Through-type fully sealed current transformer with voltage-equalizing mesh embedded in the inner wall

Abstract

The present application relates to the technical field of transformers, and in particular to a current transformer, a through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall, comprising a magnetic core and an induction winding wound on the magnetic core; further comprising an epoxy resin layer wrapping the magnetic core and the induction winding, the epoxy resin layer being provided with a through hole passing through the center of the induction winding; a metal mesh, called a shielding mesh, is provided in the inner lining of the through hole surrounding the epoxy resin layer; a grounding wire is conductively connected to the shielding mesh; a metal plate, called a shielding plate, is further provided outside the epoxy resin layer with a through hole, called a shielding plate, the epoxy resin layer passes through the through hole of the shielding plate along the direction of the through hole; an insulating material structure, called a mounting block, is connected to the shielding plate, and the terminal of the induction winding is connected and provided on the mounting block; the outer layer of the epoxy resin layer adopts a material layer of epoxy resin mixed with soft magnetic powder, called an electromagnetic field shielding layer, and the electromagnetic field shielding layer is compounded on the outer side of the epoxy resin layer; thereby ensuring the measurement accuracy and stability of the current transformer.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to a current transformer. Background Art

[0002] A current transformer is an electrical device that uses the principle of electromagnetic induction to convert high current into low current through the transformer principle for current measurement.

[0003] The current transformer senses and measures the current in the high-voltage line. The electric field strength in the high-voltage line is very large and can easily radiate to the current transformers in other lines. A local magnetic field is generated inside the current transformer, affecting the measurement accuracy and stability of the current transformer. Utility Model Content

[0004] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the name of the utility model of this application to avoid blurring the purpose of this section, the abstract of the specification and the name of the utility model, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In view of the problems existing in the above-mentioned prior art, the present utility model is proposed.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0007] A through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall comprises a magnetic core and an induction winding wound on the magnetic core;

[0008] It also includes an epoxy resin layer wrapping the magnetic core and the induction winding, wherein the epoxy resin layer is provided with a through hole passing through the center of the induction winding;

[0009] A metal mesh, called a shielding mesh, is provided in the through hole lining around the epoxy resin layer;

[0010] The shielding net is conductively connected with a grounding wire;

[0011] The epoxy resin layer is also covered with a metal plate with through holes, called a shielding plate, and the epoxy resin layer passes through the through holes of the shielding plate along the direction of the through holes;

[0012] The thickness of the shielding plate is 1-3 cm;

[0013] The shielding plate is arranged at the middle position of the induction winding;

[0014] The shielding plate is connected to an insulating material structure, called a mounting block, and the wiring terminal of the induction winding is connected to the mounting block;

[0015] The outer layer of the epoxy resin layer is a material layer made of epoxy resin mixed with soft magnetic powder, which is called an electromagnetic field shielding layer. The electromagnetic field shielding layer is compounded on the outer side of the epoxy resin layer.

[0016] The above design, firstly, by setting an epoxy resin layer, the epoxy resin layer wraps the epoxy resin and the magnetic core, and a layer of electromagnetic field shielding layer of epoxy resin mixed with soft magnetic powder is compounded on the epoxy resin layer, which increases the sealing integrity of the current transformer and can shield the external magnetic field, reduce the influence of the external electromagnetic field on the transformer, and improve the measurement accuracy of the current transformer; secondly, by setting a shielding net, the shielding net is made of metal material and grounded, the influence of the external electromagnetic field on the line is reduced, the electromagnetic field shielding layer of the shielding net needs to be grounded, and the external interference signal can be introduced into the earth, further improving the measurement accuracy and stability of the current transformer; finally, a shielding plate is set on the epoxy resin, the current transformer can be installed through the shielding plate, and the magnetic plant is further separated by the metal shielding plate, so that the epoxy resin layer of the current transformer is grounded through the shielding plate, the electric field distribution of the current transformer is improved, the discharge in the inner cavity of the bushing is prevented, and the measurement accuracy and stability of the current transformer are ensured. The metal shielding plate can effectively absorb the electric field around the epoxy resin layer, reduce the electric field intensity, and thus reduce the possibility of corona discharge.

[0017] Preferably, the diameter of the through hole is 10-15 cm; the through hole is 10-15 cm so that the high-voltage line can pass through it, which facilitates the high-voltage transmission line of the high-voltage line to pass through the transformer through hole to use the current transformer.

