Ring main unit

Abstract

The utility model provides a ring main unit. The ring main unit comprises a gas tank, a fixed frame fixed on the inner side wall of the gas tank, a circuit breaker switch and a three-position switch, wherein the circuit breaker switch and the three-position switch are positioned in the gas tank. The solid-sealed polar pole of the circuit breaker switch comprises a polar pole body, a movable end shielding seat and a static end shielding seat, the movable end shielding seat and the static end shielding seat are located at the two ends of the polar pole body, the movable end shielding seat and the static end shielding seat can wrap the two ends of the polar pole body respectively, and therefore the electrical connection position of the polar pole body is electrically isolated from the external environment; the pole body, the moving end shielding seat and the static end shielding seat are cast into a whole through insulating resin, so that the consistency of the pole is improved; the grounding shielding seat adopts an integrally formed metal piece, and can uniformly wrap a plurality of grounding contacts in a shielding space, so that the electric field distribution of the grounding contacts is optimized. According to the ring main unit, dry air can be used as insulating gas, miniaturization of the ring main unit is achieved, and the corresponding insulating performance is met.

Description

Technical Field

[0001] The invention relates to the technical field of switchgear, and mainly to a ring network cabinet. Background Art

[0002] In order to improve the reliability of power supply and enable users to obtain power from two directions, the power supply network is usually connected into a ring, that is, a ring network power supply system, and this power supply method is referred to as ring power supply. The switchgear used in the ring network power supply system is generally called a ring network cabinet.

[0003] Among them, SF6 gas is usually used as gas insulation for switchgear because of its good insulation and arc extinguishing properties. However, as a greenhouse gas, the use of SF6 is not conducive to environmental protection. Dry air also has certain insulation properties and can be considered to replace SF6 gas. However, the insulation performance of air is lower than that of SF6 gas, and its application in ring main units is limited, especially for small ring main units. Due to their small size, it is difficult to meet the corresponding insulation requirements by using air insulation. Summary of the invention

[0004] In order to solve the problem in the related art that small ring main unit using air insulation is difficult to meet corresponding insulation requirements, the purpose of the present invention is to provide a ring main unit.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present application discloses a ring main unit, comprising:

[0007] an air box filled with dry air;

[0008] A fixed frame, fixed on the inner wall of the air box;

[0009] A circuit breaker switch, the circuit breaker switch is arranged on the fixed frame, and comprises:

[0010] A sealed pole, comprising a pole body and a moving end shielding seat and a static end shielding seat located at both ends of the pole body, wherein the pole body is fixed on the fixed frame, and the pole body, the moving end shielding seat and the static end shielding seat are formed into a whole by pouring insulating resin;

[0011] A three-position switch is arranged on the fixed frame, the circuit breaker switch is arranged on the upper layer of the fixed frame, and the three-position switch is arranged on the middle layer of the fixed frame. The three-position switch includes:

[0012] A grounding contact seat, a plurality of grounding contacts arranged on the grounding contact seat, and a grounding shielding seat, wherein the grounding contact seat is arranged on the fixed frame, the grounding shielding seat cover is arranged on the grounding contact seat, and the plurality of grounding contacts are located in a shielding space formed between the grounding shielding seat and the grounding contact seat, the grounding shielding seat is configured as an integrally formed metal part, and the grounding shielding seat is provided with a plurality of openings corresponding to the plurality of grounding contacts to expose each of the grounding contacts.

[0013] Optionally, the ring network cabinet has a cabinet width of 450 mm, a cabinet depth of 865 mm, and a cabinet height of 1800 mm.

[0014] Optionally, two convex columns are formed on the movable end shielding seat, the convex columns are located in the first shielding cavity of the movable end shielding seat, and first connecting holes are provided on the two convex columns;

[0015] The circuit breaker switch further comprises a pole movable end, which comprises a movable conductive rod, one end of which passes through the movable end shielding seat and extends into the vacuum interrupter chamber of the pole body; and

[0016] A transmission crank arm, comprising a middle portion and a first end and a second end located at two ends of the middle portion, the other end of the conductive rod being connected to the first end of the transmission crank arm; and

[0017] an insulating pull rod connected to the second end of the transmission crank arm; and

[0018] The crank arm shaft is passed through the middle part of the transmission crank arm, and the parts of the crank arm shaft extending to the outside of the transmission crank arm at both axial ends are inserted into the two first connecting holes of the movable end shielding seat through connecting pieces and locked.

[0019] Optionally, the movable end of the pole also includes a transmission pin and a connecting cover plate, and the transmission pin and the connecting cover plate are both located in the first shielding cavity of the movable end shielding seat, the transmission pin is passed through the first end of the transmission crank arm, and the other end of the movable conductive rod is provided with a groove with an opening facing upward, and the transmission pin is installed in the movable conductive rod through the groove, and the connecting cover plate is covered above the groove and connected to the movable conductive rod so that the transmission pin is limited to be located in the groove.

[0020] Optionally, the circuit breaker switch further includes a circuit breaker operating mechanism, the ring main unit is further provided with a mechanism chamber, the circuit breaker operating mechanism is located in the mechanism chamber, the circuit breaker switch further includes a first input shaft, the first input shaft is transmission-connected to the insulating pull rod, so as to drive the conductive rod to move in the vacuum interrupter chamber under the drive of the circuit breaker operating mechanism;

[0021] The first input shaft dynamic seal is installed at the connection between the air box and the mechanism chamber.

[0022] Optionally, the movable end shielding seat is located at the movable end of the pole body, the movable end shielding seat is provided with a first shielding cavity and a first opening, the convex column, the movable conductive rod and the crank arm shaft are located in the first shielding cavity, and the transmission crank arm extends into the first shielding cavity through the first opening;

[0023] The static end shielding seat is located at the static end of the pole body, and the static end shielding seat is provided with a second shielding cavity and a second opening. The three-position switch also includes an isolating static contact, a moving contact seat, and a moving contact rotatably arranged on the moving contact seat. The isolating static contact is located in the second shielding cavity, and the moving contact can rotate relative to the moving contact seat to selectively combine with the isolating static contact or the grounding contact.

[0024] Optionally, a first insulating plate protruding from the surface is provided on the surface of the pole body, the first opening and the second opening are both located on the same side of the pole body, the first insulating plate is located on the side where the circuit breaker operating mechanism is transmission-connected to the crank arm shaft, and the first insulating plate is provided between the moving end shielding seat and the static end shielding seat;

[0025] The first insulating plate is integrally connected to the pole body by pouring the insulating resin.

[0026] Optionally, the moving contact comprises a middle portion and a first end and a second end located at both ends of the middle portion, the first end of the moving contact is rotatably connected to the moving contact seat, and the second end of the moving contact is used to selectively electrically connect to the grounding contact or the isolating static contact;

[0027] The three-position switch also includes a connecting crank arm and a second input shaft, and the ring network cabinet also includes a three-position operating mechanism arranged in the mechanism chamber. The two ends of the connecting crank arm are respectively connected between the middle part of the moving contact and the three-position operating mechanism, and the second input shaft dynamic seal is installed at the connection between the air box and the mechanism chamber.

[0028] Optionally, the circuit breaker switch also includes a soft connection, one end of which is connected to the pole body through a fixing member, and the connection between the soft connection and the pole body is located in the first shielding cavity of the moving end shielding seat, and a third opening connected to the first shielding cavity is provided above the moving end shielding seat, and the other end of the soft connection extends upward through the third opening to connect the conductive circuit.

[0029] Optionally, the air box further comprises:

[0030] The side expansion sleeves are respectively installed on the side walls of the gas box and located above the sealed pole. A conductive rod is inserted into the side expansion sleeve. The conductive rod includes a first end and a second end arranged along the axial direction. The first end of the conductive rod is used to cooperate with the mother coupler for connection.

[0031] A main busbar, two ends of which are electrically connected to the second ends of the conductive bars on both sides to form the conductive loop;

[0032] A branch copper busbar connected between the flexible connector and the main busbar;

[0033] Among them, the side expansion sleeve is provided with a uniform electric field cavity, and the uniform electric field cavity is surrounded by an insulating partition. The second end of the conductive rod extends to the uniform electric field cavity, and the second end of the conductive rod is provided with a fifth connecting hole opening downward relative to the horizontal installation direction of the side expansion sleeve. One end of the main busbar is inserted from below into the fifth connecting hole of one of the conductive rods through a connecting piece and locked, and the other end of the main busbar is inserted from below into the fifth connecting hole of another conductive rod through a connecting piece and locked.

