Insulation structure of pouring type current transformer and pouring type current transformer

Abstract

The utility model relates to the technical field of current transformers, in particular to an insulation structure of a pouring type current transformer and the pouring type current transformer, the insulation structure of the pouring type current transformer comprises a main body, the main body is used for filling an insulation gap between a primary winding and a secondary winding, and the main body comprises a buffer layer. The buffer layer is used for being wrapped outside a conducting layer of the formed primary winding, the shielding layer is wrapped outside the buffer layer, the insulating layer is sleeved outside the shielding layer, the insulating layer is of a cylindrical structure, the inner diameter of the insulating layer is equal to the outer diameter of the shielding layer, and the outer diameter of the insulating layer is equal to the inner diameter of the secondary winding. The current transformer has the advantages that operation is convenient, the insulating layer can be prepared in advance, the insulating function can be achieved, the secondary winding can be supported, the primary winding and the secondary winding are reliably fixed, air gaps are prevented from being generated between the primary winding and the secondary winding, and the insulating performance of the current transformer is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of current transformers, in particular to an insulation structure of a cast-type current transformer and the cast-type current transformer. Background Art

[0002] The core structure of the epoxy-resin-cast current transformer is a tightly integrated body, formed by the epoxy resin casting compound. The body consists of precisely wound and wrapped primary and secondary windings. These two windings are assembled together in the body manufacturing workshop, ensuring that the primary winding is external and the secondary winding is internal, maintaining the required insulation distance between them. This insulation distance increases with the voltage level of the product, effectively isolating high and low voltage circuits to ensure safe and stable operation of the equipment.

[0003] After assembly, the entire device is placed in a vacuum environment for epoxy resin pouring. As an excellent insulating material, epoxy resin not only offers excellent electrical insulation properties but also forms a strong protective layer after curing, further enhancing the transformer's structural strength and weather resistance. However, epoxy resin undergoes a significant volume shrinkage during the curing process, which continues until the cure is complete. This shrinkage causes the epoxy resin to exert pressure toward the center of the device during curing, squeezing the primary winding internally. Conversely, the secondary winding may experience a slight tendency to separate from the inside due to uneven shrinkage.

[0004] If this subtle separation tendency is not properly controlled, it can form tiny air gaps between the primary and secondary windings. These air gaps not only weaken the original insulation barrier but also become potential pathways for electrical breakdown, posing a serious threat to the transformer's insulation performance. During subsequent product testing and long-term operation, if these air gaps are affected by external factors such as voltage fluctuations, temperature changes, or mechanical vibration, they can trigger partial discharge or even electrical breakdown, leading to equipment failure or even damage, seriously affecting the stable operation of the power system. Utility Model Content

[0005] In order to solve the technical problem that epoxy resin casting material will continue to shrink during the curing process, which will squeeze the primary winding, tend to separate from the inner side of the secondary winding, and easily form an air gap between the primary winding and the secondary winding, the utility model proposes, on the one hand, an insulation structure of a cast current transformer, and on the other hand, a cast current transformer.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the insulation structure of a cast-type current transformer in the present invention is as follows:

[0007] An insulation structure of a cast current transformer includes a main body, which is used to fill the insulation gap between the primary winding and the secondary winding. The main body includes a buffer layer, which is used to wrap the outside of the conductive layer of the molded primary winding. The outside of the buffer layer is wrapped with a shielding layer, and the outside of the shielding layer is covered with an insulating layer. The insulating layer has a cylindrical structure, the inner diameter of the insulating layer is equal to the outer diameter of the shielding layer, and the outer diameter of the insulating layer is equal to the inner diameter of the secondary winding.

[0008] With this structural solution, the buffer layer and shielding layer are sequentially wrapped around the exterior of the formed primary winding conductive layer, followed by the insulating layer and secondary winding. This facilitates operation, allows for the insulation layer to be prepared in advance, and features a simple cylindrical structure. The mold is simple and efficient, resulting in high production efficiency. Once installed, the insulating layer provides both insulation and support for the secondary winding, reliably securing the primary and secondary windings, preventing air gaps between them and ensuring the insulation performance of the current transformer.

[0009] As a preferred implementation of the insulation structure of a cast-type current transformer, the buffer layer has elasticity.

[0010] With the above structural solution, the buffer layer is elastic, which facilitates compensating for dimensional errors caused by processing and production, and can protect and buffer the primary winding, thereby extending the service life of the current transformer.

[0011] As a preferred implementation of the insulation structure of a cast-type current transformer, the material of the shielding layer is copper, aluminum or thin steel plate.

[0012] Electric shielding is a shielding measure that uses conductive material grounding to suppress electric field coupling interference between common ground circuits. Using the above structural scheme, the shielding layer in this application can shield the interference of high-frequency magnetic fields and electric fields between windings.

[0013] As a preferred implementation of the insulation structure of a cast current transformer, the material of the insulation layer is a cured epoxy resin.

[0014] With the above structural solution, the insulating layer material is consistent with the vacuum casting material, which ensures the consistency of electrical performance and avoids uneven field strength inside the current transformer.

[0015] The technical solution adopted by a cast current transformer in the utility model is:

[0016] A cast current transformer comprises a body and an insulation structure of any one of the cast current transformers described above, wherein the body comprises a primary winding and a secondary winding, an insulation gap is provided between the primary winding and the secondary winding, and the main body is located between the primary winding and the secondary winding.

