealing problem of the high-pressure gas and the burning problem of the arc extinguishing contacts are difficult to solve. Regular maintenance or replacement of the arc contacts is required. The third type is a vacuum load switch, which uses the vacuum arc extinguishing principle to extinguish the arc during the opening and closing process. The vacuum arc extinguishing chamber fracture of this load switch cannot be used as a safety fracture, and an isolating switch needs to be connected in series as a safety fracture. It has many components, a large size, a complex structure and a high cost.

[0003] The utility model with application number CN201620690543.5 (CN205811405U) provides an environmentally friendly dry air insulated ring network cabinet, which includes a ring network cabinet, a cable chamber arranged in the ring network cabinet, a stainless steel gas box arranged in the ring network cabinet, and a three-position disconnector arranged in the ring network cabinet. The cable chamber is arranged at the inner bottom of the ring network cabinet, and a pressure relief chamber is arranged at the inner bottom of the ring network cabinet at the rear side of the cable chamber. A vacuum load switch is arranged at the upper part of the pressure relief chamber. The three-position disconnector is arranged at the upper part of the vacuum load switch and is connected to the vacuum load switch. A first top outlet sleeve is arranged at the upper part of the ring network cabinet, and the first top outlet sleeve extends into the ring network cabinet and cooperates with the three-position disconnector. An operating mechanism for controlling the vacuum load switch is arranged on one side of the ring network cabinet, and a conductive connecting rod is connected to the lower part of the vacuum load switch, and a second top outlet sleeve is connected to the lower part of the conductive connecting rod. The utility model adopts compressed dry air as the insulating medium and has the characteristics of green environmental protection. However, the utility model encloses primary components such as vacuum load switches, circuit breakers and three-position disconnectors in a housing with dry air as the insulating medium, that is, all high-voltage components are sealed in a white steel gas box, and the three-position disconnector used in the ring network cabinet is connected in series with the vacuum load switch in the gas box. The three-position disconnector and the vacuum load switch are respectively operated by mechanisms outside the gas box, resulting in a complex structure and high cost.

[0004] The invention with application number CN200710019229.X (CN101030500A) discloses a vacuum load switch for high-voltage fixed switch cabinet, which includes an upper outlet of a knife switch, an isolating knife switch, an isolating knife seat, a vacuum interrupter, a lower moving contact, a lower outlet seat, a connecting busbar, a cable outlet board, an isolating knife insulating rod assembly, an interrupter insulating rod assembly, an operating mechanism and a grounding device. The isolating knife switch is connected in series with the vacuum interrupter, the isolating knife insulating rod assembly and the interrupter insulating rod assembly are both connected to the operating mechanism by transmission, the isolating knife seat, the vacuum interrupter and the lower outlet seat are sealed together, the hinged end of the isolating knife switch is provided with a finger spring, the finger spring contacts the isolating knife switch and the isolating knife seat respectively, and the moving end of the vacuum interrupter is provided with a finger spring, the finger spring contacts the lower moving contact and the lower outlet seat respectively. The invention meets environmental protection requirements and has good insulation capacity, but has a complex structure, large size, high cost, and is not conducive to product miniaturization.

