A contact structure and a high-voltage vacuum arc-extinguishing chamber using the same

Abstract

The application relates to the technical field of high-voltage switch equipment, and discloses a contact structure and a high-voltage vacuum arc-extinguishing chamber adopting the contact structure. The contact assembly in the contact structure corresponds to a cup-shaped contact seat, a fan-shaped iron sheet assembly, a contact sheet and a conductive rod. A plurality of fan-shaped iron sheet assemblies are arranged in the inner cavity of the cup-shaped contact seat in a circumferential interval. Each group of the fan-shaped iron sheet assemblies is formed by alternately stacking a plurality of layers of fan-shaped iron sheets and annular gaskets. A plurality of inclined grooves are formed in the circumferential direction of the cup wall of the cup-shaped contact seat and penetrate the cup wall. The contact sheet covers and seals the open end of the cup-shaped contact seat. A plurality of grooves are formed in the surface of the contact sheet. The inclined grooves and the grooves are used for jointly changing the current path to generate a longitudinal magnetic field component in the contact gap. The application can significantly improve the short-circuit current breaking capacity of the vacuum arc-extinguishing chamber and reduce the contact temperature rise under the rated current.

Description

Technical Field

[0001] This invention relates to the field of high-voltage switchgear technology, and more specifically, to a contact structure and a high-voltage vacuum interrupter using the contact structure. Background Technology

[0002] As a core component of high-voltage vacuum circuit breakers, the structure and performance of the arc-controlling contacts within the high-voltage vacuum interrupter directly determine the rated current carrying capacity and short-circuit current breaking capacity of the equipment. With the continuous upgrading of the power grid, the system voltage level and transmission capacity are constantly increasing, and operating conditions are becoming more stringent, placing higher demands on the comprehensive performance of the vacuum interrupter contacts.

[0003] Currently, the mainstream longitudinal magnetic contacts for high-voltage vacuum interrupters are mainly divided into two categories: cup-shaped longitudinal magnetic contacts and horseshoe-shaped longitudinal magnetic contacts. Cup-shaped contacts generate a longitudinal magnetic field through the inclined groove structure of the cup wall, while horseshoe-shaped contacts achieve magnetic focusing and form a longitudinal magnetic field using magnetic conductive sheets. However, both types of traditional contacts are single-function structural designs, unable to simultaneously meet the requirements of low-temperature operation under high rated current conditions and the requirements of strong magnetic field arc stabilization and control under large opening distance conditions. During operation, arc contraction and accumulation are prone to occur, leading to problems such as accelerated contact erosion and limited short-circuit breaking performance of the equipment.

[0004] Specifically, while the cup-shaped longitudinal magnetic contact has a simple overall structure and a continuous and stable conductive path, its current distribution is concentrated due to the limitations of the single cup wall conductive structure, resulting in excessive local current density and significant temperature rise issues during long-term current flow operation. The horseshoe-shaped longitudinal magnetic contact, although capable of outputting a high-intensity longitudinal magnetic field and exhibiting excellent arc control performance, experiences rapid magnetic field decay under large contact gap conditions, significantly reducing arc control effectiveness. Furthermore, its accompanying magnetic sheet structure is relatively large, leading to complex manufacturing processes, high production costs, and significant eddy current losses. In summary, the traditional single longitudinal magnetic contact structure struggles to simultaneously meet the dual requirements of temperature rise control and high-intensity breaking capacity, severely hindering the optimization and improvement of the overall performance of the vacuum interrupter. Summary of the Invention

