Voltage transformer with fuse for plateau area

Abstract

The utility model relates to a high-voltage measuring device of an electric power system, in particular to a voltage transformer with a fuse for a plateau area. Comprising a main insulator and a coil device body sealed in the main insulator, fuse cavities are formed in the two ends of the top of the main insulator in the vertical direction, primary high-voltage terminals are arranged at the upper ends of the fuse cavities, fuses are arranged in the fuse cavities, the upper ends of the fuses make contact with the primary high-voltage terminals, and the lower ends of the fuses make contact with the primary high-voltage terminals. The lower end of the fuse is connected with a primary leading-out terminal of the coil device body; a shielding net is arranged on the inner wall of the fuse cavity, the shielding net is formed by spot welding of a cylindrical iron gauze externally connected with a metal piece with an arc-shaped end, and the shielding net is used for shielding a high-voltage electric field. According to the utility model, the high-voltage electric field is effectively shielded, the distribution of the electric field is uniform, the partial discharge amount is small, the fuse protection is provided, and the simplified and miniaturized development of the switch cabinet is realized.

Description

Technical Field

[0001] The utility model relates to a high-voltage measuring device for an electric power system, in particular to a voltage transformer with a fuse for use in plateau areas. Background Art

[0002] Voltage transformer is a device for measuring voltage and electric energy in power system or electrical control system. In recent years, most voltage transformers have been widely promoted and applied due to their small size, high operational safety, and suitability for various high-altitude environments. The voltage transformers with fuses developed and designed in recent years cannot meet the requirements of high-altitude areas. According to the design requirements, the high-voltage fuse is electrically connected to the primary terminal of the transformer, which is slightly larger in size and has many replacement parts. When installed in the switch cabinet together with the transformer, there are problems such as severe withstand voltage discharge, poor insulation, and large partial discharge. Therefore, switch cabinet manufacturers and the market particularly need a voltage transformer that can be directly equipped with a fuse and has small partial discharge and is suitable for use in high-altitude areas. Utility Model Content

[0003] In view of the above problems, the purpose of the utility model is to provide a voltage transformer with fuse for use in plateau areas, so as to solve the problems that the existing voltage transformer with fuse for switch cabinet has severe withstand voltage discharge, poor insulation, large partial discharge and other problems that it is not suitable for use in high altitude areas.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a voltage transformer with fuse for use in plateau areas, comprising a main insulator and a coil body sealed in the main insulator, both ends of the top of the main insulator are provided with fuse cavities in the vertical direction, the upper end of the fuse cavity is provided with a primary high-voltage terminal, a fuse is provided in the fuse cavity, the upper end of the fuse is in contact with the primary high-voltage terminal, the lower end of the fuse is connected with a primary lead-out terminal of the coil body, the primary lead-out terminal is a bottom disc-type metal part with an upper boss with internal and external threaded metal parts, and the primary lead-out terminal is sufficiently insulated from the ground; the inner wall of the fuse cavity is provided with a shielding net, the shielding net is made of an arc-shaped metal part at the end and an external cylindrical wire mesh by spot welding, the primary lead-out terminal is threadedly connected to the shielding net, and the shielding net is used to shield the high-voltage electric field.

[0006] The upper port of the fuse cavity is threadedly connected with a threaded bolt, and the primary high-voltage terminal is threadedly connected with the threaded bolt.

[0007] A spring is arranged between the lower end of the fuse and the primary lead-out terminal of the coil body.

[0008] The main insulator and the fuse cavity are an integrated structure cast by epoxy resin; the main insulator is a rectangular parallelepiped structure, the fuse cavity is a cylindrical structure, and the two fuse cavities are arranged diagonally.

[0009] The main insulator is provided with small sheds on both side walls of the wide side; and a rectangular large shed is provided along the width direction at the middle position of the top of the main insulator.

[0010] The lower parts of the two side surfaces of the main insulator located at the long sides are both provided with grooves.

[0011] A plurality of high-voltage sheds are arranged on the outer circumference of the fuse cavity along the height direction.

