Contact with opening limiting structure and vacuum arc-extinguishing chamber applying same

Abstract

The application discloses a contact with a breaking limiting structure and a vacuum arc-extinguishing chamber applying the same, and the contact with the breaking limiting structure comprises a static end contact and a dynamic end contact; the static end contact comprises a static end excitation structure, a static end fixed structure is welded at the back center area of a static end contact piece, a hollow static end support structure is fixed inside the static end excitation structure, and the static end support structure is not fixed with the static end fixed structure and has a gap; a static end limiting structure is located in the hollow cavity of the static end support structure, is welded at the back of the static end fixed structure close to one end of the static end contact piece, and has a gap with the static end excitation structure at the other end; the structure of the dynamic end contact is completely same as that of the static end contact; due to the limitation of the static end limiting structure and the dynamic end limiting structure, the deformation of the static end support structure and the dynamic end support structure is limited, and thus the deformation of the static end contact piece, the static end excitation structure, the dynamic end contact piece and the dynamic end excitation structure is limited.

Description

Technical Field

[0001] This invention relates to the field of high-voltage vacuum circuit breaker technology, specifically to a contact with a tripping limit structure and a vacuum interrupter chamber for its application. Background Technology

[0002] With the rapid development of vacuum circuit breakers in power systems, the performance requirements for vacuum interrupters and vacuum circuit breakers have significantly increased. The mechanical life of the contact structure of a high-voltage vacuum circuit breaker is an important indicator for evaluating its excellent breaking performance. Therefore, how to reduce the damage to the contact structure caused by the impact force during the opening process and improve the mechanical life of the contact structure has become an urgent problem to be solved in the field of high-voltage vacuum circuit breakers.

[0003] Due to the strong greenhouse effect of SF6, research on environmentally friendly alternatives to high-voltage switches that widely use SF6 gas is currently a hot research topic. However, because current 126 kV and higher voltage level circuit breakers have fast closing and opening speeds and large opening distances, especially vacuum circuit breakers, the closing collision and the initial opening process will cause deformation and damage to the contact excitation structure, necessitating optimization and improvement of the contact structure. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a contact with a tripping limit structure and a vacuum interrupter for application. Taking into account the current path of the high-voltage vacuum interrupter contact during the tripping and closing processes, as well as the potential deformation characteristics of the contact during the tripping process, the present invention combines three components—a fixing structure welded to the back of the contact plate, a support structure inside the excitation coil, and a limit structure—to limit the deformation of the contact plate and the excitation coil during the tripping process.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A contact with a tripping limit structure includes a stationary contact 201 and a moving contact 202, the contact being used in a vacuum interrupter with a high voltage level of 126 kV and above;

[0007] The stationary contact 201 includes a stationary contact piece 106, a stationary excitation structure 102, a stationary support structure 103, a stationary limiting structure 104 for limiting the position during opening, and a stationary fixing structure 105 for fixing the stationary limiting structure 104. The stationary excitation structure 102 is welded to the back edge of the stationary contact piece 106, and the stationary fixing structure 105 is welded to the central area of ​​the back of the stationary contact piece 106. The hollow stationary support structure 103 is fixed inside the stationary excitation structure 102, and the stationary support structure 103 and the stationary fixing structure 105 are not fixed and there is a gap between them. The stationary limiting structure 104 is located in the hollow cavity of the stationary support structure 103. One end of the stationary limiting structure 104 near the stationary contact piece 106 is welded to the back of the stationary fixing structure 105, and the other end is not fixed and there is a gap between it and the stationary excitation structure 102.

