Parallel reverse double-fuse voltage transformer

Abstract

The utility model relates to electric power equipment technical field provides a kind of parallel reverse double-fuse tube voltage transformer, including voltage transformer main body, fuse tube cavity subassembly and at least two fuse tubes, the fuse tube cavity subassembly is fixedly arranged in the top of the voltage transformer main body, two parallelly arranged and the opening direction opposite fuse tube seat are equipped in the fuse tube cavity subassembly, the two fuse tubes are respectively pluggably installed in two the fuse tube seat, so that the high voltage connection terminal distribution of two fuse tube tail portions is in the opposite side of the voltage transformer main body, increase the phase spacing between primary end A and primary end B. The utility model increases the phase spacing between high voltage terminal significantly under the prerequisite of not increasing the overall external dimension of product by the parallel reverse layout of fuse tube, optimizes electric field distribution, improves insulation strength and lightning-impulse withstand performance, so that it is suitable for the line with high rated primary voltage.

Description

Technical Field

[0001] This utility model relates to the field of power equipment technology, specifically to a parallel reverse double fuse tube voltage transformer. Background Technology

[0002] Voltage transformers are critical devices in power systems, used for voltage transformation, electrical isolation, and measurement and protection. In medium- and high-voltage distribution systems ranging from 10kV to 24kV, the requirements for insulation performance and safety of these devices are extremely high. Traditional voltage transformers often employ a longitudinal or transverse parallel layout, resulting in close phase spacing at the same end. In lines with high rated primary voltages, insufficient phase spacing can lead to uneven electric field distribution, decreased insulation strength, and easily cause partial discharge or even insulation breakdown, severely limiting their application in high-voltage or space-constrained environments. Furthermore, the limited operating space during installation and maintenance in existing designs also causes inconvenience, affecting the reliability and safety of the system.

[0003] To address the phase spacing issue, existing technologies either add external insulating sleeves or use multi-stage transformers connected in series. However, these methods often lead to complex structures, increased costs, and the potential introduction of new fault points. Therefore, there is an urgent need for a new voltage transformer structure that is compact, low-cost, and can fundamentally increase phase spacing and improve insulation performance. Utility Model Content

[0004] In view of this, the purpose of this utility model is to propose a parallel reverse double fuse tube voltage transformer. By using the parallel reverse layout of the fuse tubes, the problem of the phase spacing at the same end of the traditional voltage transformer is solved. Without increasing the overall external size of the product, the phase spacing between the high-voltage terminals is significantly increased through the layout and parallel reverse design of the fuse tubes, thereby optimizing the electric field distribution, improving the insulation strength and lightning impulse resistance, and making the installation and maintenance more convenient, making it suitable for lines with high rated primary voltage.

[0005] To achieve the above objectives, this utility model provides the following technical solution: This utility model provides a parallel reverse double fuse tube voltage transformer, including a voltage transformer body, a fuse tube cavity assembly, and at least two fuse tubes. The fuse tube cavity assembly is fixedly disposed above the voltage transformer body. The fuse tube cavity assembly has two fuse tube seats arranged in parallel with opposite opening directions. The two fuse tubes are respectively pluggably installed in the two fuse tube seats, so that the high voltage connection terminals at the tails of the two fuse tubes are distributed on opposite sides of the voltage transformer body, increasing the phase distance between the primary terminal A and the primary terminal B.

[0006] As a further embodiment of this utility model, the main body of the voltage transformer is an epoxy resin casting structure, forming an insulating shell. The main body of the voltage transformer is provided with an iron core and windings, and the bottom of the main body of the voltage transformer is fixed to a base plate.

[0007] As a further embodiment of this utility model, the axes of the two melt tube seats in the melt tube cavity assembly are parallel and the openings of the two melt tube seats face opposite directions, forming a back-to-back parallel reverse layout.

[0008] As a further embodiment of this utility model, inside the fusible tube cavity assembly, between the two electrodes of the primary terminal A and the primary terminal B corresponding to the two high-voltage connection terminals, an integrally formed reinforcing rib is provided to extend the creepage distance.

[0009] As a further embodiment of this utility model, the reinforcing rib and the two electrodes are integrally formed by epoxy resin casting. The shape of the reinforcing rib is an arc-shaped or rib-like structure optimized by electric field simulation, and its surface is smoothly connected to the electrodes of primary terminal A and primary terminal B.

