Current transformer
The current transformer, designed with a U-shaped blade core and a hollow cylindrical frame, solves the problems of high-frequency loss and mechanical strength, reduces costs, enhances stability and EMC performance, and increases the upper limit of rated current.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DONGGUAN SUNLORD POWER DEVICE CO LTD
- Filing Date
- 2025-04-18
- Publication Date
- 2026-07-09
AI Technical Summary
Existing current transformers suffer from severe losses in high-frequency environments, are prone to core cracking, have insufficient mechanical strength, are costly, are susceptible to fatigue fracture at terminals, and have poor EMC performance.
The magnetic core with a U-shaped blade structure and a hollow cylindrical frame design, combined with the primary coil and secondary terminals on the same side, enhances stability and EMC performance, and reduces core loss and material costs.
Reduce core loss, decrease overall size, lower material costs, enhance product stability and EMC performance, and increase the upper limit of rated current.
Smart Images
Figure CN2025089841_09072026_PF_FP_ABST
Abstract
Description
A current transformer Technical Field
[0001] This invention relates to the field of current transformer technology, and more particularly to a current transformer. Background Technology
[0002] Currently, mainstream current transformers use EE, EF, or EP type magnetic cores and corresponding frames. These current transformers have the following problems:
[0003] (1) During use, there is a serious problem of loss. When the magnetic core is in an alternating magnetic field, especially when the driving transformer is working in a high-frequency environment, the hysteresis loss and eddy current loss will be more serious.
[0004] (2) These magnetic cores may be subjected to various mechanical stresses during manufacturing, transportation and use. If the mechanical strength is insufficient, the magnetic core is prone to cracking, which will affect the performance and reliability of the transformer.
[0005] (3) Nowadays, the mainstream material for the magnetic core used in current transformers is manganese-zinc ferrite, which is relatively expensive and will increase the manufacturing cost of the transformer.
[0006] (4) The mechanical strength of the terminals of the current transformer may be insufficient. If fatigue cracks appear on the terminals, they will gradually expand until they break, making the transformer unable to work properly.
[0007] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention
[0008] To address the aforementioned technical problems, this invention proposes a current transformer that not only reduces core losses but also enhances the product's EMC (Electromagnetic Compatibility) performance.
[0009] To achieve the above objectives, the present invention adopts the following technical solution:
[0010] This invention discloses a current transformer, comprising a frame, a winding, a first magnetic core, a second magnetic core, a first terminal, and a second terminal. The frame includes a first side portion, a second side portion, and a connecting portion. The connecting portion is a hollow cylindrical structure. The first side portion and the second side portion are integrally connected to both ends of the connecting portion. The winding is wound around the outer wall of the connecting portion. The first terminal and the second terminal are respectively connected to the first side portion and the second side portion and are electrically connected to the winding. The first magnetic core and the second magnetic core each adopt a U-shaped blade structure, and the openings of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected to the frame opposite to each other. The first ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are interconnected in the inner cavity of the connecting portion, and the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are interconnected above the winding.
[0011] Furthermore, the first terminal and the second terminal are integrally connected to the first side and the second side, respectively.
[0012] Furthermore, the skeleton is made by injection molding, and the first terminal and the second terminal are placed in the injection molding mold before the skeleton is injection molded so as to be integrally connected to the first side and the second side, respectively.
[0013] Further, the first terminal includes a first primary coil and a first secondary terminal, the first secondary terminal being disposed between the two ends of the first primary coil and electrically connected to the winding; and / or,
[0014] The second terminal includes a second primary coil and a second secondary terminal, the second secondary terminal being disposed between the two ends of the second primary coil and electrically connected to the winding.
[0015] Furthermore, the primary terminal includes 1 to 5 first sub-secondary terminals, each of which is disposed parallel to each other between the two ends of the first primary coil; and / or,
[0016] The second secondary terminal includes 1 to 5 second sub-secondary terminals, each of which is arranged parallel to each other between the two ends of the second primary coil.
[0017] Furthermore, the width of the end of the first primary coil is greater than the width of the end of each of the first sub-secondary terminals; and / or,
[0018] The width of the end of the second primary coil is greater than the width of the end of each of the second sub-secondary terminals.
[0019] Furthermore, the width of the end of the first primary coil is 1.2 to 3 times the width of the end of each of the first sub-secondary terminals; and / or,
[0020] The width of the end of the second primary coil is 1.2 to 3 times the width of the end of each of the second sub-secondary terminals.