[0034] Optionally, the top outer surface of the second end of the conductive rod is set to be an arc surface.

[0035] Optionally, a cut surface is formed on the circumferential side wall of the second end of the conductive rod, and the cut surface is used to fit with the main busbar when the main busbar is installed, and the fifth connecting hole is located at the cut surface.

[0036] Optionally, the insulating partition is arranged on an end face of the side expansion sleeve facing the other side expansion sleeve, and the insulating partition includes three shielding surfaces, and the three shielding surfaces enclose the uniform electric field cavity, wherein the end face of the side expansion sleeve and the three shielding surfaces form four faces of a hexahedral structure, and the other two faces of the hexahedral structure are in an open state, one of the open faces is arranged toward the bottom of the side expansion sleeve and opposite to the sealed pole, and the fifth connecting hole is arranged toward one of the open faces.

[0037] Optionally, the ring main unit further includes:

[0038] An outlet bushing, which is arranged below the three-position switch, and comprises a first outer sleeve and an outlet conductive end arranged in the first outer sleeve; and

[0039] A copper rod, one end of which is electrically connected to the moving contact, and the other end of which is connected to the conductive end of the outgoing line. The connection between the copper rod and the conductive end of the outgoing line is located in the first outer sleeve.

[0040] Optionally, a fixing insert is further provided on the pole body, the fixing insert is connected between the pole body and the fixing frame, and the fixing insert and the pole body are integrally connected by pouring the insulating resin.

[0041] Optionally, the number of the fixing inserts is three, and the positions of the three fixing inserts constitute three vertices of a triangle.

[0042] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0043] The present disclosure provides a ring network cabinet, which includes an air box, a fixed frame fixed to the inner wall of the air box, a circuit breaker switch and a three-position switch located in the air box. The sealed pole of the circuit breaker switch includes a pole body and a moving end shielding seat and a static end shielding seat located at both ends of the pole body. The moving end shielding seat and the static end shielding seat partially cover the two ends of the pole body respectively, so as to better electrically isolate the electrical connection of the pole body from other adjacent electrical components. The pole body, the moving end shielding seat and the static end shielding seat are cast into a whole by insulating resin. The insulating resin, as an insulating material, can not only tightly connect the pole body, the moving end shielding seat and the static end shielding seat, but also the connection between each component can be covered by the insulating material, thereby providing a good electrical isolation effect for the whole of the sealed pole, providing a uniform electric field for the circuit breaker, and improving the insulation strength of the whole sealed pole. Moreover, the grounding shielding seat in the three-position switch adopts an integrally formed metal part, and multiple grounding contacts can be uniformly wrapped by the grounding shielding seat in the shielding space enclosed between the grounding shielding seat and the grounding contact seat, thereby optimizing the electric field distribution of the grounding contact, and having a good electromagnetic shielding effect on the grounding contact, further making the structure on one side of the grounding contact more compact, improving the insulation strength of the three-position switch and reducing the overall size of the three-position switch. In general, the ring network cabinet of the present application improves the insulation strength of the circuit breaker switch and the three-position switch by optimizing the electric field distribution of the circuit breaker switch and the three-position switch, thereby improving the overall insulation level of the ring network cabinet, so that the ring network cabinet can use dry air as the insulating gas while realizing the miniaturization of the cabinet and meeting the corresponding insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A three-dimensional diagram of a ring main unit in a first perspective of an embodiment of the present application;

[0045] Figure 2 A stereoscopic diagram of a ring main unit according to an embodiment of the present application under a second visual perspective;

[0046] Figure 3 for Figure 1 The front view of the ring main unit is shown;

[0047] Figure 4 for Figure 1 The right side view of the ring main unit is shown;

[0048] Figure 5 This is a schematic diagram of the connection between the sealed pole and the pole moving end according to an embodiment of the present application;

[0049] Figure 6 A three-dimensional diagram of a sealed pole according to an embodiment of the present application;

[0050] Figure 7 A cross-sectional view of a sealed pole according to an embodiment of the present application;

[0051] Figure 8 for Figure 7 A partial enlarged view of point C;

[0052] Fig. 9 This is one of the schematic diagrams of a moving end shielding seat according to an embodiment of the present application;

[0053] Fig.10 This is a second schematic diagram of a moving end shielding seat according to an embodiment of the present application;

[0054] Fig.11 A schematic diagram of a static end shielding seat according to an embodiment of the present application;

[0055] Fig.12 for Figure 4 A local enlarged view of point A;

[0056] Fig.13 for Figure 5 A partial enlarged view of point D;

[0057] Fig.14 This is a cross-sectional view of the connection between the sealed pole and the pole moving end according to an embodiment of the present application;

[0058] Fig.15 for Fig.14 A local enlarged view of point E;

[0059] Fig.16 A cross-sectional view of a connection structure between a side expansion bushing and a main busbar according to an embodiment of the present application;

[0060] Fig.17 for Fig.16 A partial enlarged view of point F;

[0061] Fig.18 A schematic diagram of a side expansion sleeve according to an embodiment of the present application;

[0062] Fig.19 A cross-sectional view of a side expansion sleeve according to an embodiment of the present application;

[0063] Fig. 20A schematic diagram of a three-position switch according to an embodiment of the present application;

[0064] Fig.21 This is a schematic diagram of installing a ground contact according to an embodiment of the present application;

[0065] Fig. 22 for Figure 4 A partial enlarged view of point B;

[0066] The corresponding relationship between the reference numerals and the component names is as follows:

[0067] 100 gas box, 200 low pressure room, 300 mechanism room, 400 cable room;

[0068] 1Fixed frame;

[0069] 2 circuit breaker switch, 201 first shielding cavity, 202 first opening, 203 third opening, 204 first connecting hole, 205 second shielding cavity, 206 first groove, 207 second groove, 208 second opening, 209 sixth connecting hole, 210 through hole; 21 sealed pole, 211 pole body, 2111 cylinder, 2112 silicone sleeve, 2113 insulating resin layer, 212 moving end shielding seat, 2121 first connecting plate, 2122 first Shielding plate, 2123 boss, 2124 boss; 213 static end shielding seat, 2131 second connecting plate, 2132 second shielding plate; 22 pole moving end, 221 conductive rod, 222 transmission crank arm, 223 insulating pull rod, 224 crank arm shaft, 225 transmission pin, 226 connecting cover plate; 23 circuit breaker operating mechanism, 24 first insulating plate, 25 second insulating plate, 26 third insulating plate, 27 first input shaft, 28 soft connection, 29 fixed insert;

[0070] 3 three-position switch, 301 opening, 31 grounding contact seat, 32 grounding contact, 33 grounding shield seat, 34 isolating static contact, 35 moving contact seat, 36 moving contact, 37 connecting crank arm, 38 second input shaft;

[0071] 4Three-station operating mechanism;

[0072] 5 first shielding cover;

[0073] 6 second shielding cover;

[0074] 7 side expansion sleeve, 701 uniform electric field cavity, 702 shielding surface, 71 insulating partition, 72 second outer sleeve;

[0075] 8 conductive rod, 801 fifth connecting hole, 802 cut surface, 81 first end of the conductive rod, 82 second end of the conductive rod;

[0076] 9 main busbar;

[0077] 10-branch copper busbar;

[0078] 11 outlet casing;

[0079] 12 copper rods;

[0080] 13 Connecting parts. DETAILED DESCRIPTION

[0081] The present invention provides a ring main unit. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of protection of the present invention.

[0082] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0083] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In order to improve the reliability of power supply and enable users to obtain power from two directions, the power supply network is usually connected into a ring, that is, a ring network power supply system, and this power supply method is referred to as ring power supply. The high-voltage switchgear used in the ring network power supply system is generally called a ring network cabinet.

[0085] See also Figure 1 As shown, the present disclosure provides a ring main unit, which includes a gas box 100, a fixed frame 1 fixed to the inner wall of the gas box 100, a circuit breaker switch 2 and a three-position switch 3 located in the gas box 100.