[0012] The front bottom of the main insulator is provided with a secondary wiring platform, and the secondary wiring platform is covered with a secondary protective cover.

[0013] A bottom plate is provided at the bottom of the main insulator, and a grounding terminal is provided on the bottom plate near the secondary wiring station.

[0014] The utility model has the following advantages and beneficial effects: The utility model provides a voltage transformer with fuse for plateau areas. Through the fuse shielding net and the overall optimized structural design, the high-voltage fuse insulation and sealing metal shielding is placed inside the product, solving the problem of large partial discharge of existing voltage transformer products with fuses. It is suitable for switch cabinets of various voltage levels in complex environments. The main advantages are:

[0015] 1. Simple structure and easy operation: The primary fuse and the shielding net of the utility model are integrally cast, and the high-voltage fuse is sealed inside the product. The overall structure is simple and easy to operate.

[0016] 2. With fuse protection and high insulation strength: The high-voltage fuse sealed inside the product can effectively ensure that there will be no burning failure when the product system fails. It is sealed in the iron core and primary and secondary windings by epoxy resin vacuum casting, and has high insulation strength.

[0017] 3. Uniform electric field and small local discharge: The primary high-voltage fuse is placed in the fuse cavity, and the fuse shielding net completely shields the high-voltage electric field. The electric field inside and outside the product is uniform, the local discharge of the product is small, and the product operation is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the internal structure of a voltage transformer with fuse for use in plateau areas according to the utility model;

[0019] Figure 2 This is a front view of the external structure of the voltage transformer with fuse for use in plateau areas of the utility model;

[0020] Figure 3 for Figure 2 A top view of

[0021] Figure 4 for Figure 2 Left view of .

[0022] In the figure: 1. iron core; 2. secondary winding; 3. primary winding; 4. insulation frame; 5. primary high-voltage terminal; 6. bottom plate; 7. screw bolt; 8. fuse; 9. high-voltage shed; 10. main insulator; 11. small shed; 12. secondary terminal block; 13. secondary protective cover; 14. grounding terminal; 15. large shed; 16. shielding net; 17. groove; 18. fuse cavity; 19. primary lead terminal; 20. spring. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 4 As shown, the utility model provides a voltage transformer with fuse for use in plateau areas, including a main insulator 10 and a coil body sealed in the main insulator 10, both ends of the top of the main insulator 10 are provided with fuse cavities 18 in the vertical direction, the upper end of the fuse cavity 18 is provided with a primary high-voltage terminal 5, a fuse 8 is arranged in the fuse cavity 18, the upper end of the fuse 8 is in contact with the primary high-voltage terminal 5, the lower end of the fuse 8 is connected to a primary lead-out terminal 19 of the coil body, the primary lead-out terminal 19 is a bottom disc-type metal part with an upper boss with internal and external threaded metal parts, and the primary lead-out terminal 19 is sufficiently insulated from the ground; the inner wall of the fuse cavity 18 is provided with a shielding net 16, the shielding net 16 is made of an arc-shaped metal part at the end and an external cylindrical wire mesh by spot welding, the primary lead-out terminal 19 is threadedly connected to the shielding net 16, and the shielding net 16 is used to shield the high-voltage electric field.

[0025] like Figure 1 As shown, in the embodiment of the utility model, the upper port of the fuse cavity 18 is threadedly connected with a screw sleeve bolt 7, the screw sleeve bolt 7 is a hollow sleeve structure, and the outer surface is provided with an external thread, the inner wall is provided with an internal thread, and the primary high-voltage terminal 5 is connected with the internal thread of the screw sleeve bolt 7, which is convenient for reliable high-voltage connection and ensures personal safety during operation. The upper end of the fuse 8 is in contact with the screw sleeve bolt 7, and a spring 20 is provided between the lower end of the fuse 8 and the primary lead-out terminal 19 of the coil body.