[0005] In view of this, the present invention proposes a contact structure and a high-voltage vacuum interrupter using the contact structure. Specifically, the contact structure is a composite arc-controlling contact pair for a high-voltage vacuum interrupter (vacuum circuit breaker), which can significantly improve the short-circuit current breaking capacity of the vacuum interrupter and reduce the contact temperature rise under rated current. It is widely applicable to high-voltage switchgear such as 126kV and above high-voltage vacuum circuit breakers.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] First, this invention provides a contact structure, including a moving contact assembly and a stationary contact assembly. The moving contact assembly and the stationary contact assembly have the same structure and are arranged symmetrically face-to-face. Each contact assembly includes a cup-shaped contact seat, a sector-shaped iron sheet assembly, a contact plate, and a conductive rod. A plurality of sector-shaped iron sheet assemblies are embedded in the inner cavity of the cup-shaped contact seat, arranged circumferentially along the inner cavity. Each group of sector-shaped iron sheet assemblies is composed of multiple layers of sector-shaped iron sheets and annular gaskets stacked alternately. Through holes are provided at the top and bottom of the multiple layers of sector-shaped iron sheets, and a conductive fixing rod is installed in the through holes. The fixing rod securely connects the stacked sector-shaped iron sheet assemblies. The cup-shaped contact base has several inclined grooves extending circumferentially through the cup wall. The contact piece covers and closes the opening end of the cup-shaped contact base. The fan-shaped iron plate assembly is located inside the contact piece. The surface of the contact piece also has several slots, and the number and position of the slots correspond one-to-one with the inclined grooves and are aligned vertically. The inclined grooves and the slots are used to change the current path together to generate a longitudinal magnetic field component in the contact gap. The conductive rod and the contact piece are respectively disposed on both sides of the cup-shaped contact base. The conductive rod is fixedly connected to the center of the cup-shaped contact base and serves as the external current input / output terminal of the entire contact assembly.

[0008] Preferably, the outer side of the contact assembly is also entirely covered by a shield.

[0009] Preferably, the cup-shaped contact seat is made of high-conductivity copper; the fan-shaped iron sheet is made of electrical pure iron or silicon steel sheet; and the annular gasket is made of insulating material.

[0010] Preferably, the annular gasket is positioned directly opposite the center of the fan-shaped iron sheet, and the through hole is formed in the center of the fan-shaped iron sheet.

[0011] Preferably, the number of stacked layers of the fan-shaped iron sheet and the annular gasket is 2 to 6.

[0012] Preferably, the central angle of the fan-shaped iron sheet is adjusted within the range of 5° to 85°, and the number of fan-shaped iron sheet assemblies is 3 to 8.

[0013] Preferably, the cup-shaped contact seat has 3 to 8 oblique grooves circumferentially formed on the cup wall, and the contact plate has 3 to 8 corresponding grooves formed on its surface.

[0014] Preferably, the fan-shaped iron sheet assembly is provided in four groups, and the four groups of fan-shaped iron sheet assemblies are arranged symmetrically in four directions relative to the center of the conductive rod to form a quadrupole longitudinal magnet.

[0015] Preferably, the gap between adjacent fan-shaped iron sheets and the diameter of the fixing rod in each group of fan-shaped iron sheet assemblies need to be matched and adjusted according to the required magnetic field strength distribution.

[0016] Secondly, the present invention further provides a high-pressure vacuum interrupter chamber, which adopts the contact structure described above.

[0017] Compared with the prior art, the contact structure of the present invention and the high-voltage vacuum interrupter using the contact structure have the following advantages: (1) The present invention uses a composite structure of a cup-shaped contact seat and an array of fan-shaped iron sheets stacked in multiple directions, and combines the synergistic effect of the inclined groove on the cup wall of the cup-shaped contact seat and the slot on the contact sheet to form a multi-pole composite longitudinal magnetic field, while a shielding cover is provided. This structure achieves uniform current distribution (significantly reducing the temperature rise of the rated current) and strong longitudinal magnetic arc control (improving the short-circuit current breaking capacity).

[0018] (2) This invention employs an alternating stacking structure of fan-shaped iron sheets and insulating annular gaskets. The insulating gaskets can block large-area eddy current paths, thereby significantly reducing the heat generated by the core material (such as electrical pure iron or silicon steel sheets) in a high-frequency alternating magnetic field due to the eddy current effect. This helps control the temperature rise of the contact system during the breaking process, avoids the decrease in the magnetic properties of the material due to overheating, and improves the energy efficiency and long-term thermal stability of the arc-extinguishing chamber.

[0019] (3) In this invention, the alternating stacking structure of the fan-shaped iron sheet and the insulating annular gasket is fastened by a through fixing rod, forming a modular component with strong integrity. It has the advantages of simple structure, convenient processing and high mechanical strength, and can reliably withstand the huge electrodynamic and mechanical impact during the opening and closing process. At the same time, the combination of this robust structure and the multi-pole longitudinal magnetic arc control technology also ensures that the arc is evenly dispersed and the contact is less eroded, thereby greatly extending the electrical life and mechanical life of the contacts.