[0010] As a further embodiment of this utility model, the reinforcing ribs are provided such that the shortest surface creepage distance between the two electrodes at primary end A and primary end B is greater than the straight-line air distance between the two electrodes.

[0011] As a further embodiment of this utility model, the contact surface of the high-voltage connection terminal has a silver-plated layer or a copper-plated layer, and the phase spacing between the two high-voltage connection terminals is greater than or equal to the width of the voltage transformer body in the terminal distribution direction.

[0012] As a further embodiment of this utility model, the fuse tube cavity assembly includes a fuse tube cavity insert, a spring, a spring insert, a fuse retaining ring, and a fuse retaining ring insert; wherein, the fuse tube cavity insert is pre-embedded before the epoxy resin of the voltage transformer body is cast, and a fuse tube cavity is formed after casting; the spring is installed at the bottom of the fuse tube cavity, the fuse tube is placed on the spring, and is fixed by the screwed-in fuse retaining ring.

[0013] As a further embodiment of this utility model, the high voltage path in the fuse tube cavity assembly is as follows: it is connected from the primary terminal A or the primary terminal B, passes sequentially through the fuse retaining ring insert, the fuse retaining ring, the fuse tube, the spring, and the spring insert, and is finally input to the primary winding inside the voltage transformer body.

[0014] As a further embodiment of this utility model, the fuse tube cavity assembly is detachably mounted on the voltage transformer body by fasteners. The axes of the two fuse tube seats in the fuse tube cavity assembly are parallel to each other, with the opening of one fuse tube seat facing the left side of the voltage transformer body and the opening of the other fuse tube seat facing the right side of the voltage transformer body.

[0015] As a further embodiment of this invention, the tube body of the fusion tube is made of high-strength ceramic or composite insulating material.

[0016] As a further embodiment of this utility model, the parallel reverse double-fuse voltage transformers form a voltage transformer group. When using one voltage transformer, the primary terminal A is connected to the high-voltage line, and the primary terminal B is grounded. When using two voltage transformers, the primary terminal A of the first transformer is connected to the high-voltage line, the primary terminal B of the first transformer is connected to the primary terminal B of the second transformer, and the primary terminal C of the second transformer is connected to the high-voltage line, thus forming a VV connection method.

[0017] As a further aspect of this utility model, the assembly of the parallel reverse double fuse voltage transformer includes the following steps: a) Pre-assembly: The molten tube insert is pre-placed in the casting mold of the voltage transformer body; b) Casting: Pour epoxy resin mixture into the mold to integrally cast the voltage transformer body, the molten tube insert and the reinforcing ribs connecting the primary terminal A and the primary terminal B electrodes to form a shell with a molten tube chamber. c) Install internal components: Install springs at the bottom of the melt tube chamber of the cooled and solidified shell; d) Inserting the fusible tube: Place the fusible tube into the chamber so that its bottom end contacts the spring; e) Fixing: Screw the fuse retainer ring into the thread at the top of the fuse tube chamber, tighten the fuse tube, and complete the assembly.

[0018] As a further embodiment of this invention, in step b), the epoxy resin mixture is cast in a vacuum environment to prevent the generation of air bubbles.

[0019] Compared with the prior art, the parallel reverse double fuse voltage transformer proposed in this utility model has the following advantages: This invention fundamentally solves the problem of excessively close phase spacing on the same end of traditional voltage transformers by using a parallel and reverse-oriented fuse tube layout. By maximizing the separation of the two high-voltage connection terminals on both sides of the product, the phase spacing is significantly increased, greatly improving the uniformity of the electric field distribution between the high-voltage terminals. This effectively eliminates electric field concentration and distortion caused by insufficient spacing, significantly reduces the risk of partial discharge, and avoids breakdown faults caused by insulation deterioration during long-term operation or under overvoltage conditions. As a result, the reliability and safety of the equipment in medium and high voltage environments such as 10kV to 24kV are greatly improved.

[0020] This invention incorporates a reinforcing rib with a specific shape, integrally cast with epoxy resin between the electrodes connecting primary terminals A and B inside the molten tube cavity. This not only directly and effectively increases the creepage distance along the surface of the insulating material between the two electrodes, making the surface flashover path longer and more tortuous, but also, the shape optimized by electric field simulation can guide and disperse electric field lines, playing a role in voltage equalization and shielding, suppressing electric field concentration at the electrode edges. This allows the product to withstand higher levels of lightning impulse voltage and switching overvoltage, providing dual protection for the stable operation of the power system under severe weather conditions and reducing the probability of equipment damage caused by lightning strikes.

