Current transformer

Abstract

The utility model discloses a current transformer, and particularly relates to the technical field of current transformers, the current transformer comprises a casting body shell, a support, a primary coil and a secondary coil, the support, the primary coil and the secondary coil are all fixed in the casting body shell, outgoing lines at two ends of the primary coil are respectively connected with a primary wiring terminal, and outgoing lines at two ends of the secondary coil are respectively connected with a secondary wiring terminal. The primary coil is divided into a primary coil I and a primary coil II, the primary coil I and the primary coil II respectively have different winding turns, the secondary coil comprises a ring-shaped secondary winding I and a ring-shaped secondary winding II, and the secondary winding I and the secondary winding II are respectively fixed at two ends of the support. The axis of the secondary winding I and the axis of the secondary winding II are parallel and are both perpendicular to the support, the primary coil I penetrates through the secondary winding I and the support, the primary coil II penetrates through the secondary winding II and the support, and the secondary winding I and the secondary winding II are connected with the secondary wiring terminal. The utility model can improve the measurement precision, has various capacities, and is compact in structure, small in volume and good in stability.

Description

Technical Field

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

[0002] Current transformer is an instrument that converts large current on the primary side into small current on the secondary side for measurement based on the principle of electromagnetic induction. As one of the important components in the isolation vacuum circuit breaker, the current transformer plays an indispensable role in the basic construction and oil-free transformation of the power system. With the development of the power industry, the requirements for the measurement accuracy, capacity, function and volume of the current transformer in the power system are getting higher and higher, and the existing current transformers have gradually failed to meet user needs. Utility Model Content

[0003] The purpose of the utility model is to provide a current transformer to solve the problems existing in the above-mentioned prior art, which can improve the measurement accuracy, has various capacities, a compact structure, a small size and good stability.

[0004] To achieve the above purpose, the utility model provides the following solutions:

[0005] The utility model provides a current transformer, comprising a cast body shell, a bracket, a primary coil and a secondary coil, wherein the bracket, the primary coil and the secondary coil are all fixed inside the cast body shell, lead wires at both ends of the primary coil are respectively connected to primary wiring terminals, the primary coil is divided into two parts, a primary coil I and a primary coil II, the primary coil I and the primary coil II respectively have different numbers of winding turns, the secondary coil comprises annular secondary windings I and secondary windings II, the secondary windings I and the secondary windings II are respectively fixed at two ends of the bracket, the axes of the secondary windings I and the secondary windings II are parallel and both perpendicular to the bracket, the primary coil I passes through the secondary windings I and the bracket, the primary coil II passes through the secondary windings II and the bracket, and the secondary windings I and the secondary windings II are respectively connected to secondary wiring terminals.

[0006] Preferably, the number of the secondary windings I is two, and the two secondary windings I are respectively fixedly arranged on both sides of one end of the bracket, and the number of the secondary windings II is two, and the two secondary windings II are respectively fixedly arranged on both sides of the other end of the bracket.

[0007] Preferably, it further comprises a mounting insert, wherein the mounting insert is integrally formed with the bracket and is disposed outside the casting body shell.

[0008] Preferably, the secondary winding I comprises an annular iron core, an iron core insulation layer, a coil and a buffer layer, the iron core insulation layer is wound around the outer side of the annular iron core, the coil is wound around the iron core insulation layer, and the buffer layer is wound around the outer side of the coil.

[0009] Preferably, the material of the annular iron core is ultra-fine crystal alloy or silicon steel sheet.

[0010] Preferably, the casting body shell is made of epoxy resin.

[0011] Preferably, the casting body shell is provided with an umbrella skirt.

[0012] Compared with the prior art, the utility model has achieved the following technical effects:

[0013] The utility model provides a current transformer, which is characterized in that: a primary coil I and a primary coil II respectively have different numbers of winding turns, and different requirements for various capacities and precisions can be achieved through different ampere-turns; a secondary winding I and a secondary winding II are respectively installed on the upper and lower parts of a bracket, and the stability is high. The secondary winding I and the secondary winding II on both sides of the primary coil are fixed by increasing the length of the bracket to reduce the size of the transformer in the length direction. The current transformer has a compact structure and a small volume, and can meet the installation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a structural schematic diagram of the current transformer of the utility model.

[0016] In the figure: 1-casting body shell; 2-primary coil I; 3-primary coil II; 4-secondary winding I; 5-secondary winding II; 6-bracket; 7-primary terminal; 8-secondary terminal; 9-installation insert; 10-umbrella skirt. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0018] The purpose of the utility model is to provide a current transformer to solve the problems existing in the above-mentioned prior art, which can improve the measurement accuracy, has various capacities, a compact structure, a small size and good stability.

