A voltage transformer

Abstract

The utility model belongs to the technical field of mutual inductor, concretely relates to a voltage mutual inductor, and the voltage mutual inductor includes the box body, is provided with the body inside the box body, and the body includes the iron core and the step type coil;The iron core is installed on the box base through the clamp piece, and the step type coil is arranged around the outer periphery of the iron core, and the step type coil includes the insulating cylinder and the conductor line that is wound on the insulating cylinder, and the conductor line is segmented along the axial direction and is wound to form a plurality of step structures, and the outer diameter of the step structure changes layer by layer, and constitutes the ladder-shaped winding structure, and the structure increases the face creeping distance in the limited space through the step type coil design, effectively improves the electrical insulation performance, cooperates the miniaturized iron core structure, and realizes the mutual inductor design of volume reduction, compact arrangement, reliable insulation performance as a whole, and is suitable for the compactification, high density deployment demand of high-voltage gas insulated switchgear system.

Description

Technical Field

[0001] The utility model belongs to the technical field of instrument transformers, and particularly relates to a voltage transformer. Background Technique

[0002] Traditional 500kV voltage transformers are bulky and occupy a large space, making it difficult to meet the requirements of intelligent substations for equipment miniaturization, integration, and high-density layout. Miniature voltage transformers have emerged as one of the key development directions in the high-voltage measurement link of intelligent substations. Such devices can accurately convert high-voltage signals of 500kV into standard low-voltage signals, while realizing real-time monitoring and data acquisition of the power grid operation status, providing reliable data support for functions such as power grid dispatching control, status assessment, and fault warning. Due to their small size and compact structure, they are convenient for flexible layout in substations, thus building a denser sensing network and improving the overall intelligent level and efficiency of the power grid operation.

[0003] To achieve the miniaturized design of the instrument transformer, core components such as the iron core and coil structure need to be optimized accordingly. In terms of iron core design, silicon steel sheet materials with high magnetic permeability are usually used to reduce flux loss and increase flux density. Compared with the traditional iron core structure, the silicon steel sheets used in miniature instrument transformers are smaller in size and are stacked in a staggered manner, so that each silicon steel sheet forms a continuous magnetic path in the overlapping area, effectively avoiding the increase in magnetic resistance caused by air gaps, thereby realizing a more compact flux channel.

[0004] However, in terms of coil design in the prior art, traditional voltage transformers mostly use windings with trapezoidal or square structures. Such structures are large in volume under the design requirements of meeting electrical insulation distance and surface field strength, and it is difficult to further compress. Content of the Utility Model

[0005] The utility model aims at the problems in the prior art and provides a voltage transformer, which solves the problem that traditional voltage transformers in the prior art mostly use winding designs with trapezoidal or square structures, resulting in a large volume and being difficult to further compress.

[0006] The technical solution adopted by the utility model is as follows:

[0007] The present application provides a voltage transformer, including a box body, and a body is arranged inside the box body. The body includes an iron core and a stepped coil;

[0008] The iron core is installed on the base of the box body through clamping parts, and the stepped coil is wound around the outer periphery of the iron core;

[0009] The stepped coil includes an insulating cylinder and a conductor wire wound around the insulating cylinder. The conductor wire is wound in segments along the axial direction to form a plurality of stepped structures, and the outer diameters of the stepped structures change layer by layer to form a stepped winding structure;

[0010] A shielding cover is provided on the top of the device body, and a conductive rod is installed inside the shielding cover. One end of the conductive rod is connected to the high-voltage end of the stepped coil, and the other end is connected to a basin-type insulator installed on the top of the box body. The basin-type insulator is used for the insulation lead-out of the high-voltage end.

[0011] Furthermore, the core is composed of several silicon steel sheets stacked alternately, with each layer of silicon steel sheets arranged in a stepped overlapping manner.

[0012] Furthermore, the stepped coil includes three or more layers of winding steps, which are arranged sequentially along the axial direction, and each layer of coil is provided with a uniformly distributed radial insulating pad.