[0017] This structural solution facilitates installation, allows for the insulation layer to be prepared in advance, and features a simple cylindrical structure. This requires a simple mold and results in high production efficiency. The insulation layer not only insulates but also supports the secondary winding, reliably securing the primary and secondary windings, preventing air gaps between them and ensuring the insulation performance of the current transformer.

[0018] As a preferred implementation of a cast-type current transformer, the primary winding is electrically connected to the terminal block, the terminal block is electrically connected to the secondary winding, and the wire passes through the buffer layer, the shielding layer and the insulating layer.

[0019] With this structural solution, the terminal block provides a connection point for the primary and secondary circuits. Through the terminal block, the transformer can be easily connected to the power system, achieving a direct connection to the primary circuit while simultaneously providing the required current signal to the secondary equipment. The terminal block also provides a certain degree of electrical isolation. In high-voltage power systems, the cast-type current transformer can effectively isolate the high-voltage current on the primary side from the low-voltage circuit on the secondary side, ensuring the safety of secondary-side equipment and personnel.

[0020] The beneficial effects of the utility model include:

[0021] During use, the buffer layer and shielding layer are sequentially wrapped around the outside of the primary winding, followed by the insulation layer and secondary winding. This makes operation easy, and the insulation layer can be prepared in advance. The insulation layer has a simple cylindrical structure, and the mold is simple, resulting in high production efficiency. Once installed, the insulation layer not only insulates but also supports the secondary winding, reliably securing the primary and secondary windings, preventing air gaps between them and ensuring the insulation performance of the current transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a structural schematic diagram of a cast current transformer in a specific implementation manner of the utility model.

[0024] List of parts and reference numerals:

[0025] 1. Terminal block; 2. Primary winding conductive layer; 3. Buffer layer; 4. Shielding layer; 5. Insulation layer; 6. Secondary winding. DETAILED DESCRIPTION

[0026] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the specific embodiments. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] Reference Figure 1 This embodiment proposes a cast current transformer, comprising a body and an insulation structure of the cast current transformer. The body comprises a primary winding and a secondary winding 6, with an insulation gap between the primary winding and the secondary winding 6. The insulation structure of the cast current transformer comprises a main body, which is used to fill the insulation gap between the primary winding and the secondary winding 6. The main body comprises a buffer layer 3, which is used to wrap around the outside of the molded primary winding conductive layer 2. The outside of the buffer layer 3 is wrapped with a shielding layer 4, and the outside of the shielding layer 4 is covered with an insulating layer 5. The insulating layer 5 is a cylindrical structure, and the inner diameter of the insulating layer 5 is equal to the outer diameter of the shielding layer 4, and the outer diameter of the insulating layer 5 is equal to the inner diameter of the secondary winding 6. The buffer layer 3 has elasticity and insulation properties; the shielding layer 4 is made of copper, aluminum, or thin steel plate; the insulating layer 5 is pre-cured and formed using epoxy resin casting material, and the thickness of the insulating layer 5 meets the insulation distance requirements. The primary winding is electrically connected to the terminal block 1 , the terminal block 1 is electrically connected to the secondary winding 6 , and the wires pass through the buffer layer 3 , the shielding layer 4 and the insulating layer 5 .

[0028] The working principle of this embodiment is:

[0029] During use, the buffer layer 3 and shielding layer 4 are sequentially wrapped around the exterior of the formed primary winding conductive layer 2, and then the insulating layer 5 and secondary winding 6 are installed. This facilitates operation, and the insulating layer 5 can be prepared in advance. The insulating layer 5 has a simple cylindrical structure, and the mold is simple, resulting in high production efficiency. After installation, the insulating layer 5 not only insulates but also supports the secondary winding 6, reliably securing the primary and secondary windings 6, preventing air gaps between them and ensuring the insulation performance of the current transformer.

[0030] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An insulation structure of a cast current transformer, comprising a main body, the main body being used to fill an insulation gap between a primary winding and a secondary winding (6), characterized in that: The main body includes a buffer layer (3), the buffer layer (3) is used to be wrapped around the outside of the formed primary winding conductive layer (2), the outside of the buffer layer (3) is wrapped with a shielding layer (4), the outside of the shielding layer (4) is covered with an insulating layer (5), the insulating layer (5) is a cylindrical structure, the inner diameter of the insulating layer (5) is equal to the outer diameter of the shielding layer (4), and the outer diameter of the insulating layer (5) is equal to the inner diameter of the secondary winding (6).

2. The insulation structure of a cast current transformer according to claim 1, characterized in that: The buffer layer (3) has elasticity.

3. The insulation structure of a cast current transformer according to claim 1, characterized in that: The material of the shielding layer (4) is copper, aluminum or thin steel plate.

4. The insulation structure of a cast current transformer according to claim 1, characterized in that: The material of the insulating layer (5) is a cured epoxy resin.

5. A cast current transformer, characterized in that: The invention relates to a cast current transformer comprising a body and an insulation structure as claimed in any one of claims 1 to 4, wherein the body comprises a primary winding and a secondary winding (6), an insulation gap is provided between the primary winding and the secondary winding (6), and the main body is located between the primary winding and the secondary winding (6).

6. A cast current transformer according to claim 5, characterized in that: The primary winding is electrically connected to the terminal board (1), the terminal board (1) is electrically connected to the secondary winding (6), and the wire passes through the buffer layer (3), the shielding layer (4) and the insulating layer (5).

Images