A ring main unit cabinet

Abstract

The utility model discloses an embodiment provides a kind of ring main unit of ring network cabinet, comprising: multiple cable support, multiple current transformers, multiple expansion mother connectors;Each cable support includes two, one is set in the left inner wall of the ring network cabinet mother connection cabinet, another is set in the right inner wall of the ring network cabinet mother connection cabinet;The number of the cable support group is same with the number of the expansion mother connector, and one expansion mother connector is connected between each cable support group;The number of the expansion mother connector is same with the number of the current transformer;One current transformer is provided outside each expansion mother connector. Through the scheme of the embodiment of the utility model, cable support can be set in the left and right inner walls of ring network cabinet mother connection cabinet, and expansion mother connector is set between each cable support, so that current transformer is set outside expansion mother connector, the setting of current transformer is realized, and the problem that current transformer cannot be set in traditional ring network cabinet mother connection cabinet is solved.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment technology, and in particular to a ring main unit bus tie cabinet. Background Technology

[0002] Currently, ring main units (RMUs) and bus tie units, as electrical equipment for assembled ring main power supply units, are widely used in substations and prefabricated substations in load centers such as urban residential areas, high-rise buildings, large public buildings, and factories. Fully insulated RMU bus tie units typically have all internal components sealed within a gas-insulated enclosure, with cabinets connected via special busbar connectors. There are no externally accessible components, and the bus tie unit also connects the busbars at both ends. However, with current fully insulated and sealed designs, the copper busbars are all inside the stainless steel gas-insulated enclosure, making it impossible to install current transformers and thus preventing corresponding protective actions based on current signals. Utility Model Content

[0003] The purpose of this utility model embodiment is to provide a ring main unit bus tie cabinet to solve the problem that current transformers cannot be installed in the ring main unit bus tie cabinet. The specific technical solution is as follows:

[0004] This utility model provides a ring main unit with multiple cable supports, multiple current transformers, and multiple expansion connectors.

[0005] Each set of cable supports includes two, one located on the left inner wall of the ring main unit bus coupler cabinet and the other located on the right inner wall of the ring main unit bus coupler cabinet;

[0006] The number of cable support groups is the same as the number of expansion female connectors, and each group of cable support groups is connected by an expansion female connector.

[0007] The number of expansion female connectors is the same as the number of current transformers; each expansion female connector has a current transformer on its outer side.

[0008] In one possible implementation, the cable support is located at the bottom of the ring main unit bus coupler.

[0009] Each set of cable supports includes two, one located on the left inner wall at the bottom of the ring main unit and the other located on the right inner wall at the bottom of the ring main unit.

[0010] In one possible implementation, each set of cable supports includes two, one connected to the incoming cable and the other connected to the outgoing cable.

[0011] In one possible implementation, a sealed air chamber is also provided on the upper part of the ring main unit.

[0012] In one possible implementation, the air chamber is provided with a plurality of circuit breakers; the number of circuit breakers is the same as the number of groups of cable supports;

[0013] Each circuit breaker is connected to a set of cable supports, with one end of the circuit breaker connected to one of the cable supports in the set and the other end of the circuit breaker connected to another of the cable supports in the set.

[0014] In one possible implementation, the air chamber is further provided with a plurality of busbar inner cones; the number of the busbar inner cones is the same as the number of sets of cable supports;

[0015] Each busbar inner cone is connected to a set of cable supports, one end of which is connected to the circuit breaker, and the other end of which is connected to one of the cable supports in the set.

[0016] In one possible implementation, the plurality of current transformers are arranged in a stepped manner.

[0017] In one possible implementation, the cabinet of the ring main unit is a metal or non-metal insulated cabinet.

[0018] In one possible implementation, the cable support comprises three sets, each connected to one phase of the busbar.

[0019] In one possible implementation, the current transformer is a bushing current transformer.

[0020] This utility model provides a ring main unit (RNB) bus coupler cabinet, comprising: multiple sets of cable supports, multiple current transformers, and multiple expansion connectors; each set of cable supports includes two, one disposed on the left inner wall of the RNB bus coupler cabinet and the other disposed on the right inner wall of the RNB bus coupler cabinet; the number of sets of cable supports is the same as the number of expansion connectors, and each set of cable supports is connected by an expansion connector; the number of expansion connectors is the same as the number of current transformers; a current transformer is disposed on the outside of each expansion connector. Through the solution of this utility model embodiment, cable supports are disposed on the left and right inner walls of the RNB bus coupler cabinet, and expansion connectors are disposed between each cable support, thereby allowing current transformers to be disposed on the outside of the expansion connectors, thus solving the problem of the inability to install current transformers in traditional RNB bus coupler cabinets.