[0005] The utility model with application number CN201220171659.X (CN202957217U) discloses a "disconnector and vacuum circuit breaker composite system", wherein the disconnector and the vacuum circuit breaker are connected in series to form a composite switch system associated with the disconnection break and the vacuum interrupter break, wherein the disconnection break is a spaced area between the disconnector knife of the disconnector and the tail end of the moving contact of the vacuum circuit breaker, and the vacuum interrupter break is another spaced area between the moving contact and the static contact of the vacuum circuit breaker. According to the description of the utility model, the vacuum circuit breaker of the utility model is provided with a limit plate, and a trip spring is provided between the limit plate and the moving contact. The utility model uses the trip spring to drive the vacuum interrupter to trip, and drives the disconnector moving contact to move synchronously during the vacuum interrupter trip process. After the vacuum interrupter is in place, the trip spring stops working externally, and the disconnector moving contact is in place by inertia. The problem is that, since the vacuum interrupter has a requirement for the opening speed, when the opening spring drives the moving contact of the vacuum interrupter and the moving contact of the disconnector to move at the same speed at the same time, the opening spring is required to provide more energy than operating only the moving contact of the vacuum interrupter. The energy of the opening spring is provided and stored by the disconnector mechanism during the closing process, which makes the disconnector operating mechanism more complicated and more expensive. Since there will be differences in the opening speed and friction force each time, it is difficult for the disconnector moving contact to rely on inertial opening to ensure that each phase can be reliably opened synchronously in place each time. The difference will cause the insulation capacity of the isolation fracture to decrease, and even lead to a breakdown discharge accident. In addition, the structure described in the utility model is that the disconnector and the vacuum interrupter are connected in series outside the disconnector, and the linear motion of the moving contact of the disconnector is used to drive the linear motion of the moving contact of the vacuum interrupter to achieve the circuit closing. The problem is that since the vacuum interrupter needs to complete the arc extinguishing function, the opening and closing speed is required to be faster, which will cause the disconnector to output a larger stroke and have a very high speed, and the operating mechanism of the disconnector will become very complicated and the cost will increase. Summary of the invention

[0006] The problem to be solved by the present invention is to overcome the shortcomings and defects of the prior art and to provide a load switch for clean dry air insulated metal enclosed switchgear that meets environmental protection requirements, improves the arc extinguishing ability of clean dry air insulated switchgear, and has a simple structure, low cost and is conducive to product miniaturization.

[0007] The load switch of the present invention is a three-phase structure, each phase includes an upper static contact, a main knife, a vacuum arc extinguishing chamber assembly, a lower static contact and a fixed insulating bracket, the upper static contact and the lower static contact are connected to the fixed insulating bracket, the main drive shaft is installed in the circular holes of the three lower static contacts, a locking pin is installed on the upper static contact, an arc extinguishing chamber drive plate is installed on the main knife, the arc extinguishing chamber drive plate is fixedly connected to the main knife, the main knife is pressed on the upper static contact by an upper tension spring, and is pressed on the lower static contact by a lower tension spring, the An auxiliary knife is fixedly installed on the upper part of the vacuum arc chamber assembly. The vacuum arc chamber assembly is installed in parallel between the two main knives and can rotate relative to the two main knives. A sliding pin is installed at the lower part of the vacuum arc chamber assembly. A curved guide groove is provided on the arc chamber driving plate. When the vacuum arc chamber assembly rotates with the main driving shaft driven by the two main knives, the sliding pin slides back and forth along the curved guide groove on the arc chamber driving plate, so that the vacuum arc chamber assembly is respectively in the vacuum arc chamber closed position or the vacuum arc chamber open position.

[0008] The vacuum interrupter assembly comprises encapsulated silica gel, a vacuum interrupter, a reset spring hanging plate, a moving end outlet seat, a vacuum interrupter static contact and a vacuum interrupter moving contact. The upper end of the vacuum interrupter is connected to the auxiliary knife, the lower end of the vacuum interrupter is connected to the sliding pin through the moving end outlet seat, and a reset spring is hung on the reset spring hanging plate.

[0009] The main knife and the auxiliary knife are both made of copper plates.

[0010] The diameter of the vacuum interrupter static contact and the vacuum interrupter moving contact is 12-14 mm, and the opening distance between the vacuum interrupter static contact and the vacuum interrupter moving contact is 5-6 mm.

[0011] The outer diameter of the vacuum interrupter is 37 mm and the height is 64 mm.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The present invention connects the main switch and the vacuum interrupter in parallel to form a load switch, thereby solving the short-circuit current closing problem and the load current breaking problem of the load switch separately. The main switch completes the closing of the short-circuit current, and the vacuum interrupter completes the breaking of the load current, avoiding the problem of arc erosion of contacts in clean and dry air, and without the use of SF6 gas. The product structure is simple and the cost is low.