[0086] like Figure 1 and Figure 2 As shown, the ring main unit includes a shell, and a plurality of functional chambers are provided in the shell. The functional chambers include an air box 100, a low-voltage chamber 200, a mechanism chamber 300, and a cable chamber 400. It is understandable that in order to more clearly show the structure in the air box 100, Figure 1 and Figure 2The air box 100 in the embodiment hides part of the shell.

[0087] In the ring main unit disclosed in the present application, dry air is filled in the gas box 100. Compared with the existing related art which mainly uses SF6 gas as the insulating gas, the present application uses dry air as the insulating gas used in the ring main unit, which can not only reduce the adverse impact of using greenhouse gas SF6 gas on the environment, achieve environmental protection, but also reduce the manufacturing cost of preparing the ring main unit.

[0088] like Figure 3 As shown, the gas box 100 is a rectangular parallelepiped as a whole. It should be noted that the shape of the gas box 100 can be improved accordingly according to actual use and needs. The gas box 100 can be welded by a welding robot through programming and cooperation with a rotating tooling. The welding positioning is accurate and the weld is uniform, which can effectively improve the accuracy and strength of the gas box 100, and also reduce the gas leakage rate of the gas box 100, thereby making the gas box 100 have good air tightness.

[0089] The inner wall of the gas box 100 is provided with a fixed frame 1, and the fixed frame 1 and the inner wall of the ring main unit can be fixedly connected by welding. From the height direction of the ring main unit, the circuit breaker switch 2 is arranged on the upper layer of the fixed frame 1, and the three-position switch 3 is arranged on the middle layer of the fixed frame 1. The circuit breaker switch 2 and the three-position switch 3 are arranged up and down in the space of the gas box 100.

[0090] like Figure 4 As shown, three sealed poles 21 are arranged on the fixed frame 1 , and the three sealed poles 21 can correspond to three phases in the power supply network.

[0091] Please refer to Figure 4 and Figure 5 As shown, the circuit breaker switch 2 includes a sealed pole 21, a pole movable end 22, and a circuit breaker operating mechanism 23. The sealed pole 21 is arranged in the gas box 100, and the circuit breaker operating mechanism 23 is arranged in the mechanism chamber 300. The circuit breaker operating mechanism 23 is connected to the sealed pole 21 through the pole movable end 22. Under the drive of the circuit breaker operating mechanism 23, the static conductive rod and the movable conductive rod in the sealed pole 21 can be connected and disconnected.

[0092] like Figure 5 and Figure 6As shown, the solid-sealed pole 21 includes a pole body 211 and a moving end shielding seat 212 and a static end shielding seat 213 located at both ends of the pole body 211. The pole body 211 is fixed on the fixed frame 1, and the pole body 211, the moving end shielding seat 212 and the static end shielding seat 213 are cast into a whole by insulating resin. In this way, the design of integral casting of the solid-sealed pole 21 makes the contact between the pole body 211, the moving end shielding seat 212 and the static end shielding seat 213 closer. Compared with the separate arrangement of the pole body 211, the moving end shielding seat 212 and the static end shielding seat 213, these components are integrally cast by insulating resin to reduce the problems such as gaps or poor contact that may exist between the connection points of the components, so that the three can form a tight connection.

[0093] It should be noted that, as an insulating material, insulating resin can tightly combine the pole body 211, the moving end shielding seat 212 and the static end shielding seat 213 together by integral casting, thereby forming an integral insulating resin layer 2113, which provides electrical isolation for the whole composed of the pole body 211, the moving end shielding seat 212 and the static end shielding seat 213, reduces the risk of arcing and breakdown caused by the high voltage difference when the sealed pole 21 is used in the switch equipment, plays a more effective uniform electric field effect, and improves the insulation performance of the entire sealed pole 21.

[0094] Optionally, the insulating resin is epoxy resin.

[0095] like Figure 7 As shown, the pole body 211 includes a cylinder 2111 with a vacuum arc extinguishing chamber formed therein, a silicone sleeve 2112 wrapped around the outer surface of the cylinder 2111 , and an insulating resin layer 2113 coated on the outer surface of the silicone sleeve 2112 .

[0096] Specifically, a vacuum arc chamber is formed inside the pole body 211, and the two ends of the vacuum arc chamber are the first end and the second end respectively. It can be understood that the first end and the second end of the vacuum arc chamber correspond to the first end and the second end of the pole body 211 respectively. The second end of the vacuum arc chamber is correspondingly provided with a static conductive rod, and the second end of the vacuum arc chamber is correspondingly provided with a dynamic conductive rod 221 of the pole movable end 22. Among them, the dynamic conductive rod of the pole movable end 22 is used for transmission connection with the circuit breaker operating mechanism 23, so as to control the opening and breaking coordination between the dynamic conductive rod and the static conductive rod.

[0097] A silicone sleeve 2112 is nested on the outer surface of the cylinder 2111 of the pole body 211, so that the insulating resin covers the silicone sleeve 2112. In this way, compared with the problem of low bonding rate and easy generation of bubbles when the insulating resin and the vacuum interrupter are directly cast together, the surface of the vacuum interrupter is first coated with the silicone sleeve 2112. Since the silicone sleeve 2112 has a certain elasticity, it can be tightly connected with the vacuum interrupter. At the same time, after the insulating resin is cured and formed on the outer surface of the silicone sleeve 2112, the silicone sleeve 2112 can be more tightly combined with the insulating resin, and then the vacuum interrupter can be more tightly wrapped by the insulating resin, thereby forming a multi-layer tightly connected integrated structure, which has a better electrical isolation effect.

[0098] As attached Figure 7 and Figure 8 As shown, the moving end shielding seat 212 protrudes a boss 2124 toward the vacuum arc extinguishing chamber, and the boss 2124 contacts the top surface of the silicone sleeve 2112 .

[0099] As attached Figure 8 and Fig.10 As shown, the boss 2124 extends from the first connecting plate 2121 of the moving end shielding seat 212 toward the vacuum interrupter and abuts against the silicone sleeve 2112. In this way, in the process of integrally casting the moving end shielding seat 212 and the pole body 211, the boss 2124 can more effectively block the insulating resin outside the connection between the first connecting plate 2121 and the moving conductive rod 221 of the vacuum interrupter, and prevent the epoxy resin from penetrating into the vacuum interrupter through the connection between the moving end shielding seat 212 and the pole body 211 and solidifying, thereby affecting the movement of the moving conductive rod and reducing the flexibility of the moving conductive rod. In this way, the setting of the boss 2124 can reduce the problem of affecting the operating performance of the sealed pole due to the solidification of the epoxy resin outside the pole body 211.

[0100] like Fig. 9 and Fig.14 As shown, the movable end shielding seat 212 is provided with a first shielding cavity 201, so that the connection between the movable end 22 of the pole and the pole body 211 is located in the first shielding cavity 201, and the movable end shielding seat 212 can evenly distribute the electric field at the connection between the movable end 22 of the pole and the pole body 211.

[0101] like Fig. 9 and Fig.10 As shown, the moving end shielding seat 212 includes a first connecting plate 2121 and three first shielding plates 2122 extending upward from the first connecting plate 2121 . The first connecting plate 2121 and the first shielding plates 2122 together enclose a first shielding cavity 201 .

[0102] Optionally, the moving end shielding seat 212 can be formed by metal casting. The outer surface of the first shielding cavity 201 enclosed by the first connecting plate 2121 and the first shielding plate 2122 is covered with insulating resin, and the inner surface of the first shielding cavity 201 is a metal surface. Among them, the metal surface has good electrical conductivity and electromagnetic shielding effect, which can further optimize the electric field at the connection between the pole moving end 22 and the pole body 211.

[0103] Furthermore, the moving end shielding seat 212 is provided with a first opening 202, and the first opening 202 is communicated with the first shielding cavity 201. Figure 6 and Fig. 9 As shown, the first opening 202 is formed between two first connecting plates 2121 arranged opposite to each other, so that the pole movable end 22 can extend into the first shielding cavity 201 through the first opening 202. In this way, the risk of the electric field at the conductive connection part formed by the pole body 211 and the pole movable end 22 spreading outward can be reduced, and the phase-to-phase electric field interference in multi-phase electrical equipment or the interference of other externally generated electromagnetic fields on the pole movable end 22 can be reduced, thereby improving the insulation performance of the circuit breaker.

