Main busbar structure for electrical connection between ring main units, and ring network power supply system

Abstract

Provided in the present disclosure are a main busbar structure (200) for electrical connection between ring main units (6), and a ring network power supply system (100). The main busbar structure comprises side-expansion bushings (1), electrically conductive connection portions (2) and a main busbar (3), wherein the two side-expansion bushings (1) are respectively mounted on two sides of each ring main unit (6); a uniform electric field cavity (101) enclosed by an insulating partition plate (11) is provided at one end of each side-expansion bushing (1); each electrically conductive connection portion (2) is provided in the corresponding uniform electric field cavity (1); each electrically conductive connection portion (2) is provided with a first connection hole (201) having a downward opening relative to the horizontal mounting direction of the corresponding side-expansion bushing (1); and one end of the main busbar (3) is inserted from below into the first connection hole (201) of one side-expansion bushing (1) by means of one connection member (4) and locked, and the other end of the main busbar (3) is inserted from below into the first connection hole (201) of the other side-expansion bushing (1) by means of the other connection member (4) and locked. By means of the optimization of the structural design of the main busbar (3) and the side-expansion bushings (1), the problem of insufficient mounting space for the overlap between the ring main units (6) and the main busbar is solved; and the uniform electric field cavity (101) is arranged at an electrical connection position between the main busbar (3) and each side-expansion bushing (1), thereby achieving the miniaturization of the ring main units (6) while improving the electric field uniformity and phase-to-phase insulation strength.

Description

Main busbar structure for electrical connection between ring main units and ring power supply system

[0001] This application claims priority to Chinese Patent Application No. 2024106901823, filed on May 30, 2024, and Chinese Patent Application No. 202421220952.X, filed on May 30, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of ring main unit technology, and mainly to a main busbar structure for electrical connection between ring main units and a ring power supply system. Background Technology

[0003] In power grid systems, to improve power supply reliability, the power grid is typically connected in a ring, allowing users to obtain power from two directions; this power supply method is called ring network power supply. Multiple ring main units are connected via main busbars, which are usually locked to the bushings from the side with screws. However, for smaller cabinets, due to the poor insulation properties of air, side-locking can lead to insufficient spacing between bushings, failing to meet insulation performance requirements. Furthermore, the limited cabinet width restricts the space for installing the main busbars, requiring skilled installers and increasing installation difficulty. Increasing the cabinet width would increase the space required for the ring main unit, hindering its miniaturization design. Summary of the Invention

[0004] This application proposes a ring main unit that can achieve miniaturization and improve the insulation performance of the ring main unit.

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

[0006] This application discloses a main busbar structure for electrical connection between ring main units, comprising: two side expansion sleeves configured to be installed on both sides of a ring main unit respectively, each side expansion sleeve having a uniform electric field cavity at one end, the uniform electric field cavity being enclosed by an insulating partition, a conductive connection portion being provided inside the uniform electric field cavity, the conductive connection portion having a first connection hole opening downward relative to the horizontal installation direction of the side expansion sleeve; and a main busbar, one end of which is inserted from below into the first connection hole of one of the side expansion sleeves and locked by a connector, and the other end of which is inserted from below into the first connection hole of another side expansion sleeve and locked by another connector.

[0007] This application discloses a ring network power supply system, including multiple ring network cabinets. The ring network power supply system includes a main busbar structure for electrical connection between ring network cabinets as described in any of the above embodiments. The main busbar structure is disposed in a ring network cabinet. The other end of the expansion sleeve on one side of the main busbar structure is connected to one of the adjacent ring network cabinets, and the other end of the expansion sleeve on the other side of the main busbar structure is connected to another adjacent ring network cabinet.