[0021] This invention utilizes a modular fuse tube cavity assembly and a reverse parallel layout to increase operating space. When the fuse tube needs to be replaced, the operator only needs to unscrew the fuse retainer to remove the old fuse tube and replace it with a new one, without the need for special tools or adjustment or disassembly of the external main circuit. The increased operating space reduces the difficulty of operation and the risk of misoperation. As an independent module, the fuse tube cavity assembly facilitates production, inspection, and maintenance. Even if damaged, it can be replaced individually, reducing the maintenance cost and time throughout the entire life cycle. It fundamentally solves the long-standing problems of insufficient phase spacing and insulation reliability in the field of high-voltage transformers.

[0022] These or other aspects of this application will become more apparent from the following description of embodiments. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the scope of this application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or related technologies, the accompanying drawings used in the description of the exemplary embodiments or related technologies will be briefly introduced below. The drawings are used to provide a further understanding of this utility model and constitute a part of the specification. They are used together with the embodiments of this utility model to explain this utility model and do not constitute a limitation on this utility model. In the drawings: Figure 1 This is a schematic diagram of the structure of a parallel reverse double fuse voltage transformer according to an embodiment of the present invention; Figure 2 This is a top perspective view of a parallel reverse double fuse voltage transformer according to an embodiment of the present invention; Figure 3 This is a side view of the primary terminal A fuse outlet in a parallel reverse double fuse voltage transformer according to an embodiment of the present invention; Figure 4 This is a side view of the primary terminal B fuse outlet in a parallel reverse double fuse voltage transformer according to an embodiment of the present invention; Figure 5This is a top front view of a parallel reverse double fuse voltage transformer according to an embodiment of the present invention; Figure 6 This is a cross-sectional view (AA) of a parallel reverse double fuse voltage transformer according to an embodiment of the present invention.

[0024] Marked in the image: 1-Voltage transformer body, 11-Iron core, 12-Winding, 13-Insulating shell, 14-Base plate, 2-Fuse tube cavity assembly, 21-Fuse tube seat, 22-Fuse tube cavity insert, 23-Spring, 24-Spring insert, 25-Fuse retaining ring, 26-Fuse retaining ring insert, 3-Fuse tube, 31-Primary terminal A, 32-Primary terminal B, 4-Reinforcing rib, 5-High voltage side connection terminal, 6-Low voltage side connection terminal. Detailed Implementation

[0025] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model are further described in detail below with reference to specific examples and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit this application.

[0027] It should be noted that all uses of the terms "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two different entities or different parameters with the same name. Therefore, "first" and "second" are merely for convenience of expression and should not be construed as limiting the embodiments of this utility model. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as other steps or units inherent in a process, method, system, product, or device that includes a series of steps or units.

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0030] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] See Figures 1 to 6 As shown, an embodiment of this utility model provides a parallel reverse double fuse tube voltage transformer, including a voltage transformer body 1, a fuse tube cavity assembly 2, and at least two fuse tubes 3. The fuse tube cavity assembly 2 is fixedly disposed above the voltage transformer body 1. The fuse tube cavity assembly 2 is provided with two fuse tube seats 21 arranged in parallel with opposite opening directions. The two fuse tubes 3 are respectively pluggable and detachable installed in the two fuse tube seats 21, so that the high voltage connection terminals at the tails of the two fuse tubes 3 are distributed on opposite sides of the voltage transformer body 1, increasing the phase distance between the primary terminal A31 and the primary terminal B32.

[0032] In this embodiment, the fuse chamber assembly 2 is detachably mounted on the voltage transformer body 1 by fasteners. The axes of the two fuse holders 21 in the fuse chamber assembly 2 are parallel to each other. The opening of one fuse holder 21 faces the left side of the voltage transformer body 1, and the opening of the other fuse holder 21 faces the right side of the voltage transformer body 1.