[0008] The moving end contact 202 includes a moving end contact piece 107, a moving end excitation structure 111, a moving end support structure 110, a moving end limiting structure 109 for limiting the position when the circuit is opened, and a moving end fixing structure 108 for fixing the moving end limiting structure 109; the moving end contact piece 107 is placed opposite to the stationary end contact piece 106, and the structure of the moving end contact 202 is exactly the same as that of the stationary end contact 201;

[0009] During the contact opening movement, the stationary contact piece 106 separates from the moving contact piece 107. At the moment of separation, the stationary contact 201 and the moving contact 202 deform. A gap D exists between the side of the stationary support structure 103 near the stationary contact piece 106 and the side of the stationary fixing structure 105 away from the stationary contact piece 106. The side of the stationary support structure 103 away from the stationary contact piece 106 contacts the side of the stationary limiting structure 104 near the stationary contact piece 106. The side of the moving support structure 110 near the moving contact piece 107 contacts the moving contact piece 107. The fixed end structure 108 is separated from the moving end contact piece 107 by a gap D. The moving end support structure 110 is in contact with the moving end limiting structure 109 near the moving end contact piece 107 on the side away from the moving end contact piece 107. Due to the restriction of the stationary end limiting structure 104 and the moving end limiting structure 109, the deformation of the stationary end support structure 103 and the moving end support structure 110 is limited, thereby limiting the deformation of the stationary end contact piece 106, the stationary end excitation structure 102, the moving end contact piece 107 and the moving end excitation structure 111.

[0010] Preferably, a boss is provided in the middle of the hollow cavity of the stationary end support structure 103, dividing the hollow cavity into an upper cavity and a lower cavity. The stationary end limiting structure 104 adopts a T-shaped structure, and the stationary end fixing structure 105 adopts a V-shaped structure. The upper part of the T-shaped structure of the stationary end limiting structure 104 is located in the upper cavity of the stationary end support structure 103, the upper part of the V-shaped structure of the stationary end fixing structure 105 is located in the lower cavity of the stationary end support structure 103, and the lower part of the T-shaped structure of the stationary end limiting structure 104 is located in the upper cavity of the V-shaped structure of the stationary end fixing structure 105. The mutual cooperation of the shapes and positions of the three components—stationary end support structure 103, stationary end limiting structure 104, and stationary end fixing structure 105—limits the deformation of the stationary end contact piece 106 and the stationary end excitation structure 102 during the opening process.

[0011] Preferably, the stationary contact piece 106 and the moving contact piece 107 are made of highly conductive Cu or arc-resistant CuCr alloy to ensure good current conduction during the closed-hold state. The stationary support structure 103, stationary limit structure 104, stationary fixing structure 105, moving support structure 110, moving limit structure 109, and moving fixing structure 108 are made of high-hardness, high-strength, and corrosion-resistant stainless steel to ensure that the structure can fully limit the deformation of the contact structure during the opening process.

[0012] Preferably, the stationary end excitation structure 102 and the moving end excitation structure 111 adopt a coil longitudinal magnetic structure, a cup-shaped longitudinal magnetic structure, a swastika-shaped slot transverse magnetic structure, or a spiral slot transverse magnetic structure. This ensures that the electric arc is well controlled during the opening and closing process.

[0013] Preferably, the gap D is in the range of 0.1 mm to 5 mm to ensure that the contact structure is not excessively deformed under certain movable gap conditions.

[0014] Preferably, the contact surfaces of the stationary end limiting structure 104 and the stationary end supporting structure 103 are both coated with an insulating coating, or one of their surfaces is coated with an insulating coating; the contact surfaces of the moving end limiting structure 109 and the moving end supporting structure 110 are both coated with an insulating coating, or one of their surfaces is coated with an insulating coating. This ensures that no current flows through the stainless steel components during the opening process.

[0015] Preferably, the insulating coating is made of ceramic material, plasma spraying material, or high-temperature resistant insulating material to ensure that the structure has good insulation and corrosion resistance.

[0016] A vacuum interrupter, specifically a high-voltage vacuum interrupter of 126 kV and above, includes contacts with a tripping limit structure. At the moment of contact separation, the stationary contact 201 and the moving contact 202 deform. Due to the limitations imposed by the stationary limit structure 104 and the moving limit structure 109, the deformation of the stationary support structure 103 and the moving support structure 110 is restricted, thereby limiting the deformation of the stationary contact piece 106, the stationary excitation structure 102, the moving contact piece 107, and the moving excitation structure 111. This structural design significantly improves the mechanical strength of the contacts and the breaking capacity of the vacuum circuit breaker without affecting its normal current-carrying capacity.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1) The deformation of the contact plate and the excitation structure is limited; Compared with the traditional contact structure, the present invention improves the contact support structure. Through the combination of three components, namely the moving and stationary end fixing structure welded on the back of the moving and stationary end contact plate, the moving and stationary end support structure inside the moving and stationary end excitation structure coil, and the moving and stationary end limiting structure, the deformation of the contact plate and the excitation structure coil during the opening process is limited.