[0008] This application provides a main busbar structure for electrical connection between ring main units, comprising side expansion sleeves, conductive connecting parts, and a main busbar. By providing a downward-facing opening for the first connecting hole on the conductive connecting part, the main busbar can be inserted and locked from below using a connector. This eliminates the need to consider the installation space between the two side expansion sleeves when installing the main busbar on the side expansion sleeves, effectively avoiding space limitations on both sides and achieving efficient installation even in small cabinets. Furthermore, workers do not need to perform complex operations in confined spaces; they can simply insert and lock the connector, simplifying the installation process and improving efficiency. Simultaneously, a uniform electric field cavity is provided at one end of the side expansion sleeve, enclosed by an insulating partition. This insulating partition isolates the overlap between the conductive rod and the main busbar from external electrical sources, preventing electrical leakage at the connection point. This results in a more uniform electric field distribution at the overlap between the main busbar and the ring main unit, reducing electric field concentration and increasing interphase insulation strength. In summary, the main busbar structure for electrical connection between ring main units disclosed in this application solves the problem of insufficient installation space in small-sized cabinets by optimizing the structural design of the main busbar and the side expansion bushing, thereby reducing the overall size of the ring main unit and achieving miniaturization of the cabinet. While reducing the cabinet volume, the insulation performance of the cabinet is also taken into account. By setting a uniform electric field cavity enclosed by an insulating partition at the electrical connection between the main busbar and the side expansion bushing, the uniformity of the electric field and the interphase insulation strength are improved, which further promotes the miniaturization design of the cabinet. Attached Figure Description

[0009] The above and / or additional aspects and features of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0010] Figure 1 is a schematic diagram of the connection between the main busbar structure and the ring main unit of a ring power supply system according to an exemplary embodiment;

[0011] Figure 2 is a schematic diagram of a ring network power supply system according to an exemplary embodiment;

[0012] Figure 3 is a cross-sectional view of the connection between the main busbar structure and the ring main unit of a ring power supply system according to an exemplary embodiment;

[0013] Figure 4 is a magnified view of part A in Figure 3;

[0014] Figure 5 is a magnified view of part B in Figure 3;

[0015] Figure 6 is a perspective view of a side-expanding sleeve according to an exemplary embodiment;

[0016] Figure 7 is a side view of a side-expanding sleeve according to an exemplary embodiment;

[0017] Figure 8 is a cross-sectional view at the section line in Figure 7;

[0018] Figure 9 is a schematic diagram showing the electrical connection between the switching mechanism and the main busbar structure according to an exemplary embodiment.

[0019] Implementation of this disclosure

[0020] The embodiments of this application are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0021] Figures 1 and 2 illustrate the electrical connection structure between two ring network cabinets in the ring network power supply system 100. Figures 1 through 8 only show the parts of the structure that differ from the prior art.

[0022] As shown in Figure 2, to improve power supply reliability and allow users to obtain power from two directions, the power supply network is usually connected in a ring, i.e., a ring power supply system 100. This power supply method is simply referred to as ring power supply. The high-voltage switchgear used in the ring power supply system 100 is generally referred to as a ring main unit.

[0023] Ring main units typically have multiple internal compartments, such as circuit breaker compartments, busbar compartments, cable compartments, and relay / instrument compartments. Additionally, the ring main unit 6 shown in Figures 1 and 3 is actually the side panel of the ring main unit; the structural diagram of the ring main unit is simplified here.

[0024] Multiple ring main units 6 are electrically connected through main busbar structures 200. Typically, as shown in Figure 1, the main busbar structure 200 includes three groups, each group of main busbar structures 200 corresponding to one phase of the ring power supply system 100, that is, the three phase main busbar structures 200 of the three-phase power supply.

[0025] Please refer to Figure 3. Taking one set of main busbar structures 200 used for electrical connection between ring main units 6 as an example, the main busbar structure 200 is installed in the cabinet of a ring main unit. The main busbar structure 200 includes a side expansion sleeve 1 and a main busbar 3.

[0026] The two ends of the main busbar 3 are connected by a side expansion sleeve 1 and a bus coupler, respectively, so that the two ring main units adjacent to the main busbar unit can be connected by busbar. A conductive rod 13 is provided inside the side expansion sleeve 1. The end of the conductive rod 13 away from the main busbar 3 is connected to one end of the bus coupler. The other end of the bus coupler is connected to the conductive rod 13 of the side expansion sleeve 1 of another ring main unit. In this way, adjacent ring main units can be electrically connected through the side expansion sleeve 1.