[0013] Furthermore, the insulating gaskets are made of polytetrafluoroethylene, polyimide, or epoxy glass fiber.

[0014] Furthermore, in the stepped coil, the number of turns in the stepped layer near the high-voltage side winding structure is less than the number of turns in the stepped layer near the low-voltage side winding structure, and the conductor cross-sectional area near the high-voltage side winding structure is greater than the conductor cross-sectional area near the low-voltage side winding structure.

[0015] Furthermore, the clamping component includes a lower fixing part, a middle limiting ring, and an upper positioning shaft. The lower fixing part is provided with an external thread and mates with the threaded hole of the housing base. The limiting ring fits against the lower end face of the coil for positioning. The positioning shaft passes through the central through hole of the iron core and connects to the top shielding structure.

[0016] Furthermore, the clamps are made of galvanized steel or aluminum alloy and have several heat dissipation holes or slots.

[0017] Furthermore, an electric field equalization ring is provided between the shielding cover and the conductive rod.

[0018] Furthermore, the enclosure adopts a cylindrical structure, and the interior of the enclosure is filled with insulating gas.

[0019] Furthermore, the insulating gas is any one of sulfur hexafluoride, nitrogen, or carbon tetrafluoride.

[0020] As can be seen from the above technical solutions, this utility model has the following advantages:

[0021] 1. By incorporating a core and stepped coil within the enclosure, and combining this with the top and bottom lead-out arrangements of the conductive rods and basin-type insulators, a compact high-voltage transformer design with sufficient high-voltage side insulation distance and convenient installation is achieved. In particular, the introduction of the stepped coil effectively increases the creepage distance along the winding surface, enhancing electrical insulation capabilities within a limited space, making it suitable for integrated installation in miniaturized GIS equipment.

[0022] 2. The iron core is constructed using staggered, stepped silicon steel sheets, which significantly reduces the magnetic resistance at the overlapping areas, improves the continuity of the magnetic circuit, and reduces local eddy current losses, thereby enhancing the magnetic performance and measurement accuracy of the current transformer. Simultaneously, proper control of the lamination method contributes to core miniaturization, improves internal space utilization, and meets the dual requirements of GIS equipment for compact structure and thermal stability.

[0023] 3. Setting three or more winding steps and arranging them orderly along the axial direction helps to extend the electrical path and enhance surface insulation without increasing the overall height. Simultaneously, the use of insulating pads allows for control of interlayer insulation distance, improving local electric field distribution and increasing the insulation safety margin for high-voltage operation, making it particularly suitable for high-voltage, small-volume electrical equipment. Furthermore, by reducing the number of turns and increasing the conductor cross-sectional area on the high-voltage side of the stepped coil design, the unit turn voltage can be reduced, minimizing local electric field concentration effects and improving the thermal stability and electric field uniformity of the high-voltage winding, thereby optimizing overall electrical performance. This structure effectively suppresses corona and breakdown risks, making it particularly suitable for the safe operation requirements of transformers in high-voltage applications.

[0024] 4. The clamps employ a structural design with lower-end fixing, middle-section limiting, and upper-end positioning. This ensures stable installation of the core and coil assembly within the enclosure and precise positioning between the transformer body and the top insulating lead-out structure. This structure improves the mechanical strength and positioning consistency of the transformer assembly, facilitating production, transportation, and on-site installation. It also helps reduce assembly errors and the risk of vibration-induced loosening. The clamps are made of a metal material with good thermal conductivity and are equipped with heat dissipation holes or slots, which can serve as heat conduction paths during operation, guiding heat from the transformer body to the enclosure shell and enhancing system heat dissipation efficiency. This design effectively controls internal temperature rise, improves the thermal stability and operational reliability of the transformer, and is particularly suitable for long-term operation under high-current loads or in sealed environments.

[0025] 5. The cylindrical structure of the enclosure simplifies the manufacturing process, reduces structural complexity, and provides more usable internal space, which helps to achieve the goal of miniaturization. The internal filling with insulating gas can improve the overall electrical insulation performance, suppress discharge phenomena, meet high voltage insulation requirements, and improve the long-term operational safety and environmental adaptability of the equipment. Attached Figure Description

[0026] To more clearly illustrate the technical solution of this utility model, the drawings used in the description 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 without creative effort.