[0014] (2) In the present invention, each phase vacuum interrupter is installed between two main cutters. The vacuum interrupter is connected in parallel with the two main cutters. When closing the circuit, the main cutter and the vacuum interrupter rotate synchronously to complete the closing operation. When opening the circuit, the main cutter is separated first and reaches a safe distance. Since the circuit is connected by the vacuum interrupter, no arc is generated between the main cutter and the upper static contact. The vacuum interrupter is separated later. The arc is extinguished during the separation process of the vacuum interrupter. After the arc is extinguished, the vacuum interrupter returns to between the two main cutters. The external operating mechanism connected to it only needs to provide energy for the rotation of the main cutter. Therefore, the structure is simple and the cost is low.

[0015] (3) The three phases of the main switch of the present invention share the same main shaft and are synchronously operated by the external operating mechanism connected thereto. The opening and closing positions have fixed limit parts in the external operating mechanism, and the three phases have good synchronization, which can ensure that they are in the opening and closing positions reliably and accurately.

[0016] (4) Since the vacuum arc chamber of the present invention only completes the interruption of load current, the bearing of load current and the closing of short-circuit current are completed by the main knife. Therefore, compared with the prior art, the vacuum arc chamber of the present invention eliminates the internal shielding tube and the internal magnetic field system for short-circuit current interruption, reduces the diameter of the moving and static contacts inside the vacuum arc chamber, and reduces the opening distance of the moving and static contacts inside the vacuum arc chamber, thereby reducing the outer dimensions of the vacuum arc chamber. The outer diameter of the vacuum arc chamber is 37 mm and the height is 64 mm. Compared with the prior art, the volume is reduced by 70%. Therefore, the vacuum arc chamber assembly of the present invention is a miniaturized and simplified vacuum arc chamber with a simple structure, low cost, and small volume, which is conducive to the miniaturization of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 It is a structural schematic diagram of the main switch closing position and the vacuum interrupter closing position of the present invention.

[0019] Figure 3 It is a structural schematic diagram of the middle position of the main knife and the sub-gate position of the vacuum interrupter of the present invention.

[0020] Figure 4 It is a structural schematic diagram of the main switch opening position and the vacuum interrupter closing position of the present invention.

[0021] Figure 5 It is a schematic diagram of the structure of the vacuum interrupter assembly;

[0022] Figure 6 It is the assembly diagram of the main cutter, arc extinguishing chamber drive plate and main shaft.

[0023] In the figure:

[0024] 1. Upper static contact,

[0025] 2. Locking pin,

[0026] 3. Surgeon,

[0027] 4. Auxiliary knife,

[0028] 5. Vacuum interrupter assembly,

[0029] 5-1. Encapsulated silica gel, 5-2. Vacuum interrupter,

[0030] 5-2-1. Vacuum interrupter static contact, 5-2-2. Vacuum interrupter moving contact,