[0021] Furthermore, each of the first sub-secondary terminals adopts a C-type pin, an L-type pin, or a seagull-type pin; and / or, each of the second sub-secondary terminals adopts a C-type pin, an L-type pin, or a seagull-type pin.
[0022] Furthermore, the thickness of the top blade on the U-shaped blade structure of the first and second magnetic cores, located above the winding, is greater than or equal to 0.5 mm.
[0023] Furthermore, the top blades on the U-shaped blade structures of the first and second magnetic cores, located above the windings, are respectively semi-circular, semi-elliptical, or polygonal.
[0024] Furthermore, the bottom surfaces of the top blades on the U-shaped blade structures of the first and second magnetic cores, located above the winding, respectively abut against the top surfaces of the first and second sides; the inner walls of the openings of the U-shaped blade structures of the first and second magnetic cores abut against the sides of the first and second sides, respectively.
[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: The current transformer disclosed in the present invention has a frame including a connecting part of a hollow column structure and a first side and a second side connected to both ends of the connecting part. The first magnetic core and the second magnetic core respectively adopt a U-shaped blade structure and are connected to the frame. On the one hand, the bottom blades of the U-shaped blade structure of the first magnetic core and the second magnetic core are connected in the cavity of the hollow column structure of the connecting part to form the core column. Compared with the existing EE type magnetic core, EF type magnetic core or EP type magnetic core, the first magnetic core and the second magnetic core with this structure no longer need the magnetic columns on both sides of the core, and the overall volume is significantly reduced, thereby reducing the core loss. At the same time, the core material cost is also reduced due to the reduction in overall size. On the other hand, the top blades of the U-shaped blade structure of the first magnetic core and the second magnetic core are located above the winding, which is equivalent to shielding the winding. This can absorb some of the interference emitted by the winding, thereby increasing the EMC effect of the product.
[0026] In a further embodiment, the current transformer of this invention combines the primary coil and secondary terminals on the same side, that is, combines the primary and secondary sides on the same side. This increases the stability of the product and also increases the upper limit of the rated current, meeting the needs of users in more operating environments within the same size. Furthermore, the width of the two ends of the primary coil is 1.2 to 3 times the width of the end of the secondary terminal, and the two ends of the primary coil are located outside the secondary coil, resulting in better overall product stability. Attached Figure Description
[0027] Figure 1 is a schematic diagram of the current transformer according to a preferred embodiment of the present invention;
[0028] Figure 2 is a schematic diagram of the exploded structure of the current transformer in Figure 1;
[0029] Figure 3 is a schematic diagram of the structure in which the first terminal and the second terminal are integrally connected to the frame.
[0030] Explanation of reference numerals in the attached diagram: 10, frame; 11, first side; 12, second side; 13, connecting part; 20, winding; 31, first magnetic core; 32, second magnetic core; 41, first terminal; 411, first primary coil; 412, first primary terminal; 4121, first sub-secondary terminal; 42, second terminal; 421, second primary coil; 422, second secondary terminal; 4221, second sub-secondary terminal. Detailed Implementation
[0031] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.
[0032] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for both fixing and circuit / signal connectivity.
[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.
[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0035] As shown in Figure 1, a preferred embodiment of the present invention discloses a current transformer, including a frame 10, a winding 20, a first magnetic core 31, a second magnetic core 32, a first terminal 41, and a second terminal 42. The frame 10 includes a first side portion 11, a second side portion 12, and a connecting portion 13. The connecting portion 13 has a hollow cylindrical structure, and the first side portion 11 and the second side portion 12 are integrally connected to both ends of the connecting portion 13. The winding 20 is wound around the outer wall of the connecting portion 13, and the first terminal 41 and the second terminal 42 are respectively connected to... The first magnetic core 31 and the second magnetic core 32 are electrically connected to the winding 20 on the first side portion 11 and the second side portion 12 respectively; the first magnetic core 31 and the second magnetic core 32 respectively adopt U-shaped blade structure, and the openings of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are connected to the frame 10 respectively. The first ends of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are connected to each other in the inner cavity of the connecting portion 13, and the second ends of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are connected to each other above the winding 20.
[0036] The first terminal 41 and the second terminal 42 are integrally connected to the first side portion 11 and the second side portion 12, respectively. Furthermore, the skeleton 10 is made by injection molding, and the first terminal 41 and the second terminal 42 are placed in the injection mold before the injection molding of the skeleton 10 so as to be integrally connected to the first side portion 11 and the second side portion 12, respectively.