[0020] (4) The contact structure of the present invention is particularly suitable for use in high-voltage, high-capacity vacuum interrupters, meeting the stringent requirements of such equipment for high reliability, high breaking capacity and long service life. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the contact structure in the embodiment (including the shielding cover).

[0023] Figure 2 This is a schematic diagram of the fan-shaped iron sheets embedded in the cup-shaped contact seat in the embodiment, stacked in four directions (including the annular gasket and the fixing rod).

[0024] Figure 3 yes Figure 2 A cross-sectional structural diagram of one of the embedded fan-shaped iron plates.

[0025] Figure 4 yes Figure 1 Cross-sectional view of the middle contact structure.

[0026] Figure 5 This is a schematic diagram showing the position and structure of the embedded fan-shaped iron sheet stacked in four directions (including the gasket and fixing rod) and the cup-shaped contact seat on its outer side in the embodiment.

[0027] In the diagram: 1-cup-shaped contact seat, 2-fan-shaped iron sheet, 3-contact plate, 4-conductive rod, 5-sloping groove, 6-groove, 7-annular gasket, 8-fixing rod, 9-shielding cover. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0031] Example: This invention provides a contact structure and a high-voltage vacuum interrupter using the contact structure, aiming to solve the contradictions in the prior art such as the temperature rise of cup-shaped contacts, the attenuation of magnetic field with a large opening gap in horseshoe-shaped longitudinal magnetic contacts, and insufficient current shunting.

[0032] like Figures 1-5 As shown, the contact structure is a composite arc-controlling contact pair, which specifically includes a moving contact assembly and a stationary contact assembly. The moving contact assembly and the stationary contact assembly have the same structure and are arranged symmetrically face to face. Each of the two contact assemblies includes a cup-shaped contact seat 1, a fan-shaped iron sheet assembly, a contact sheet 3, and a conductive rod 4.

[0033] The cup-shaped contact base 1 has an outer cup-shaped structure and is made of high-conductivity copper material. It serves as the main conductive frame and external heat sink, and has excellent conductivity in the main current path.

[0034] Several sector-shaped iron sheet assemblies are embedded in the inner cavity of the cup-shaped contact seat 1, see reference. Figure 2 and Figure 5 Several fan-shaped iron sheet assemblies are arranged at circumferential intervals along the inner cavity of the cup-shaped contact seat.

[0035] See Figure 2 and Figure 3 Each fan-shaped iron sheet assembly is formed by alternating stacking of multiple fan-shaped iron sheets 2 and annular gaskets 7, forming a stacked structure of iron sheet-gasket-iron sheet. The upper and lower parts of the multiple fan-shaped iron sheets 2 are provided with through holes, and a fixing rod 8 made of conductive material is installed in the through holes. The fixing rod 8 realizes the tight connection of the stacked structure fan-shaped iron sheet assembly and provides an auxiliary conductive path.

[0036] See Figure 1 , Figure 3 and Figure 5 The cup-shaped contact base 1 has several inclined grooves 5 extending through the cup wall along the circumference. The contact piece 3 covers and closes the opening end of the cup-shaped contact base 1. The contact piece 3 is connected to the cup-shaped contact base 1. The fan-shaped iron plate assembly is located inside the contact piece 3. The surface of the contact piece 3 also has several slots 6, and the number and position of the slots 6 correspond one-to-one with the inclined grooves 5 and are aligned vertically. The inclined grooves 5 and the slots 6 are used to change the current path together (the inclined grooves 5 are used to change the current path to generate a basic longitudinal magnetic field, and the slots 6 are used to further change the current path) so as to generate a longitudinal magnetic field component in the contact gap and form a composite longitudinal magnetic field with the magnetic focusing effect of the fan-shaped iron plate 2.

[0037] The conductive rod 4 and the contact piece 3 are respectively located on both sides of the cup-shaped contact base 1. The conductive rod 4 is fixedly connected to the center of the cup-shaped contact base 1, serving as the external current input / output terminal of the entire contact assembly.