[0021] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0023] Figure 1 A diagram showing the orientation of a ring main unit busbar cabinet provided for an embodiment of this utility model;

[0024] Figure 2 A diagram showing another orientation of a ring main unit bus coupler provided for an embodiment of this utility model;

[0025] Figure 3 This is another view of a ring main unit / bus connector provided for an embodiment of this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Cable support; 2. Current transformer; 3. Busbar connector; 4. Busbar inner cone; 5. Circuit breaker. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art based on this application are within the protection scope of the present utility model.

[0029] To address the problem that current transformers cannot be installed in traditional ring main unit bus tie cabinets, this utility model provides a ring main unit bus tie cabinet.

[0030] See Figure 1 ,Book Figure 1 A diagram showing the orientation of a ring main unit bus coupler cabinet provided for an embodiment of this utility model includes: multiple sets of cable supports 1, multiple current transformers 2, and multiple expansion connectors 3; specifically, the... Figure 1 This can be a schematic diagram of the ring main unit and bus coupler unit viewed from back to front.

[0031] Each set of cable supports 1 includes two, one set on the left inner wall of the ring main unit bus coupler cabinet, and the other set on the right inner wall of the ring main unit bus coupler cabinet;

[0032] The number of cable support posts 1 is the same as the number of expansion female connectors 3, and each group of cable support posts 1 is connected by an expansion female connector 3.

[0033] The number of expansion connectors 3 is the same as the number of current transformers 2; each expansion connector 3 has a current transformer 2 on its outer side.

[0034] In this embodiment of the invention, the cable support 1 can be used to support and fix the cable, ensuring cable stability. Specifically, in actual use, the cable support 1 in this embodiment can be made of metal or composite material. Specifically, the metal material can be angle steel, and the composite material can be fiberglass. The current transformer 2 in this embodiment can be used to convert the measured current signal into a usable electrical signal. Specifically, the current transformer 2 can convert a large current into a small current and output it based on the principle of electromagnetic induction. The expansion connector 3 in this embodiment, as a dedicated expansion connection component for ring main units, can be used for busbar splicing between cabinets to achieve a fully insulated and fully sealed electrical connection. Specifically, the expansion connector 3 can include conductive components and insulating materials. The conductive components can include high-purity silver-plated copper parts with built-in spring contacts, which optimize current carrying capacity through linear contact surfaces and can support 360° rotation and ±30° deflection. The insulating material can include a silicone rubber jacket, which provides full shielding protection, is high-temperature resistant and anti-aging, and ensures uniform distribution of the internal electric field. In one embodiment of this utility model, the expansion connector 3 can be a side-expansion type, which enables horizontal expansion. In this embodiment, the expansion connector 3 not only facilitates installation but also allows for easy electrical connection simply by inserting the connector, eliminating the need for complex wiring and enabling standardized production.

[0035] In this embodiment, multiple sets of cable supports 1 are included. Each set of cable supports 1 includes two supports: one disposed on the left inner wall of the ring main unit's bus tie cabinet, and the other disposed on the right inner wall of the same unit. Specifically, one side can be the incoming side, and the other side can be the outgoing side. For example, the left side can be the incoming side and the right side the outgoing side, or vice versa. It should be noted that the ring main unit's bus tie cabinet in this embodiment can be a special type of cabinet within a ring main unit, used to connect the busbars at both ends. Therefore, the lines connected to the cable supports 1 in this embodiment can be busbars. Furthermore, each set of cable supports 1 is connected via expansion connectors 3. Specifically, multiple expansion connectors 3 can be included, and the number of expansion connectors 3 can be the same as the number of sets of cable supports 1, with a one-to-one correspondence.