[0033] In this embodiment, the parallel reverse double-fuse voltage transformer includes a voltage transformer body 1, a fuse chamber assembly 2, and two fuse tubes 3. The voltage transformer body 1 is integrally molded from epoxy resin mixture through vacuum casting to form a robust insulating shell 13. The voltage transformer body 1 internally encapsulates an iron core 11 made of high-permeability silicon steel sheets and a precision-wound winding 12, which includes a primary winding and a secondary winding. The bottom of the voltage transformer body 1 is bolted to a metal base plate 14 for easy overall installation and fixation. The fuse chamber assembly 2 is detachably bolted to the top of the voltage transformer body 1. The fuse chamber assembly 2 internally has two parallel fuse tube seats 21, and the two fuse tubes 3 are pluggably installed into these two fuse tube seats 21. The tube body of the fuse tube 3 is made of high-strength ceramic material and contains a fuse wire for overcurrent protection. In this embodiment, as shown... Figure 2 and Figure 4 As shown, the axes of the two fuse holders 21 are parallel to each other, and the opening directions of the two fuse holders 21 are opposite. The opening of one fuse holder 21 faces the left side of the voltage transformer body 1, and the opening of the other fuse holder 21 faces the right side of the voltage transformer body 1, so that the two fuse tubes 3 are installed back to back in parallel and opposite directions. The primary terminals A31 and B32 of the high voltage connection terminals at the tails of the two fuse tubes 3 are distributed to the maximum extent on the left and right sides of the voltage transformer body 1.

[0034] This invention fundamentally solves the problem of excessively close phase spacing on the same end of traditional voltage transformers by using a parallel and reverse-oriented fuse tube layout. By maximizing the separation of the two high-voltage connection terminals on both sides of the product, the phase spacing is significantly increased, greatly improving the uniformity of the electric field distribution between the high-voltage terminals. This effectively eliminates electric field concentration and distortion caused by insufficient spacing, significantly reduces the risk of partial discharge, and avoids breakdown faults caused by insulation deterioration during long-term operation or under overvoltage conditions. As a result, the reliability and safety of the equipment in medium and high voltage environments such as 10kV to 24kV are greatly improved.

[0035] In this embodiment, the voltage transformer body 1 is an epoxy resin casting structure that forms an insulating shell 13. The voltage transformer body 1 is provided with an iron core 11 and a winding 12. The bottom of the voltage transformer body 1 is fixed on the base plate 14.

[0036] In this embodiment, the axes of the two fuse holders 21 in the fuse chamber assembly 2 are parallel and the openings of the two fuse holders 21 face opposite directions, forming a back-to-back parallel reverse layout. Inside the fuse chamber assembly 2, between the two electrodes of the primary terminal A31 and the primary terminal B32 corresponding to the two high-voltage connection terminals, an integrally formed reinforcing rib 4 is provided to extend the creepage distance.

[0037] The reinforcing rib 4 is integrally molded with the two electrodes by epoxy resin casting. The shape of the reinforcing rib 4 is an arc-shaped or rib-like structure optimized by electric field simulation, and its surface smoothly transitions to the electrodes of primary terminals A31 and B32. The setting of the reinforcing rib 4 ensures that the shortest surface creepage distance between the two electrodes of primary terminals A31 and B32 is greater than the straight-line air distance between the two electrodes.

[0038] In this embodiment, the contact surface of the high-voltage connection terminal has a silver-plated layer or a copper-plated layer, and the phase spacing between the two high-voltage connection terminals is greater than or equal to the width of the voltage transformer body 1 in the terminal distribution direction. See also Figure 5 As shown, the phase distance D between the primary terminals A31 and B32 of the two high-voltage connection terminals is 242mm, and the creepage distance h between the primary terminals A31 and B32 is 420mm. The high-voltage side connection terminal 5 and the low-voltage side connection terminal 6 are used to connect the high-voltage line and the low-voltage measuring instruments, respectively.

[0039] In this embodiment, the fuse tube cavity assembly 2 includes a fuse tube cavity insert 22, a spring 23, a spring insert 24, a fuse retaining ring 25, and a fuse retaining ring insert 26. The fuse tube cavity insert 22 is pre-embedded before the epoxy resin is poured into the voltage transformer body 1, and forms a fuse tube cavity after pouring. The spring 23 is installed at the bottom of the fuse tube cavity, and the fuse tube 3 is placed on the spring 23 and fixed by the screwed-in fuse retaining ring 25.

[0040] The high voltage path in the fuse tube cavity assembly 2 is as follows: it is connected from the primary terminal A31 or the primary terminal B32, passes through the fuse retainer insert 26, the fuse retainer 25, the fuse tube 3, the spring 23, the spring insert 24, and is finally input to the primary winding 12 inside the voltage transformer body 1.

[0041] In this embodiment, the tube body of the fusion tube 3 is made of high-strength ceramic or composite insulating material.