[0104] like Figure 5 As shown, the movable end shielding seat 212 is provided with a third opening 203, and the third opening 203 is communicated with the first shielding cavity 201. Specifically, the third opening 203 is formed at the top of the three first connecting plates 2121.

[0105] like Figure 5 and Fig. 9 As shown, two bosses 2123 are also provided on the moving end shielding seat 212, and the two bosses 2123 are respectively provided with first connection holes 204, so that the transmission arm 222 of the moving end 22 of the pole can be fixed on the moving end shielding seat 212 through the locking of the transmission pin 225 and the first connection hole 204, thereby avoiding the need to open a side hole on the pole body 211 to connect the transmission pin 225, improving the consistency of the sealed pole 21, effectively reducing potential insulation breakdown points, and thus improving the insulation performance of the circuit breaker switch 2. On the other hand, since there is no need to open a through hole or process hole on the pole body 211, the manufacturing process of the sealed pole 21 can be simplified and the assembly efficiency can be improved.

[0106] like Fig.11 As shown, the static end shielding seat 213 is provided with a second shielding cavity 205, and the second shielding cavity 205 can partially surround the connection between the second end of the pole body 211 and the conductive member. The conductive member may include but is not limited to an isolating static contact, a connector between the static end shielding seat 213 and the second end of the vacuum arc chamber, etc.

[0107] In detail, Figure 4 and Fig.12As shown, the isolating static contact 34 of the three-position switch 3 is located in the second shielding cavity 205, so that the electrical connection between the moving contact 36 of the three-position switch 3 and the isolating static contact 34 is located in the second shielding cavity 205, and the static end shielding seat 213 can form a physical barrier for the electrical connection between the two, thereby playing a role of electrical isolation.

[0108] like Fig.11 As shown, the static end shielding seat 213 includes a second connecting plate 2131 and two second shielding plates 2132 extending downward from the second connecting plate 2131. The second shielding plates 2132 are relatively arranged on opposite sides of the second connecting plate 2131. The second connecting plate 2131 and the second shielding plates 2132 enclose a second shielding cavity 205. Figure 6 As shown, a second opening 208 is formed between the second connecting plates 2131 arranged opposite to each other, and the second opening 208 allows the moving contact 36 of the three-position switch 3 to extend into the second shielding cavity 205 and further be electrically connected to the isolating static contact 34 .

[0109] As attached Figure 5 , Figure 6 and Figure 7 As shown, the surface of the pole body 211 is provided with a first insulating plate 24 protruding from the surface, and the first insulating plate 24 and the pole body 211 are integrally connected by pouring insulating resin. In this way, the surface of the first insulating plate 24 is covered with insulating resin. The provision of the first insulating plate 24 can increase the creepage distance of the surface of the pole body 211, thereby improving the overall insulation level of the sealed pole 21.

[0110] As attached Figure 6 As shown, the first opening 202 of the moving end shielding seat 212 and the second opening 208 of the static end shielding seat 213 are located on the same side of the pole body 211, and the first insulating plate 24 is located on the side where the circuit breaker operating mechanism 23 is transmission-connected to the crank arm shaft 224 of the moving end 22 of the pole, and the first insulating plate 24 is located between the moving end shielding seat 212 and the static end shielding seat 213. In this way, the first insulating plate 24 can be located between the high-voltage metal and the grounded metal positions. The provision of the first insulating plate 24 can increase the creepage distance, improve the creepage level of the sealed pole 21, and more effectively reduce the risk of the insulating resin layer 2113 on the surface of the pole body 211 being polarized and charged, thereby improving the overall insulation performance of the sealed pole 21.

[0111] Furthermore, two first insulating plates 24 are provided, and the two first insulating plates 24 are arranged opposite to each other, so as to further improve the creepage level and insulation performance of the surface of the sealed pole 21 .

[0112] As attached Figure 6 and Figure 7As shown, a second insulating plate 25 and a third insulating plate 26 are also provided on the surface of the pole body 211, wherein the second insulating plate 25 and the third insulating plate 26 are both located on the side of the pole body 211 away from the first insulating plate 24, the second insulating plate 25 is correspondingly arranged on the end where the moving end shielding seat 212 is located, and the third insulating plate 26 is correspondingly arranged on the end of the static end shielding seat 213, and the second insulating plate 25 and the third insulating plate 26 are both cast and connected to the pole body 211 by insulating resin.

[0113] The number of the second insulating plate 25 and the third insulating plate 26 can be set according to actual needs. Figure 7 As shown, the second insulating plates 25 and the third insulating plates 26 each include two.

[0114] In this way, from the perspective of the overall structure of the sealed pole 21, the pole body 211 is provided with a first insulating plate 24 on the side connected to the circuit breaker operating mechanism 23, and a second insulating plate 25 and a third insulating plate 26 on the side away from the side connected to the circuit breaker operating mechanism 23, which can more comprehensively and effectively increase the creepage distance on the surface of the pole body 211.

[0115] It should be noted that, from the position layout of the first insulating plate 24, the second insulating plate 25 and the third insulating plate 26, since the first end and the second end of the pole body 211 are the key parts for connecting the pole body 211 with the external circuit, the second insulating plate 25 and the third insulating plate 26 are respectively arranged on the movable end shielding seat 212 and the static end shielding seat 213 corresponding to these two ends, and the first insulating plate 24 is arranged on the side where the pole body 211 is transmission-connected to the circuit breaker operating mechanism 23, and the plate surfaces on the opposite sides of the first insulating plate 24 are respectively facing the positions of the high-voltage metal and the grounding metal, which can effectively improve the overall creepage distance of the sealed pole 21 and more effectively improve the insulation level of the sealed pole 21.

[0116] As attached Figure 6 and Figure 7 As shown, a fixing insert 29 is also provided on the pole body 211 . The fixing insert 29 is connected between the pole body 211 and the fixing frame 1 . The fixing insert 29 is used to connect with the fixing frame 1 , thereby fixing the pole body 211 on the fixing frame 1 .

[0117] Among them, the fixed insert 29 and the pole body 211 are connected as one by pouring insulating resin, so that the fixed insert 29 and the pole body 211 can be tightly connected as one, avoiding the fixed insert 29 affecting the uniformity of the electric field of the sealed pole 21, and further improving the overall insulation strength of the sealed pole 21.

[0118] Specifically, the fixing inserts 29 include three, and the positions of the three fixing inserts 29 constitute the three vertices of a triangle, wherein the fixing inserts 29 are provided at the positions of the three vertices of a triangle. Figure 7 The dotted triangle shown indicates the three positions of the three fixing inserts. Specifically, the positions of the three fixing inserts 29 constitute the three vertices of the triangle, thereby forming a triangular lock. The triangular structure has good stability, and the triangular lock formed by it can further enhance the fixing effect of the fixed pole 21 and the fixing frame 1, preventing the fixed pole 21 from shifting or loosening during operation.

[0119] As attached Figure 6 and attached Figure 7 As shown, the fixing insert 29 is columnar as a whole, and its surface is a curved surface. The shape design of the fixing insert 29 is conducive to optimizing the electric field distribution on the surface of the pole body and reducing the problem of electric field concentration caused by the setting of the fixing insert 29.

[0120] A sixth connection hole 209 is formed inside the fixing insert 29 , and the sixth connection hole 209 can allow the connecting member 13 to pass through, so that the fixing insert 29 is connected to the fixing frame 1 .

[0121] Please see attached Figure 5 and attached Fig.14 The pole movable end 22 includes a conductive rod 221 , a transmission crank arm 222 , an insulating pull rod 223 , a crank arm shaft 224 , a transmission pin 225 and a connecting cover plate 226 .

[0122] One end of the conductive rod 221 passes through the first opening 202 of the movable end shielding seat 212 and extends into the vacuum arc extinguishing chamber of the pole body 211 .

[0123] like Fig.10 and Fig.14 As shown, a through hole 210 is provided on the first connecting plate 2121 of the moving end shielding seat 212, and one end of the moving conductive rod 221 passes through the through hole 210 and then extends into the vacuum interrupter chamber of the pole body 211. Driven by the circuit breaker operating mechanism 23, the conductive rod 221 can move up and down in the opening, and then connect or disconnect with the static conductive rod in the vacuum interrupter chamber.

