Three-position isolating switch for environment-friendly gas

Abstract

The utility model relates to the technical field of isolating switches, and discloses a three-position isolating switch for environment-friendly gas, which comprises a mounting base, a three-phase connecting copper bar, switch disconnecting links and a transmission connecting rod, a transverse switch rotating shaft is rotatably connected onto the mounting base, and three disconnecting link bases are equidistantly arranged on the switch rotating shaft. The three-phase connecting copper bar is provided with a grounding static contact matched with the switch disconnecting link, the top of each disconnecting link base is connected with one end of the switch disconnecting link, a main loop static contact is arranged above each disconnecting link base, one end of the switch rotating shaft is connected with one end of a transmission connecting rod, the other end of the transmission connecting rod is connected with a piston, and a cover body is arranged above the piston. An air outlet assembly is arranged on one side of the cover body, and an air outlet is formed in the air outlet assembly. According to the utility model, dry air is used as an insulating medium, and the matching structure of the cover body and the piston is optimized, so that the functions of opening and closing buffering and directional arc extinguishing are realized, and the problems of poor environmental protection property of traditional SF6 equipment and high cost and large size of an existing alternative scheme are solved.

Description

Technical Field

[0001] This utility model relates to the field of disconnecting switch technology, specifically a three-position disconnecting switch for environmentally friendly gases. Background Technology

[0002] SF6 gas is restricted by international agreements (Kyoto Protocol, Paris Agreement) due to its extremely high global warming potential (GWP=23,500). The EU's Fluoride Gas Regulation (F-gas) explicitly requires the phase-out of SF6 equipment. Traditional three-position disconnect switches rely on SF6 gas for insulation, but it has poor environmental performance and faces the risk of being banned by law.

[0003] Traditionally, epoxy resin encapsulation technology is used, completely eliminating gas insulation and relying on solid insulation materials; or C5 fluoroketone (C5F) is used. 10 New gases such as O) with GWP < 1 and insulation strength of 80% of SF6; or using pure N2 as the insulating medium and increasing the gas tank design pressure to 0.15 MPa to compensate for the insulation strength; or using a mixture of SF6 and N2 (usually in a ratio of 20%:80%), with GWP reduced to approximately 4,700.

[0004] However, existing three-position switches have the following drawbacks: 1. They use epoxy resin encapsulation technology, which has poor heat dissipation performance, limits the rated current to below 1250A, has weak arc extinguishing capability, and is only suitable for low short-circuit current scenarios (≤20kA). Manufacturing costs are high (50% higher than gas-insulated solutions); 2. They use C5 fluoroketone (C5F... 10 O) Its gas cost is extremely high (approximately 10 times that of SF6), limiting its commercial application. Its chemical stability needs verification, and long-term operation may decompose to produce toxic byproducts. 3. Using N2 as the insulating medium increases equipment volume by 30%, making it difficult to adapt to standard ring main unit sizes. High gas pressure increases sealing difficulty, with leakage rates generally >1%. 4. Using a mixture of SF6 and N2 still contains SF6, which does not comply with future regulatory trends towards its prohibition. Recovery of the mixed gas is difficult, resulting in high operation and maintenance costs. These existing alternatives have various problems in terms of environmental protection, economy, reliability, and functionality, and cannot meet the development needs of green and miniaturized power equipment under the "dual carbon" target. Utility Model Content

[0005] The purpose of this utility model is to provide a three-position disconnect switch for environmentally friendly gases. It adopts a unique three-position design, which enables the gas medium to be dry air, and the gas pressure to meet the 48kV power frequency withstand voltage and 75 / 85kV lightning impulse requirements even when the gas pressure is 0.025MPa. It also meets the standardized design dimensions of 12k environmentally friendly gas switchgear. It systematically solves the multiple contradictions in environmental protection, economy, reliability and functionality of traditional gas-insulated switchgear and existing alternatives, so as to solve the problems mentioned in the background art.

[0006] The technical solution of this utility model is: a three-position disconnect switch for environmentally friendly gases, including a mounting base, a three-phase connecting copper busbar, a switch knife switch, and a transmission linkage. A transverse switch rotating shaft is rotatably connected to the mounting base. Three knife switch bases are equally spaced on the switch rotating shaft. Grounding stationary contacts matching the switch knife switches are provided on the three-phase connecting copper busbar. One end of the switch knife switch is connected to the top of each knife switch base. The other end of the switch knife switch corresponds to the upper part of the three grounding stationary contacts. A main circuit stationary contact is provided above each knife switch base. The switch knife switch is located between the main circuit stationary contact and the three-phase connecting copper busbar. The three switch knife switches correspond one-to-one with the three main circuit stationary contacts and the three grounding stationary contacts. One end of the switch rotating shaft is connected to one end of the transmission linkage. The other end of the transmission linkage is connected to a piston. A cover is provided above the piston. An air outlet assembly is provided on the side of the cover near the main circuit stationary contact. An air outlet is provided on the side of the air outlet assembly near the main circuit stationary contact.

