Voltage transformer and voltage transformer manufacturing device and method

Abstract

This invention discloses a voltage transformer, including a core assembly, an insulating shell, and a wiring assembly. The core assembly transforms voltage. During operation, the primary coil can be connected to an external circuit via primary connection A and primary connection N, while the secondary coil can be connected to external equipment via secondary connection terminals. The primary coil is connected to primary connection A via a primary connection A lead, and an equalizing mesh is placed over the primary connection A lead. The insulating shell covers the equalizing mesh. The equalizing mesh shields the sharp corners, burrs, and gaps of the primary connection A lead, resulting in a more uniform local electric field distribution at the high-voltage end of the voltage transformer, reducing partial discharge, and improving the product quality of the voltage transformer. This invention also provides a voltage transformer manufacturing apparatus and method, employing a casting process to prepare the insulating shell, further improving the manufacturing quality of the voltage transformer.

Description

Technical Field

[0001] This invention relates to the technical field of power transmission and transformation equipment and its peripheral supporting facilities, and in particular to a voltage transformer and a voltage transformer manufacturing apparatus and method. Background Technology

[0002] A voltage transformer is a special type of transformer specifically designed for voltage transformation. Under normal operating conditions, its secondary voltage is substantially proportional to the primary voltage, and when connected correctly, the phase difference between the secondary and primary voltages is close to zero. The primary winding of the voltage transformer is connected in parallel to the power system line, while the secondary winding is connected to measuring instruments, meters, relays, and other equipment. Depending on the voltage level of the power line, sufficient insulation is provided between the primary and secondary windings of the voltage transformer to ensure that all low-voltage equipment is isolated from high-voltage equipment.

[0003] With the rapid development of power construction, the long-term insulation performance of voltage transformers in power grids and high-voltage substation systems is receiving increasing attention. Improving the partial discharge level of voltage transformers can effectively improve the product quality of voltage transformers and ensure the safe operation of the power grid.

[0004] Existing technologies and processes have limitations in controlling partial discharge in voltage transformers. Current cast-insulated voltage transformers lack voltage equalization measures at the primary high-voltage end, resulting in an overly concentrated electric field distribution, high field strength, and large partial discharge. Furthermore, while existing medium-voltage transformers achieve insulation protection through epoxy resin vacuum casting, the manufacturing process inevitably produces sharp corners and burrs on the surface or inside the transformer coil, leading to increased or uneven local electric fields. Additionally, defects such as bubbles, voids, and cracks generated during casting further increase partial discharge, impacting the overall quality of the voltage transformer.

[0005] Therefore, how to change the current situation where the partial discharge of voltage transformers is large and the electric field distribution is uneven, has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a voltage transformer, a voltage transformer manufacturing apparatus and method to solve the problems existing in the prior art, reduce the partial discharge of the voltage transformer, improve the electric field distribution, and improve the product quality of the voltage transformer.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a voltage transformer, comprising:

[0008] A core assembly, comprising an iron core and a primary coil and a secondary coil disposed on the iron core, wherein an insulating layer is disposed between any two of the primary coil, the secondary coil, and the iron core; the iron core is grounded;

[0009] An insulating shell that covers the exterior of the core assembly;

[0010] The wiring assembly includes a primary coil, one end of which is connected to a primary terminal A via a primary A lead, and the other end connected to a primary terminal N. Both primary terminals A and N are embedded in the insulating shell and can be connected to external circuitry. The primary A lead is covered by an equalizing mesh, and the insulating shell covers the outside of the equalizing mesh. The secondary coil is connected to a secondary terminal, which is embedded in the insulating shell and can be connected to external equipment.

[0011] Preferably, the primary A-end lead is spiral-shaped.

[0012] Preferably, the primary coil is sleeved outside the secondary coil, and the primary coil is covered with a primary shielding electrostatic shield.

[0013] Preferably, both the primary coil and the secondary coil are wound on the iron core, and a shielding mesh is provided between the primary coil and the iron core, and the shielding mesh is grounded.