[0038] When the circuit is closed, the current is diverted to the contact plate through a composite path (the path of the inclined groove of the cup-shaped contact seat + the path of the internal fixing rod and the fan-shaped iron plate assembly), reducing the current density; when the circuit is opened, the arc is evenly dispersed and burned under the action of the longitudinal magnetic field generated by the inclined groove of the cup-shaped contact seat and the slot of the contact plate and the magnetic field formed by the concentrated magnetic field of the fan-shaped iron plate, avoiding contraction and improving the arc extinguishing efficiency.

[0039] In this embodiment, the cup-shaped contact seat serves as the carrier and main current path. The inner cavity is equipped with an array of fan-shaped iron plates (each group of plates is much smaller than a traditional horseshoe). Through the design of "fan-shaped iron plate assemblies arranged circumferentially" combined with "cup wall grooves" and "contact plate slots aligned vertically," the current path is forcibly altered, efficiently generating a longitudinal magnetic field in the contact gap (arc-extinguishing region). This multi-pole longitudinal magnetic field effectively confines the arc plasma, allowing it to diffuse uniformly across the contact surface, preventing localized overheating and welding, thereby significantly improving the vacuum interrupter's ability and stability to interrupt large currents (especially short-circuit currents).

[0040] In a further specific embodiment, such as Figure 1 As shown, the outer side of the contact assembly is also covered by a shield 9. The shield 9 can effectively capture and condense the metal vapor and arc products generated during the breaking process, prevent them from contaminating the inner wall of the insulating shell of the vacuum interrupter, maintain the high vacuum and insulation strength in the interrupter, and ensure the reliability of the product in long-term operation.

[0041] In a further specific embodiment, the sector-shaped iron sheet 2 is made of electrical pure iron or silicon steel sheet, which can efficiently generate and guide a strong longitudinal magnetic field, thereby improving the arc control capability and breaking performance.

[0042] The annular gasket 7 is made of insulating material to effectively cut off the eddy current loop and reduce eddy current loss.

[0043] In a further specific embodiment, the annular gasket 7 is positioned directly opposite the center of the fan-shaped iron sheet 2, and a through hole is formed in the center of the fan-shaped iron sheet 2 to balance the stress distribution of the fan-shaped iron sheet assembly. This effectively prevents the assembly from deforming, loosening, or suffering fatigue damage when subjected to electrodynamic forces, thermal stress, and mechanical vibration over a long period of time, thus ensuring the long-term structural stability of the magnetic field generating unit.

[0044] In a further specific embodiment, the number of stacked layers of the sector-shaped iron sheet 2 and the annular gasket 7 is 2 to 6, in order to adapt to different voltage levels (e.g., 12kV / 24kV / 126kV).

[0045] The central angle of the fan-shaped iron sheet 2 can be adjusted within the range of 5° to 85°, and the number of fan-shaped iron sheet assemblies is 3 to 8.

[0046] Furthermore, the cup-shaped contact seat 1 has 3 to 8 oblique grooves along the circumferential direction on its cup wall, and the contact piece 3 has 3 to 8 corresponding grooves on its surface.

[0047] The number of inclined grooves on the cup wall of the cup-shaped contact seat and the number of slots on the contact plate need to match the number of sets of the sector-shaped iron plate assembly in order to further optimize the magnetic field uniformity.

[0048] More preferably, in this embodiment, the fan-shaped iron sheet assembly is provided in four groups. The four groups of fan-shaped iron sheet assemblies are arranged in a symmetrical array relative to the center of the conductive rod in four directions (left / right / front / back) to form a quadrupole longitudinal magnet, thereby achieving effective confinement of the arc plasma, enabling it to diffuse rapidly and uniformly, and greatly improving the stability and breaking capacity of the vacuum interrupter when interrupting large currents (especially short-circuit currents).

[0049] Compared with traditional single-pole or two-pole longitudinal magnetic field structures, the "quadrupole symmetrical array" design in this embodiment can generate a stronger and more uniformly distributed magnetic field, thereby bringing better arc control capability, higher short-circuit current breaking limit, longer contact life and more stable breaking performance to the vacuum interrupter.

[0050] In a further specific embodiment, the gap between adjacent sector-shaped iron sheets in each group of sector-shaped iron sheet assemblies and the diameter of the fixing rod need to be matched and adjusted according to the required magnetic field strength distribution in order to achieve the optimal magnetic field strength distribution.