[0007] Furthermore, the cover includes an upper cover and a lower cover. The upper cover includes an arc-shaped cover, a U-shaped cover, and a groove. The arc-shaped cover has a notch. An air vent assembly mounting piece is provided on the outside of the arc-shaped cover. The air vent assembly is engaged with the air vent assembly mounting piece. The lower cover is a hollow cylinder, and the piston is disposed inside the hollow cylinder.

[0008] Furthermore, the air outlet component mounting part includes a mounting frame one and a plurality of ribs, the ribs being spaced apart within the mounting frame one; the air outlet component includes a mounting frame two and a triangular air outlet chamber, the mounting frame two being snap-fitted to the mounting frame one.

[0009] The diameter of the hollow cylinder is matched with the size of the piston to ensure that the piston generates appropriate friction with the inner wall of the hollow cylinder cavity when it moves. This, combined with the piston's own resistance, achieves buffering during opening and closing, reducing overshoot and rebound.

[0010] The air outlet assembly is fixed to the enclosure by a snap-fit ​​method, and the air outlet is oriented to the contact point between the main circuit stationary contact and the switch knife switch. When the disconnect switch is opened, the piston moves upward to compress the air inside the enclosure, and the high-pressure airflow is precisely sprayed into the arc area through the air outlet to quickly extinguish the arc and improve the arc extinguishing efficiency.

[0011] Driven by the rotating shaft of the switch, the piston moves up and down inside the enclosure. During the movement, friction is generated between the piston and the enclosure, which, together with its own resistance, buffers the opening and closing process of the disconnecting switch, reducing overshoot and rebound. At the same time, when opening, the air inside the enclosure is compressed and blown out through the air outlet to extinguish the electric arc.

[0012] Furthermore, an insulating cover is provided above the mounting base, and the knife switch base, main circuit stationary contact, and grounding stationary contact are all located inside the insulating cover. An outer edge is provided at the bottom of the lower cover, and the outer edge is snapped into connection with the insulating cover. The insulating cover is made of transparent plastic.

[0013] Furthermore, a voltage equalization shield is provided above and on the outside of the main circuit stationary contact. The voltage equalization shield is used to uniformly distribute the electric field, reduce electric field concentration, and improve the insulation performance and reliability of the equipment.

[0014] Furthermore, a spring is provided on the outside of the switch rotating shaft, and the spring is connected to an external power mechanism. The external mechanism can drive the switch rotating shaft to rotate under the action of the spring.

[0015] Furthermore, the air outlet assembly mounting piece, the upper cover, and the lower cover are integrally formed structures.

[0016] Furthermore, a notch 2 is provided on the lower part of the cover near the air outlet assembly mounting part to facilitate the passage of the transmission link.

[0017] Furthermore, the transmission link is an insulated rod. The design of the insulated rod ensures insulation performance during transmission, preventing leakage and electric shock accidents.

[0018] The principle of this utility model is as follows:

[0019] Driven by an external power mechanism, the switch rotating shaft rotates, which in turn drives the switch knife switch to move through the knife switch base. This enables the switch knife switch to close and open with the main circuit stationary contact and the grounding stationary contact, thus completing the opening and closing operations of the disconnecting switch.

[0020] When the grounding switch is in the closed state and the external power mechanism opens the circuit, the piston moves downward. Under the combined action of the frictional force between the piston and the cover and the downward resistance of the piston, the overshoot and rebound of the grounding switch can be effectively reduced.

[0021] When the grounding switch is in the open state and the external power mechanism closes it, the piston moves upward. Under the combined action of the friction force between the piston and the cover and the downward resistance of the piston, it can play a certain role in buffering the closing. However, because the stroke is short, it has almost no impact on the grounding closing speed.

[0022] When the disconnector is in the closed state and the external power mechanism opens the circuit, the piston moves upward. Under the combined action of the frictional force between the piston and the housing and the upward resistance of the piston, the overshoot and rebound of the disconnector can be effectively reduced. At the same time, it can also compress the air inside the housing and blow out the electric arc through the air outlet.