[0027] Figure 1This is a cross-sectional view of the voltage transformer in a specific embodiment of this utility model;

[0028] Figure 2 This is a partial structural cross-sectional view of the voltage transformer in a specific embodiment of this utility model.

[0029] In the diagram: 1. Protective cap; 2. Insulator; 3. Shielding cover; 4. Stepped coil; 5. Iron core; 6. Housing; 7. Air filling valve; 8. Explosion-proof device; 9. Base. Detailed Implementation

[0030] Various embodiments of this disclosure will be described more fully in the following detailed description. This disclosure may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this disclosure to the specific embodiments disclosed herein, but rather this disclosure should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this disclosure.

[0031] To facilitate a clear description of the technical solutions in the embodiments of this application, some terms and technologies involved in the embodiments of this application will be briefly introduced below:

[0032] In the following, the terms “comprising” or “may include”, which may be used in various embodiments of this disclosure, indicate the presence of the disclosed functions, operations, or elements, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of this disclosure, the terms “comprising,” “having,” and their cognates are intended only to indicate a particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or the possibility of adding one or more combinations of the foregoing.

[0033] In various embodiments of this disclosure, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0034] The terms used in the various embodiments of this disclosure (such as "first," "second," etc.) may modify various components in the various embodiments, but do not limit the corresponding components. For example, the above terms do not limit the order and / or importance of the components. The above terms are only used for the purpose of distinguishing one component from others. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, a first component may be referred to as a second component without departing from the scope of the various embodiments of this disclosure, and similarly, a second component may also be referred to as a first component.

[0035] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0036] See Figure 1 and Figure 2 As shown, this utility model provides a voltage transformer, including a housing 6. The housing 6 adopts a cylindrical metal structure with a continuous internal space, which facilitates the installation of the transformer components and gas filling. One end of the housing 6 is connected and fixed to the base 9 by bolts. The base 9 is used to support the entire transformer structure and is provided with mounting screw holes and a central through hole.

[0037] The housing 6 houses the core assembly, which includes an iron core 5 and a stepped coil 4. The iron core 5 is composed of several high-permeability silicon steel sheets, which are staggered along the circumference. The overlapping parts are arranged in a stepped staggered structure to form a continuous closed magnetic circuit and reduce magnetic reluctance and eddy current losses. A central through-hole is provided in the center of the iron core 5 to accommodate positioning components.

[0038] A stepped coil 4 is wound around the outer periphery of the iron core 5, consisting of an insulating cylinder and multiple layers of conductor wire wound on the outer surface of the insulating cylinder. The conductor wire is wound in segments along the axial direction, forming a stepped structure of three or more layers. The outer diameter of each winding step decreases progressively from bottom to top, forming a stepped layout. Uniformly distributed radial insulating pads are placed between each winding step. The pad material is polytetrafluoroethylene, polyimide, or epoxy glass fiber, which has excellent heat resistance and dielectric properties.

[0039] The number of turns in the winding step layer near the high-voltage end is less than that in the low-voltage side winding layer, and the conductor cross-sectional area is increased accordingly. This helps to realize nonlinear voltage distribution and high-voltage field uniformity design, reduce the field strength gradient in the high-potential region, and improve insulation stability.

[0040] The device body is fixed to the base 9 by clamps. The clamps include a lower fixing part, a middle limiting ring, and an upper positioning shaft. The fixing part has threads on the outside, which are screwed into the screw holes of the base 9 for locking; the limiting ring fits tightly against the lower end face of the coil to prevent axial displacement of the assembly; the positioning shaft passes through the center hole of the iron core 5 and extends to the upper structure to support the shielding cover 3 and the lead-out structure. The clamps are made of aluminum alloy or galvanized steel, and the surface has multiple heat dissipation holes or grooves to assist in heat conduction and dissipation during operation.