[0026] like Figures 2 to 4As shown, in the embodiment of the utility model, the main insulator 10 and the fuse cavity 18 are an integrated structure cast by epoxy resin; the main insulator 10 is a rectangular parallelepiped structure, the fuse cavity 18 is a cylindrical structure, and the two fuse cavities 18 are diagonally arranged on both sides of the main insulator 10. Small sheds 11 are arranged on both side walls of the wide side of the main insulator 10; a rectangular large shed 15 is arranged at the middle position of the top of the main insulator 10 along the width direction.

[0027] Furthermore, grooves 17 are provided at the lower parts of the two side surfaces of the main insulator 10 located at the long sides. A plurality of high-voltage sheds 9 are provided on the outer circumference of the fuse cavity 18 along the height direction.

[0028] Furthermore, a secondary connection platform 12 is provided at the front bottom of the main insulator 10, and a secondary protection cover 13 is provided on the secondary connection platform 12. A bottom plate 6 is provided at the bottom of the main insulator 10, and a grounding terminal 14 is provided on the side of the bottom plate 6 close to the secondary connection platform 12.

[0029] In the embodiment of the utility model, the coil body comprises an iron core 1, a secondary winding 2, a primary winding 3 and an insulating frame 4, wherein the secondary winding 2 is wound on the iron core 1, and the primary winding 3 is wound on the insulating frame 4 and then integrally sheathed on the outside of the secondary winding 2. Preferably, the iron core 1 is an R-type C-type iron core.

[0030] The utility model provides a voltage transformer with fuse for use in plateau areas, and the manufacturing process thereof is as follows:

[0031] The secondary winding 2 is wound on the iron core 1, and the primary winding 3 is wound on the insulating frame 4 and then integrally mounted on the outside of the secondary winding 2. After being insulated and buffered, it is fixed in a mold and cast with epoxy resin into an integrated structure having a primary high-voltage terminal 5 and a secondary terminal block 12. The integrated structure is then installed on the bottom plate 6. The inner wall of the fuse cavity 18 of the integrated structure is enclosed by a shielding net 16, which shields the high-voltage electric field in the fuse cavity 18, making the electric field distribution more uniform and the shielding effect better. The primary lead-out terminal 19 of the primary winding 3 is a metal part with a bottom disc and an upper boss with internal and external threads, and the shielding net 16 is suitable for the structural requirements of the high-altitude plateau environment; the inner wall of the fuse cavity 18 is provided with a shielding net 16, and the shielding net 16 is made of a circular arc-shaped metal part at the end and an external cylindrical wire mesh by spot welding. The primary lead-out terminal 19 is threadedly connected to the shielding net 16, and one end of the fuse 8 is in contact with the primary lead-out terminal 19 of the primary winding 3 through a spring 20, and the other end is in contact with the end face of the threaded bolt 7, so the electrical connection is more reliable and the local discharge of the product is small. The primary high-voltage terminal 5 is located on both sides of the upper part of the main insulator 10, one front and one back, and the fuse 8 built into the fuse cavity 18 is vertically upward. The periphery of the fuse cavity 18 is provided with a high-voltage umbrella skirt 9, and the outer cylindrical shape intersects with the main insulator 10, and the primary lead terminal 19 of the primary winding 3 is located at the bottom of the fuse cavity 18, and the distance from the bottom of the main insulator 10 is large enough to ensure sufficient insulation distance for the primary high voltage, which is suitable for high withstand voltage requirements in high altitude areas. A large umbrella group 15 is arranged in the middle of the upper part of the main insulator 10, and the four-side rounded corners transition vertically downward to form a rectangular shape as a whole. Wedge-shaped grooves 17 are arranged on the left and right sides of the main insulator 10 to ensure uniform insulation distance. The secondary wiring station 12 is located below the main insulator 10, and a secondary protective cover 13 is arranged on its upper part to facilitate the user's secondary wiring. The secondary terminal is reliably sealed to prevent electricity theft, and the grounding terminal 14 is located on the same side of the secondary wiring station 12. The bottom plate 6 is convenient for the user to ground. When in use, first fix the bottom plate 6, electrically connect the primary high-voltage terminal 4 to the high-voltage component, and then connect the secondary wiring to the instrument. The installation of the voltage transformer with fuse is completed in plateau areas.