[0014] Preferably, the bottom of the insulating shell is provided with a mounting plate and the two are connected, and the mounting plate is provided with an embedded nut, and the shielding mesh is grounded by the embedded nut.

[0015] Preferably, the iron core is treated with shielding and wrapping.

[0016] Preferably, the iron core is wrapped with a shielding and buffering material.

[0017] Preferably, the insulating shell is manufactured by casting.

[0018] The present invention provides a voltage transformer manufacturing apparatus for manufacturing the aforementioned voltage transformer, comprising a casting mold, wherein the core assembly and the wiring assembly are both disposed within the casting mold, and the primary wiring A terminal, the primary wiring N terminal and the secondary wiring terminal are all detachably disposed on the casting mold, and the space between the core assembly, the wiring assembly and the inner wall of the casting mold is used to accommodate casting material to form the insulating shell.

[0019] The present invention also provides a method for manufacturing a voltage transformer, wherein the core assembly and the wiring assembly are both disposed in a casting mold, and a casting material is introduced into the casting mold. The casting material fills the space between the core assembly, the wiring assembly and the inner wall of the casting mold to form the insulating shell.

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] The voltage transformer of the present invention can transform voltage using core components. When the voltage transformer is working, the primary coil can be connected to an external line using primary connection A and primary connection N, and the secondary coil can be connected to an external device using the secondary connection. The primary coil is connected to primary connection A using a primary connection A lead, and an equalizing mesh is provided outside the primary connection A lead. An insulating shell covers the outside of the equalizing mesh. The equalizing mesh can shield the sharp corners, burrs, gaps, etc. of the primary connection A lead, so that the local electric field distribution of the high voltage end of the voltage transformer is uniform, reducing partial discharge and improving the product quality of the voltage transformer.

[0022] The present invention also provides a voltage transformer manufacturing apparatus and manufacturing method for manufacturing the aforementioned voltage transformer. During manufacturing, the core assembly and wiring assembly are placed in a casting mold, and the insulating shell is prepared by casting, thereby improving the manufacturing quality of the voltage transformer. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a front view of the voltage transformer disclosed in the embodiments of the present invention;

[0025] Figure 2 This is a side view of the voltage transformer disclosed in an embodiment of the present invention.

[0026] Among them, 100 is the core component and 200 is the wiring component;

[0027] 1 is the insulating shell, 2 is the iron core, 3 is the primary coil, 4 is the secondary coil, 5 is the primary A terminal lead, 6 is the primary wiring A terminal, 7 is the primary wiring N terminal, 8 is the secondary wiring terminal, 9 is the equalizing mesh cover, 10 is the primary shielding electrostatic shield, 11 is the shielding mesh, 12 is the mounting plate, and 13 is the embedded nut. Detailed Implementation

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

[0029] The purpose of this invention is to provide a voltage transformer, a voltage transformer manufacturing apparatus and method to solve the problems existing in the prior art, reduce the partial discharge of the voltage transformer, improve the electric field distribution, and improve the product quality of the voltage transformer.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This invention provides a voltage transformer, comprising a core assembly 100, an insulating shell 1, and a wiring assembly 200. The core assembly 100 includes an iron core 2 and a primary coil 3 and a secondary coil 4 disposed on the iron core 2. An insulating layer is provided between any two of the primary coil 3, the secondary coil 4, and the iron core 2. The iron core 2 is grounded. The insulating shell 1 covers the outside of the core assembly 100. One end of the primary coil 3 is connected to a primary wiring A terminal 6 via a primary A terminal lead 5, and the other end is connected to a primary wiring N terminal 7. Both the primary wiring A terminal 6 and the primary wiring N terminal 7 are embedded in the insulating shell 1 and can be connected to external circuits. A voltage equalization mesh 9 is provided over the primary A terminal lead 5, and the insulating shell 1 covers the outside of the voltage equalization mesh 9. The secondary coil 4 is connected to a secondary wiring terminal 8, which is embedded in the insulating shell 1 and can be connected to external devices.