[0031] 5-3. Reset spring hanging plate, 5-4 moving end outlet seat,

[0032] 6. Return spring,

[0033] 7.Interrupter drive board,

[0034] 8. Curved guide groove,

[0035] 9. Sliding pin,

[0036] 10. Main drive shaft,

[0037] 11. Lower static contact,

[0038] 12.Fix the insulation bracket,

[0039] 13. Upper tension spring,

[0040] 14. Lower tension spring,

[0041] A. Vacuum interrupter is closed,

[0042] B. Vacuum interrupter chamber positions. DETAILED DESCRIPTION

[0043] like Figure 1 to Figure 6As shown, the load switch described in the present invention is a three-phase structure, each phase includes an upper static contact 1, two main blades 3, a vacuum interrupter assembly 5, a main drive shaft 10 and a lower static contact 11, the upper static contact 1 and the lower static contact 11 are connected to a fixed insulating bracket 12 by screws, the main drive shaft 10 is installed in the circular holes of the three lower static contacts 11, the main drive shaft 10 is a hexagonal shaft, one end of the main drive shaft 10 extends out to be connected to the operating mechanism, the main drive shaft 10 can rotate freely in the circular holes of the three lower static contacts 11, a locking pin 2 is installed on the upper static contact 1, and an interrupter drive plate 7 is fixedly connected to the two main blades 3 by rivets, the interrupter drive plate 7 and the main blade 3 are processed with hexagonal holes and are mounted on the main drive shaft 10 together, and rotate with the main drive shaft 10, the two main blades 3 are pressed on the upper static contact 1 by the upper tension spring 13, and are pressed on the lower by the lower tension spring 14. On the static contact 11, the vacuum arc chamber assembly 5 includes an encapsulated silica gel 5-1, a vacuum arc chamber 5-2, a reset spring hanging plate 5-3, a moving end outlet seat 5-4, a vacuum arc chamber static contact 5-2-1 and a vacuum arc chamber moving contact 5-2-2; the upper end of the vacuum arc chamber 5-2 is connected with an auxiliary knife 4, and a reset spring 6 is hung on the reset spring hanging plate 5-3. The vacuum arc chamber assembly 5 is installed between two main knives 3 and can rotate relative to the two main knives 3. A sliding pin 9 is connected to the lower moving end outlet seat 5-4 of the vacuum arc chamber assembly 5, and a curved guide groove 8 is provided on the arc chamber drive plate 7. Under the action of the reset spring 6 and the locking pin 2, the vacuum arc chamber assembly 5 rotates relative to the main knife 3, and the sliding pin 9 slides back and forth along the curved guide groove 8 on the arc chamber drive plate 7, so that the vacuum arc chamber 5-2 is respectively in the vacuum arc chamber closed position A or the vacuum arc chamber open position B.

[0044] The vacuum arc extinguishing chamber assembly 5 described in the present invention is a miniaturized and simplified arc extinguishing chamber with a simple structure and low cost. The main functions of the load switch in the power system are to be able to carry and open and close the load current and to close the short-circuit current. The vacuum arc extinguishing chamber assembly 5 described in the present invention only completes the opening and closing of the load current, and the carrying of the load current and the closing of the short-circuit current are completed by the main switch. Therefore, compared with the prior art, the vacuum arc extinguishing chamber 5-2 described in the present invention eliminates the internal shielding tube and the internal magnetic field system for short-circuit current breaking, and at the same time reduces the diameters of the internal vacuum arc extinguishing chamber static contact 5-2-1 and the vacuum arc extinguishing chamber moving contact 5-2-2. The diameters of the arc chamber static contact 5-2-1 and the vacuum arc chamber moving contact 5-2-2 are 12 to 14 mm, and the opening distance between the vacuum arc chamber static contact 5-2-1 and the vacuum arc chamber moving contact 5-2-2 is 5 to 6 mm, thereby reducing the outer dimensions of the vacuum arc chamber 5-2, so that the diameter of the vacuum arc chamber is only 37 mm and the height is 64 mm, which is 70% smaller than the prior art; the main knife 3 is made of copper plate, and completes load current carrying and short-circuit current closing in the structure of the present invention; the auxiliary knife 4 is also made of copper plate, and cooperates with the vacuum arc chamber 5-2 in the structure of the present invention to complete load current breaking.

[0045] like Figure 2 As shown, during the closing operation, the two main blades 3 drive the vacuum interrupter assembly 5 to move rapidly in the counterclockwise direction to the closing position, and are pressed into contact with the upper static contact 1 under the action of the upper tension spring 13. During this process, if a short circuit occurs in the circuit, the main blade 3 completes the closing of the short-circuit current; if no short circuit occurs in the circuit, the main blade 3 completes the closing of the load current; after closing, the load current flows through the circuit composed of the upper static contact 1, the main blade 3, and the lower static contact 11, and no load current flows through the vacuum interrupter assembly 5; the auxiliary blade 4 on the upper part of the vacuum interrupter assembly 5 moves with the vacuum interrupter assembly 5, and in the closing position, the auxiliary blade 4 passes over the locking pin 2 on the upper static contact 1 and is locked by the locking pin 2.

[0046] like Figure 3 As shown, during the opening operation, the main drive shaft 10 drives the main knife 3 to rotate in the clockwise direction. After the main knife 3 is separated from the upper static contact 1, the load current briefly flows through the circuit formed by the upper static contact 1, the locking pin 2, the auxiliary knife 4, the vacuum arc chamber assembly 5, the main knife 3, and the lower static contact 11; the locking pin 2 prevents the vacuum arc chamber assembly 5 from moving with the main knife 3, so that the vacuum arc chamber assembly 5 rotates relative to the main knife 3, and the sliding pin 9 at the bottom of the vacuum arc chamber assembly 5 slides along the curved guide groove 8 on the arc chamber drive plate 7, so that the vacuum arc chamber 5-2 is opened to the vacuum arc chamber position B, thereby interrupting the load current.