[0027] Further, please refer to Figure 1. In this embodiment, the two side expansion sleeves 1 are respectively installed inside the ring main unit 6 and are located on opposite sides of the ring main unit 6. The two side expansion sleeves 1 are respectively connected to their respective adjacent ring main units through bus couplers.

[0028] The side expansion sleeve 1 includes an insulating partition 11, an outer sleeve 12, and a conductive rod 13. The conductive rod 13 is provided with a first connection hole 201, through which the main busbar 3 is electrically connected to the conductive rod 13.

[0029] The main busbar 3 and the conductive rod 13 are electrically connected by a connector 4. For example, the first connecting hole 201 is a threaded hole, and the connector 4 is a bolt or screw. After the connector 4 passes through the main busbar 3, it is locked to the conductive rod 13 through the first connecting hole 201.

[0030] The outer sleeve 12 has two axial ends, namely a first end 121 and a second end 122. An insulating partition 11 is provided on the first end 121, and the second end 122 is used to install on the ring main unit 6. For example, the second end 122 of the outer sleeve 12 is fastened to the cabinet of the ring main unit 6 by bolts, so as to achieve a stable connection between the side expansion sleeve 1 and the ring main unit 6.

[0031] As shown in Figures 7 and 8, the side expansion sleeve 1 provided in this embodiment also includes a convex ring 14. The tube surface of the outer sleeve 12 is provided with a convex ring 14 that protrudes relative to the tube surface. There are multiple convex rings 14, and the multiple convex rings 14 are spaced apart along the axial direction of the outer sleeve 12.

[0032] In electrical equipment, uneven electric field distribution may lead to partial discharge and electrical faults. By setting the convex ring 14 and spacing it along the axial direction of the outer sleeve 12, the electric field can be distributed more evenly on the surface of the outer sleeve 12, reducing the risk of electric field distortion and electric field concentration.

[0033] For example, the outer tube 12 is made of epoxy resin. The raised ring 14 is an epoxy resin that is cast and molded to protrude from the tube surface of the outer tube 12. Epoxy resin has good insulation properties; similarly, the outer tube 12 can be made of other materials with good insulation properties.

[0034] In actual preparation and production, the outer sleeve 12 and the convex ring 14 can be integrally formed.

[0035] As shown in Figures 3 and 6, a uniform electric field cavity 101 is provided at one end of the side expansion sleeve 1. The uniform electric field cavity 101 is surrounded by an insulating partition 11, and the connection between the conductive rod 13 and the main busbar 3 is located inside the uniform electric field cavity 101.

[0036] It is understandable that the insulating partition 11 is made of insulating material. The insulating partition 11 forms a uniform electric field cavity 101, which can provide electrical isolation for the electrical connection structure inside the cavity. That is, the uniform electric field cavity 101 formed by the insulating partition 11 can make the overlap of the electrical connection between the conductive rod 13 and the main busbar 3 form an isolation area from the external electrical environment, thereby preventing the influence of external electrical interference on the electrical connection and preventing electrical leakage at the electrical connection between the conductive rod 13 and the main busbar 3, thereby improving the insulation strength of the main busbar structure 200.

[0037] For example, the insulating material used for the insulating partition 11 may be epoxy resin.

[0038] In some implementations, the insulating partition 11 can be designed to be integrally cast with the outer sleeve 12 using epoxy resin. Specifically, the insulating partition 11 is disposed on one end face of the outer sleeve 12 facing the other side of the expansion sleeve 1. As shown in Figures 1 and 3, the outer sleeves 12 disposed on the two sides of the ring main unit 6 are arranged opposite each other, and the ends of the outer sleeves 12 with the insulating partition 11 are adjacent to each other.