[0032] The voltage transformer of this invention utilizes the core assembly 100 to transform voltage. During operation, the primary coil 3 can be connected to external circuits via primary connection A terminal 6 and primary connection N terminal 7, while the secondary coil 4 can be connected to external equipment via secondary connection terminal 8. The primary coil 3 is connected to primary connection A terminal 6 via primary connection A terminal lead 5, and an equalizing mesh cover 9 is provided outside the primary connection A terminal lead 5. An insulating shell 1 covers the outside of the equalizing mesh cover 9. The equalizing mesh cover 9 is a conductor. The equalizing mesh cover 9 shields the sharp corners, burrs, and gaps of the primary connection A terminal lead 5, resulting in a uniform local electric field distribution at the high-voltage end of the voltage transformer, reducing partial discharge, and improving the product quality of the voltage transformer. In this specific embodiment, the equalizing mesh cover 9 is made of brass. Brass has high structural strength and good corrosion resistance, which can extend the service life of the equalizing mesh cover 9 and improve its operational reliability. It should be explained here that the line voltage of the primary coil 3 of the voltage transformer is high, and the line voltage of the secondary coil 4 is low. Therefore, the primary A terminal lead 5 is the high voltage terminal. The line voltage of the voltage transformer is common knowledge to those skilled in the art, and will not be elaborated here.

[0033] Among them, the primary A-end lead 5 is spiral-shaped and adopts a structure similar to a cylindrical helical spring. The spiral shape of the primary A-end lead 5 increases the radius of the conductor, thereby increasing the radius of curvature of the high-voltage electrode, which can reduce the surface field strength of the high-voltage electrode and further reduce partial discharge.

[0034] In this specific embodiment, the primary coil 3 is sleeved outside the secondary coil 4, and the primary coil 3 is sleeved with a primary shielding electrostatic screen 10. By placing the primary shielding electrostatic screen 10 on the outer ring of the primary coil 3, the radius of curvature of the primary shielding electrostatic screen 10 is increased. After the primary coil 3 is shielded and wrapped, the field strength is reduced, which can also reduce partial discharge and improve the voltage transformer's overvoltage resistance and lightning strike resistance.

[0035] Specifically, both the primary coil 3 and the secondary coil 4 are wound on the iron core 2. A shielding mesh 11 is provided between the primary coil 3 and the iron core 2. The shielding mesh 11 is grounded. The shielding mesh 11 can shield the air gap and the tip electrode at ground potential from the high voltage electric field, making the insulating medium singular, the field strength distribution more uniform, reducing the field strength, and reducing partial discharge.

[0036] In addition, a mounting plate 12 is provided at the bottom of the insulating shell 1 and the two are connected. An embedded nut 13 is provided on the mounting plate 12, and the shielding mesh 11 is grounded by the embedded nut 13, which facilitates the grounding of the shielding mesh 11. In practical applications, the voltage transformer can also be fixedly installed on other equipment or work sites using the mounting plate 12, which improves the ease of operation and working stability of the voltage transformer.

[0037] It should also be noted that the iron core 2 is shielded and wrapped. In other specific embodiments of the present invention, the iron core 2 is wrapped with a shielding buffer material, which can also shield the residual air gap within the shielding buffer material from the high-voltage electric field, reduce the field strength, and reduce partial discharge. In practical applications, the shielding buffer material can be selected from materials such as polyurethane and semi-conductive crepe paper, or a suitable shielding buffer material can be selected according to the actual working conditions to meet the specific operating requirements of the voltage transformer.

[0038] More specifically, the insulating shell 1 is made by casting, and the casting insulating material can be selected according to the actual working conditions to meet the working requirements of the voltage transformer.