[0019] 2) This invention comprehensively considers the current path of the high-voltage vacuum interrupter contacts during the opening and closing processes, as well as the potential deformation characteristics of the contacts during the opening process. Through the mutual cooperation of the conductive and non-conductive surfaces of the three components—the stainless steel fixed structure, the stainless steel support structure inside the excitation coil, and the stainless steel limiting structure—it achieves that the stainless steel components do not carry current during the opening process, but carry current during the closing static state. Attached Figure Description

[0020] Figure 1(a) and Figure 1(b) are respectively a side view and an axial sectional view of the contact closing and holding stage of the present invention with a tripping limit structure.

[0021] Figure 2 This is an axial sectional view of the three components of the present invention—the stationary end support structure, the stationary end limiting structure, and the stationary end fixing structure—during the closing and holding phase.

[0022] Figures 3(a) and 3(b) are side views and axial cross-sectional views, respectively, of the contact opening movement process of the present invention with the opening limit structure.

[0023] Figure 4 This is a plan view of a vacuum interrupter chamber with a contact featuring a tripping limit structure, according to the present invention.

[0024] Figure 5 This is a schematic diagram of the flow path during the contact closing and holding stage of the present invention with a tripping limit structure. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figures 1(a) and 1(b) are respectively a side view and an axial sectional view of the contact with the tripping limit structure of the present invention during the closing holding stage. As shown in Figures 1(a) and 1(b), the contact with the tripping limit structure of the present invention includes two parts: a stationary contact 201 and a moving contact 202. The stationary contact 201 includes a stationary contact piece 106, a stationary excitation structure 102, a stationary support structure 103, a stationary limit structure 104 for limiting the tripping action, and a stationary fixing structure 105 for fixing the stationary limit structure 104. The stationary contact piece 106 is made of Cu or CuCr alloy. The stationary excitation structure 102 adopts a coil longitudinal magnetic structure, a cup-shaped longitudinal magnetic structure, a swastika-shaped slot transverse magnetic structure, or a spiral slot transverse magnetic structure, and the stationary excitation structure 102 is welded to the back edge of the stationary contact piece 106. A stationary conductive rod 101 is welded to the central region of the back of the stationary excitation structure 102. A stationary fixing structure 105 is welded to the central region of the back of the stationary contact piece 106. A stationary limiting structure 104 is welded to the central region of the back of the stationary fixing structure 105. A hollow stationary support structure 103 is welded inside the stationary excitation structure 102. The stationary support structure 103 and the stationary fixing structure 105 are not fixed and there is a gap between them. The stationary limiting structure 104 is located in the hollow cavity of the stationary support structure 103. One end of the stationary limiting structure 104 near the stationary contact piece 106 is welded to the back of the stationary fixing structure 105, and the other end is not fixed and there is a gap between it and the stationary excitation structure 102. The moving contact structure 202 includes a moving contact piece 107, a moving excitation structure 111, a moving support structure 110, a moving limiting structure 109 for limiting the movement when opening, and a moving fixing structure 108 for fixing the moving limiting structure 109. The moving end contact piece 107 is made of Cu or CuCr alloy. The moving end excitation structure 111 adopts a coil longitudinal magnetic structure, a cup-shaped longitudinal magnetic structure, a swastika-shaped slot transverse magnetic structure, or a spiral slot transverse magnetic structure. The moving end excitation structure 111 is welded to the back edge of the moving end contact piece 107. A moving end conductive rod 112 is welded to the center region of the back of the moving end excitation structure 111. A moving end fixing structure 108 is welded to the center region of the back of the moving end contact piece 107. A moving end limiting structure 109 is welded to the center region of the back of the moving end fixing structure 108. A hollow moving end support structure 110 is welded inside the moving end excitation structure 111. The moving end support structure 110 and the moving end fixing structure 108 are not fixed and there is a gap between them. The moving end limiting structure 109 is located in the hollow cavity of the moving end support structure 110. One end of the moving end limiting structure 109 near the moving end contact piece 107 is welded to the back of the stationary end fixing structure 105, and the other end is not fixed and there is a gap between it and the moving end excitation structure 111.