[0037] The first terminal 41 includes a first primary coil 411 and a first secondary terminal 412. The first secondary terminal 412 is disposed between the two ends of the first primary coil 411 and is electrically connected to the winding 20. The first primary coil 411 does not need to be electrically connected to the winding 20. The first secondary terminal 412 includes 1 to 5 first sub-secondary terminals 4121, and each first sub-secondary terminal 4121 is disposed parallel to each other between the two ends of the first primary coil 411. In this embodiment, the first secondary terminal 412 includes 3 first sub-secondary terminals 4121, and each first sub-secondary terminal 4121 adopts a C-type PIN, an L-type PIN, or a seagull-type PIN. The width of the end of the first primary coil 412 is greater than the width of the end of each first sub-secondary terminal 4121. Specifically, the width of the end of the first primary coil 412 is 1.2 to 3 times the width of the end of each first sub-secondary terminal 4121; for example, the width of the end of each first sub-secondary terminal 4121 is 0.6 mm to 0.8 mm, and the width of the end of the first primary coil 412 is 1.0 mm to 1.5 mm.
[0038] The second terminal 42 includes a second primary coil 421 and a second secondary terminal 422. The second secondary terminal 422 is disposed between the two ends of the second primary coil 421 and is electrically connected to the winding 20. The second primary coil 421 does not need to be electrically connected to the winding 20. The second secondary terminal 422 includes 1 to 5 second sub-secondary terminals 4221, each of which is disposed parallel to each other between the two ends of the second primary coil 421. In this embodiment, the second secondary terminal 422 includes 3 second sub-secondary terminals 4221, each of which adopts a C-type PIN, an L-type PIN, or a seagull-type PIN. The width of the end of the second primary coil 421 is greater than the width of the end of each second sub-secondary terminal 4221. Specifically, the width of the end of the second primary coil 421 is 1.2 to 3 times the width of the end of each second sub-secondary terminal 4221; for example, the width of the end of each second sub-secondary terminal 4221 is 0.6 mm to 0.8 mm, and the width of the end of the second primary coil 422 is 1.0 mm to 1.5 mm.
[0039] The first primary coil 4411 and each of the first sub-secondary terminals 4121, the second secondary terminal 422 and each of the second sub-secondary terminals 4221 are placed in their molds before the skeleton 10 is injection molded so as to be integrally connected with the skeleton 10.
[0040] In this embodiment, the winding 20 is formed by winding copper wire on the outer wall of the connecting part 13. The tail end of the copper wire is wound around each first sub-secondary terminal 4121 and each second sub-secondary terminal 4221, and the ends of the copper wire are soldered to each first sub-secondary terminal 4121 and each second sub-secondary terminal 4221 respectively by tin soldering.
[0041] A wider primary coil 411 and a wider secondary coil 421 are respectively provided at both ends of the primary terminal 412 of the first terminal 41 and the secondary terminal 42 of the second terminal 42 to provide support and increase the overall stability of the product. Furthermore, combining the primary and secondary coils on both sides of the frame 10 increases product stability and also increases the upper limit of the rated current, allowing for more user applications within the same size.
[0042] The thickness of the top blades on the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32, located above the winding 20, is greater than or equal to 0.5 mm. The size of the top blades can be adjusted according to electrical requirements, improving product performance and EMC performance. Besides rectangular structures, the top blades of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 can also adopt semi-circular, semi-elliptical, or other polygonal structures, forming a flat top surface that facilitates product adsorption and assembly.
[0043] In this configuration, the bottom surfaces of the top blades of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32, located above the winding 20, abut against the top surfaces of the first side portion 11 and the second side portion 12, respectively. The inner walls of the openings of the U-shaped blade structures of the first magnetic core 31 and the second magnetic core 32 abut against the sides of the first side portion 11 and the second side portion 12, respectively.
[0044] In a specific embodiment, the first magnetic core 31 and the second magnetic core 32 can be glued to the frame 10. For example, glue can be applied to the sidewalls of the second ends of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 to bond them together. Alternatively, glue can be applied to the inner sidewalls of the openings of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 to bond them to the inner wall of the connecting part 13. The two ends of the first magnetic core 31 are respectively connected to the two ends of the second magnetic core 32, integrated into a single loop of wiring. Parallel connection on both sides can increase the rated current on the primary side, reduce the overall product size, meet various application environments of users, and improve the overall strength of the product.
