Transformer core, transformer coil, and current transformer

Abstract

The present application relates to the technical field of current transformers, and discloses a transformer core, a transformer coil, and a current transformer, the transformer core comprising a protective shell, a core body, and a limiting assembly. The protective shell is provided with an annular first accommodating cavity. The core body is located in the first accommodating cavity. An inner top wall and an inner bottom wall of the first accommodating cavity are each configured with a plurality of first triangular teeth that protrude therefrom and are uniformly arranged along the circumference of the inner top wall and the inner bottom wall. The limiting assembly comprises an elastic structure and two annular limiting plates. The two limiting plates are located on two axial sides of the core body, respectively. Surfaces of the limiting plates are configured with a plurality of second triangular teeth that protrude therefrom and are uniformly arranged along the circumference of the surfaces of the limiting plates. Inclined surfaces of the second triangular teeth are engaged with inclined surfaces of the first triangular teeth. An elastic force of the elastic structure is used for forcing the two limiting plates to rotate circumferentially relative to the protective shell. The inclined surfaces of the second triangular teeth are partially engaged with the inclined surfaces of the first triangular teeth, so that there are axial gaps between tooth tips of the second triangular teeth and tooth roots of the first triangular teeth. The present application can improve the structural stability and position stability of the core body.

Description

A current transformer core, a current transformer coil, and a current transformer. Technical Field

[0001] This application belongs to the field of current transformer technology and relates to a transformer core, a transformer coil and a current transformer. Background Technology

[0002] A current transformer coil generally includes a transformer core and an electromagnetic wire wound around the outside of the transformer core. The transformer core includes a housing and a core body set inside the housing. The housing has a cover plate. After the core body is placed in the receiving cavity of the housing, the receiving cavity is covered by the cover plate, thereby completing the installation of the core.

[0003] To reduce the shaking and collision of the core within the housing, the surface of the core is designed to fit snugly against the inner wall of the housing, thereby achieving stable positioning of the core. However, during the assembly of the current transformer coil into the current transformer, axial assembly pressure needs to be applied to the current transformer coil. When the assembly pressure is too high, it will be transmitted to the core through the housing, which can easily lead to compression of the core and a decrease in magnetic permeability. Summary of the Invention

[0004] To balance the stability of the core installation and reduce the pressure on the core, a current transformer core, a current transformer coil, and a current transformer are provided.

[0005] This application provides a current transformer core, which is implemented using the following technical solution:

[0006] A current transformer core includes a casing, a core, and a limiting assembly. The casing has an annular first receiving cavity, and the core is located within the first receiving cavity. The inner top and bottom walls of the first receiving cavity are each formed with a plurality of circumferentially evenly arranged first triangular teeth. The length direction of the first triangular teeth extends radially along the casing, and the cross-sectional profile of the first triangular teeth is triangular. The limiting assembly includes an elastic structure and two annular limiting plates, which are located on opposite axial sides of the core. The surfaces of the limiting plates are formed with a plurality of circumferentially evenly arranged second triangular teeth. The length direction of the second triangular teeth extends radially along the casing. The triangular tooth has a triangular cross-sectional profile; the elastic force of the elastic structure forces the two limiting plates to rotate circumferentially relative to the protective shell, causing the inclined surface of the second triangular tooth to fit against the inclined surface of the first triangular tooth, and the second triangular tooth, guided by the inclined surface of the first triangular tooth, drives the limiting plate to move axially along the direction closer to the core. When the two limiting plates fit against the core, the inclined surface of the second triangular tooth partially fits against the inclined surface of the first triangular tooth, resulting in an axial gap between the tooth tip of the second triangular tooth and the tooth root of the first triangular tooth; the protective shell includes an annular cover plate, an annular bottom plate, and an annular intermediate plate, the surface of the bottom plate fitting against the intermediate plate, and the intermediate plate... The middle part of the structure has an integrally formed annular reinforcing cylinder, the inner diameter of the base plate has an integrally formed annular inner cylinder, and the outer diameter of the base plate has an integrally formed annular first outer cylinder. The cover plate is fixedly connected to the reinforcing cylinder, and the outer diameter of the cover plate has an integrally formed annular second outer cylinder. The cover plate, reinforcing cylinder, inner cylinder, and middle plate together form the first receiving cavity. The surface of the cover plate and the surface of the middle plate are the inner top wall and inner bottom wall of the first receiving cavity, respectively. The first outer cylinder has a first latch, and the second outer cylinder has a second latch. The limiting component also includes a fixing structure and a limiting sleeve. Both the limiting plate and the limiting sleeve are made of rubber. The limiting sleeve is coaxially arranged with the inner ring cylinder. The outer circumferential surface of the inner ring cylinder has a protruding structure with multiple circumferentially evenly arranged third triangular teeth. The inner circumferential surface of the limiting sleeve has a protruding structure with multiple circumferentially evenly arranged fourth triangular teeth. The inclined surfaces of the fourth triangular teeth are in contact with the inclined surfaces of the third triangular teeth. The elastic structure is a rubber rope, and the two ends of the rubber rope are connected to the limiting plate and the limiting sleeve, respectively. The outer circumferential surface of the limiting sleeve is in contact with the inner circumferential surface of the core, and there is a gap between the outer circumferential surface of the core and the inner circumferential surface of the reinforcing cylinder. The fixing structure is located in the first and second bayonet openings and is used to fix the first and second outer ring cylinders.