[0047] like Figure 4As shown, the main drive shaft 10 continues to operate the main knife 3 to rotate, the vacuum interrupter assembly 5 continues to rotate relative to the main knife 3, the auxiliary knife 4 gradually slides away from the locking pin 2, and the vacuum interrupter assembly 5 rotates in the opposite direction relative to the main knife 3 under the action of the reset spring 6, returns to the middle of the two main knives 3, and reaches the opening position with the main knife 3. In this process, the sliding pin 9 at the bottom of the vacuum interrupter 5 slides in the opposite direction along the curved guide groove 8 on the interrupter driving plate, so that the vacuum interrupter 5-2 is closed to the vacuum interrupter closing position A, preparing for the next load current interruption.

Claims

1. A load switch for a clean dry air insulated metal-enclosed switchgear, the load switch being a three-phase structure, each phase comprising an upper static contact (1), a main switch (3), a vacuum interrupter assembly (5), a lower static contact (11) and a fixed insulating bracket (12), the upper static contact (1) and the lower static contact (11) being connected to the fixed insulating bracket (12), a main drive shaft (10) being installed in the circular holes of the three lower static contacts (11), characterized in that: A locking pin (2) is mounted on the upper static contact (1), an arc extinguishing chamber drive plate (7) is mounted on the main knife (3), the arc extinguishing chamber drive plate (7) is fixedly connected to the main knife (3), the main knife (3) is pressed against the upper static contact (1) by an upper tension spring (13), and is pressed against the lower static contact (11) by a lower tension spring (14), an auxiliary knife (4) is fixedly mounted on the upper part of the vacuum arc extinguishing chamber assembly (5), the vacuum arc extinguishing chamber assembly (5) is mounted in parallel between the two main knives (3) and can rotate relative to the two main knives (3), and a sliding pin (9) is mounted on the lower part of the vacuum arc extinguishing chamber assembly (5). A curved guide groove (8) is provided on the arc extinguishing chamber drive plate (7). When the vacuum arc extinguishing chamber assembly (5) rotates together with the main drive shaft (10) under the drive of the two main blades (3), the sliding pin (9) slides back and forth along the curved guide groove (8) on the arc extinguishing chamber drive plate (7), so that the vacuum arc extinguishing chamber assembly (5) is respectively in a vacuum arc extinguishing chamber closed position (A) or a vacuum arc extinguishing chamber open position (B); the vacuum arc extinguishing chamber assembly (5) comprises an encapsulated silica gel ( 5-1), a vacuum interrupter (5-2), a reset spring hanging plate (5-3), a moving end outlet seat (5-4), a vacuum interrupter static contact (5-2-1) and a vacuum interrupter moving contact (5-2-2), the upper end of the vacuum interrupter (5-2) is connected to an auxiliary knife (4), the lower end of the vacuum interrupter (5-2) is connected to a sliding pin (9) through the moving end outlet seat (5-4), and a reset spring (6) is hung on the reset spring hanging plate (5-3).

2. The load switch for clean dry air insulated metal enclosed switchgear according to claim 1, characterized in that: The main knife (3) and the auxiliary knife (4) are both made of copper plates.

3. The load switch for clean dry air insulated metal enclosed switchgear according to claim 1, characterized in that: The diameters of the vacuum interrupter static contact (5-2-1) and the vacuum interrupter moving contact (5-2-2) are 12 to 14 mm, and the opening distance between the vacuum interrupter static contact (5-2-1) and the vacuum interrupter moving contact (5-2-2) is 5 to 6 mm.

4. The load switch for clean dry air insulated metal enclosed switchgear according to claim 1, characterized in that: The vacuum interrupter (5-2) has an outer diameter of 37 mm and a height of 64 mm.

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