[0027] During the contact closing and holding phase, the stationary contact piece 106 and the moving contact piece 107 are in contact with each other. Due to internal compression of the contact components, the surface of the stationary support structure 103 near the stationary contact piece 106 contacts the surface of the stationary fixing structure 105 away from the stationary contact piece 106, and there is a gap between the surface of the stationary support structure 103 away from the stationary contact piece 106 and the surface of the stationary limiting structure 104 near the stationary contact piece 106. The surface of the moving support structure 110 near the moving contact piece 107 contacts the surface of the stationary fixing structure 105 away from the moving contact piece 107, and there is a gap between the surface of the moving support structure 110 away from the moving contact piece 107 and the surface of the moving limiting structure 109 near the contact piece.

[0028] Figure 2 This is an axial sectional view of the three components of the present invention—the stationary end support structure 103, the stationary end limiting structure 104, and the stationary end fixing structure 105—during the closing and holding phase. Figure 2 As shown, a boss is provided in the middle of the hollow cavity of the stationary end support structure 103, dividing the hollow cavity into an upper cavity and a lower cavity. The stationary end limiting structure 104 adopts a T-shaped structure, and the stationary end fixing structure 105 adopts a figure-eight structure. The upper part of the T-shaped structure of the stationary end limiting structure 104 is located in the upper cavity of the stationary end support structure 103, the upper part of the figure-eight structure of the stationary end fixing structure 105 is located in the lower cavity of the stationary end support structure 103, and the lower part of the T-shaped structure of the stationary end limiting structure 104 is located in the upper cavity of the figure-eight structure of the stationary end fixing structure 105. The contact surfaces of the stationary end limiting structure 104 and the stationary end support structure 103 are coated with an insulating coating, or one of the surfaces is coated with an insulating coating. The insulating coating material is a ceramic material, a plasma spraying material, or a high-temperature resistant insulating material. During the contact closing and holding phase, due to the internal compression of the contact components, the surface of the stationary end support structure 103 near the stationary end contact piece 106 contacts the side of the stationary end fixing structure 105 away from the stationary end contact piece 106. There is a gap D between the surface of the stationary end support structure 103 away from the stationary end contact piece 106 and the surface of the stationary end limiting structure 104 near the stationary end contact piece 106. The gap D ranges from 0.1 mm to 5 mm.

[0029] Figures 3(a) and 3(b) are side views and axial sectional views of the contact with the tripping limit structure of the present invention during the tripping movement. As shown in Figures 3(a) and 3(b), during the tripping movement, the stationary contact piece 106 separates from the moving contact piece 107. At the moment of separation, the stationary contact 201 and the moving contact 202 deform. The surface of the stationary support structure 103 near the stationary contact piece 106 separates from the surface of the stationary fixing structure 105 away from the stationary contact piece 106, and the surface of the stationary support structure 103 away from the stationary contact piece 106 contacts the surface of the stationary limit structure 104 near the stationary contact piece 106. The surface of the moving end support structure 110 near the moving end contact piece 107 is separated from the surface of the moving end fixing structure 108 away from the moving end contact piece 107. The surface of the moving end support structure 110 away from the moving end contact piece 107 is in contact with the surface of the moving end limiting structure 109 near the moving end contact piece 107. Due to the restriction of the stationary end limiting structure 104 and the moving end limiting structure 109, the deformation of the stationary end support structure 103 and the moving end support structure 110 is limited, thereby limiting the deformation of the stationary end contact piece 106, the stationary end excitation structure 102, the moving end contact piece 107, and the moving end excitation structure 111.

