Ring main unit

Abstract

The invention relates to the technical field of power distribution switch equipment, in particular to a ring main unit. The ring main unit comprises a box body, the left side wall and the right side wall of the box body are respectively provided with a three-position switch module and a circuit breaker module which are mutually independent, the three-position switch module comprises a three-position module fixing frame and three-position switches which are installed on the three-position module fixing frame side by side in a front-back mode, and the three-position switches are direct-acting three-position switches. The isolating static contact and the grounding static contact are arranged on the upper side and the lower side respectively, the switch moving contact base and the moving contact arranged in the switch moving contact base are located between the isolating static contact and the grounding static contact, and the circuit breaker module comprises a circuit breaker module fixing frame and circuit breakers installed on the circuit breaker module fixing frame side by side front and back. And the moving contact of the circuit breaker moves up and down to open and close. The three-position switch module and the circuit breaker module can realize a bus-side three-position scheme and a line-side three-position scheme through different combination modes, the standardization of the modules is realized, and the universality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution switch equipment, and in particular to a ring network cabinet. Background Art

[0002] The main circuit structure of the current environmental protection ring main unit basically adopts the scheme of vacuum switch + three-position switch. According to the arrangement of the three-position switch, the environmental protection ring main unit is divided into two schemes: three-position on the bus side and three-position on the line side. Both schemes have their own advantages and disadvantages. For the three-position scheme on the bus side, a circuit breaker with the ability to close short-circuit fault current is connected in series between the three-position switch and the cable outlet. The performance is reliable, but a reliable interlocking mechanism is required to ensure that the circuit breaker will not be opened when the grounding switch and the circuit breaker are both closed; for the three-position scheme on the line side, the grounding switch is directly connected to the grounded outlet cable, which meets the safety regulations. However, when the three-position on the line side is directly closed by the grounding switch on the cable outlet short-circuit fault current, the arc erosion generated during pre-breakdown must be overcome, so the closing speed must be very fast, which is more difficult. The market demand for these two schemes is also different. In the prior art, the structures of the three-position environmentally friendly ring main unit on the bus side and the three-position environmentally friendly ring main unit on the line side are very different. For both arrangements, the vacuum switch and the three-position switch need to be specially designed. The vacuum switch and the three-position switch are not interchangeable, which causes inconvenience in production and assembly. Summary of the invention

[0003] The object of the present invention is to provide a ring main unit to solve the problem that the vacuum switch and the three-position switch of the existing ring main unit cannot be used interchangeably, causing inconvenience in production and assembly.

[0004] The ring main unit of the present invention adopts the following technical solutions: A ring network cabinet comprises a box body, on the left and right side walls of the box body are respectively mounted a three-position switch module and a circuit breaker module which are independent of each other, the three-position switch module comprises a three-position module fixing frame and a three-position switch which is mounted on the three-position module fixing frame in parallel front and back, the three-position switch is a direct-acting three-position switch, and an isolating static contact and a grounding static contact are respectively arranged on the upper and lower sides, a switch moving contact seat and a moving contact arranged therein are arranged between the isolating static contact and the grounding static contact, the circuit breaker module comprises a circuit breaker module fixing frame and a circuit breaker which is mounted on the circuit breaker module fixing frame in parallel front and back, the moving contact of the circuit breaker moves up and down to open and close, two wiring terminals of the circuit breaker are respectively located at one end in the up and down direction and one side in the left and right direction, and a wiring terminal arranged on the switch moving contact seat and a wiring terminal on the side of the circuit breaker are one facing left and one facing right.

[0005] Further, the three-position module fixing bracket includes a three-position switch fixing side plate. Connecting structures for fixedly connecting to the box body are respectively provided at the front and rear ends of the three-position switch fixing side plate. A grounding bar is fixedly connected to the three-position switch fixing side plate, and three-phase grounding static contacts are fixedly installed on the grounding bar according to the phase spacing.

[0006] Further, the moving contact of the three-position switch includes a separately arranged isolating moving contact and a grounding moving contact, and the two are fixedly connected.

[0007] Further, the breaker module fixing bracket includes a breaker frame extending forward and backward and front and rear support plates fixedly connected to the front and rear ends of the breaker frame. The breakers are arranged side by side in the front and rear on the breaker frame, and connecting structures for fixedly connecting to the box body are respectively provided on the front and rear support plates.

[0008] Further, the cross-sections of the front and rear support plates are both "several"-shaped. The flanges at both ends of the front and rear support plates are fixedly attached to the box body, and connection holes are respectively provided on the flanges at both ends. The flanges at both ends constitute the connecting structure.