[0007] When installing the core, first place the core, limiting plate, rubber rope, and limiting sleeve onto the middle plate. Then, fix the cover plate onto the reinforcing cylinder. At this time, the rubber rope is in a slack state, and the first and second triangular teeth are in clearance engagement. Then, the bottom plate is engaged with the middle plate, and the bottom plate can rotate relative to the middle plate. The third and fourth triangular teeth are engaged, and the first and second latches are misaligned. Then, keeping the cover plate and the middle plate stationary, the bottom plate drives the inner ring cylinder to rotate relative to the middle plate by a certain angle, so that the first latch of the first outer ring cylinder is aligned with the second latch of the second outer ring cylinder. During this process, the inner ring cylinder first drives the limiting sleeve to rotate circumferentially by a certain angle, and the rubber rope is stretched. The elasticity of the rubber rope is converted into a force that forces the two limiting plates to approach each other axially through the engagement between the second and first triangular teeth. The two limiting plates together clamp the core. At this time, the first latch is aligned with the second latch. Finally, the first and second outer ring cylinders are fixed by the fixing structure.

[0008] In this way, by setting rubber limiting plates and limiting sleeves, the core can be fixed. Furthermore, when the protective shell is subjected to axial assembly pressure, this pressure is converted into circumferential rotation of the two limiting plates relative to the protective shell through the engagement of the second and first triangular teeth. This forces the rubber rope to elastically deform. Due to the large friction between the second and first triangular teeth, frictional heat is generated during their reciprocating sliding motion, converting impact kinetic energy into heat energy, thus achieving a shock absorption effect. Moreover, the initial engagement position of the inner ring and the limiting sleeve can be adjusted, meaning the rotation angle of the base plate is adjustable, thereby controlling and adjusting the final elastic force of the rubber rope to adjust the clamping force of the core, making it suitable for different usage environments and cores with different material properties.

[0009] Optionally, the fixing structure includes a vertical plate, with pressure plates fixed at both ends of the vertical plate and an insertion rod fixed in the middle of the vertical plate. The insertion rod passes through both the first and second bayonets, and the two pressure plates are elastically pressed against the outer surface of the cover plate and the outer surface of the bottom plate, respectively.

[0010] Through the above technical solution, the insertion rod passes through the first and second bayonets simultaneously to circumferentially limit the protective shell, while the elastic pressure of the pressure plate axially limits the protective shell, thereby ensuring the stability of the protective shell installation.

[0011] Optionally, the fixing structure includes a bolt with a groove at the bolt head, and protrusions fixed on the outer circumferential surfaces of the first outer ring and the second outer ring. When the first and second locking slots are aligned, the bolt passes through both the first and second locking slots simultaneously, and the bolt is threadedly connected to the reinforcing cylinder. The groove simultaneously engages with both protrusions.

[0012] With the above technical solution, the bolt passes through both the first and second bayonets to circumferentially limit the protective shell, while the groove and protrusion cooperate to axially limit the protective shell, thereby ensuring the stability of the protective shell installation.