[0045] In this invention, the first magnetic core 31 and the second magnetic core 32 each adopt a U-shaped blade structure and are connected to the frame 10. On the one hand, the bottom blades of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are connected in the cavity of the hollow column structure of the connecting part 13 to form the core column. Compared with the existing EE type, EF type or EP type magnetic cores, the first magnetic core 31 and the second magnetic core 32 with this structure no longer need the magnetic columns on both sides of the core, and the overall volume is significantly reduced, thereby reducing the core loss. At the same time, due to the reduction in overall size, the core material cost is also reduced. On the other hand, the top blades of the U-shaped blade structure of the first magnetic core 31 and the second magnetic core 32 are located above the winding 20, which is equivalent to shielding the winding 20. This can absorb some of the interference emitted by the winding, thereby increasing the EMC effect of the product.
[0046] Furthermore, the current transformer in this invention combines the primary coil and the secondary terminal on the same side, that is, combines the primary side and the secondary side on the same side, which increases the stability of the product and also increases the upper limit of the rated current, so as to meet more user usage environments with the same size.
[0047] The background section of this invention may include background information about the problems or circumstances surrounding the invention, rather than a description of prior art by others. Therefore, the content included in the background section is not an admission of prior art by the applicant.
[0048] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification without contradiction. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope defined by the appended claims.
Claims
1. A current transformer, characterized in that, Includes a frame, windings, a first magnetic core, a second magnetic core, a first terminal, and a second terminal. The frame includes a first side, a second side, and a connecting part. The connecting part is a hollow column structure. The first side and the second side are integrally connected to both ends of the connecting part. The winding is wound around the outer wall of the connecting part. The first terminal and the second terminal are respectively connected to the first side and the second side and are respectively electrically connected to the winding. The first magnetic core and the second magnetic core each adopt a U-shaped blade structure, and the openings of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected to the frame respectively. The first ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected to each other in the inner cavity of the connecting part, and the second ends of the U-shaped blade structures of the first magnetic core and the second magnetic core are connected to each other above the winding.
2. The current transformer according to claim 1, characterized in that, The first terminal and the second terminal are integrally connected to the first side and the second side, respectively.
3. The current transformer according to claim 2, characterized in that, The skeleton is made by injection molding, and the first terminal and the second terminal are placed in the injection mold before the skeleton is injection molded so as to be integrally connected to the first side and the second side respectively.
4. The current transformer according to claim 1, characterized in that, The first terminal includes a first primary coil and a first secondary terminal, the first secondary terminal being disposed between the two ends of the first primary coil and electrically connected to the winding; and / or, The second terminal includes a second primary coil and a second secondary terminal, the second secondary terminal being disposed between the two ends of the second primary coil and electrically connected to the winding.
5. The current transformer according to claim 4, characterized in that, The primary terminal includes 1 to 5 primary sub-secondary terminals, each of which is disposed parallel to each other between the two ends of the primary coil; and / or, The second secondary terminal includes 1 to 5 second sub-secondary terminals, each of which is arranged parallel to each other between the two ends of the second primary coil.
6. The current transformer according to claim 5, characterized in that, The width of the end of the first primary coil is greater than the width of the end of each of the first sub-secondary terminals; and / or, The width of the end of the second primary coil is greater than the width of the end of each of the second sub-secondary terminals.
7. The current transformer according to claim 6, characterized in that, The width of the end of the first primary coil is 1.2 to 3 times the width of the end of each of the first sub-secondary terminals; and / or, The width of the end of the second primary coil is 1.2 to 3 times the width of the end of each of the second sub-secondary terminals.
8. The current transformer according to claim 5, characterized in that, Each of the first sub-secondary terminals uses a C-type pin, an L-type pin, or a seagull-type pin; and / or, each of the second sub-secondary terminals uses a C-type pin, an L-type pin, or a seagull-type pin.
9. The current transformer according to claim 1, characterized in that, The thickness of the top blade on the U-shaped blade structure of the first and second magnetic cores, located above the winding, is greater than or equal to 0.5 mm.
10. The current transformer according to claim 1, characterized in that, The top blades on the U-shaped blade structures of the first and second magnetic cores, located above the windings, are respectively semi-circular, semi-elliptical, or polygonal.