[0124] The transmission crank arm 222 includes a middle portion and a first end and a second end located at both ends of the middle portion. The first end of the transmission crank arm 222 extends into the first shielding cavity 201 through the first opening 202, and is then connected to the other end of the conductive rod 221. In this way, the portion where the conductive rod 221 is connected to the first end of the transmission crank arm 222 is located in the first shielding cavity 201. The moving end shielding seat 212 can electrically isolate the connection between the moving conductive rod 221 and the transmission crank arm 222, thereby reducing the influence of the electric field on the electric field of adjacent phases.

[0125] like Fig.14As shown, the second end of the transmission crank arm 222 is connected to the insulating pull rod 223 , and the circuit breaker switch 2 further includes a first input shaft 27 , which is transmission-connected between the second end of the transmission crank arm 222 and the circuit breaker operating mechanism 23 .

[0126] The first input shaft 27 is dynamically sealed and installed at the connection between the gas box 100 and the mechanism chamber 300 , so that the sealing performance of the gas box 100 can be improved, thereby reducing the risk of gas leakage between the transmission connection between the pole moving end 22 and the circuit breaker operating mechanism 23 .

[0127] It should be noted that the middle part of the transmission crank arm 222 constitutes the fulcrum of the lever, the second end of the transmission crank arm 222 is connected to the insulating pull rod 223, and the second end of the transmission crank arm 222 serves as the power input end. When the circuit breaker operating mechanism 23 drives the first input shaft 27 to rotate, the insulating pull rod 223 rotates with the rotation of the first input shaft 27, thereby driving the transmission crank arm 222 to rotate around its middle part. At this time, the force will be transmitted to the first end through the transmission crank arm 222, and the first end of the transmission crank arm 222 serves as the power output end, thereby driving the conductive rod 221 to move, and realizing the opening and breaking functions of the circuit breaker.

[0128] As attached Fig.14 And attached Fig.15 As shown, the other end of the movable conductive rod 221 is provided with a first groove 206 with an opening facing upward, and the transmission pin 225 penetrates the first end of the transmission crank arm 222 and is installed in the movable conductive rod 221 through the first groove 206. The connecting cover plate 226 is covered above the first groove 206 and connected to the movable conductive rod 221, so that the transmission pin 225 is limited in the first groove 206. In this way, the transmission pin 225 can be prevented from escaping from the first groove 206, so that the transmission pin 225 is limited in the first groove 206.

[0129] In detail, the transmission pin 225 on the transmission crank arm 222 can be firstly embedded in the other end of the moving conductive rod 221 through the first groove 206, and then covered on the first groove 206 through the connection cover plate 226 and installed on the other end of the moving conductive rod 221. The connection cover plate 226 is arranged correspondingly to the other end of the moving conductive rod 221, so that the connection cover plate 226 can cover the opening of the first groove 206 to limit the transmission pin 225 in the first groove 206. When the transmission crank arm 222 is driven by the circuit breaker operating mechanism 23 to perform the opening and closing operation, the first end of the transmission crank arm 222 uses the power to pull the moving conductive rod 221 to move through the transmission pin 225, thereby driving the moving conductive rod 221 to connect or disconnect with the static conductive rod.

[0130] Furthermore, since the connecting cover plate 226 is covered on the other end of the moving conductive rod 221, it can cover the electrical connection between the moving conductive rod 221 and the transmission crank arm 222, thereby reducing the exposed electrical connection part, so that the moving conductive rod 221, which is a conductive connecting piece 13, can reduce the problem of electric field concentration caused by the formation of a tip due to the transmission connection with the transmission crank arm 222, thereby improving the insulation performance of the transmission connection structure of the pole body 211.

[0131] like Fig.15 As shown, the movable conductive rod 221 is provided with two third connecting holes (not shown) located on the outer side of the first groove 206, the openings of the third connecting holes are arranged upward, and the two third connecting holes are arranged opposite to each other on both sides of the first groove 206, and fourth connecting holes (not shown) corresponding to the third connecting holes are respectively penetrated at both ends of the connecting cover plate 226, so that the connecting member 13 can pass through the third connecting hole and the fourth connecting hole to lock the connecting cover plate 226 and the movable conductive rod 221.

[0132] It should be noted that, by providing a first groove 206 on the other end of the moving conductive rod 221, and connecting the moving conductive rod 221 with the connecting cover plate 226 to connect the moving conductive rod 221 with the transmission crank arm 222, it is possible to avoid drilling holes on the pole body 211 as connecting holes, avoid destroying the consistency of the pole body 211, reduce potential breakdown points, and reduce the easy occurrence of breakdown due to the connecting holes, which is beneficial to improving the overall insulation performance of the circuit breaker.

[0133] like Figure 5 and Fig.13 As shown, the first end of the transmission crank arm 222 is provided with a second groove 207. The opening direction of the second groove 207 points from the outside to the inside, and the second groove 207 has a first side wall and a second side wall arranged opposite to each other. The other end of the moving conductive rod 221 and the connecting cover plate 226 are both inserted into the second groove 207. In this way, the first side wall, the second side wall and the connecting cover plate 226 of the transmission crank arm 222 can wrap the other end of the moving conductive rod 221, reduce the exposed electrical connection part, and further optimize the electric field distribution at the connection between the pole body 211 and the pole moving end 22.

[0134] As attached Fig. 9 and Fig.13 As shown, a crank arm shaft 224 is passed through the middle portion of the transmission crank arm 222, two bosses 2123 are formed on the movable end shielding seat 212, and the two bosses 2123 are respectively provided with first connecting holes 204, and the axial ends of the crank arm shaft 224 extending to the outside of the transmission crank arm 222 are inserted into the two first connecting holes 204 of the movable end shielding seat 212 through the connecting piece 13 and locked.

[0135] In this way, the transmission crank arm 222 is connected to the moving end shielding seat 212 through the crank arm shaft 224 and the connector 13, instead of directly opening a through hole or a process hole on the pole body 211 for pin connection, so that drilling holes on the pole body 211 can be avoided, thereby maintaining the consistency of the pole body 211, effectively reducing potential insulation breakdown points, and improving the insulation performance of the pole body 211. On the other hand, since there is no need to open a through hole or a process hole on the pole body 211, the manufacturing process of the circuit breaker is simplified, and the assembly process of the circuit breaker is simpler, which is conducive to improving assembly efficiency.

[0136] Furthermore, if Fig. 9 As shown, the first connection hole 204 is located in the first shielding cavity 201, so that the fixed connection point of the middle part of the transmission crank arm 222 can be located in the first shielding cavity 201, and the movable end shielding seat 212 can provide electrical isolation for the fixed connection end of the transmission crank arm 222, thereby improving the insulation level.

[0137] In another embodiment, Fig.13 As shown, a baffle is further provided at the location where the two first shielding plates 2122 form the first opening 202 , and the two protruding columns 2123 are disposed adjacent to the baffle and located on the inner side of the baffle.

[0138] In detail, Fig. 9 and Fig.13 As shown, second connecting holes (not shown) are respectively provided at both axial ends of the crank arm shaft 224, and the first connecting hole 204 is correspondingly arranged to allow the connecting member 13 to be inserted from above into the second connecting hole and the first connecting hole 204 to lock the crank arm shaft 224 and the boss 2123.

[0139] like Fig.13 As shown, a through hole is provided in the middle portion of the transmission crank arm 222 for the crank arm shaft 224 to pass through, and the crank arm shaft 224 is fixedly connected to the boss 2123 . Driven by the insulating pull rod 223 , the transmission crank arm 222 can rotate relative to the crank arm shaft 224 .

[0140] Please see attached Fig.14 The circuit breaker switch 2 further includes a flexible connection 28. One end of the flexible connection 28 is connected to the pole body 211 through a fixing member, and the connection between the flexible connection 28 and the pole body 211 is located in the first shielding cavity 201. The other end of the flexible connection 28 extends upward through the third opening 203 to connect the conductive loop. In this way, the portion of the flexible connection 28 and the pole body 211 that forms an electrical connection is located in the first shielding cavity 201, and the movable end shielding seat 212 can play a role in electric field isolation for the electrical connection between the flexible connection 28 and the pole body 211, thereby further improving the insulation level of the circuit breaker.