[0039] The insulating partition 11 includes three shielding surfaces 102, which together form a uniform electric field cavity 101. The shielding surfaces 102 provide electrical isolation between the conductive rod 13 and the main busbar 3, preventing the electric field from leaking from the conductor to the external environment, reducing the risk of electric field concentration at the electrical connection between the main busbar 3 and the expansion sleeve, and improving the insulation strength.

[0040] As shown in Figure 6, the insulating partition 11 is composed of two oppositely arranged partitions and a third partition connecting the two oppositely arranged partitions. The two oppositely arranged partitions are located on both sides of the overlap between the main busbar 3 and the ring main unit 6, which further increases the phase-to-phase insulation strength.

[0041] In some implementations, the connections between the shielding surfaces 102 are rounded. In this way, compared with sharp corners, the rounded transitions between the shielding surfaces 102 can reduce the abrupt changes in the electric field at the connection of the shielding surfaces 102, making the electric field distribution more uniform. This helps to reduce the risk of the electric field being too concentrated at the connection of the shielding surfaces of the insulating partition 11, thereby improving the electrical insulation performance of the main busbar 3 and the ring main unit 6 overlapping in the uniform electric field cavity 101.

[0042] The connection points between each shielding surface 102 of the insulating partition 11 and the end face of the outer sleeve 12 are rounded. In this way, the connection points between the shielding surfaces 102 enclosed by the insulating partition 11, as well as the connection points between the shielding surfaces 102 and the end faces, are all rounded, reducing the risk of the formation of electric field concentration areas within the uniform electric field cavity 101, and further improving the effect of uniform electric field distribution within the uniform electric field cavity 101.

[0043] As shown in Figures 3 and 8, the conductive rod 13 is partially located inside the outer sleeve 12. Specifically, the conductive rod 13 is arranged axially within the outer sleeve 12. One end of the conductive rod 13 extending outwards from the first end forms the conductive connection part 2, and the other end of the conductive rod 13 is used for connection with the bus coupler. In this way, both ends of the conductive rod 13 are connected to the main busbar 3 and the bus coupler, respectively, enabling the various ring main units 6 to form a ring circuit through this structure.

[0044] One axial end of the conductive rod 13 is configured as a conductive connection part 2, which is disposed within the uniform electric field cavity 101. The conductive connection part 2 is provided with a first connection hole 201 positioned relative to the horizontal installation direction of the side expansion sleeve 1, with the opening of the first connection hole 201 facing downwards. By providing a downward-facing opening for the first connection hole 201 on the conductive connection part 2, the main busbar 3 can be inserted and locked from below by the connector 4. Thus, when installing the main busbar 3 on the side expansion sleeve 1, it is not restricted by the installation space between the two side expansion sleeves 1.

[0045] Understandably, because of the bottom-insertion locking method, workers do not need to perform complicated operations in a confined space. They can simply insert and lock the connector, which simplifies the installation process and improves installation efficiency.

[0046] Furthermore, the end faces of the insulating partition 11 and the outer sleeve 12 form four faces of a hexahedral structure, and the other two faces of the hexahedral structure are in an open state. The first connecting hole 201 is set facing one of the open faces.

[0047] As shown in Figure 6, the insulating partition 11 is configured with three circumferential surfaces of the conductive connection part 2, and the other surface is the end face of the outer sleeve 12. One of the surfaces of the hexahedron structure that is set to be open is opposite to the end face of the outer sleeve 12, and the other surface of the hexahedron structure that is set to be open is opposite to the side facing the first connection hole 201.

[0048] The first connection hole 201 has one side facing the open state that allows the operator to operate it, so that the operator can connect the main busbar 3 to the conductive rod 13 through the open state.

[0049] In some implementations, the hexahedral structure is configured with one of its open faces facing downwards, allowing the operator to install the main busbar 3 and the conductive connection part 2 from bottom to top through this open face.

[0050] Furthermore, the top outer surface 203 of the conductive connection portion 2 is configured as an arc surface.