[0009] Further, reinforcing ribs are provided on the back surfaces of the front and rear support plates.

[0010] Further, the switch moving contact seat and the isolating static contact are integrally epoxy-potted.

[0011] Further, an installation hole is provided in the switch moving contact seat, the moving contact is installed in the installation hole, and spring fingers are provided at both ends of the installation hole to abut against the moving contact.

[0012] Further, spring fingers are provided on the isolating static contact to abut against the moving contact during isolating closing.

[0013] Further, petal-shaped fingers are provided on the grounding static contact to abut against the moving contact during grounding closing.

[0014] Beneficial effects: The present invention is a pioneering invention. The three-position switch and the breaker are respectively modularly designed. The three-phase three-position switch is integrated on the three-position module fixing bracket to form a three-position switch module, and the three-phase breaker is integrated on the breaker module fixing bracket to form a breaker module. The three-position switch module and the breaker module are independent of each other. The three-position switch is a direct-acting three-position switch and the opening and closing directions are up and down directions, and the opening and closing directions of the breaker are also up and down directions, which are consistent with the incoming and outgoing line directions of the ring main unit. The three-position switch module and the breaker module are arranged left and right, and the terminal provided on the switch moving contact seat and the terminal on the side of the breaker are one facing left and the other facing right. With such a structural design, the three-position switch module and the breaker module can achieve the bus-side three-position scheme and the line-side three-position scheme through different combination methods. The three-position switch module and the breaker module are standardized, improving the versatility, thus making the production and assembly more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the assembly diagram of the three-position switch module; Figure 2 It is a structural schematic diagram of a single-phase three-position switch in the isolated and closed state; Figure 3 It is a schematic diagram of the structure of a single-phase three-position switch in the isolation, grounding and opening states; Figure 4 It is a structural schematic diagram of a single-phase three-position switch in the grounded closed state; Figure 5 It is a schematic diagram of the assembly of the inverted circuit breaker module; Figure 6 It is a schematic diagram of the assembly of the positive circuit breaker module; Figure 7 This is the assembly diagram of the three-station top expansion main busbar on the busbar side of the ring main unit; Figure 8 This is the assembly diagram of the three-station side expansion main busbar on the busbar side of the ring main unit; Fig. 9 This is a schematic diagram of the assembly of the three-station top expansion main busbar on the line side of the ring main cabinet; Fig.10 This is the assembly diagram of the three-station side expansion main busbar on the line side of the ring main unit; In the figure: 1. Fixed side plate of three-position switch; 2. Insulated transmission shaft; 3. Grounding bar; 4. Three-position switch; 5. Front support plate; 6. Circuit breaker frame; 7. Circuit breaker; 8. Rear support plate; 9. Ejector busbar bushing; 10. Circuit breaker module; 11. Inlet bushing; 12. Three-position switch module; 13. Side expansion busbar bushing; 14. Reinforcement ribs; 4-1, isolating static contact; 4-2, switch moving contact seat; 4-3, transmission gear; 4-4, spur rack; 4-5, grounding static contact; 4-6, grounding shield; 4-7, grounding moving contact; 4-8, isolating moving contact; 4-9, spring contact finger. DETAILED DESCRIPTION

[0016] The existing environmental protection ring network cabinets need to be specially designed for the three-position scheme on the bus side and the three-position scheme on the line side. The vacuum switch and the three-position switch cannot be universal, which causes inconvenience in production and assembly. The present invention proposes a ring network cabinet that can improve the universality of the vacuum switch and the three-position switch, which is more convenient for production and assembly. The basic inventive concept of the present invention is: the three-phase three-position switch is modularly designed, the three-phase circuit breaker is modularly designed, the three-position switch module and the circuit breaker module are independent of each other, so that the opening and closing direction of the three-position switch and the opening and closing direction of the circuit breaker are both in the up and down direction, which is consistent with the incoming and outgoing line direction of the ring network cabinet, and the three-position switch module and the circuit breaker module are arranged left and right, so that the three-position switch module and the circuit breaker module can realize the three-position scheme on the bus side and the three-position scheme on the line side through different combinations, and the three-position switch module and the circuit breaker module are standardized, thereby improving universality.

[0017] Based on the above inventive concept, the embodiments of the present invention are described in detail below.