[0051] The specific working process of the contact structure in this invention is as follows: When the circuit is closed, the current enters the cup-shaped contact seat from the conductive rod. Part of the current is diverted to the slotted area of ​​the contact plate through the inclined groove path and part of the current is diverted through the internal fixed rod path, forming a low-density current distribution on the arcing surface of the contact plate, and at the same time generating a composite longitudinal magnetic field.

[0052] During arc extinguishing, the arc rapidly spreads to multiple regions for combustion under the constraint of the composite longitudinal magnetic field, avoiding the concentration of anode spots. After arc extinguishing, residual ions diffuse rapidly, and the vacuum level is quickly restored, achieving reliable interruption.

[0053] The present invention further provides a high-voltage vacuum interrupter using the above contact structure.

[0054] Applying the aforementioned high-performance contact structure to a high-voltage vacuum interrupter directly endows the interrupter with higher breaking capacity, longer electrical life, smaller current-carrying capacity, and higher operational reliability. This makes the vacuum circuit breaker or switchgear using this invention more competitive and valuable in power systems, especially in the medium- and high-voltage power transmission and distribution fields.

[0055] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0056] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A contact structure comprising a male contact assembly and a female contact assembly, characterized in that, The moving contact assembly and the stationary contact assembly have the same structure and are arranged symmetrically face-to-face. Each contact assembly includes a cup-shaped contact base, a sector-shaped iron sheet assembly, a contact plate, and a conductive rod. The inner cavity of the cup-shaped contact base is fitted with several sector-shaped iron sheet assemblies spaced circumferentially along the inner cavity. Each group of sector-shaped iron sheet assemblies is composed of multiple layers of sector-shaped iron sheets and annular gaskets stacked alternately. Through holes are provided at the top and bottom of the multiple layers of sector-shaped iron sheets, and a conductive fixing rod is installed in each through hole. The fixing rod securely connects the stacked sector-shaped iron sheet assemblies and provides an auxiliary conductive path. The cup-shaped contact base... The cup-shaped contact seat has several inclined grooves extending circumferentially through the cup wall. The contact piece covers and closes the opening end of the cup-shaped contact seat. The fan-shaped iron plate assembly is located inside the contact piece. The surface of the contact piece also has several slots, and the number and position of the slots correspond one-to-one with the inclined grooves and are aligned vertically. The inclined grooves and the slots are used to change the current path together to generate a longitudinal magnetic field component in the contact gap. The conductive rod and the contact piece are respectively disposed on both sides of the cup-shaped contact seat. The conductive rod is fixedly connected to the center of the cup-shaped contact seat and serves as the external current input / output terminal of the entire contact assembly.

2. The contact structure according to claim 1, characterized in that, The outer side of the contact assembly is also entirely covered by a shield.

3. The contact structure according to claim 1, characterized in that, The cup-shaped contact seat is made of high-conductivity copper; the fan-shaped iron sheet is made of electrical pure iron or silicon steel sheet; and the annular gasket is made of insulating material.

4. The contact structure according to claim 1, characterized in that, The annular gasket is positioned directly opposite the center of the fan-shaped iron sheet, and the through hole is formed in the center of the fan-shaped iron sheet.

5. A contact structure according to claim 1, characterized in that, The number of stacked layers of the fan-shaped iron sheet and the annular gasket is 2 to 6.

6. A contact structure according to claim 1 or 5, characterized in that, The central angle of the fan-shaped iron sheet is adjusted within the range of 5° to 85°, and the number of fan-shaped iron sheet assemblies is 3 to 8.

7. A contact structure according to claim 6, characterized in that, The cup-shaped contact seat has 3 to 8 oblique grooves along its circumference on the cup wall, and the contact plate has 3 to 8 corresponding grooves on its surface.

8. A contact structure according to claim 6, characterized in that, The fan-shaped iron sheet assembly is provided in four groups, and the four groups of fan-shaped iron sheet assemblies are arranged symmetrically in four directions relative to the center of the conductive rod to form a quadrupole longitudinal magnet.

9. A contact structure according to claim 1, characterized in that, The gap between adjacent sector-shaped iron sheets and the diameter of the fixing rod in each group of sector-shaped iron sheet assemblies need to be matched and adjusted according to the required magnetic field strength distribution.

10. A high-pressure vacuum interrupter, characterized in that, The contact structure described in any one of claims 1-9 is adopted.

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