[0036] In this embodiment, the number of expansion connectors 3 is the same as the number of current transformers 2; each expansion connector 3 has a current transformer 2 disposed on its outer side. In one example, the current transformer 2 in this embodiment can measure current through electromagnetic induction, so the current transformer 2 can be disposed on the outer side of the expansion connector 3, specifically, it can be nested on the outer side of the expansion connector 3. Traditional bus tie cabinets usually use circuit breaker cabinets, and for the circuit breaker to achieve its protective function, it needs to be used in conjunction with relay protection. The relay protection needs to collect the signal from the current transformer 2. Existing solutions generally follow a fully insulated and sealed approach, with the copper busbars inside a stainless steel air chamber. Therefore, it is impossible to install the current transformer 2, resulting in the circuit breaker not being able to achieve its protective function. However, the solution proposed in this application can achieve the installation of the current transformer 2, thereby realizing the protective function of the circuit breaker.

[0037] As can be seen, the solution of this utility model embodiment includes: multiple sets of cable supports 1, multiple current transformers 2, and multiple expansion connectors 3; each set of cable supports 1 includes two, one disposed on the left inner wall of the ring main unit bus tie cabinet, and the other disposed on the right inner wall of the ring main unit bus tie cabinet; the number of sets of cable supports 1 is the same as the number of expansion connectors 3, and each set of cable supports 1 is connected by an expansion connector 3; the number of expansion connectors 3 is the same as the number of current transformers 2; a current transformer 2 is disposed on the outside of each expansion connector 3. Through the solution of this utility model embodiment, by setting cable supports 1 on the left and right inner walls of the ring main unit bus tie cabinet and setting expansion connectors 3 between each cable support 1, a current transformer 2 can be disposed on the outside of the expansion connector 3, thus solving the problem that current transformers 2 cannot be disposed in traditional ring main unit bus tie cabinets.

[0038] In one possible implementation, the cable support 1 is located at the bottom of the ring main unit's bus coupler cabinet; each set of cable supports 1 includes two, one located on the left inner wall of the bottom of the ring main unit's bus coupler cabinet, and the other located on the right inner wall of the bottom of the ring main unit's bus coupler cabinet. It should be noted that, in this embodiment, to achieve the installation of the cable support 1 at the bottom of the ring main unit's bus coupler cabinet, the cabinet body of the ring main unit's bus coupler cabinet can be heightened, for example, the height of the cabinet body can be 1.4m, 1.5m…2m, etc. In one example, the height of the cabinet body can be 1400mm, the length is 753mm, and the width is 696mm. In one possible implementation, each set of cable supports 1 includes two, one connected to the incoming cable and the other connected to the outgoing cable. For example, the left side can be the incoming side and the right side the outgoing side, or vice versa. In one possible implementation, the cabinet body of the ring main unit's bus coupler cabinet is a metal or non-metal insulated cabinet.

[0039] In one possible implementation, a sealed gas chamber is also provided at the top of the ring main unit's bus coupler cabinet. The gas chamber in this embodiment can be filled with SF6 (sulfur tetrafluoride) gas or other insulating gases. These gases have excellent insulation properties, effectively isolating high-voltage components and preventing arcing, short circuits, and other electrical faults. The gas chamber design in this embodiment allows high-voltage components such as circuit breakers and disconnectors to be sealed within a gas-filled housing, making them less susceptible to external environmental influences such as condensation, dirt, small animals, and chemicals. Specifically, the gas chamber's functions also include: insulation protection: the gas within the chamber provides excellent insulation, ensuring effective protection for high-voltage components under normal operation and fault conditions, preventing arcing, short circuits, and other electrical faults; environmental isolation: the gas chamber isolates high-voltage components from the external environment, preventing external factors such as condensation, dirt, small animals, and chemicals from affecting the equipment, thereby extending the equipment's service life and stability; and the gas chamber design also enables miniaturization of the cabinet: due to the insulating properties of the gas, switchgear can be miniaturized, reducing volume and weight, and improving portability and installation flexibility. The protective and insulating function of the air chamber ensures the safe and stable operation of the electrical components in the ring main unit and bus coupler cabinet in this embodiment of the invention.