[0032] The utility model provides a voltage transformer with fuse for plateau areas, which is a new product designed in full accordance with national standards and special requirements of switch cabinets. It adopts rolled iron core and electromagnetic conversion principle, so that the secondary voltage can accurately reflect the change of primary voltage. It is used for voltage measurement and relay protection. It adopts epoxy resin vacuum casting, and the shielding net is placed outside the fuse. The creepage distance umbrella skirt works together and is suitable for various switch cabinets in plateau areas, so that the high-voltage electric field of the product is effectively shielded, the electric field is evenly distributed, the partial discharge is small, and it is protected by fuses, so as to realize the simplification and miniaturization of switch cabinets. The utility model has small size, flexible installation, fuse protection, uniform electric field, long maintenance cycle, and wide application.

[0033] The above description is only an implementation method of the utility model and is not intended to limit the protection scope of the utility model. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the utility model are included in the protection scope of the utility model.

Claims

1. A voltage transformer with fuse for use in plateau areas, characterized in that: The invention comprises a main insulator (10) and a coil body sealed in the main insulator (10); both ends of the top of the main insulator (10) are provided with fuse cavities (18) in the vertical direction; the upper end of the fuse cavity (18) is provided with a primary high-voltage terminal (5); a fuse (8) is provided in the fuse cavity (18); the upper end of the fuse (8) is in contact with the primary high-voltage terminal (5); the lower end of the fuse (8) is connected to a primary lead-out terminal (19) of the coil body; a shielding net (16) is provided on the inner wall of the fuse cavity (18); the shielding net (16) is made by spot welding an arc-shaped metal part at the end to an external cylindrical iron wire mesh.

2. The voltage transformer with fuse for use in plateau areas according to claim 1, characterized in that: The upper port of the fuse cavity (18) is threadedly connected with a threaded bolt (7), and the primary high-voltage terminal (5) is threadedly connected to the threaded bolt (7).

3. The voltage transformer with fuse for use in plateau areas according to claim 1, characterized in that: A spring (20) is provided between the lower end of the fuse (8) and the primary lead terminal (19) of the coil body. The primary lead terminal (19) is a metal part with a bottom disc and an upper boss with internal and external threads. The primary lead terminal (19) is threadedly connected to the shielding net (16).

4. The voltage transformer with fuse for use in plateau areas according to claim 1, characterized in that: The main insulator (10) and the fuse cavity (18) are an integrated structure cast with epoxy resin; the main insulator (10) is a rectangular parallelepiped structure, the fuse cavity (18) is a cylindrical structure, and the two fuse cavities (18) are arranged diagonally.

5. The voltage transformer with fuse for use in plateau areas according to claim 4, characterized in that: Small sheds (11) are provided on both side walls of the main insulator (10) at the wide side; and a rectangular large shed (15) is provided in the middle of the top of the main insulator (10) along the width direction.

6. The voltage transformer with fuse for use in plateau areas according to claim 4, characterized in that: The main insulator (10) is provided with grooves (17) at the lower parts of the two side surfaces located on the long sides.

7. The voltage transformer with fuse for use in plateau areas according to claim 4, characterized in that: A plurality of high-voltage umbrella skirts (9) are provided on the outer circumference of the fuse cavity (18) along the height direction.

8. The voltage transformer with fuse for use in plateau areas according to claim 1, characterized in that: A secondary wiring platform (12) is provided at the front bottom of the main insulator (10), and a secondary protective cover (13) is provided on the secondary wiring platform (12).

9. The voltage transformer with fuse for use in plateau areas according to claim 8, characterized in that: A bottom plate (6) is provided at the bottom of the main insulator (10), and a grounding terminal (14) is provided on the bottom plate (6) at a side close to the secondary wiring station (12).

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