[0023] When the disconnecting switch is in the open state and the external power mechanism closes it, the piston moves downward. The combined action of the frictional force between the piston and the cover and the downward resistance of the piston can play a role in buffering the closing.

[0024] This utility model provides an improved three-position disconnect switch for environmentally friendly gases, which has the following improvements and advantages compared with the prior art:

[0025] 1. The cover of this utility model, through the combination design of U-shaped cover and hollow cylinder, not only provides a stable movement space for piston, but also converts mechanical motion into airflow power through the cooperation of sealed cavity and air outlet, while taking into account structural strength and functional integration.

[0026] 2. This utility model systematically solves the pain points of traditional equipment, such as high pollution, low compatibility, complex operation and high maintenance costs, through environmentally friendly gas substitution and three-station integrated design, which is in line with the development trend of green and miniaturized power equipment under the dual carbon target.

[0027] 3. This three-position switch, through its reasonable layout, uses dry air as the inflation medium. When the inflation pressure is 0.025MPa, it can meet the 48kV power frequency withstand voltage test and the 75 / 85kV lightning impulse test.

[0028] 4. This utility model systematically solves the multiple contradictions in environmental protection, economy, reliability, and functionality of traditional SF6 gas-insulated switchgear and existing alternatives. Using dry air as the insulating medium ensures good environmental performance; the reasonable structural design enables the equipment to meet electrical performance requirements while also possessing good economy, reliability, and functionality, thus better aligning with the development trend of green and miniaturized power equipment. Attached Figure Description

[0029] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0030] Figure 1 This is a schematic diagram of the structure of the disconnecting switch of this utility model when it is in the open state;

[0031] Figure 2 This is a schematic diagram of the grounding switch of this utility model in the closed state;

[0032] Figure 3 This is a schematic diagram of the disconnector switch of this utility model in the closed state;

[0033] Figure 4 This is a schematic diagram of the structure of the cover and the air outlet component of this utility model;

[0034] Figure 5 This is a schematic diagram of the cover structure of this utility model;

[0035] Figure 6 This is a schematic diagram of the cover body of this utility model from another direction;

[0036] Figure 7 This is a schematic diagram of the air outlet component structure of this utility model;

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Three-phase connecting copper busbar; 2. Switch knife switch; 3. Grounding stationary contact; 4. Switch rotating shaft; 5. Main circuit stationary contact; 6. Transmission connecting rod; 7. Piston; 8. Cover; 81. Upper cover; 82. Lower cover; 83. Arc-shaped cover (83); 84. U-shaped cover; 85. Groove; 86. Air outlet assembly mounting part; 861. Mounting frame one; 862. Rib; 87. Notch one, 88. Notch two; 9. Air outlet; 10. Air outlet assembly; 101. Mounting frame two; 102. Triangular air outlet chamber; 11. Insulating cover; 12. Knife switch base; 13. Equalizing cover. Detailed Implementation

[0039] The present invention will now be described in detail, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0040] For examples, see Figure 1-7This utility model provides an improved three-position disconnect switch for environmentally friendly gases, including a mounting base, a three-phase connecting copper busbar 1, a switch knife switch 2, and a transmission linkage 6. A transverse switch rotating shaft 4 is rotatably connected to the mounting base. An insulating cover 11 is provided above the mounting base. Three knife switch bases 12 are evenly spaced on the switch rotating shaft 4. The three-phase connecting copper busbar 1 is provided with grounding stationary contacts 3 that match the switch knife switch 2. The top of each knife switch base 12 is connected to one end of the switch knife switch 2, and the other end of the switch knife switch 2 corresponds to the three grounding stationary contacts 3. On the upper side of the ground stationary contact 3, a main circuit stationary contact 5 is provided above each knife switch base. The switch knife switch 2 is located between the main circuit stationary contact 5 and the three-phase connecting copper busbar 1. The three switch knife switches 2 correspond one-to-one with the three main circuit stationary contacts 5 and the three ground stationary contacts 3 respectively. One end of the switch rotating shaft 4 is connected to one end of the transmission connecting rod 6, and the other end of the transmission connecting rod 6 is connected to the piston 7. A cover 8 is provided above the piston 7. An air outlet assembly is provided on the side of the cover 8 near the main circuit stationary contact 5. An air outlet 9 is provided on the side of the air outlet assembly near the main circuit stationary contact 5.