[0030] Figure 4 This is a plan view of a vacuum interrupter with a tripping limit contact, as described in this invention. Figure 4As shown, the arrangement of the guide rod and contacts in the arc-extinguishing chamber is the same as that of a conventional arc-extinguishing chamber. From top to bottom, there is the arc-extinguishing chamber stationary end cover plate 121 and the stationary end conductive rod 101 passing through the center of the arc-extinguishing chamber stationary end cover plate 121. The stationary end contact 201 is connected to the lower end of the stationary end conductive rod 101. The stationary end contact 201 includes a stationary end excitation structure 102, a stationary end support structure 103, a stationary end limiting structure 104, a stationary end fixing structure 105, and a stationary end contact piece 106. Among them, the stationary end excitation structure 102 is welded to the back edge of the stationary end contact piece 103. The lower end of the stationary end conductive rod 101 is welded to the central area of ​​the back of the stationary end excitation structure 102. The stationary end fixing structure 105 is welded to the central area of ​​the back of the stationary end contact piece 106, and there is a gap between the stationary end fixing structure 105 and the stationary end support structure 103. The stationary end limiting structure 104 is welded to the central region of the back of the stationary end fixing structure 105, and there is a gap between the stationary end limiting structure 104 and the stationary end excitation structure 102. The stationary end support structure 103 is welded inside the stationary end excitation structure 102. The stationary end cover plate 121 of the arc-extinguishing chamber is connected to the stationary end insulating shell 123. The stationary end insulating shell 123 is connected to the moving end insulating shell 125. The moving end cover plate 127 of the arc-extinguishing chamber is placed on the lower side of the arc-extinguishing chamber, and the moving end conductive rod 112 passes through the center of the moving end cover plate 127. A moving end contact 202 is connected above the moving end conductive rod 112. The moving end contact 202 includes a moving end excitation structure 111, a moving end support structure 110, a moving end limiting structure 109, a moving end fixing structure 108, and a moving end contact piece 107. The moving end excitation structure 111 is welded to the back edge of the moving end field contact piece 107. The lower end of the moving-end conductive rod 112 is welded to the central region of the back of the moving-end excitation structure 107. The moving-end fixing structure 108 is welded to the central region of the back of the moving-end contact piece 107, and there is a gap between the moving-end fixing structure 108 and the moving-end support structure 110. The moving-end limiting structure 109 is welded to the central region of the back of the moving-end fixing structure 108, and there is a gap between the moving-end limiting structure 109 and the moving-end excitation structure 111. The moving-end support structure 110 is welded inside the moving-end excitation structure 107. Inside the arc-extinguishing chamber, from top to bottom, are the stationary end shield 122, the central shield 124, and the moving end shield 126.

[0031] Figure 5 This is a schematic diagram of the current flow path during the closing and holding stage of the contact with the tripping limit structure of the present invention. Figure 5 As shown, during the contact closing and holding stage, the current flows sequentially through the moving end conductive rod 112, the moving end excitation structure 111, the moving end support structure 110, the moving end fixed structure 108, the moving end contact piece 107, the stationary end contact piece 106, the stationary end fixed structure 105, the stationary end support structure 103, the stationary end excitation structure 102, and the stationary end conductive rod 101, thus maintaining the contact closing and achieving current flow.

[0032] This invention is not limited to the preferred embodiments described above. Those skilled in the art can make modifications and variations to the vacuum interrupter with a tripping limit structure and its application in vacuum circuit breakers based on the teachings of this invention. All such modifications and variations should fall within the protection scope of this invention.

