Current transformer

Abstract

The utility model provides a current transformer, and relates to the technical field of transformers. The current transformer comprises a primary winding and a secondary winding, the primary winding comprises a primary conducting rod, a busbar and two supporting plates, the primary conducting rod is a copper rod, the two ends of the copper rod are connected to the first ends of the two supporting plates respectively, the second ends of the two supporting plates are connected with the busbar, and a cavity is formed in the copper rod; the primary conducting rod penetrates through the secondary winding to enable the primary winding to be sleeved on the secondary winding; wherein the primary winding is sequentially and alternately wrapped with a plurality of shielding layers and a plurality of buffer layers in the radial direction of the primary winding, an equipotential line is arranged between every two adjacent shielding layers, and the two ends of each equipotential line are connected with the primary winding and the corresponding shielding layer respectively. According to the current transformer, temperature rise can be reduced, so that the qualified rate and long-term stability of products are improved, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of current transformer technology, and in particular to a current transformer. Background Technology

[0002] Current transformers (CTs) are critical devices used for measurement and protection in power systems. They proportionally convert high currents to low currents for safe measurement and control. However, existing current transformers often experience rapid temperature rise when the rated current is high, leading to lower product yield, reduced long-term stability, and increased costs. Utility Model Content

[0003] The purpose of this invention is to provide a current transformer that can reduce temperature rise, thereby improving product qualification rate and long-term stability, and reducing production costs.

[0004] To achieve this objective, the present invention adopts the following technical solution: a current transformer, comprising:

[0005] A primary winding includes a primary conductive rod, a busbar, and two support plates. The primary conductive rod is a copper rod, with its two ends connected to the first ends of the two support plates, and the second ends of the two support plates connected to the busbar. A cavity is provided inside the copper rod.

[0006] A secondary winding, wherein the primary conductive rod passes through the secondary winding so that the primary winding is fitted onto the secondary winding;

[0007] The primary winding is alternately wrapped with multiple shielding layers and multiple buffer layers along its radial direction, and an equipotential line is provided between adjacent shielding layers. The two ends of the equipotential line are respectively connected to the primary winding and the corresponding shielding layer.

[0008] As a further technical solution, the cavity extends along the rod direction of the copper rod and penetrates the copper rod, so that the copper rod is in the shape of a hollow tube.

[0009] As a further technical solution, the inner diameter of the copper rod is equal at all points.

[0010] As a further technical solution, each of the two support plates has a connecting channel at its first end, and the two ends of the copper rod are respectively inserted into the two connecting channels and welded to the inner wall of the corresponding connecting channel.

[0011] As a further technical solution, both ends of the copper rod are configured as welding sections, and the outer diameter of the two welding sections is smaller than the outer diameter of the middle part of the copper rod. The two welding sections are inserted into the two connecting channels in a one-to-one correspondence.

[0012] As a further technical solution, the connection channel extends through the corresponding support plate, and the primary winding also includes two auxiliary copper sheets, which are respectively welded to the two ends of the copper rod in the corresponding connection channel.

[0013] As a further technical solution, the end face of the auxiliary copper sheet facing away from the middle of the copper rod is flush with the end face of the corresponding support plate facing away from the middle of the copper rod.

[0014] As a further technical solution, an exhaust hole is provided in the middle of the auxiliary copper sheet.

[0015] As a further technical solution, the diameter of the exhaust hole is set to 3cm.

[0016] As a further technical solution, the material of the shielding layer is at least one of semiconductive paper, semiconductor self-adhesive tape, surface-type semiconductor material, and semiconductor crepe paper.

[0017] Compared with the prior art, the current transformer provided by this utility model has the following technical advantages:

[0018] Because the primary conductive rod is made of copper rod with a cavity, the surface area of ​​the copper rod can be increased, improving its heat dissipation effect, thereby reducing temperature rise, improving product qualification rate and long-term stability, and reducing production costs. At the same time, because the copper rod has a cavity, the amount of copper material required during the production of the copper rod can be reduced, thereby further reducing production costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model 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 the content of the embodiments of this utility model and these drawings without creative effort.

[0020] Figure 1 This is a simplified front view of the current transformer provided in this embodiment of the utility model;

[0021] Figure 2 This is a simplified side view of the current transformer provided in this embodiment of the utility model;

[0022] Figure 3 This is a partial structural cross-sectional view of the primary conductive rod in the current transformer provided in this embodiment of the utility model;

[0023] Figure 4This is a partial structural cross-sectional view of the support plate in the current transformer provided in this embodiment of the utility model.