[0041] The knife switch base is used to fix the knife switch 2 and rotates with the rotation of the switch shaft 4, thereby driving the knife switch 2 to move and achieve contact or separation with the main circuit stationary contact 5 and the grounding stationary contact 3.

[0042] The cover 8 includes an upper cover 81 and a lower cover 82. The upper cover 81 includes an arc-shaped cover 83, a U-shaped cover 84 and a groove 85. The arc-shaped cover 83 has a notch 87. An air outlet component mounting piece 86 is provided on the outside of the arc-shaped cover 83. The air outlet component is engaged with the air outlet component mounting piece 86. The lower cover 82 is a hollow cylinder, and the piston 7 is disposed in the hollow cylinder.

[0043] The air outlet component mounting part 86 includes a mounting frame 861 and a plurality of ribs 862, which are spaced apart within the mounting frame 861; the air outlet component 10 includes a mounting frame 102 and a triangular air outlet chamber 103, which is snap-fitted to the mounting frame 861.

[0044] The diameter of the hollow cylinder is matched with the size of the piston 7 to ensure that the piston 7 generates appropriate friction with the inner wall of the hollow cylinder cavity when it moves. This, combined with the piston 7's own resistance, achieves buffering for opening and closing, reducing overshoot and rebound.

[0045] The air outlet assembly is fixed to the housing 8 by a snap-fit ​​method, and the air outlet 9 is oriented to the contact point between the main circuit stationary contact 5 and the switch knife switch 2. When the disconnecting switch is opened, the piston 7 moves upward to compress the air inside the housing 8, and the high-pressure airflow is precisely sprayed into the arc area through the air outlet 9 to quickly extinguish the arc and improve the arc extinguishing efficiency.

[0046] Driven by the rotating shaft 4 of the switch, the piston 7 moves up and down inside the housing 8. During the movement, friction is generated between the piston 7 and the housing 8, which, together with its own movement resistance, buffers the opening and closing process of the disconnecting switch, reducing overshoot and rebound. At the same time, when opening, the air inside the housing 8 is compressed and blown out through the air outlet 9 to extinguish the electric arc.

[0047] The cover, through the combination of a U-shaped cover and a hollow cylinder, provides a stable movement space for the piston, and through the cooperation of the sealed cavity and the air outlet, it converts mechanical motion into airflow power, while taking into account both structural strength and functional integration.

[0048] An insulating cover 11 is provided above the mounting base. The knife switch base 12, the main circuit stationary contact 5, and the grounding stationary contact 3 are all located inside the insulating cover 11. The bottom of the lower cover 82 is provided with an outer edge, which is snapped into the insulating cover 11. The insulating cover 11 is made of transparent plastic.

[0049] A voltage equalization shield 13 is provided above and on the outside of the stationary contact 5 in the main circuit. The voltage equalization shield 13 is used to uniformly distribute the electric field, reduce electric field concentration, and improve the insulation performance and reliability of the equipment.

[0050] A spring is provided on the outside of the switch rotating shaft 4. The spring is connected to an external power mechanism, which can drive the switch rotating shaft 4 to rotate under the action of the spring.

[0051] The vent assembly mounting part 86, the upper cover 81, and the lower cover 82 are integrally molded structures.

[0052] The lower cover 82 has a notch 2 88 on the side near the air outlet component mounting part 86 to facilitate the passage of the transmission link 6.

[0053] The transmission link 6 is an insulated rod. The design of the insulated rod ensures insulation performance during the transmission process, preventing leakage and electric shock accidents.

[0054] The principle of this utility model is as follows:

[0055] Driven by an external power mechanism, the switch rotating shaft 4 rotates, which in turn drives the switch knife switch 2 to move through the knife switch base, thereby realizing the closing and opening of the switch knife switch 2 with the main circuit stationary contact 5 and the grounding stationary contact 3, and completing the opening and closing operations of the disconnecting switch.

[0056] When the grounding switch is in the closed state and the external power mechanism opens the circuit, the piston 7 moves downward. Under the combined action of the friction force between the piston 7 and the cover 8 and the downward resistance of the piston 7, the overshoot and rebound of the grounding switch can be effectively reduced.

[0057] When the grounding switch is in the open state and the external power mechanism closes it, the piston 7 moves upward. Under the combined action of the friction force between the piston 7 and the cover 8 and the downward resistance of the piston 7, it can play a certain role in buffering the closing. However, because the stroke is short, it has almost no impact on the grounding closing speed.