[0018] like Figure 7-10 As shown, the ring main unit of the present invention comprises a box body, and the left and right side walls of the box body are respectively installed with a three-position switch module 12 and a circuit breaker module 10 which are independent of each other. Figure 1 As shown, the three-position switch module includes a three-position module fixing frame and a three-phase three-position switch 4 installed on the three-position module fixing frame in parallel. The three-position module fixing frame includes a three-position switch fixing side plate 1. The front and rear ends of the three-position switch fixing side plate 1 are respectively provided with connection structures for fixing to the box body. The three-position switch fixing side plate 1 is fixedly connected with a grounding bar 3. The three-phase grounding static contacts 4-5 are fixedly installed on the grounding bar 3 according to the phase spacing. The three-position module fixing frame has a simple structure, is easy to process, and is light in weight. The three-position switch 4 is a direct-acting three-position switch, such as Figure 2-4 As shown, it includes components such as an isolating static contact 4-1, a grounding static contact 4-5, a switch moving contact seat 4-2, and a moving contact. The isolating static contact 4-1 and the grounding static contact 4-5 are respectively placed on the upper and lower sides, and the switch moving contact seat 4-2 and the moving contact arranged therein are located between the isolating static contact 4-1 and the grounding static contact 4-5. The moving contact is connected to the three-position operating mechanism in a transmission manner so that the switch can be opened and closed in a linear motion driven by the three-position operating mechanism. Specifically, a spur rack 4-4 extending up and down is fixedly installed on the moving contact, and a transmission gear 4-3 meshing with the spur rack 4-4 is fixedly installed on the insulating transmission shaft 2, which can be seen in FIG. Figure 1 The three-phase transmission gears 4-3 are fixedly installed on the insulating transmission shaft 2 according to a certain phase spacing. The insulating transmission shaft 2 is connected to the three-position operating mechanism to realize the synchronous action of the three-phase moving contacts.

[0019] The moving contact includes a separately arranged isolating moving contact 4-8 and a grounding moving contact 4-7, which are fixedly connected to realize synchronous action, and the grounding moving contact 4-7 is fixedly connected to the bottom of the isolating moving contact 4-8 by bolts. The isolating moving contact and the grounding moving contact of the existing direct-acting three-position switch share one moving contact. During the grounding closing operation, the end of the moving contact used to close the switch with the grounding static contact will be severely burned. When the terminal on the moving contact or the moving contact seat is close to the end of the moving contact used to close the switch with the grounding static contact, the burning may spread to the terminal during the grounding closing, causing the moving contact to affect the flow capacity of the main circuit when it is used for isolation closing. In the present invention, the isolating moving contact 4-8 and the grounding moving contact 4-7 of the three-position switch 4 are not shared, so that the burning of the grounding moving contact 4-7 during the grounding closing operation will not affect the flow capacity of the main circuit. The switch moving contact seat 4-2 and the isolating static contact 4-1 are epoxy cast as one body, which helps to ensure the accuracy of the isolating closing. A mounting hole is provided in the switch moving contact seat 4-2, and the moving contact is installed in the mounting hole. Spring contact fingers 4-9 are provided at both ends of the mounting hole to abut against the moving contact. The isolating static contact 4-1 is provided with a spring contact finger 4-9 to abut against the moving contact when the isolating closing is performed. The grounding static contact 4-5 is provided with a petal-shaped contact finger to abut against the moving contact when the grounding closing is performed. The outside of the grounding static contact 4-5 is provided with a grounding shield 4-6, and the grounding shield 4-6 is made of 1060 aluminum alloy by spin forming process. Copper tungsten alloy is added to the bottom of the grounding moving contact 4-7 to improve the ablation resistance and have a 5-time grounding closing capability.

[0020] When the isolation is closed, Figure 2 As shown, the isolating moving contact 4-8 is inserted into the isolating static contact 4-1 and electrically contacts each other through the spring contact finger 4-9. Figure 3 As shown, the insulating transmission shaft 2 is operated, and the transmission gear 4-3 on the insulating transmission shaft 2 drives the three-phase isolating moving contact 4-8 through the spur rack 4-4 to move it, so that it separates from the isolating static contact 4-1 and reaches the middle position. Figure 4 As shown, the insulating transmission shaft 2 is operated, and the transmission gear 4-3 on the insulating transmission shaft 2 drives the three-phase grounding moving contact 4-7 through the spur rack 4-4 to make it electrically contact with the petal-shaped contact fingers of the grounding static contact 4-5.