[0141] Specifically, the moving conductive rod 221 of the moving end 22 of the pole passes through one end of the soft connection 28 and extends into the vacuum arc extinguishing chamber in the pole body 211. A fixing part is connected to the moving conductive rod 221, and the fixing part fixes the soft connection 28 on the moving end of the pole body 211. The other end of the soft connection 28 extends upward through the opening at the top of the moving end shielding seat 212 and is connected to the conductive circuit.

[0142] Please see attached Fig.16 The gas box 100 also includes a side expansion sleeve 7, a main busbar 9 and a branch copper busbar 10.

[0143] The side expansion sleeves 7 are respectively installed on the two side walls of the air box 100 and are located above the sealed pole 21. A conductive rod 8 is passed through the side expansion sleeve 7. The conductive rod 8 includes a first end and a second end arranged along the axial direction. The first end 81 of the conductive rod is used to cooperate with the mother coupler for connection; the two ends of the main busbar 9 are respectively electrically connected to the second ends 82 of the conductive rods on both sides to form a conductive loop.

[0144] One end of the branch copper busbar 10 is connected to the main busbar 9 , and the other end of the branch copper busbar 10 is connected to the soft connection 28 .

[0145] Among them, the first end 81 of the conductive rod set in the expansion sleeve 7 on both sides can respectively realize busbar connection with the adjacent ring network cabinet, and the second end 82 of the conductive rod set in the expansion sleeve 7 on both sides is respectively connected to the two ends of the main busbar 9, so as to form a conductive loop. One end of the branch copper bar 10 is connected to the main busbar 9, and the other end of the branch copper bar 10 is connected to the soft connection 28, so that the circuit breaker switch 2 can be electrically connected to the conductive loop, so that the power supply system can supply power to each ring network cabinet, and when the circuit breaker switch 2 in the ring network cabinet receives the power supply system, it can be distributed according to the preset control logic to realize the power supply function.

[0146] Please see attached Fig.17 To Attachment Fig.19 The side expansion sleeve 7 includes an insulating partition 71 and a second outer sleeve 72. The second outer sleeve 72 has two axial ends, a first end and a second end. The first end is provided with an insulating partition 71, and the second end is used to be installed on the ring main unit. The conductive rod 8 is provided in the second outer sleeve 72 along the axial direction of the second outer sleeve 72. The second end 82 of the conductive rod extends out of the second outer sleeve 72 and extends to the insulating partition 71. The first end 81 of the conductive rod is configured as a ball for connecting with the mother coupling.

[0147] Among them, the insulating partition 71 encloses and forms a uniform electric field cavity 701, the second end 82 of the conductive rod is located in the uniform electric field cavity 701, and the second end 82 of the conductive rod is provided with a fifth connection hole 801 with an opening facing downward relative to the horizontal installation direction of the side expansion sleeve 7, one end of the main busbar 9 is inserted from below into the fifth connection hole 801 of one of the conductive rods 8 through the connector 13 and locked, and the other end of the main busbar 9 is inserted from below into the fifth connection hole 801 of the other conductive rod 8 through the connector 13 and locked. By setting the opening of the fifth connection hole 801 on the conductive rod 8 to face downward, the main busbar 9 can be inserted from below and locked through the connector 13, so that when the main busbar 9 is installed on the side expansion sleeve 7, it will not be limited by the installation space between the expansion sleeves 7 on both sides.

[0148] It is understandable that, due to the insertion and locking method from below, the staff does not need to perform complicated operations in a small space, and only needs to simply insert and lock the connector 13, which simplifies the installation process and improves the installation efficiency. On the other hand, it is conducive to designing a smaller ring network cabinet, and when the space on both sides is limited, it does not affect the effective installation between the main busbar 9 and the side expansion sleeve 7.

[0149] Furthermore, the uniform electric field cavity 701 enclosed by the insulating partition 71 can provide electrical isolation for the electrical connection structure in the cavity, which is equivalent to the uniform electric field cavity 701 formed by the insulating partition 71 can make the overlap of the electrical connection between the conductive rod 8 and the main busbar 9 isolated from the external electrical formation area, thereby preventing the influence of external electrical interference on the electrical connection, and preventing electrical leakage from the electrical connection between the conductive rod 8 and the main busbar 9, thereby improving the insulation strength of the electrical connection structure of the main busbar 9. In this way, while the overall size of the ring network cabinet can be reduced, the uniformity of the electric field and the interphase insulation strength can be improved to meet the corresponding insulation performance requirements of the small ring network cabinet.

[0150] The insulating partition 71 may be made of an insulating material. For example, the insulating material used by the insulating partition 71 may be epoxy resin. The insulating partition 71 may be designed to be integrally cast with the second outer sleeve 72 by epoxy resin.

[0151] Please see attached Fig.18 The insulating partition 71 is composed of two oppositely arranged partitions and a third partition connected between the two oppositely arranged partitions. The two oppositely arranged partitions are located on both sides of the overlap between the main busbar 9 and the conductive rod 8. The electrical connection structure of the main busbar 9 and the conductive rod 8 adjacent to each other on the same side can be separated by the insulating partition 71, thereby further increasing the interphase insulation strength.

[0152] The connection between each shielding surface 702 of the insulating partition 71 is an arc transition. In this way, the arc transition between each shielding surface 702 can reduce the sudden change of the electric field at the connection between the shielding surfaces 702, make the electric field distribution more uniform, and avoid the electric field being too concentrated at the connection between the shielding surfaces 702 of the insulating partition 71, thereby improving the electrical insulation performance of the main busbar 9 and the ring network cabinet in the uniform electric field cavity 701.

[0153] Please see attached Fig.18 and attached Fig.19 The top outer surface of the second end 82 of the conductive rod is set to be an arc surface.

[0154] like Fig.19 As shown, the top outer surface of the second end 82 of the conductive rod is also the surface of the end of the conductive rod 8. Setting the surface as an arc surface can make the electric field smoothly transition on the end surface of the conductive rod 8, thereby reducing the electric field concentration phenomenon and making the electric field distribution more uniform. In addition, the arc surface also has good electrical insulation performance, is not easy to generate charge accumulation, and thus optimizes the electric field distribution at the electrical connection between the side expansion sleeve 7 and the conductive rod 8.

[0155] As attached Fig.16 and attached Fig.19 As shown, a cut surface 802 is formed on the circumferential side wall of the second end 82 of the conductive rod, and the cut surface 802 is used to fit with the main busbar 9 when the main busbar 9 is installed, and the fifth connection hole 801 is located at the cut surface 802. In this way, when the main busbar 9 is installed, the cut surface 802 can form a tight fit with the main busbar 9, which not only increases the contact area, improves the efficiency of current transmission, and reduces the risk of electrical failure caused by poor contact, but also, after the main busbar 9 is assembled at the cut surface 802 and locked with the conductive rod 8, it can avoid that the connection structure between the main busbar 9 and the conductive rod 8 is too thin, and more effectively reduce the occurrence of electric field concentration at the tip of the main busbar 9.

[0156] The fifth connection hole 801 provided on the second end 82 of the conductive rod is configured as a blind hole so that the end of the connector 13 is covered in the conductive rod 8 to prevent the other end of the connector 13 from passing through the conductive rod 8 through the fifth connection hole 801 to form a tip electric field concentration.

[0157] Please see attached Figure 3 , Attachment Figure 4 And attached Fig. 20 The ring main unit also includes a three-position switch 3 arranged in the gas box 100 and a three-position operating mechanism 4 arranged in the mechanism chamber 300. The three-position switch 3 includes a grounding contact seat 31, a plurality of grounding contacts 32 and a grounding shielding seat 33 arranged on the grounding contact seat 31, an isolating static contact 34, a moving contact seat 35 and a moving contact 36 rotatably arranged on the moving contact seat 35.

[0158] There are three grounding contacts 32 , three isolating static contacts 34 and three moving contacts 36 , respectively corresponding to the three phases in the power supply network.

[0159] like Fig. 20 As shown, the three-position operating mechanism 4 is transmission-connected to the moving contact 36 of the three-position switch 3. Driven by the three-position operating mechanism 4, the moving contact 36 can be selectively electrically connected to the isolating static contact 34 or the grounding contact 32 by rotating.