[0058] When the disconnecting switch is in the closed state and the external power mechanism opens the switch, the piston 7 moves upward. Under the combined action of the friction force between the piston 7 and the housing 8 and the upward resistance of the piston 7, the overshoot and rebound of the disconnecting switch can be effectively reduced. At the same time, it can also compress the air inside the housing 8 and blow out the electric arc through the air outlet 9.

[0059] When the disconnecting switch is in the open state and the external power mechanism closes it, the piston 7 moves downward. Under the combined action of the frictional force between the piston 7 and the cover 8 and the downward resistance of the piston 7, it can play a role in buffering the closing.

[0060] A prototype was manufactured and sent to a third-party testing institution, Xi'an High Voltage Electrical Research Institute Changzhou Co., Ltd. According to GB / T3906-2020, tests were conducted on power frequency withstand voltage, lightning impulse withstand voltage, partial discharge measurement, main circuit short-time withstand current and peak withstand current 20kA 4S, grounding switch short-time withstand current and peak withstand current 20kA 3S, and grounding circuit short-time withstand current and peak withstand current 20kA 2S. All tests were successfully passed.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-position disconnector for environmentally friendly gases, characterized in that: The system includes a mounting base, a three-phase connecting copper busbar (1), a switch knife switch (2), and a transmission link (6). A transverse switch rotating shaft (4) is rotatably connected to the mounting base. Three knife switch bases (12) are evenly spaced on the switch rotating shaft (4). Grounding stationary contacts (3) that match the switch knife switch (2) are provided on the three-phase connecting copper busbar (1). The top of each knife switch base (12) is connected to one end of the switch knife switch (2), and the other end of the switch knife switch (2) corresponds to the upper side of the three grounding stationary contacts (3). A main circuit stationary contact (5) is provided above each knife switch base. The knife switch (2) is located between the main circuit stationary contact (5) and the three-phase connecting copper busbar (1). The three knife switches (2) correspond one-to-one with the three main circuit stationary contacts (5) and the three grounding stationary contacts (3). One end of the switch rotating shaft (4) is connected to one end of the transmission link (6). The other end of the transmission link (6) is connected to a piston (7). A cover (8) is provided above the piston (7). An air outlet assembly (10) is provided on the side of the cover (8) near the main circuit stationary contact (5). An air outlet (9) is provided on the side of the air outlet assembly near the main circuit stationary contact (5).

2. The three-position disconnector for environmentally friendly gases according to claim 1, characterized in that: The cover (8) includes an upper cover (81) and a lower cover (82). The upper cover (81) includes an arc-shaped cover (83), a U-shaped cover (84) and a groove (85). The arc-shaped cover (83) has a notch (87). An air outlet component mounting piece (86) is provided on the outside of the arc-shaped cover (83). The air outlet component is engaged with the air outlet component mounting piece (86). The lower cover (82) is a hollow cylinder. The piston (7) is disposed in the hollow cylinder.

3. The three-position disconnector for environmentally friendly gases according to claim 2, characterized in that: The air outlet component mounting part (86) includes a mounting frame one (861) and a plurality of ribs (862), the ribs (862) being spaced apart within the mounting frame one (861); the air outlet component (10) includes a mounting frame two (101) and a triangular air outlet chamber (102), the mounting frame two (101) being snap-fitted to the mounting frame one (861).

4. The three-position disconnector for environmentally friendly gases according to claim 1, characterized in that: A pressure equalization cover (13) is provided above and on the outside of the main circuit stationary contact (5).

5. The three-position disconnector for environmentally friendly gases according to claim 1, characterized in that: A spring is provided on the outside of the switch rotating shaft (4), and the spring is connected to an external power mechanism.

6. The three-position disconnector for environmentally friendly gases according to claim 2, characterized in that: The air outlet assembly mounting piece (86), the upper cover, and the lower cover are integrally formed structures.

7. The three-position disconnector for environmentally friendly gases according to claim 1, characterized in that: The transmission link (6) is an insulating rod.

8. The three-position disconnector for environmentally friendly gases according to claim 2, characterized in that: The lower cover (82) has a notch 2 (88) on the side near the air outlet component mounting part (86).

9. The three-position disconnector for environmentally friendly gases according to claim 2, characterized in that: An insulating cover (11) is provided above the mounting base. The knife switch base (12), the main circuit stationary contact (5), and the grounding stationary contact (3) are all located inside the insulating cover (11). The bottom of the lower cover (82) is provided with an outer edge, which is snapped into the insulating cover (11).

10. The three-position disconnector for environmentally friendly gases according to claim 9, characterized in that: The insulating cover is made of transparent plastic.

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