[0040] In one possible implementation, see Figure 2 ,Book Figure 2This diagram illustrates another perspective of a ring main unit (RMU) bus coupler cabinet provided in this embodiment of the present invention. Specifically, it is a schematic diagram of the RMU bus coupler cabinet provided in this embodiment of the present invention viewed from right to left. The RMU bus coupler cabinet provided in this embodiment of the present invention may further include circuit breakers 5. Specifically, multiple circuit breakers 5 are installed inside the air chamber; the number of circuit breakers 5 is the same as the number of cable support groups 1; each circuit breaker 5 is connected to a group of cable support groups 1, with one end of the circuit breaker 5 connected to one of the cable support groups 1, and the other end of the circuit breaker 5 connected to another cable support group 1. The main function of the circuit breaker 5 in this embodiment of the present invention is to protect the circuit and equipment safety, specifically including overload protection, short circuit protection, personal safety protection, equipment isolation, and system stability maintenance functions. Specifically, the circuit protection features include overload and short-circuit protection. When the circuit exceeds its rated value, it automatically disconnects to prevent overheating of wires or damage to equipment. The specific circuit can be referenced based on the current detected by the circuit sensor. For short-circuit protection, it provides rapid response to short-circuit faults, preventing damage to equipment and the system from high current. In terms of safety protection, the circuit breaker 5 prevents electric shock accidents, provides electrical isolation, and ensures personnel safety. Regarding system stability maintenance, the circuit breaker 5 prevents fault propagation and ensures the normal operation of other parts of the power grid. Through the solution of this embodiment, by adding a top-expansion busbar connector to connect the cable supports 1 on both sides, and installing a bushing-type current transformer 2 on the busbar section of the busbar connector, the relay protection can monitor the circuit current, thus achieving overcurrent and instantaneous trip protection in conjunction with the circuit breaker 5.

[0041] In one possible implementation, see Figure 3 ,Book Figure 3This diagram illustrates another perspective of the ring main unit bus tie cabinet provided in this embodiment of the present invention. Specifically, it is a schematic diagram of the ring main unit bus tie cabinet provided in this embodiment of the present invention viewed from left to right. The air chamber is further equipped with multiple inner busbar cones 4; the number of inner busbar cones 4 is the same as the number of cable support groups 1; each inner busbar cone 4 is connected to a group of cable support groups 1, one end of the inner busbar cone 4 is connected to the circuit breaker 5, and the other end of the inner busbar cone 4 is connected to one of the cable support groups 1. The main function of the inner busbar cone 4 in this embodiment of the present invention is to reduce eddy current losses and improve heat dissipation. Since the busbar plays the role of connecting cables in the bus tie cabinet, it needs to withstand heat and electrodynamic forces during short-circuit faults. The inner cone design can reduce eddy current losses, improve the conductivity of the busbar, and at the same time, its heat dissipation effect is better, allowing it to carry a larger current within the allowable heating temperature. Specifically, firstly, the inner cone 4 of the busbar optimizes the electric field distribution and reduces the risk of partial discharge. The inner cone design guides the electric field lines to a uniform distribution through a specific geometry (conical profile), avoiding the formation of electric field concentration points at busbar connections or where the busbar passes through insulating bushings. This homogenization effect significantly reduces the possibility of partial discharge, thereby improving the long-term stability of the insulation system and the lifespan of the equipment. Secondly, the inner cone 4 of the busbar enhances insulation fit and sealing performance. The inner cone typically fits tightly with insulating bushings (such as epoxy resin bushings or silicone rubber insulators) to form a reliable interface seal. This structure not only provides physical support but also blocks creepage paths when the busbar passes through partitions or cabinets, preventing surface flashover and ensuring effective isolation between the busbar compartment and other functional areas (such as the circuit breaker compartment). Thirdly, the inner cone 4 of the busbar can adapt to thermal expansion and contraction and mechanical stress. During operation, the busbar will undergo thermal expansion and contraction due to changes in current. The conical interface of the inner cone allows for a certain degree of displacement compensation, reducing the damage of thermal stress to the insulation structure while maintaining the tightness of the connection and the integrity of the insulation. Finally, the inner cone 4 of the busbar supports standardized connections and modular design. The inner cone interface is often used as a standardized connection point, facilitating busbar expansion, cabinet assembly, and subsequent maintenance. Its standardized design simplifies the equipment integration process and improves engineering efficiency.