[0021] The circuit breaker module can be placed upright or inverted according to the assembly requirements. Figure 5-6As shown, two states of the circuit breaker module, namely inverted and upright, are respectively displayed. In the inverted state, the pole column of the circuit breaker extends downward, and in the upright state, the pole column of the circuit breaker extends upward. The circuit breaker module 10 includes a circuit breaker module fixing frame and circuit breakers 7 installed side by side front and back on the circuit breaker module fixing frame. The moving contact of the circuit breaker 7 moves up and down for opening and closing. The two terminal ends of the circuit breaker 7 are respectively at one end in its up and down direction and one side surface in its left and right direction. The circuit breaker module fixing frame includes a circuit breaker frame 6 extending front and back and front support plates 5 and rear support plates 8 fixedly connected to the front and rear ends of the circuit breaker frame 6. Three-phase circuit breakers 7 are installed side by side front and back on the circuit breaker frame 6. Support plate connection structures for fixedly connecting to the box body are respectively provided on the front and rear support plates. The cross-sections of the front and rear support plates are both in the shape of "Ji". The flanges at both ends of the front and rear support plates are fitted and fixed to the box body. Connection holes are respectively provided on the flanges at both ends, and the flanges at both ends constitute the support plate connection structure. The front and rear support plates adopt such a structure. On the one hand, it improves the structural strength of the front and rear support plates and ensures the reliable fixation of the circuit breaker module fixing frame to the three-phase circuit breaker. On the other hand, it increases the fitting area between the front and rear support plates and the box body and improves the connection reliability. Reinforcing ribs 14 are also provided on the back surfaces of the front and rear support plates to further improve the structural strength.

[0022] Figure 7-10 It is a schematic assembly diagram of different functional structures of the ring main unit, which realizes different functional requirements through different combination methods of the three-position switch module 12 and the circuit breaker module 10. Taking Figure 7 the assembly schematic diagram of the three-position top-expanded main bus on the bus side of the ring main unit as an example, a top-out bushing 9 is provided at the top of the box body, and an incoming line bushing 11 is provided at the bottom of the box body. The three-position switch module 12 and the circuit breaker module 10 are arranged inside the box body. The circuit breaker module 10 is inverted and fixed to the side wall of the gas tank through the front support plate 5 and the rear support plate 8. The three-position switch module 12 is fixed through the three-position switch fixed side plate 1, the stud on the front plate of the box body, and the fixed mounting plate on the rear plate. The top-out bushing 9 is connected to the isolating static contact 4-1 of the three-position switch module 12 through a copper bar. The moving terminal ends on the side surfaces of the circuit breaker 7 of the inverted circuit breaker module 10 and the terminal ends provided on the switch moving contact seat 4-2 of the three-position switch module 12 face left and right respectively and are connected through a copper bar. The static terminal end of the inverted circuit breaker module 10 is connected to the incoming line bushing 11 through a copper rod. Figure 8 It is a schematic assembly diagram of the three-position side-expanded main bus on the bus side of the ring main unit. Except that the top-out bushing 9 is replaced by a side-expanded bushing 13 and the lengths of the connected copper bars and copper rods are changed, the rest are the same as Figure 7 the scheme.

[0023] Fig. 9The figure is a schematic diagram of the assembly of the three-position top expansion main busbar on the line side of the ring main unit. The top of the box is provided with a top busbar bushing 9, the bottom of the box is provided with an incoming line bushing 11, and the three-position switch module 12 and the circuit breaker module 10 are arranged inside the box. The circuit breaker module 10 is upright and fixed to the side wall of the gas box through the front support plate 5 and the rear support plate 8. The three-position switch module 12 is fixed to the box front plate studs and the rear plate fixed mounting plate through the three-position switch fixed side plate 1. The ejector busbar bushing 9 is connected to the static end terminal of the upright circuit breaker module 10 through a copper busbar, the dynamic end terminal on the side of the circuit breaker 7 of the upright circuit breaker module 10 is connected to the isolating static contact 4-1 of the three-position switch module 12 through a copper busbar, the dynamic end terminal on the side of the circuit breaker 7 of the upright circuit breaker module 10 and the terminal set on the switch dynamic contact seat 4-2 of the three-position switch module 12 are one facing left and the other facing right, and the terminal set on the switch dynamic contact seat 4-2 of the three-position switch module 12 is connected to the incoming line bushing 11 through a copper rod. Fig.10 This is a schematic diagram of the assembly of the three-station side-expanded main busbar on the line side of the ring main unit. The core components are the same as those of the previous one, except that the top busbar bushing 9 is replaced with the side-expanded busbar bushing 13 and the length of the connected copper bar and copper rod is changed. Fig. 9 The plan is consistent.