[0042] In some embodiments, parallel reverse double-fuse voltage transformers form a voltage transformer group. When using one voltage transformer, the primary terminal A31 is connected to the high-voltage line, and the primary terminal B32 is grounded. When using two voltage transformers, the primary terminal A31 of the first transformer is connected to the high-voltage line, the primary terminal B32 of the first transformer is connected to the primary terminal B32 of the second transformer, and the primary terminal C of the second transformer is connected to the high-voltage line, thus forming a VV connection method.

[0043] This invention incorporates a reinforcing rib 4 with a specific shape, integrally cast with epoxy resin between the electrodes connecting primary terminals A31 and B32 inside the molten tube cavity. This not only directly and effectively increases the creepage distance along the surface of the insulating material between the two electrodes, making the surface flashover path longer and more tortuous, but also, the shape optimized by electric field simulation can guide and disperse electric field lines, playing a role in voltage equalization and shielding, suppressing electric field concentration at the electrode edges, enabling the product to withstand higher levels of lightning impulse voltage and switching overvoltage. This provides dual protection for the stable operation of the power system under severe weather conditions and reduces the probability of equipment damage caused by lightning strikes.

[0044] In this embodiment, the assembly of the parallel reverse double fuse voltage transformer includes the following steps: a) Pre-assembly: The metal insert of the melt cavity insert 22, including the melt cavity insert 22, the electrode and the reinforcing rib 4, is pre-placed in the casting mold of the voltage transformer body 1; b) Casting: Under vacuum conditions below -0.095MPa, epoxy resin mixture heated to about 70℃ is injected into the mold, and epoxy resin mixture is poured into the mold to integrally cast the voltage transformer body 1, the fused tube cavity insert 22 and the reinforcing rib 4 connecting the primary terminal A31 and the primary terminal B32 electrodes, forming a shell with a fused tube cavity; wherein, the casting of epoxy resin mixture is carried out in a vacuum environment to prevent the generation of air bubbles.

[0045] c) Install internal components: Install spring 23 at the bottom of the melt tube chamber of the cooled and solidified shell; d) Inserting the fusible tube 3: Place the fusible tube 3 into the chamber so that its bottom end contacts the spring 23; e) Fixing: Screw the fuse retainer ring 25 into the thread at the top of the fuse tube chamber, tighten the fuse tube 3, and complete the assembly.

[0046] Exemplary, this embodiment of the present invention provides a parallel reverse double-fuse voltage transformer, a compact parallel reverse double-fuse voltage transformer suitable for 24kV systems, particularly suitable for parallel reverse double-fuse voltage transformers in space-constrained indoor switchgear. The voltage transformer in this embodiment also consists of a voltage transformer body 1, a fuse chamber assembly 2, and two fuses 3. Its overall layout employs a parallel reverse arrangement of fuses to maximize phase spacing. The design goal of this embodiment is to maintain a compact size even at higher 24kV voltage levels, to accommodate standard switchgear units.

[0047] For a 24kV voltage level, the key insulation dimensions in this embodiment include the phase spacing (D) as follows: Figure 5 As shown, the straight-line air distance (phase spacing D) between primary terminals A31 and B32 is designed to be ≥350mm to meet the electrical clearance requirements under higher voltages. The creepage distance (h) is optimized by adjusting the shape of the reinforcing rib 4, ensuring that the minimum creepage distance h between the primary terminals A31 and B32 reaches ≥630mm, far exceeding the minimum requirement specified for the 24kV system, thus ensuring extremely high insulation reliability even in polluted environments.

[0048] Among them, the reinforcing rib 4 is still cast integrally with the electrode, but its shape has been optimized by in-depth simulation for the 24kV electric field distribution. The cross-section is designed as a multi-arc surface combination structure to achieve a more extreme electric field uniformity effect in a limited space and suppress the maximum electric field intensity to a lower level. The fuse tube 3 adopts a high-voltage fuse tube that can withstand higher breaking capacity and rated current. The tube body uses a silicone rubber composite insulation material with better performance, which has both high strength and excellent water repellency. The primary winding 12 inside the voltage transformer body 1 is wound with high-insulation enameled wire and the interlayer insulation is strengthened. The iron core 11 is made of nanocrystalline or cold-rolled oriented silicon steel sheet to reduce no-load loss and improve measurement accuracy and product efficiency.