[0051] As shown in Figures 6 and 8, the top outer surface 203 of the conductive connection portion 2, i.e., the end surface, is designed as an arc surface. This allows the electric field to transition smoothly across the end surface of the conductive connection portion 2, thereby reducing electric field concentration and making the electric field distribution more uniform. Moreover, the arc surface also has better electrical insulation properties, as it has no sharp edges and corners, making it less prone to charge accumulation.

[0052] As shown in Figure 6, the conductive connection part 2 is spherical in shape. A cut surface 202 is formed on the circumferential sidewall of the conductive connection part 2. When the main busbar 3 is installed, the cut surface 202 is used to fit with the main busbar 3. The first connection hole 201 is located at the cut surface 202.

[0053] First, considering that the overlap between the conductive connection part 2 and the main busbar 3 is usually a sharp point, which is prone to electric field concentration and discharge phenomenon, the conductive connection part 2 is designed as a sphere. The outer surface of the sphere is smoothly transitioned, which can reduce electric field concentration at the corners and distribute the electric field evenly.

[0054] Secondly, the cut surface 202 provided on the circumferential sidewall of the conductive connection part 2 can ensure that the cut surface 202 fits tightly with the main busbar 3 when it is installed. This not only increases the contact area but also improves the efficiency of current transmission and reduces the risk of electrical faults caused by poor contact. Moreover, when the main busbar 3 is assembled at the cut surface 202 and locked with the conductive connection part 2, the structure of the main busbar 3 and the conductive connection part 2 is prevented from being too thin, thus more effectively preventing the electric field concentration at the tip of the main busbar 3.

[0055] Referring to Figures 3 and 4, it can be understood that after the main busbar 3 and the conductive connection part 2 are locked together, the main busbar 3 and the conductive connection part 2 form an integral whole. The integral conductive connection part 2 is spherical, which can effectively avoid electric field concentration, and is conducive to achieving uniform electric field distribution, high efficiency of current transmission and structural stability, thus providing reliable electrical performance guarantee for the electrical connection between the ring main units 6.

[0056] As shown in Figure 8, the first connection hole 201 provided on the conductive connection part 2 is configured as a blind hole so that the end of the connector 4 is covered inside the conductive connection part 2. In this way, the risk of the other end of the connector 4 forming a sharp point after passing through the first connection hole 201 and the conductive connection part 2, thereby causing electric field concentration, can be reduced.

[0057] Furthermore, considering the aforementioned conductive connection part 2 is provided with a cut surface 202 and a first connection hole 201, when the main busbar 3 is assembled at the cut surface 202 and locked with the conductive connection part 2, the main busbar 3 is equivalent to forming an integral whole with the conductive connection part 2, and the connector 4 is also covered inside the conductive connection part 2, which can achieve a more uniform electric field distribution and make the overlap between the main busbar 3 and the conductive connection part 2 have good electrical insulation performance.

[0058] As shown in Figure 8, the other end of the conductive rod 13 is configured as a ball, which is used to connect with the bus coupler (not shown). Since the end of the conductive rod 13 that connects to the bus coupler is spherical, it can achieve a smooth and tight connection with the bus coupler, reducing friction and resistance during the connection process. This makes the ring network power supply structure formed by the connection between the ring main units reliable and has stable electrical connection.

[0059] As shown in Figure 4, the connector head of the connector has an arc-shaped surface. Based on the installation structure of connector 4, main busbar 3, and conductive connection part 2, it can be seen that after connector 4 locks the main busbar 3 to conductive connection part 2, the connector head of connector 4 abuts against the other end of the main busbar 3 away from conductive connection part 2. By setting the connector head of connector 4 to an arc-shaped surface, the arc-shaped surface is less prone to charge accumulation, thereby reducing electric field concentration and distortion, and lowering the risk of partial discharge.

[0060] From the electrical connection structure between the main busbar 3 and the ring main units 6 on both sides, one end of the main busbar 3 is locked by inserting a connector 4 from below into the first connection hole 201 of one side of the expansion sleeve 1, and the other end is locked by inserting another connector 4 from below into the first connection hole 201 of the other side of the expansion sleeve 1.