Claims

1. A contact with a tripping limit structure, comprising a stationary contact (201) and a moving contact (202), characterized in that: The contacts are used in vacuum interrupters with high voltage levels of 126 kV and above. The stationary contact (201) includes a stationary contact piece (106), a stationary excitation structure (102), a stationary support structure (103), a stationary limiting structure (104) for limiting the position during opening, and a stationary fixing structure (105) for fixing the stationary limiting structure (104). The stationary excitation structure (102) is welded to the back edge of the stationary contact piece (106), and the stationary fixing structure (105) is welded to the central area of ​​the back of the stationary contact piece (106). The stationary contact piece is hollow. The stationary end support structure (103) is fixed inside the stationary end excitation structure (102). The stationary end support structure (103) and the stationary end fixing structure (105) are not fixed and there is a gap between them. The stationary end limiting structure (104) is located in the hollow cavity of the stationary end support structure (103). One end of the stationary end limiting structure (104) near the stationary end contact piece (106) is welded to the back of the stationary end fixing structure (105), and the other end is not fixed and there is a gap between it and the stationary end excitation structure (102). The moving end contact (202) includes a moving end contact piece (107), a moving end excitation structure (111), a moving end support structure (110), a moving end limiting structure (109) for limiting the circuit when opening, and a moving end fixing structure (108) for fixing the moving end limiting structure (109); the moving end contact piece (107) is placed opposite to the stationary end contact piece (106), and the structure of the moving end contact (202) is exactly the same as that of the stationary end contact (201); During the contact opening process, the stationary contact piece (106) separates from the moving contact piece (107). At the moment of separation, the stationary contact (201) and the moving contact (202) deform. The stationary support structure (103) near the stationary contact piece (106) separates from the stationary fixing structure (105) away from the stationary contact piece (106), creating a gap D. The stationary support structure (103) away from the stationary contact piece (106) contacts the stationary limiting structure (104) near the stationary contact piece (106). The moving support structure (110) near the moving contact piece (107) contacts the moving contact piece (107). The fixed end structure (108) is separated from the moving end contact piece (107) by a gap D. The moving end support structure (110) is in contact with the moving end limiting structure (109) near the moving end contact piece (107) on the side away from the moving end contact piece (107). Due to the restriction of the stationary end limiting structure (104) and the moving end limiting structure (109), the deformation of the stationary end support structure (103) and the moving end support structure (110) is restricted, thereby restricting the deformation of the stationary end contact piece (106), the stationary end excitation structure (102), the moving end contact piece (107), and the moving end excitation structure (111). The hollow cavity of the stationary end support structure (103) is provided with a boss in the middle, which divides the hollow cavity into an upper cavity and a lower cavity. The stationary end limiting structure (104) adopts a T-shaped structure, and the stationary end fixing structure (105) adopts a figure-eight structure. The upper part of the T-shaped structure of the stationary end limiting structure (104) is located in the upper cavity of the stationary end support structure (103), the upper part of the figure-eight structure of the stationary end fixing structure (105) is located in the lower cavity of the stationary end support structure (103), and the lower part of the T-shaped structure of the stationary end limiting structure (104) is located in the upper cavity of the figure-eight structure of the stationary end fixing structure (105).

2. The contact with a tripping limit structure according to claim 1, characterized in that: The stationary contact piece (106) and the moving contact piece (107) are made of Cu or CuCr alloy; the stationary support structure (103), the stationary limiting structure (104), the stationary fixing structure (105), the moving support structure (110), the moving limiting structure (109), and the moving fixing structure (108) are made of stainless steel.

3. The contact with a tripping limit structure according to claim 1, characterized in that: The stationary end excitation structure (102) and the moving end excitation structure (111) adopt a coil longitudinal magnetic structure, a cup-shaped longitudinal magnetic structure, a swastika-shaped slot transverse magnetic structure, or a spiral slot transverse magnetic structure.

4. A contact with a tripping limit structure according to claim 1, characterized in that: The gap D ranges from 0.1 mm to 5 mm.

5. A contact with a tripping limit structure according to claim 1, characterized in that: The contact surfaces of the stationary end limiting structure (104) and the stationary end supporting structure (103) are coated with an insulating coating, or one of their surfaces is coated with an insulating coating; the contact surfaces of the moving end limiting structure (109) and the moving end supporting structure (110) are coated with an insulating coating, or one of their surfaces is coated with an insulating coating.

6. A contact with a tripping limit structure according to claim 5, characterized in that: The insulating coating is made of ceramic material, plasma spraying material, or high-temperature resistant insulating material.

7. A vacuum interrupter, characterized in that: The vacuum interrupter is a high-voltage vacuum interrupter of 126 kV or above, including the contact with the tripping limit structure as described in any one of claims 1 to 6.

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