[0019] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0020] The utility model provides a current transformer, such as Figure 1 As shown, it includes a cast body shell 1, a bracket 6, a primary coil and a secondary coil. The bracket 6, the primary coil and the secondary coil are all fixed inside the cast body shell 1. The lead wires at both ends of the primary coil are respectively connected to the primary terminal 7. The primary coil is divided into two parts, the primary coil Ⅰ2 and the primary coil Ⅱ3. The primary coil Ⅰ2 and the primary coil Ⅱ3 have different numbers of winding turns. The secondary coil includes an annular secondary winding Ⅰ4 and a secondary winding Ⅱ5. The secondary winding Ⅰ4 and the secondary winding Ⅱ5 are respectively fixed at both ends of the bracket 6. The axes of the secondary winding Ⅰ4 and the secondary winding Ⅱ5 are parallel and perpendicular to the bracket 6. The primary coil Ⅰ2 passes through the secondary winding Ⅰ4 and the bracket 6. The primary coil Ⅱ3 passes through the secondary winding Ⅱ5 and the bracket 6. The secondary winding Ⅰ4 and the secondary winding Ⅱ5 are respectively connected to the secondary terminal 8. The primary coil Ⅰ2 and the primary coil Ⅱ3 have different numbers of winding turns, and the secondary winding Ⅰ4 is consistent with the primary coil Ⅰ2 in ampere-turns, and the secondary winding Ⅱ5 is consistent with the primary coil Ⅱ3 in ampere-turns. Different ampere-turns are used to meet different requirements for various capacities and accuracies; the upper and lower parts of the bracket 6 are respectively provided with the secondary winding Ⅰ4 and the secondary winding Ⅱ5, and the stability is high. By increasing the length of the bracket 6 to fix the secondary winding Ⅰ4 and the secondary winding Ⅱ5 on both sides of the primary coil, the size of the transformer in the length direction can be reduced. The current transformer has a compact structure and a small size, which can meet the installation requirements.

[0021] It is further preferred in the implementation manner of the present invention that the number of secondary windings I4 is two, and the two secondary windings I4 are respectively fixedly arranged on both sides of one end of the bracket 6, and the number of secondary windings II5 is two, and the two secondary windings II5 are respectively fixedly arranged on both sides of the other end of the bracket 6.

[0022] In the embodiment of the present invention, the current transformer further preferably includes a mounting insert 9, which is integrally formed with the bracket 6 and is placed outside the casting body shell 1. The mounting insert 9 and the bracket 6 are an integrated structure, which increases the stability of the transformer body during installation and is firmly fixed.

[0023] It is further preferred in the implementation manner of the utility model that the secondary winding I4 includes an annular iron core, an iron core insulation layer, a coil and a buffer layer, the outer side of the annular iron core is wound with an iron core insulation layer, the outer side of the iron core insulation layer is wound with a coil, and the outer side of the coil is wound with a buffer layer.

[0024] In the embodiment of the present invention, it is further preferred that the material of the annular iron core is an ultra-fine crystal alloy or silicon steel sheet.

[0025] In the embodiment of the present invention, it is further preferred that the material of the casting body shell 1 is epoxy resin. The casting body shell 1 is installed in a fixed mold after the transformer body is manufactured, and is formed by vacuum casting of epoxy resin, so that the product has a compact structure, high stability, and high insulation strength, and plays a role in electrical isolation.

[0026] In the embodiment of the present invention, it is further preferred that the cast body shell 1 is provided with sheds 10. The current transformer increases the creepage distance by adding a plurality of sheds 10 to meet the requirements of high altitude.

[0027] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A current transformer, characterized in that: It includes a cast body shell, a bracket, a primary coil and a secondary coil. The bracket, the primary coil and the secondary coil are all fixed inside the cast body shell. The lead wires at both ends of the primary coil are respectively connected to the primary wiring terminals. The primary coil is divided into two parts, a primary coil I and a primary coil II. The primary coil I and the primary coil II have different numbers of winding turns. The secondary coil includes an annular secondary winding I and a secondary winding II. The secondary winding I and the secondary winding II are respectively fixed at the two ends of the bracket. The axes of the secondary winding I and the secondary winding II are parallel and perpendicular to the bracket. The primary coil I passes through the secondary winding I and the bracket, the primary coil II passes through the secondary winding II and the bracket, and the secondary winding I and the secondary winding II are respectively connected to the secondary wiring terminals.

2. The current transformer according to claim 1, characterized in that: The number of the secondary windings I is two, and the two secondary windings I are respectively fixedly arranged on both sides of one end of the bracket. The number of the secondary windings II is two, and the two secondary windings II are respectively fixedly arranged on both sides of the other end of the bracket.

3. The current transformer according to claim 1, characterized in that: It also includes a mounting insert, which is integrally formed with the bracket and is placed outside the casting body shell.

4. The current transformer according to claim 1, characterized in that: The secondary winding I comprises an annular iron core, an iron core insulation layer, a coil and a buffer layer. The iron core insulation layer is wound around the outer side of the annular iron core, the coil is wound around the iron core insulation layer, and the buffer layer is wound around the outer side of the coil.

5. The current transformer according to claim 4, characterized in that: The material of the annular iron core is ultra-fine crystal alloy or silicon steel sheet.

6. The current transformer according to claim 1, characterized in that: The casting body shell is made of epoxy resin.

7. The current transformer according to claim 1, characterized in that: The casting body shell is provided with shed skirts.

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