[0160] It should be noted that the three-position switch 3 includes three working states, including the closed position in which the moving contact 36 is connected to the isolating switch, that is, the moving contact 36 is in a position electrically connected to the isolating static contact 34; including the grounding position with the grounding side, that is, the moving contact 36 is in a position electrically connected to the grounding contact 32; including the isolating position in which the main break is separated, that is, the moving contact 36 is in a state of being disconnected from both the isolating static contact 34 and the grounding contact 32.

[0161] like Fig.21 As shown, the grounding contact seat 31 is arranged on the fixed frame 1, the grounding shield seat 33 is covered on the grounding contact seat 31, and the three grounding contacts 32 are located in the shielding space formed between the grounding shield seat 33 and the grounding contact seat 31. The grounding shield seat 33 is configured as an integrally formed metal part, and the grounding shield seat 33 is provided with a plurality of openings 301 corresponding to the plurality of grounding contacts 32 to expose each grounding contact 32.

[0162] Among them, the grounding shielding seat 33 is made of a conductive metal part, and the three-phase grounding contact 32 is uniformly wrapped by the same metal part, which can evenly distribute the electric field of the grounding contact 32 and reduce the risk of excessive local electric field; moreover, the metal material of the grounding shielding seat 33 can have a good electromagnetic shielding effect on the grounding contact 32, reducing the risk of electric field diffusion during the electrical connection between the moving contact 36 and the grounding contact 32, which is beneficial to the electrical stability of the three-position switch 3.

[0163] Furthermore, compared with the single-phase grounding contact 32 in the related art that is individually shielded, the grounding shielding seat 33 is formed in one piece with metal parts, which can reduce the manufacturing and installation costs and reduce the assembly and welding processes. The traditional single-phase individual shielding may easily increase the risk of electrical failure due to assembly or connection problems. The integrated design of the grounding shielding seat 33 reduces this risk and improves the insulation performance and reliability of the three-position switch 3. Based on the overall size of the three-position switch 3, the integrated molding of the grounding shielding seat 33 can wrap the grounding contact 32 more compactly, which is conducive to reducing the overall size of the three-position switch 3, making the structure more compact and suitable for small-sized ring network cabinets.

[0164] For example, the ground shielding seat 33 can be formed by an integrated sheet metal.

[0165] Please see attached Fig.21 The ground shielding seat 33 is an arched plate formed by bending a metal part. The arched plate and the grounding contact seat 31 enclose a shielding space. Each grounding contact 32 is distributed in the shielding space at intervals, and each grounding contact 32 is exposed through the opening 301 of the arched plate. The arched plate is formed by bending a metal part, and the preparation process of the grounding shielding seat 33 is relatively simple and the cost is low.

[0166] like Figure 4 and Fig.12 As shown, each isolating static contact 34 is located in the second shielding cavity 205 of the corresponding static end shielding seat 213. The static end shielding seat 213 can provide electrical isolation for the isolating static contact 34, so that the electric field between the three phases of the circuit breaker is isolated and the insulation performance is improved.

[0167] like Fig. 20 As shown, the moving contact 36 includes a middle portion and a first end and a second end located at both ends of the middle portion. The first end is rotatably disposed on the moving contact seat 35. The second end of the moving contact 36 is used to selectively electrically connect to the grounding contact 32 or the isolating static contact 34. The middle portion is used for transmission connection with the three-position operating mechanism 4.

[0168] The three-position switch 3 further includes a connecting arm 37 and a second input shaft 38 , and two ends of the connecting arm 37 are respectively connected between the middle portion of the moving contact 36 and the three-position operating mechanism 4 .

[0169] The second input shaft 38 is dynamically sealed and installed at the connection between the gas box 100 and the mechanism chamber 300. In this way, the sealing performance of the gas box 100 can be improved, thereby reducing the risk of gas leakage between the transmission connection of the three-position switch 3 and the three-position operating mechanism 4.

[0170] Specifically, under the drive of the three-station operating mechanism 4, the second input shaft 38 can rotate around its axis. For example, the second input shaft 38 rotates clockwise around its axis, thereby driving the connecting crank arm 37 and the moving contact 36 connected to the connecting crank arm 37 to rotate clockwise, and the second end of the moving contact 36 can rotate to the grounding shielding seat 33 along the clockwise rotation, and extend into the shielding space through the opening 301 of the grounding shielding seat 33, and connect with the grounding contact 32 located in the shielding space. The second end of the moving contact 36 can rotate to the bottom of the static end shielding seat 213 along the counterclockwise rotation, and extend into the second shielding cavity 205 through the second opening 208 of the static end shielding seat 213, and connect with the isolating static contact 34 located in the second shielding cavity 205. In this way, the three-position switch 3 disclosed in the present application can optimize the electric field at the electrical connection positions of the moving contact 36, the grounding contact 32 and the isolating static contact 34, reduce the risk of electric field interference between multiple phases or other external electromagnetic field interference, thereby improving the insulation level of the three-position switch 3.

[0171] As attached Fig. 20 As shown, a first shielding cover 5 is provided at the connection between the first end of each moving contact 36 and the moving contact seat 35, so that the first end of the moving contact 36 is located in the space surrounded by the first shielding cover 5, thereby improving the electric field distribution at the first end of the moving contact 36.

[0172] The second end of the moving contact 36 is provided with a second shielding cover 6, which is used to make the electric field of the second end uniform, and the second shielding cover 6 can extend into the static end shielding seat 213 or the grounding shielding seat 33 as the second end rotates.

[0173] Please see attached Figure 1 The ring main unit also includes an outlet bushing 11, which is arranged below the three-position switch 3, and includes a first outer bushing and an outlet conductive end arranged in the first outer bushing. One end of the first outer bushing is connected to the side wall of the ring main unit gas box 100.

[0174] Please see attached Figure 4 And attached Fig. 22 The ring main unit further comprises a copper rod 12, one end of the copper rod 12 is electrically connected to the moving contact 36, the other end of the copper rod 12 is connected to the outgoing conductive end, and the connection between the copper rod 12 and the outgoing conductive end is located in the first outer sleeve. Figure 3 As shown, the first outer sleeve can wrap the electrical connection between the copper rod 12 and the conductive end of the outgoing line, thereby forming a physical barrier for the electrical connection between the two and playing a role in electrical isolation.

[0175] In the present application, the electric field distribution of the circuit breaker switch 2 and the three-position switch 3 is optimized at places where electric field concentration may occur, so as to meet the insulation performance requirements of a small-sized ring main unit filled with dry air as the insulating gas. Among them, the sealed pole 21 in the circuit breaker switch 2 is cast into a whole by using insulating resin to form the pole body 211 and the moving end shielding seat 212 and the static end shielding seat 213 located at both ends of the pole body 211. The transmission crank arm 222 is connected to the moving end shielding seat 212 through the crank arm shaft 224 to avoid penetrating the connection hole on the pole body 211, which can maintain the consistency of the sealed pole 21, thereby effectively improving the insulation performance of the circuit breaker switch 2; by uniformly wrapping the grounding contact 32 in the three-position switch 3 in the shielding space surrounded by the grounding shielding seat 33 and the grounding contact seat 31, the electric field distribution of the grounding contact 32 can be uniform, reducing the risk of excessive local electric field, and the one-piece molding of the grounding shielding seat 33 can more compactly wrap the grounding contact 32, and can also reduce the size of the three-position switch 3. Furthermore, the design of optimizing the electric field is also made at the incoming and outgoing ends of the ring network cabinet. At the incoming line end of the ring network cabinet, by fastening the main busbar 9 and the side expansion sleeve 7 in an up-and-down connection, it is conducive to designing a ring network cabinet with a smaller size, so that when the space on both sides is limited, it does not affect the effective installation between the main busbar 9 and the side expansion sleeve 7, and the electric field is also optimized at the electrical connection between the main busbar 9 and the side expansion sleeve 7, further improving the insulation performance of the electrical connection between the main busbar 9 and the side expansion sleeve 7. At the outgoing line end of the ring network cabinet, the electrical connection between the copper rod 12 and the conductive end of the outgoing line is wrapped to make the electric field of the electrical connection between the two uniform. Through the above-mentioned structural improvement, the purpose of reducing the size of the ring network cabinet is achieved, and the insulation capacity requirements of the dry air filled in the ring network cabinet as the insulating gas are met. The cabinet depth of the ring network cabinet disclosed in the present invention can be reduced to 865mm, the cabinet width can be reduced to 450mm, and the cabinet height is 1800mm. Compared with the traditional ring main unit with a cabinet depth of more than 900 mm and a cabinet width of more than 550 mm, the size of the ring main unit disclosed in the present invention is significantly reduced, and the dry air filled in the air box 100 is also more environmentally friendly.