[0061] As shown in Figure 3, the two ends of the main busbar 3 are connected to the two side ring network cabinets 6 through the side expansion sleeves 1. The conductive connection part 2 of the side expansion sleeve 1 has a first connection hole 201 facing downward, so that the two ends of the main busbar 3 can be installed on the side expansion sleeves 1 on both sides in an up-down installation manner.

[0062] It should be noted that the smaller the size of the ring main unit 6, the weaker its insulation. In particular, during the miniaturization design of the ring main unit 6, which uses dry air as the insulating gas, the insulation performance of the unit must be considered while reducing its size.

[0063] The main busbar structure 200 of this application provides an insulating partition 11 at the electrical connection between the main busbar 3 and the conductive connection part 2. The insulating partition 11 forms a uniform electric field cavity 101, thereby surrounding the electrical connection between the main busbar 3 and the conductive connection part 2 and providing electrical isolation for the electrical connection structure inside the cavity. This is equivalent to the insulating partition 11 forming an electrical isolation area between the uniform electric field cavity 101 and the outside.

[0064] Furthermore, within the uniform electric field cavity 101, the connection between the shielding surfaces 102 of the insulating partition 11 is an arc transition, and the top outer surface 203 of the conductive connection part 2 is set as an arc surface. The cut surface 202 formed by the circumferential sidewall of the conductive connection part 2 can fit against the main busbar 3, thereby installing the main busbar 3 and the conductive connection part 2 together. In this way, the conductive connection part 2 and the main busbar 3 can form an integral spherical structure after connection. The above structural improvement can make the electric field distribution at the overlap between the main busbar 3 and the conductive connection part 2 within the uniform electric field cavity 101 more uniform, thereby increasing the interphase insulation strength, reducing electric field concentration, and enabling the ring main unit 6 to meet the electrical insulation performance requirements in miniaturized design.

[0065] Based on the electrical insulation performance requirements for miniaturizing the ring main unit 6, the installation structure of the side expansion sleeve 1 and the main busbar 3 is further optimized. Specifically, the main busbar 3 can be inserted and locked from below through the connector 4, so that when designing the ring main unit 6, there is no need to consider the space limitations on both sides, further realizing the miniaturization design of the ring main unit 6.

[0066] It should be noted that, compared to existing technologies, this main busbar structure 200 can be applied to a 24KV ring main unit 6, and the air box of the ring main unit 6 only needs to be filled with dry air. The main busbar structure 200 of this application improves upon the aforementioned structural aspects. For example, addressing the problem of electric field concentration due to charge accumulation at the tip of the electrical connection between the conductive connection part 2 and the main busbar 3, an insulating plate is added around the conductive connection part 2 to provide electrical isolation. Setting the top outer surface 203 of the conductive connection part 2 as an arc surface uniformly improves the electric field at the electrical connection between the conductive connection part 2 and the main busbar 3, thereby effectively enhancing the insulation performance of the ring main unit 6. Furthermore, the main busbar and the side expansion bushing are connected vertically, thus solving the problem of insufficient installation space in a small cabinet width, allowing for a reduction in the overall size of the ring main unit 6, thereby achieving miniaturization of the ring main unit.

[0067] As shown in Figures 3 and 5, the main busbar structure 200 of this embodiment also includes a branch copper busbar 5, which is connected to the main busbar 3 via a connector 4. The other end of the branch copper busbar 5 is used for electrical connection with the switching mechanism 7 of the ring main unit 6. In this way, the power supply system supplies power to the power supply trunk line formed by the electrical connection between the main busbar 3 and the ring main unit 6, and the branch copper busbar 5 can draw power from the power supply trunk lines on both sides, thereby improving the reliability of power supply.