[0024] The ring network cabinet of the present invention performs modular design on the three-position switch and the circuit breaker respectively. The three-position switch module 12 and the circuit breaker module 10 are independent of each other, and can meet the requirements of the three-position bus side, the three-position line side, the top expansion main bus and the side expansion main bus of the ring network cabinet through different combinations when the circuit breaker module 10 and the three-position switch module 12 are common, and the standardization of the modules is realized, which greatly reduces the production and assembly costs. Moreover, the interface dimensions of the three-position scheme on the bus side and the three-position scheme on the line side are consistent with the dimensions required by the state grid standardization, which meets the interchangeability of different equipment schemes. The three-position on the line side adopts a direct-acting three-position switch, which has a uniform electric field and does not require a high closing speed when grounding, which greatly improves the performance of the ring network cabinet product.

[0025] Of course, the present invention is not limited to the implementation methods in the above embodiments.

[0026] For example, in other embodiments, the isolating movable contact and the grounding movable contact of the three-position switch may share one movable contact.

[0027] For example, in other embodiments, the front and rear support plates of the circuit breaker module fixing frame can also be flat plates, the width of the front and rear support plates is greater than the height of the circuit breaker frame, the front and rear support plates have plate surface portions that extend upward and downward beyond the circuit breaker frame, and connection holes are provided on the extended plate surface portions, and the front and rear support plates are attached to the side walls of the box body and fixedly connected by fasteners.

[0028] For example, in other embodiments, the switch moving contact seat and the isolating static contact may also be provided independently of each other, and are not cast as one body.

[0029] Of course, the structures of the three-station module fixing frame and the circuit breaker module fixing frame are not limited to the structures in the above embodiments, and may have various modified structures, which are not listed here.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A ring main unit, characterized in that: It includes a box body. On the left and right side walls of the box body, an independent three-position switch module and a circuit breaker module are respectively installed. The three-position switch module includes a three-position module fixing bracket and three-position switches arranged side by side front and back on the three-position module fixing bracket. The three-position switch is a direct-acting three-position switch, and the isolating static contact and the grounding static contact are respectively placed on the upper and lower sides. The switch moving contact base and the moving contact arranged therein are between the isolating static contact and the grounding static contact. The circuit breaker module includes a circuit breaker module fixing bracket and a circuit breaker arranged side by side front and back on the circuit breaker module fixing bracket. The moving contact of the circuit breaker moves up and down for opening and closing. The two wiring terminals of the circuit breaker are respectively at one end in its up and down direction and one side surface in its left and right direction. The wiring terminals arranged on the switch moving contact base and the wiring terminal on the side surface of the circuit breaker face left and right respectively.

2. The ring main unit according to claim 1, characterized in that: The three-position module fixing bracket includes three-position switch fixing side plates. At the front and rear ends of the three-position switch fixing side plates, connection structures for fixedly connecting to the box body are respectively provided. A grounding bar is fixedly connected to the three-position switch fixing side plates. Three-phase grounding static contacts are fixedly installed on the grounding bar according to the phase spacing.

3. The ring main unit according to claim 1, characterized in that: The moving contact of the three-position switch includes an isolating moving contact and a grounding moving contact which are separately arranged and fixedly connected.

4. The ring main unit according to any one of claims 1 to 3, characterized in that: The circuit breaker module fixing bracket includes a circuit breaker frame extending front and back and front and rear support plates fixedly connected to the front and rear ends of the circuit breaker frame. The circuit breaker is arranged side by side front and back on the circuit breaker frame. Support plate connection structures for fixedly connecting to the box body are respectively provided on the front and rear support plates.

5. The ring main unit according to claim 4, characterized in that: The cross-sections of the front and rear support plates are both "L"-shaped. The flanges at both ends of the front and rear support plates are fitted and fixed to the box body. Connection holes are respectively provided on the flanges at both ends. The flanges at both ends constitute the support plate connection structure.

6. The ring main unit according to claim 5, characterized in that: Reinforcing ribs are provided on the back surfaces of the front and rear support plates.

7. The ring main unit according to any one of claims 1 to 3, characterized in that: The switch moving contact base and the isolating static contact are integrally epoxy potted.

8. The ring main unit according to any one of claims 1 to 3, characterized in that: An installation hole is provided in the switch moving contact base. The moving contact is installed in the installation hole. Spring fingers are provided at both ends of the installation hole to abut against the moving contact.

9. The ring main unit according to any one of claims 1 to 3, characterized in that: Spring fingers are provided on the isolating static contact to abut against the moving contact during isolating closing.

10. The ring main unit according to any one of claims 1 to 3, characterized in that: Petal-shaped fingers are provided on the grounding static contact to abut against the moving contact during grounding closing.

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