[0024] In the picture:

[0025] 100. Primary winding; 110. Primary conductor rod; 111. Cavity; 112. Welding section; 120. Busbar; 130. Support plate; 131. Connecting channel; 140. Auxiliary copper sheet; 141. Vent hole;

[0026] 200. Secondary winding. Detailed Implementation

[0027] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0028] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0029] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0030] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0031] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​not using relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0032] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0033] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0034] Combination Figures 1 to 4As shown, the current transformer provided in this embodiment can reduce temperature rise, thereby improving the product qualification rate and long-term stability, and reducing production costs. Specifically, the current transformer includes a primary winding 100 and a secondary winding 200: the primary winding 100 includes a primary conductive rod 110, a busbar 120, and two support plates 130. The primary conductive rod 110 is a copper rod, with both ends of the copper rod connected to the first ends of the two support plates 130 respectively. The second ends of the two support plates 130 are both connected to the busbar 120, and a cavity 111 is provided inside the copper rod. The primary conductive rod 110 passes through the secondary winding 200 so that the primary winding 100 is fitted onto the secondary winding 200. The primary winding 100 is alternately wrapped with multiple layers of shielding and multiple layers of buffering, and an equipotential line is provided between two adjacent shielding layers. The two ends of the equipotential line are respectively connected to the primary winding 100 and the corresponding shielding layer.

[0035] Since the primary conductive rod 110 is made of copper rod with a cavity 111, the surface area of ​​the copper rod can be increased, improving its heat dissipation effect, thereby reducing temperature rise, improving product qualification rate and long-term stability, and reducing production costs. At the same time, since the copper rod has a cavity 111, the amount of copper material required during copper rod production can be reduced, thereby further reducing production costs.

[0036] The shielding layer is a shielding material wrapped around the primary winding 100. The shielding layer can effectively block the influence of external electromagnetic waves on the current transformer, ensuring the stability and accuracy of the measurement signal. The buffer layer can buffer the vibration and shock generated by the current transformer during operation, thereby improving the service life and reliability of the primary winding 100.

[0037] Other structures in the current transformer, such as the base and insulating shell, are not the focus of this embodiment and can be set up with reference to existing technologies. They will not be described in detail in this embodiment.

[0038] To further improve the heat dissipation of the copper rod and save on the amount of copper material required during production, in this embodiment, the cavity 111 extends along the rod direction and penetrates the copper rod, making the copper rod a hollow tube. Along the rod direction, the cross-sectional shape of the cavity 111 is circular, and the inner diameter is equal at all points on the copper rod.

[0039] In other embodiments, the cavity 111 may be provided only on one side of the copper rod or only in the middle of the copper rod, depending on actual needs; or the cavity 111 may extend along the rod direction of the copper rod and penetrate the copper rod, but the inner diameter of the copper rod is not equal at all points; or the cross-sectional shape of the cavity 111 may be set as rectangular, elliptical, polygonal, etc. along the rod direction of the copper rod.

[0040] In order to improve the connection strength and stability between the two ends of the copper rod and the two support plates 130, in this embodiment, the first end of each of the two support plates 130 is provided with a connection channel 131, and the two ends of the copper rod are respectively inserted into the two connection channels 131 and welded to the inner wall of the corresponding connection channel 131.

[0041] Preferably, both ends of the copper rod are configured as welding sections 112, and the outer diameter of each welding section 112 is smaller than the outer diameter of the middle part of the copper rod. The two welding sections 112 are inserted into the two connecting channels 131 in a one-to-one correspondence. With this configuration, when the welding section 112 is inserted into the corresponding connecting channel, the step at the welding section 112 abuts against the corresponding support plate 130. By setting two welding sections 112, the connection strength and stability between the two ends of the copper rod and the two support plates 130 are further improved. At the same time, the relative position between the two support plates 130 is limited, avoiding the situation where the distance between the two support plates 130 is not equal for current transformers of the same specification, thereby further improving the product qualification rate.

[0042] Preferably, the connecting channel 131 extends through the corresponding support plate 130, and the primary winding 100 further includes two auxiliary copper sheets 140, which are respectively welded to the corresponding connecting channel 131 at both ends of the copper rod. In this embodiment, when welding the copper rod to the inner wall of the corresponding connecting channel 131, an induction heating device is required to heat the welding point. The auxiliary copper sheets 140 can slow down the heat loss rate during the heating process, thereby ensuring the welding effect and further improving the connection strength between the copper rod and the corresponding support plate 130.