[0049] This invention utilizes a modular fuse tube cavity assembly 2 and a reverse parallel layout to increase the operating space. When the fuse tube 3 needs to be replaced, the operator only needs to unscrew the fuse retainer ring 25 to remove the old fuse tube 3 and replace it with a new one, without the need for special tools or adjustment or disassembly of the external main circuit. The increased operating space reduces the difficulty of operation and the risk of misoperation. The fuse tube cavity assembly 2, as an independent module, facilitates production, inspection, and maintenance. Even if damaged, it can be replaced individually, reducing the maintenance cost and time throughout the entire life cycle. It fundamentally solves the long-standing problems of insufficient phase spacing and insulation reliability in the field of high-voltage transformers.

[0050] The above are exemplary embodiments disclosed in this utility model. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this utility model as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this utility model may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0051] It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the associatedly listed items. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0052] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the framework of the present invention, technical features of the above embodiments or different embodiments can also be combined, and many other variations of different aspects of the present invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A parallel reverse double-fuse voltage transformer, comprising a voltage transformer body (1), characterized in that, It also includes a melt chamber assembly (2) and at least two melt tubes (3); The fuse tube cavity assembly (2) is fixedly disposed above the voltage transformer body (1). The fuse tube cavity assembly (2) is provided with two fuse tube seats (21) arranged in parallel and with opposite opening directions. The two fuse tubes (3) are respectively pluggable and detachable installed in the two fuse tube seats (21), so that the high voltage connection terminals at the tails of the two fuse tubes (3) are distributed on opposite sides of the voltage transformer body (1), increasing the phase distance between the primary terminal A (31) and the primary terminal B (32).

2. The parallel reverse double-fuse voltage transformer as described in claim 1, characterized in that, The voltage transformer body (1) is an epoxy resin casting structure that forms an insulating shell (13). The voltage transformer body (1) is provided with an iron core (11) and a winding (12). The bottom of the voltage transformer body (1) is fixed on a base plate (14).

3. The parallel reverse double-fuse voltage transformer as described in claim 1, characterized in that, The axes of the two melt tube seats (21) in the melt tube cavity assembly (2) are parallel and the openings of the two melt tube seats (21) face opposite directions, forming a back-to-back parallel reverse layout.

4. The parallel reverse double-fuse voltage transformer as described in claim 3, characterized in that, Inside the fused tube cavity assembly (2), between the two electrodes of the primary terminal A (31) and the primary terminal B (32) corresponding to the two high-voltage connection terminals, there is an integrally formed reinforcing rib (4) for extending the creepage distance.

5. The parallel reverse double-fuse voltage transformer as described in claim 4, characterized in that, The reinforcing rib (4) and the two electrodes are integrally formed by epoxy resin casting. The shape of the reinforcing rib (4) is an arc-shaped or rib-shaped structure optimized by electric field simulation, and its surface is smoothly connected to the electrodes of the primary end A (31) and the primary end B (32).

6. The parallel reverse double-fuse voltage transformer as described in claim 5, characterized in that, The reinforcement rib (4) is provided such that the shortest surface creepage distance between the two electrodes of the primary end A (31) and the primary end B (32) is greater than the straight-line air distance between the two electrodes.

7. The parallel reverse double-fuse voltage transformer as described in claim 1 or 4, characterized in that, The contact surface of the high-voltage connection terminal has a silver plating layer or a copper plating layer, and the phase spacing between the two high-voltage connection terminals is greater than or equal to the width of the voltage transformer body (1) in the terminal distribution direction.

8. The parallel reverse double-fuse voltage transformer as described in claim 1, characterized in that, The fuse tube cavity assembly (2) includes a fuse tube cavity insert (22), a spring (23), a spring insert (24), a fuse retainer ring (25), and a fuse retainer ring insert (26); wherein, the fuse tube cavity insert (22) is pre-embedded before the epoxy resin is poured into the voltage transformer body (1), and forms a fuse tube cavity after pouring; the spring (23) is installed at the bottom of the fuse tube cavity, and the fuse tube (3) is placed on the spring (23) and fixed by the screwed-in fuse retainer ring (25).

9. The parallel reverse double-fuse voltage transformer as described in claim 8, characterized in that, The fuse chamber assembly (2) is detachably mounted on the voltage transformer body (1) by fasteners. The axes of the two fuse holders (21) in the fuse chamber assembly (2) are parallel to each other. The opening of one fuse holder (21) faces the left side of the voltage transformer body (1), and the opening of the other fuse holder (21) faces the right side of the voltage transformer body (1).

10. The parallel reverse double-fuse voltage transformer as described in claim 1, characterized in that, The tube body of the fusion tube (3) is made of high-strength ceramic or composite insulating material.

Images