[0039] Furthermore, the present invention provides a voltage transformer manufacturing apparatus for manufacturing the aforementioned voltage transformer, comprising a casting mold, a core assembly 100 and a wiring assembly 200 both disposed within the casting mold, and primary wiring terminal A 6, primary wiring terminal N 7 and secondary wiring terminal 8 all detachably disposed on the casting mold. The space between the core assembly 100, the wiring assembly 200 and the inner wall of the casting mold is used to accommodate casting material to form an insulating shell 1. Vacuum casting of the insulating shell 1 using a casting mold facilitates the manufacturing of the voltage transformer.

[0040] Furthermore, the present invention also provides a method for manufacturing a voltage transformer, used to produce the aforementioned voltage transformer. The core assembly 100 and the wiring assembly 200 are both placed within a casting mold. A vacuum casting method is used to introduce casting material into the casting mold. The casting material is an insulating material, which fills the space between the core assembly 100, the wiring assembly 200, and the inner wall of the casting mold to form an insulating shell 1. It should be noted that the casting material can be epoxy resin or other insulating materials to meet the operational requirements of the insulating shell 1 and ensure the product quality of the voltage transformer.

[0041] The voltage transformer of this invention employs a spiral-shaped primary A-end lead 5, which increases the radius of curvature of the high-voltage electrode and reduces the electric field strength on the electrode surface. Simultaneously, an equalizing mesh 9 is installed at the primary A-end lead 5 to shield the sharp corners, burrs, and gaps of the lead 5, altering the electric field distribution and reducing partial discharge. Furthermore, a shielding mesh 11 is installed between the primary coil 3 and the mounting plate 12. The shielding mesh 11 is grounded, shielding the air gap and the pointed electrodes at ground potential from the high-voltage electric field. This results in a single insulating medium, a more uniform electric field distribution, and further reduction of partial discharge, thus improving the quality of the voltage transformer product.

[0042] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A voltage transformer, characterized in that, include: A core assembly, comprising an iron core and a primary coil and a secondary coil disposed on the iron core, wherein an insulating layer is disposed between any two of the primary coil, the secondary coil, and the iron core; the iron core is grounded; An insulating shell that covers the exterior of the core assembly; The wiring assembly includes a primary coil, one end of which is connected to a primary terminal A via a primary A lead, and the other end connected to a primary terminal N. Both primary terminals A and N are embedded in the insulating shell and can be connected to external circuitry. The primary A lead is covered by an equalizing mesh, and the insulating shell covers the outside of the equalizing mesh. The secondary coil is connected to a secondary terminal, which is embedded in the insulating shell and can be connected to external equipment. The primary A-end lead is spiral-shaped; The primary coil is sleeved outside the secondary coil, and a primary shielding electrostatic shield is provided on the outer sleeve of the primary coil; both the primary coil and the secondary coil are wound on the iron core, and a shielding mesh is provided between the primary coil and the iron core, and the shielding mesh is grounded; The iron core is shielded and wrapped; the iron core is wrapped with shielding and buffering material. The insulating shell is manufactured by casting.

2. The voltage transformer according to claim 1, characterized in that: The bottom of the insulating shell is provided with a mounting plate and the two are connected. The mounting plate is provided with a nut, and the shielding mesh is grounded by the nut.

3. A voltage transformer manufacturing apparatus for manufacturing the voltage transformer according to claim 1 or 2, characterized in that: The device includes a casting mold, in which the core assembly and the wiring assembly are disposed within the casting mold. The primary wiring terminal A, the primary wiring terminal N, and the secondary wiring terminal are all detachably disposed on the casting mold. The space between the core assembly, the wiring assembly, and the inner wall of the casting mold is used to accommodate casting material to form the insulating shell.

4. A method for manufacturing a voltage transformer, used to manufacture the voltage transformer according to claim 1 or 2, characterized in that: The core assembly and the wiring assembly are both placed inside the casting mold. Casting material is introduced into the casting mold, and the casting material fills the space between the core assembly, the wiring assembly and the inner wall of the casting mold to form the insulating shell.

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