[0018] Preferably, the shielding mesh is a shielding mesh woven with stainless steel wire; the shielding plate is a copper plate made of copper material; the shielding mesh is made of stainless steel metal, which has good electromagnetic shielding effect, strong corrosion resistance, high strength and good durability, can improve the measurement accuracy of the current transformer and extend the stability of the current transformer.

[0019] Preferably, annular grooves are provided at both ends of the outer side of the epoxy resin layer, and the grooves are provided at the front and rear ends of the induction winding; by providing the annular grooves, the two ends of the current transformer are made to have an insulator structure, thereby preventing the high-voltage transmission line from passing through the inner cavity of the transformer and causing a short circuit or leakage, thereby affecting the service life of the current transformer.

[0020] Preferably, the thickness of the epoxy resin layer is 5-10 cm; the thickness of the electromagnetic field shielding layer is 0.5-1 cm; by setting a 5-10 cm epoxy resin layer, the insulation of the current transformer is improved, and the electromagnetic field shielding layer thickness of 0.5-1 cm ensures the electromagnetic shielding capability of the current transformer.

[0021] Preferably, the mounting block is provided with threaded holes with the same number as the induction winding terminals, and the wire of each induction winding terminal is inserted into one of the threaded holes; the threaded holes are provided with screws in threaded cooperation, and the screws are connected with the wires of the induction winding terminals in the threaded holes; the mounting block is a mounting block made of phenolic plastic material; at least two mounting holes are provided on the shielding plate, and the installation of the induction winding terminals is facilitated by providing the mounting block, the mounting block material is phenolic plastic to ensure the insulation of the induction winding, and the screws are provided to facilitate the connection of the terminals with other lines.

[0022] Preferably, a protective cover covering the screws is detachably provided on the shielding plate, and the protective cover on the current transformer terminal can effectively protect the terminal from the influence of the external environment, such as dust, water vapor, chemical corrosion, etc., and extend the service life of the terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0024] Figure 1 A schematic diagram of the overall structure of a through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall according to an embodiment of the utility model;

[0025] Figure 2 In a through-type fully sealed current transformer with an inner wall embedded with a voltage-equalizing mesh sheet according to an embodiment of the utility model Figure 1 Schematic diagram of the structure without the protective cover;

[0026] Figure 3 A schematic diagram of the front view structure of a through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall according to an embodiment of the utility model.

[0027] Epoxy resin layer 1; shielding net 2; shielding plate 3; grounding wire 4; groove 5; screw 6; mounting hole 7; mounting block 8; protective cover 9 DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present invention more understandable, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0031] Secondly, the "one embodiment" or "embodiment" referred to herein refers to a specific feature, structure or characteristic that can be included in at least one implementation of the utility model. The "in one embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] Example 1

[0033] Reference Figure 1 to Figure 3 This embodiment provides a through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall, including a magnetic core and an induction winding wound on the magnetic core.

[0034] A circular sleeve structure made of insulating material such as epoxy resin is sleeved on a high-voltage transmission line, and a metal plate is arranged in the middle of the circular sleeve. This can effectively absorb the electric field around the circular sleeve, reduce the electric field intensity, and thus reduce the possibility of corona discharge in the inner cavity of the circular sleeve. This is a common technical means used by technicians in this field. The present invention improves the structure of the current transformer based on this structure.