[0041] A shielding cover 3 is installed on top of the device to shield the high-voltage electric field and form an equipotential shielding layer. A conductive rod is inserted inside the shielding cover 3. The lower end of the conductive rod is connected to the high-voltage lead of the stepped coil 4, and the upper end extends to the top and connects to the insulator 2 to realize the high-voltage lead-out function. Multiple electric field equalizing rings are set between the shielding cover 3 and the conductive rod. The equalizing rings are evenly spaced along the axial direction. The rounded corner transition structure design optimizes the electric field distribution and effectively reduces the edge field strength and the risk of partial discharge.

[0042] Insulator 2 has a basin-type structure and is fixed to the top of the enclosure 6 by a flange. It is used to achieve electrical isolation and mechanical connection with the external high-voltage busbar. The top is covered with a protective cap 1 to protect against the external environment and prevent foreign objects from entering.

[0043] The enclosure 6 is filled with high-voltage insulating gas, specifically sulfur hexafluoride, nitrogen, or carbon tetrafluoride, to enhance overall insulation strength and suppress corona and discharge phenomena. For gas injection and maintenance, the enclosure 6 is equipped with a filling valve 7, and an explosion-proof device 8 is also installed to automatically release pressure when the internal gas pressure abnormally increases, ensuring safe system operation.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage transformer, characterized in that, It includes a housing (6), and the housing (6) contains a body, which includes an iron core (5) and a stepped coil (4). The iron core (5) is mounted on the base (9) of the housing (6) by a clamp, and the stepped coil (4) is arranged around the outer periphery of the iron core (5); The stepped coil (4) includes an insulating cylinder and a conductor wire wound on the insulating cylinder. The conductor wire is wound in sections along the axial direction to form several stepped structures. The outer diameter of the stepped structure changes layer by layer to form a stepped winding structure. A shield (3) is provided on the top of the device body. A conductive rod is installed inside the shield (3). One end of the conductive rod is connected to the high-voltage end of the stepped coil (4), and the other end is connected to the basin insulator (2) installed on the top of the box (6). The basin insulator (2) is used for the insulation lead-out of the high-voltage end.

2. The voltage transformer according to claim 1, characterized in that, The iron core (5) is composed of several silicon steel sheets stacked in an alternating manner, with each layer of silicon steel sheets arranged in a stepped overlapping manner.

3. The voltage transformer according to claim 1, characterized in that, The stepped coil (4) includes three or more layers of winding steps, which are arranged sequentially along the axial direction, and each layer of coil is provided with a uniformly distributed radial insulating pad.

4. The voltage transformer according to claim 3, characterized in that, The insulating gaskets are made of polytetrafluoroethylene, polyimide, or epoxy glass fiber.

5. The voltage transformer according to claim 3, characterized in that, In the stepped coil (4), the number of turns of the stepped layer near the high-voltage side winding structure is less than the number of turns of the stepped layer near the low-voltage side winding structure, and the conductor cross-sectional area near the high-voltage side winding structure is greater than the conductor cross-sectional area near the low-voltage side winding structure.

6. The voltage transformer according to claim 1, characterized in that, The clamping part includes a lower fixing part, a middle limiting ring and an upper positioning shaft. The lower fixing part is provided with an external thread and cooperates with the threaded hole of the housing (6) and the base (9). The limiting ring is in contact with the lower end face of the coil for positioning. The positioning shaft passes through the central through hole of the iron core (5) and is connected to the top shielding structure.

7. The voltage transformer according to claim 6, characterized in that, The clamps are made of galvanized steel or aluminum alloy and have several heat dissipation holes or slots.

8. The voltage transformer according to claim 1, characterized in that, An electric field equalization ring is provided between the shield (3) and the conductive rod.

9. The voltage transformer according to claim 1, characterized in that, The box (6) adopts a cylindrical structure and is filled with insulating gas.

10. The voltage transformer according to claim 9, characterized in that, The insulating gas is any one of sulfur hexafluoride, nitrogen, or carbon tetrafluoride.

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