[0068] As shown in Figure 9, the switching mechanism 7 is a key component in the ring network power supply system 100, responsible for controlling the distribution and protection of electrical energy. For example, the switching mechanism 7 can be a three-position switch. When the switching mechanism 7 receives electrical energy from the main busbar structure 200, it distributes the energy according to the preset control logic. A portion of the electrical energy continues to be transmitted to other equipment or loads through the branch copper busbar 5 to achieve the power supply function.

[0069] Specifically, the branch copper busbar 5 is provided with a second connection hole 501 that is positioned in a horizontal installation direction relative to the side expansion sleeve 1, and the opening of the second connection hole 501 is facing upward. One end of the branch copper busbar 5 is inserted into the second connection hole 501 from above and locked by a connector 4.

[0070] The second connection hole 501 on the branch copper busbar 5 faces upward, allowing the connector 4 (such as a bolt) to be inserted from above and locked between the branch copper busbar 5 and the main busbar 3. This assembly method of connecting the upper and lower parts facilitates installation by operators, especially in the space-constrained ring main unit 6, which simplifies the installation process and improves work efficiency.

[0071] Furthermore, the connector 4 connecting the branch copper busbar 5 and the main busbar 3 has an arc-shaped surface at its connector head, which makes it less likely for charge to accumulate at the overlap between the branch copper busbar 5 and the main busbar 3.

[0072] As shown in Figures 3 and 5, the second connection hole 501 is configured as a blind hole so that the end of the connector 4 is covered within the branch copper busbar 5. This blind hole design ensures that the end of the connector 4 is completely covered within the branch copper busbar 5, which not only improves the stability and reliability of current transmission and reduces the risk of electric field distortion and concentration caused by the exposed end of the connector 4 extending beyond the branch copper busbar 5, but also enhances the mechanical connection strength between the connector 4 and the branch copper busbar 5, preventing loosening or detachment due to external factors.

[0073] Another aspect of this disclosure discloses a ring network power supply system 100, including multiple ring network cabinets 6, wherein a main busbar structure 200 is provided in the ring network cabinet for electrical connection with other ring network cabinets 6, the other end of one side expansion sleeve 1 of the main busbar structure 200 is connected to one of the adjacent ring network cabinets 6, and the other end of the other side expansion sleeve 1 of the main busbar structure 200 is connected to another adjacent ring network cabinet 6.

[0074] By adopting the main busbar structure 200 described above, the ring power supply system 100 realizes the electrical connection between the ring network cabinets 6 in the ring power supply system 100. Moreover, the ring power supply system 100 can be configured with smaller ring network cabinets 6, which is conducive to making the structure of the entire ring power supply system 100 more compact and reasonable.

[0075] On the other hand, the main busbar structure 200 in the ring power supply system 100 has the structural characteristics of simple structure, easy installation, uniform electric field distribution and high electrical insulation performance, which enables the application of the main busbar structure 200 in the ring power supply system 100 to ensure stable and efficient current transmission and reduce the risk of electrical faults.

[0076] The ring main unit also includes a switching mechanism. The other end of the branch copper busbar 5 of the main busbar structure 200 is connected to the switching mechanism of the ring main unit 6 so that the switching mechanism draws power from the branch copper busbar 5.

[0077] Furthermore, the main busbar structure 200 includes three sets, each set of main busbar structure 200 corresponding to one phase of the ring power supply system 100. As shown in Figure 1, the three sets of main busbar structures 200 are correspondingly arranged for the three phases in the ring power supply system 100.

[0078] It is understood that those skilled in the art can make equivalent substitutions or changes based on the technical solutions and utility model concepts of this disclosure, and all such substitutions or changes should fall within the protection scope of this disclosure.

Claims

1. A main busbar structure for electrical connection between ring main units, comprising: The two side expansion sleeves are configured to be installed on both sides of a ring network cabinet respectively. A uniform electric field cavity is provided at one end of each side expansion sleeve. The uniform electric field cavity is surrounded by an insulating partition. A conductive connection part is provided inside the uniform electric field cavity. A first connection hole with an opening facing downward relative to the horizontal installation direction of the side expansion sleeve is provided on the conductive connection part. The main busbar has one end inserted from below into the first connecting hole of one of the side-expanding sleeves and locked, and the other end inserted from below into the first connecting hole of the other side-expanding sleeve through another connecting piece and locked.