[0035] It also includes an epoxy resin layer 1 that wraps the magnetic core and the induction winding, and the epoxy resin layer 1 is provided with a through hole that passes through the center of the induction winding; a metal mesh is arranged in the lining of the through hole surrounding the epoxy resin layer 1, which is called a shielding mesh 2; a grounding wire 4 is conductively connected to the shielding mesh 2; a metal plate with a through hole is also sleeved on the outside of the epoxy resin layer 1, which is called a shielding plate 3, and the epoxy resin layer 1 passes through the through hole of the shielding plate 3 along the direction of the through hole; the thickness of the shielding plate 3 is 1-3 cm; the shielding plate 3 is arranged in the middle position of the induction winding; an insulating material structure is connected to the shielding plate 3, which is called a mounting block 8, and the terminal of the induction winding is connected and arranged on the mounting block 8; the outer layer of the epoxy resin layer 1 adopts a material layer of epoxy resin mixed with soft magnetic powder, which is called an electromagnetic field shielding layer, and the electromagnetic field shielding layer is compounded on the outside of the epoxy resin layer 1, firstly by setting the epoxy resin layer 1, the epoxy resin Layer 1 wraps the epoxy resin and the magnetic core, and the epoxy resin layer 1 is compounded with an electromagnetic field shielding layer of epoxy resin mixed with soft magnetic powder, which increases the sealing integrity of the current transformer while shielding the external magnetic field, reducing the influence of the external electromagnetic field on the transformer, and improving the measurement accuracy of the current transformer; secondly, by setting a shielding net 2, the shielding net 2 is made of metal material and grounded, reducing the influence of the external electromagnetic field on the line, and the electromagnetic field shielding layer of the shielding net 2 needs to be grounded, and the external interference signal can be introduced into the earth, further improving the measurement accuracy and stability of the current transformer; finally, a shielding plate 3 is set on the epoxy resin, and the current transformer can be installed through the shielding plate 3, and the metal shielding plate 3 is used to further isolate the magnetic field, so that the current transformer is short-circuited through the shielding plate 3, improving the electric field distribution, preventing discharge in the inner cavity of the bushing, and ensuring the measurement accuracy and stability of the current transformer.

[0036] The diameter of the through hole is 10-15 cm; the through hole is 10-15 cm long and can pass the high-voltage line, which is convenient for the high-voltage transmission line of the high-voltage line to pass through the transformer through hole to use the current transformer.

[0037] The shielding net 2 is a shielding net 2 woven from stainless steel wires; the shielding plate 3 is a copper plate made of copper material; the shielding net 2 is made of stainless steel metal, which has good electromagnetic shielding effect, strong corrosion resistance, high strength and good durability, and can improve the measurement accuracy of the current transformer and extend the stability of the current transformer.

[0038] Annular grooves 5 are provided at both ends of the outer side of the epoxy resin layer 1, and the grooves 5 are provided at the front and rear ends of the induction winding; by providing the annular grooves 5, the two ends of the current transformer are insulator structures, which prevents short circuit or leakage when the high-voltage transmission line passes through the inner cavity of the transformer, thereby affecting the service life of the current transformer.

[0039] The thickness of the epoxy resin layer 1 is 5-10 cm; the thickness of the electromagnetic field shielding layer is 0.5-1 cm; by setting the 5-10 cm epoxy resin layer 1, the insulation of the current transformer is improved, and the thickness of the electromagnetic field shielding layer is 0.5-1 cm to ensure the electromagnetic shielding capability of the current transformer.

[0040] When in use, first place the magnetic core and the induction winding wound on the magnetic core in a mold, then mix the liquid epoxy resin with a solidifying agent and pour it into the mold, after the epoxy resin layer 1 solidifies, place the shielding net 2 in the middle through hole of the epoxy resin layer 1, put the shielding plate 3 on the epoxy resin layer 1, and then pour a layer of electromagnetic field shielding layer in which a layer of epoxy resin mixed with soft magnetic powder and a solidifying agent is added, the shielding net 2 and the shielding plate 3 are bonded and fixed by the electromagnetic field shielding layer, and the front and rear ends of the shielding net 2 are respectively against the groove 5 position of the epoxy resin layer 1 to keep the shielding net 2 The grounding end of the grounding wire 4 is exposed, and the current transformer is cast and solidified, ensuring that the current transformer is fully enclosed to improve the stability of the current transformer; the current transformer is first installed and fixed through the shielding plate 3, and then the current transformer is connected to the circuit. The high-voltage line passes through the through hole in the center of the induction winding. The electromagnetic field shielding layer reduces the influence of the external electromagnetic field on the transformer. The grounding wire 4 of the shielding net 2 is grounded, and external interference signals can be introduced into the earth. The shielding plate 3 prevents discharge in the inner cavity of the bushing, thereby ensuring the measurement accuracy and stability of the current transformer.

[0041] Example 2

[0042] Reference Figure 1 , which is the second embodiment of the utility model, and this embodiment is based on the previous embodiment.