[0176] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the present invention.

Claims

1. A ring main unit, characterized in that: include: an air box filled with dry air; A fixed frame, fixed on the inner wall of the air box; A circuit breaker switch, the circuit breaker switch is arranged on the fixed frame, and comprises: A sealed pole, comprising a pole body and a moving end shielding seat and a static end shielding seat located at both ends of the pole body, wherein the pole body is fixed on the fixed frame, and the pole body, the moving end shielding seat and the static end shielding seat are formed into a whole by pouring insulating resin; A three-position switch is arranged on the fixed frame, the circuit breaker switch is arranged on the upper layer of the fixed frame, and the three-position switch is arranged on the middle layer of the fixed frame. The three-position switch includes: A grounding contact seat, a plurality of grounding contacts arranged on the grounding contact seat, and a grounding shielding seat, wherein the grounding contact seat is arranged on the fixed frame, the grounding shielding seat cover is arranged on the grounding contact seat, and the plurality of grounding contacts are located in a shielding space formed between the grounding shielding seat and the grounding contact seat, the grounding shielding seat is configured as an integrally formed metal part, and the grounding shielding seat is provided with a plurality of openings corresponding to the plurality of grounding contacts to expose each of the grounding contacts.

2. The ring main unit according to claim 1, characterized in that: The ring main unit has a width of 450 mm, a depth of 865 mm and a height of 1800 mm.

3. The ring main unit according to claim 1 or 2, characterized in that: Two convex columns are formed on the movable end shielding seat, the convex columns are located in the first shielding cavity of the movable end shielding seat, and the two convex columns are provided with first connecting holes; The circuit breaker switch further comprises a pole movable end, which comprises a movable conductive rod, one end of which passes through the movable end shielding seat and extends into the vacuum interrupter chamber of the pole body; and A transmission crank arm, comprising a middle portion and a first end and a second end located at two ends of the middle portion, the other end of the conductive rod being connected to the first end of the transmission crank arm; and An insulating pull rod connected to the second end of the transmission crank arm; as well as The crank arm shaft is passed through the middle part of the transmission crank arm, and the parts of the crank arm shaft extending to the outside of the transmission crank arm at both axial ends are inserted into the two first connecting holes of the movable end shielding seat through connecting pieces and locked.

4. The ring main unit according to claim 3, characterized in that: The movable end of the pole also includes a transmission pin and a connecting cover plate, both of which are located in the first shielding cavity of the movable end shielding seat, the transmission pin is passed through the first end of the transmission crank arm, and the other end of the movable conductive rod is provided with a groove opening upward, the transmission pin is installed in the movable conductive rod through the groove, and the connecting cover plate is covered above the groove and connected to the movable conductive rod so that the transmission pin is limited to be located in the groove.

5. The ring main unit according to claim 3, characterized in that: The circuit breaker switch also includes a circuit breaker operating mechanism, the ring main unit is also provided with a mechanism chamber, the circuit breaker operating mechanism is located in the mechanism chamber, the circuit breaker switch also includes a first input shaft, the first input shaft is transmission-connected to the insulating pull rod, so as to drive the conductive rod to move in the vacuum interrupter chamber under the drive of the circuit breaker operating mechanism; The first input shaft dynamic seal is installed at the connection between the air box and the mechanism chamber.

6. The ring main unit according to claim 3, characterized in that: The movable end shielding seat is located at the movable end of the pole body, and the movable end shielding seat is provided with a first shielding cavity and a first opening. The convex column, the movable conductive rod and the crank arm shaft are located in the first shielding cavity, and the transmission crank arm extends into the first shielding cavity through the first opening; The static end shielding seat is located at the static end of the pole body, and the static end shielding seat is provided with a second shielding cavity and a second opening. The three-position switch also includes an isolating static contact, a moving contact seat, and a moving contact rotatably arranged on the moving contact seat. The isolating static contact is located in the second shielding cavity, and the moving contact can rotate relative to the moving contact seat to selectively combine with the isolating static contact or the grounding contact.

7. The ring main unit according to claim 6, characterized in that: The surface of the pole body is provided with a first insulating plate protruding from the surface, the first opening and the second opening are both located on the same side of the pole body, the first insulating plate is located on the side where the circuit breaker operating mechanism is transmission-connected to the crank arm shaft, and the first insulating plate is arranged between the moving end shielding seat and the static end shielding seat; The first insulating plate is integrally connected to the pole body by pouring the insulating resin.

8. The ring main unit according to claim 6, characterized in that: The moving contact comprises a middle portion and a first end and a second end located at both ends of the middle portion, the first end of the moving contact is rotatably connected to the moving contact seat, and the second end of the moving contact is used to selectively electrically connect to the grounding contact or the isolating static contact; The three-position switch also includes a connecting crank arm and a second input shaft, and the ring network cabinet also includes a three-position operating mechanism arranged in the mechanism chamber. The two ends of the connecting crank arm are respectively connected between the middle part of the moving contact and the three-position operating mechanism, and the second input shaft dynamic seal is installed at the connection between the air box and the mechanism chamber.

9. The ring main unit according to claim 1 or 2, characterized in that: The circuit breaker switch also includes a flexible connection, one end of which is connected to the pole body through a fixing member, and a connection between the flexible connection and the pole body is located in a first shielding cavity of the moving end shielding seat, and a third opening communicating with the first shielding cavity is provided above the moving end shielding seat, and the other end of the flexible connection extends upward through the third opening to connect a conductive circuit.

10. The ring main unit according to claim 9, characterized in that: The air box also includes: The side expansion sleeves are respectively installed on the side walls of the gas box and located above the sealed pole. A conductive rod is inserted into the side expansion sleeve. The conductive rod includes a first end and a second end arranged along the axial direction. The first end of the conductive rod is used to cooperate with the mother coupler for connection. A main busbar, two ends of which are electrically connected to the second ends of the conductive bars on both sides to form the conductive loop; A branch copper busbar connected between the flexible connector and the main busbar; Among them, the side expansion sleeve is provided with a uniform electric field cavity, and the uniform electric field cavity is surrounded by an insulating partition. The second end of the conductive rod extends to the uniform electric field cavity, and the second end of the conductive rod is provided with a fifth connecting hole opening downward relative to the horizontal installation direction of the side expansion sleeve. One end of the main busbar is inserted from below into the fifth connecting hole of one of the conductive rods through a connecting piece and locked, and the other end of the main busbar is inserted from below into the fifth connecting hole of another conductive rod through a connecting piece and locked.

11. The ring main unit according to claim 10, characterized in that: The top outer surface of the second end of the conductive rod is configured as an arc surface; and / or A cut surface is formed on the circumferential side wall of the second end of the conductive rod, and the cut surface is used to fit with the main busbar when the main busbar is installed, and the fifth connecting hole is located at the cut surface.

12. The ring main unit according to claim 10, characterized in that: The insulating partition is arranged on an end face of the side expansion sleeve facing the other side expansion sleeve, and the insulating partition includes three shielding surfaces, and the three shielding surfaces enclose the uniform electric field cavity, wherein the end face of the side expansion sleeve and the three shielding surfaces form four faces of a hexahedral structure, and the other two faces of the hexahedral structure are in an open state, wherein one of the open faces is arranged toward the bottom of the side expansion sleeve and opposite to the sealed pole, and the fifth connecting hole is arranged toward one of the open faces.

13. The ring main unit according to claim 6, characterized in that: Also includes: An outlet bushing, which is arranged below the three-position switch, and comprises a first outer sleeve and an outlet conductive end arranged in the first outer sleeve; as well as A copper rod, one end of which is electrically connected to the moving contact, and the other end of which is connected to the conductive end of the outgoing line. The connection between the copper rod and the conductive end of the outgoing line is located in the first outer sleeve.

14. The ring main unit according to claim 1 or 2, characterized in that: The pole body is also provided with a fixing insert, the fixing insert is connected between the pole body and the fixing frame, and the fixing insert and the pole body are integrally connected by pouring the insulating resin; The fixing inserts include three parts, and the positions of the three fixing inserts constitute three vertices of a triangle.

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