2. The main busbar structure for electrical connection between ring main units according to claim 1, wherein, The insulating partition includes three shielding surfaces, which together form the uniform electric field cavity, and the connection between the shielding surfaces is a rounded transition.

3. The main busbar structure for electrical connection between ring main units according to claim 2, wherein, The side expansion sleeve includes an outer sleeve and a conductive rod partially located inside the outer sleeve. One end of the conductive rod extending out of the outer sleeve is the conductive connection part. The insulating partition is disposed on one end face of the outer sleeve facing the other side expansion sleeve. The connection between each shielding surface of the insulating partition and the end face of the outer sleeve is a rounded transition.

4. The main busbar structure for electrical connection between ring main units according to claim 3, wherein, The outer sleeve has two axial ends, namely a first end and a second end. The first end is provided with the insulating partition, and the second end is configured to be installed on the ring main unit. The conductive rod is arranged inside the outer sleeve along the axial direction. One end of the conductive rod extends out of the first end and is the conductive connection part. The other end of the conductive rod is configured in a spherical shape to cooperate with the bus coupler.

5. The main busbar structure for electrical connection between ring main units according to claim 3, wherein, The end faces of the insulating partition and the outer sleeve form four faces of a hexahedron structure, and the other two faces of the hexahedron structure are open. The first connecting hole is oriented toward one of the open faces.

6. The main busbar structure for electrical connection between ring main units according to claim 3, wherein, The outer tube has a raised ring on its surface, which protrudes from the tube surface. There are multiple raised rings, which are spaced apart along the axial direction of the outer tube.

7. The main busbar structure for electrical connection between ring main units according to claim 1, wherein, The top outer surface of the conductive connection is set as an arc surface.

8. The main busbar structure for electrical connection between ring main units according to claim 1, wherein, The conductive connection part is spherical in shape, and a cut surface is formed on the circumferential sidewall of the conductive connection part. The cut surface is configured to fit against the main busbar when the main busbar is installed, and the first connection hole is located at the cut surface.

9. The main busbar structure for electrical connection between ring main units according to claim 1, wherein, The first connection hole is configured as a blind hole so that the end of the connector is covered within the conductive connection portion.

10. The main busbar structure for electrical connection between ring main units according to claim 1, wherein, The connector head of the connector has an arc-shaped surface.

11. The main busbar structure for electrical connection between ring main units according to any one of claims 1 to 10, wherein, It also includes branch copper busbars, which are connected to the main busbars via connectors.

12. The main busbar structure for electrical connection between ring main units according to claim 11, wherein, The branch copper busbar is provided with a second connecting hole with its opening facing upward relative to the horizontal installation direction of the side expansion sleeve. One end of the branch copper busbar is inserted into the second connecting hole from above and locked in place by a connector.

13. The main busbar structure for electrical connection between ring main units according to claim 12, wherein, The second connection hole is configured as a blind hole so that the end of the connector is covered within the branch copper busbar.

14. A ring network power supply system, comprising multiple ring network cabinets, wherein, Includes a main busbar structure for electrical connection between ring main units as described in any one of claims 1 to 13, wherein the main busbar structure is disposed in a ring main unit, the other end of one side expansion sleeve of the main busbar structure is connected to one of the adjacent ring main units, and the other end of the other side expansion sleeve of the main busbar structure is connected to another adjacent ring main unit.

15. The ring network power supply system according to claim 14, wherein, The ring main unit is also equipped with a switching mechanism. The other end of the branch copper busbar of the main busbar structure is connected to the switching mechanism so that the switching mechanism can draw power from the branch copper busbar.

16. The ring network power supply system according to claim 14 or 15, wherein, The main busbar structure includes three groups, and each group of the main busbar structure corresponds to one phase of the ring network power supply system.

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