[0043] The structure connected to the shielding plate 3 and fixed with the induction winding terminal is called a mounting block 8. The mounting block 8 is provided with threaded holes with the same number as the induction winding terminals, and the wire of each induction winding terminal is inserted into a threaded hole; the threaded hole is provided with a screw 6 in cooperation with the thread, and the screw 6 is connected with the wire of the induction winding terminal in the threaded hole; the mounting block 8 is a mounting block 8 made of phenolic plastic material; at least two mounting holes 7 are provided on the shielding plate 3; by providing the mounting block 8, the installation of the induction winding terminal is facilitated, the mounting block 8 is made of phenolic plastic to ensure the insulation of the induction winding, and the screw 6 is provided to facilitate the connection of the terminal with other lines.

[0044] A protective cover 9 covering the screw 6 is detachably provided on the shielding plate 3. The protective cover 9 on the current transformer terminal can effectively protect the terminal from the influence of the external environment, such as dust, water vapor, chemical corrosion, etc., and extend the service life of the terminal.

[0045] When in use, the current transformer is fixed to the wall of the electrical equipment or the wall through which the wires pass through the mounting hole 7 on the shielding plate 3, the protective cover 9 is opened from the mounting block 8, the contacts of the ammeter or the electric energy meter are first connected to the screws 6, and then the screws 6 are tightened to connect the ammeter or the electric energy meter to the induction winding, and then the protective cover 9 is covered to protect the terminal from the influence of the external environment and improve the stability. The induction winding terminal is connected with the ammeter or the electric energy meter quickly by connecting with the screws 6.

[0046] Importantly, it should be noted that the construction and arrangement of the present application shown in a number of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible, for example, the size, scale, structure, shape and proportion of various elements, and parameter values ​​such as temperature, pressure, etc., mounting arrangements, use of materials, color, directional changes, etc., without substantially departing from the novel angles and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present utility model. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of the execution function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present utility model, other substitutions, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to several modifications still falling within the scope of the appended claims.

[0047] Additionally, in order to provide a concise description of the exemplary embodiments, all features of the actual embodiments may not be described, ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those features that are not relevant to implementing the invention.

[0048] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, the development effort will be a routine task of design, fabrication, and production without undue experimentation.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A through-type fully sealed current transformer with a voltage-equalizing mesh buried in the inner wall, comprising a magnetic core and an induction winding wound on the magnetic core, characterized in that: It also includes an epoxy resin layer wrapping the magnetic core and the induction winding, wherein the epoxy resin layer is provided with a through hole passing through the center of the induction winding; A metal mesh, called a shielding mesh, is provided in the through hole lining around the epoxy resin layer; The shielding net is conductively connected with a grounding wire; The epoxy resin layer is also covered with a metal plate with through holes, called a shielding plate, and the epoxy resin layer passes through the through holes of the shielding plate along the direction of the through holes; The thickness of the shielding plate is 1-3 cm; The shielding plate is arranged at the middle position of the induction winding; The shielding plate is connected to an insulating material structure, called a mounting block, and the wiring terminal of the induction winding is connected to the mounting block; The outer layer of the epoxy resin layer is a material layer made of epoxy resin mixed with soft magnetic powder, which is called an electromagnetic field shielding layer. The electromagnetic field shielding layer is compounded on the outer side of the epoxy resin layer.

2. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 1 is characterized in that: The diameter of the through hole is 10-15 cm.

3. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 2, characterized in that: The shielding net is a shielding net woven from stainless steel wires; The shielding plate is a copper plate made of copper material.

4. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 3 is characterized in that: Annular grooves are arranged at two ends of the outer side of the epoxy resin layer, and the grooves are arranged at the front and rear ends of the induction winding.

5. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 1, characterized in that: The thickness of the epoxy resin layer is 5-10 cm; The thickness of the electromagnetic field shielding layer is 0.5-1 cm.

6. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 1, characterized in that: The mounting block is provided with threaded holes having the same number as the induction winding terminals, and the wire of each induction winding terminal is inserted into one of the threaded holes; The threaded hole is provided with a screw in thread matching, and the screw is connected with the wire of the induction winding terminal in the threaded hole; The shielding plate is provided with at least two mounting holes.

7. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 6, characterized in that: The mounting block is a mounting block made of phenolic plastic material.

8. The through-type fully sealed current transformer with a voltage-equalizing mesh embedded in the inner wall according to claim 6, characterized in that: The shielding plate is detachably provided with a protective cover covering the screws.

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