[0042] In one possible implementation, the multiple current transformers 2 are arranged in a stepped configuration. In this embodiment, by arranging the multiple current transformers 2 in a stepped configuration, the electric field distribution can be optimized and the problem of uneven electric field strength can be reduced. This not only reduces the amount of insulating material used, lowers the size and cost of the equipment, but also reduces energy consumption. Specifically, the current transformer 2 may contain multiple cylindrical metal screens, which are symmetrically arranged in a stepped configuration along both sides of the axial direction, forming a cylindrical capacitor shielding layer. The innermost metal screen can wrap around the expansion connector 3, leading out an electrode as a high-voltage electrode, while the penultimate metal screen and the outermost metal screen can be connected to the plug via leads. Compared to traditional designs, the solution in this invention solves the problems of traditional current and voltage sensors, such as extremely uneven electric field strength, the need for thicker insulating resin leading to larger volume, and higher energy consumption. Through this stepped arrangement design, the current transformer 2 can work more efficiently, improving its performance and reliability.

[0043] In one possible implementation, the cable support 1 comprises three sets, each connected to one phase of the busbar. In this embodiment, the busbar may include three phases: A, B, and C. In a three-phase AC system, phases A, B, and C refer to three AC circuit components with the same frequency, equal amplitude, and a phase difference of 120° between them, collectively forming the basis of power transmission. In practical use, phases A, B, and C can correspond to yellow, green, and red, respectively.

[0044] In one possible implementation, the current transformer 2 is a bushing-type current transformer. The bushing-type current transformer in this embodiment can be installed using a bushing structure, directly fitted onto the expansion connector 3. Specifically, the bushing-type current transformer can be of various brands or models. Based on electromagnetic induction, this bushing-type current transformer proportionally converts a large current into a small current signal through the iron core and secondary winding, achieving electrical isolation and safe measurement.

[0045] The solution of this utility model embodiment can be achieved by increasing the height of the cabinet, installing three cable supports 1 on each of the left and right sides of the bottom of the cabinet, and then adding a top expansion bus connector to connect the cable supports 1 on both sides. A bushing-type current transformer is installed on the bus section of the bus connector. With this solution, the relay protection can monitor the circuit current, and thus, in conjunction with the circuit breaker 5, it can achieve overcurrent and instantaneous overcurrent protection.

[0046] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the scope of protection of this utility model.

Claims

1. A ring main unit with a bus coupler, characterized in that, include: Multiple cable supports, multiple current transformers, and multiple expansion connectors; Each set of cable supports includes two, one located on the left inner wall of the ring main unit bus coupler cabinet and the other located on the right inner wall of the ring main unit bus coupler cabinet; The number of cable support groups is the same as the number of expansion female connectors, and each group of cable support groups is connected by an expansion female connector. The number of expansion female connectors is the same as the number of current transformers; each expansion female connector has a current transformer on its outer side.

2. The ring main unit bus coupler according to claim 1, characterized in that, The cable support is installed at the bottom of the ring main unit bus coupler cabinet; Each set of cable supports includes two, one located on the left inner wall at the bottom of the ring main unit and the other located on the right inner wall at the bottom of the ring main unit.

3. The ring main unit bus coupler according to claim 1, characterized in that, Each set of cable supports includes two, one connected to the incoming cable and the other connected to the outgoing cable.

4. The ring main unit bus coupler according to claim 1, characterized in that, The upper part of the ring main unit is also equipped with a sealed air chamber.

5. The ring main unit bus coupler according to claim 4, characterized in that, The air chamber is equipped with multiple circuit breakers; the number of circuit breakers is the same as the number of cable supports. Each circuit breaker is connected to a set of cable supports, with one end of the circuit breaker connected to one of the cable supports in the set and the other end of the circuit breaker connected to another of the cable supports in the set.

6. The ring main unit bus coupler according to claim 5, characterized in that, The air chamber is also provided with multiple busbar inner cones; the number of busbar inner cones is the same as the number of cable support groups; Each busbar inner cone is connected to a set of cable supports, one end of which is connected to the circuit breaker, and the other end of which is connected to one of the cable supports in the set.

7. The ring main unit bus coupler according to claim 1, characterized in that, The multiple current transformers are arranged in a stepped manner.

8. The ring main unit bus coupler according to claim 1, characterized in that, The cabinet of the ring main unit is a metal or non-metal insulated cabinet.

9. The ring main unit bus coupler according to claim 1, characterized in that, The cable support includes 3 sets, each connected to one phase of the busbar; the busbar includes three phases A, B, and C, and the three phases A, B, and C are connected one-to-one with the 3 sets of cable supports (1).

10. The ring main unit bus coupler according to claim 1, characterized in that, The current transformer is a bushing type current transformer.

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