[0043] During welding or use of the current transformer, a pressure difference may exist between the inside and outside of the copper rod. To avoid this pressure difference, in this embodiment, an vent hole 141 is provided in the middle of the auxiliary copper sheet 140. If the vent hole 141 is too large, it will affect the connection strength between the copper rod and the corresponding support plate 130; if the vent hole 141 is too small, it will not be able to eliminate the pressure difference between the inside and outside of the copper rod in time. Preferably, in this embodiment, the diameter of the vent hole 141 is set to 3 cm. In other embodiments, the size and number of vent holes 141 can be adjusted adaptively according to actual needs.

[0044] In order to improve the aesthetics of the primary winding 100 after welding the auxiliary copper sheet 140 and to avoid interference between the auxiliary copper sheet 140 and the shielding layer and buffer layer, in this embodiment, the end face of the auxiliary copper sheet 140 away from the middle of the copper rod is flush with the end face of the corresponding support plate 130 away from the middle of the copper rod.

[0045] Preferably, the material of the shielding layer is at least one of semiconductive paper, semiconductor self-adhesive tape, surface-type semiconductor material, and semiconductor crepe paper.

[0046] In this embodiment, the shielding layer is made of semiconductor crepe paper. Because the surface of semiconductor crepe paper forms tiny wrinkles, gaps are created between the paper layers, allowing charges to move freely within them, thus exhibiting semi-conductive properties. Using semiconductor crepe paper as the shielding layer effectively absorbs and disperses electromagnetic interference in the primary winding 100. The semiconductor crepe paper is wound onto the primary winding 100 in a semi-overlapping manner. Since the primary winding 100 is cast into an insulating shell (not shown in the figure) using epoxy resin, the buffer layer provides protection for the primary winding 100, reducing the impact of epoxy resin shrinkage stress during curing and lowering the probability of microscopic cracks and air gaps forming near the primary winding 100. Simultaneously, the buffer layer can buffer vibrations and shocks generated during the operation of the current transformer, thereby improving the service life and reliability of the primary winding 100. In this embodiment, the buffer layer is made of silicone rubber tape. The number of shielding and buffer layers can be adaptively set according to specific circumstances and is not specifically limited here.

[0047] The secondary winding 200 is not the focus of this embodiment. Its principle and specific structure are based on existing technology and are not specifically limited here.

[0048] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A current transformer, characterized in that, include: A primary winding (100) includes a primary conductive rod (110), a busbar (120), and two support plates (130). The primary conductive rod (110) is a copper rod, with its two ends connected to the first ends of the two support plates (130) respectively. The second ends of the two support plates (130) are connected to the busbar (120), and a cavity (111) is provided inside the copper rod. A secondary winding (200) is provided, wherein the primary conductive rod (110) passes through the secondary winding (200) so that the primary winding (100) is fitted onto the secondary winding (200); The primary winding (100) is alternately wrapped with multiple shielding layers and multiple buffer layers along its radial direction, and an equipotential line is provided between adjacent shielding layers. The two ends of the equipotential line are respectively connected to the primary winding (100) and the corresponding shielding layer.

2. The current transformer according to claim 1, characterized in that, The cavity (111) extends along the rod direction of the copper rod and penetrates the copper rod, so that the copper rod is in the shape of a hollow tube.

3. The current transformer according to claim 2, characterized in that, The inner diameter of the copper rod is the same at all points.

4. The current transformer according to claim 1, characterized in that, The first ends of the two support plates (130) are provided with connecting channels (131), and the two ends of the copper rod are respectively inserted into the two connecting channels (131) and welded to the inner wall of the corresponding connecting channel (131).

5. The current transformer according to claim 4, characterized in that, Both ends of the copper rod are configured as welding sections (112), and the outer diameter of the two welding sections (112) is smaller than the outer diameter of the middle part of the copper rod. The two welding sections (112) are inserted into the two connecting channels (131) in a one-to-one correspondence.

6. The current transformer according to claim 4, characterized in that, The connecting channel (131) passes through the corresponding support plate (130), and the primary winding (100) also includes two auxiliary copper sheets (140), which are respectively welded to the corresponding connecting channel (131) at both ends of the copper rod.

7. The current transformer according to claim 6, characterized in that, The end face of the auxiliary copper sheet (140) facing away from the middle of the copper rod is flush with the end face of the corresponding support plate (130) facing away from the middle of the copper rod.

8. The current transformer according to claim 6, characterized in that, The auxiliary copper sheet (140) has an exhaust hole (141) in the middle.

9. The current transformer according to claim 8, characterized in that, The diameter of the vent (141) is set to 3cm.

10. The current transformer according to claim 1, characterized in that, The material of the shielding layer is at least one of the following: semiconductive paper, semiconductor self-adhesive tape, surface-type semiconductor material, and semiconductor crepe paper.

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