[0013] This application also provides a current transformer core, which is implemented using the following technical solution:

[0014] A current transformer core includes a casing, a core, and a limiting assembly. The casing has an annular first receiving cavity, and the core is located within the first receiving cavity. The inner top and bottom walls of the first receiving cavity are each constructed with a plurality of circumferentially evenly arranged first triangular teeth. The length direction of the first triangular teeth extends radially along the casing, and the cross-sectional profile of the first triangular teeth is triangular. The limiting assembly includes an elastic structure and two annular limiting plates, respectively located on opposite axial sides of the core. The surfaces of the limiting plates are each constructed with a plurality of circumferentially evenly arranged second triangular teeth. The length direction of the second triangular teeth extends radially along the casing, and the cross-sectional profile of the second triangular teeth is triangular. The elastic force of the elastic structure forces the two limiting plates to rotate circumferentially relative to the casing, causing the inclined surfaces of the second triangular teeth to engage with the inclined surfaces of the first triangular teeth. Guided by the inclined surfaces of the first triangular teeth, the second triangular teeth drive the limiting plates to move axially towards the core. When the two limiting plates are engaged with the core, the inclined surfaces of the second triangular teeth partially engage with the inclined surfaces of the first triangular teeth, thus... An axial clearance exists between the tip of the second triangular tooth and the root of the first triangular tooth; the protective shell includes a lower plate and an upper plate, an annular inner diameter cylinder is integrally formed at the inner diameter of the lower plate, a middle diameter cylinder is integrally formed at the middle of the lower plate, and an outer diameter cylinder is integrally formed at the outer diameter of the lower plate; the lower plate, upper plate, middle diameter cylinder, and inner diameter cylinder together form the first receiving cavity; the surface of the upper plate and the surface of the lower plate are respectively the inner top wall and the inner bottom wall of the first receiving cavity; the elastic structure consists of two sets of elastic rods, the elastic rods are shape memory alloys, and the two sets of elastic rods are... The inner diameter of each limiting plate is provided with an axially extending groove. One end of each of the two sets of elastic rods is fixedly connected to the inner diameter cylinder, and the other end of each set of elastic rods extends into the grooves of the two limiting plates and slides with the grooves. When the temperature of the elastic rod is lower than the deformation temperature, the elastic force of the elastic rod is converted into a force that forces the two limiting plates to move axially closer through the engagement between the second triangular tooth and the first triangular tooth. When the temperature of the elastic rod is at the deformation temperature, the deformation force of the elastic rod drives the limiting plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are in clearance engagement.

[0015] Through the above technical solution, before the current transformer coil is assembled into the current transformer, the casing is heated. When the temperature of the elastic rod is at its deformation temperature, the deformation force of the elastic rod drives the limiting plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are in clearance engagement. In this state, the two limiting plates are not in direct contact with the inner top wall and the inner bottom wall, respectively, and the core is not clamped. Therefore, when axial assembly pressure is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core, thereby avoiding damage to the core due to pressure. After the casing is assembled, and during use, when the casing is below its deformation temperature, the elastic force of the elastic rod is converted into a force that forces the two limiting plates to move axially closer through the engagement between the second triangular tooth and the first triangular tooth. The limiting plates clamp the core to ensure the positional stability of the core.

[0016] Optionally, the core includes multiple first arc-shaped strips and multiple second arc-shaped strips, which are arranged in an alternating circumferential pattern. The two end faces of the first arc-shaped strips are designated as first mating surfaces, and the two end faces of the second arc-shaped strips are designated as second mating surfaces. A first guide surface is provided at the outer diameter of the first arc-shaped strips, and a second guide surface is provided at the inner diameter of the second arc-shaped strips. A first guide block, corresponding to one of the first arc-shaped strips, is fixed at the outer diameter of the limiting plate, and a second guide block, corresponding to one of the second arc-shaped strips, is fixed at the inner diameter of the limiting plate. When the two limiting plates approach each other axially, the first arc-shaped strips are forced to move radially inward through the engagement of the first guide block and the first guide surface. When the two limiting plates approach each other axially, the second arc-shaped strips are forced to move radially outward through the engagement of the second guide block and the second guide surface. When the second arc-shaped strip moves radially outward and the first arc-shaped strip moves radially inward, the first mating surface and the second mating surface are engaged.

[0017] Through the above technical solution, firstly, the core is formed by splicing together multiple first arc-shaped strips and multiple second arc-shaped strips, meaning the core has multiple breaks. Compared to a complete closed-loop core, the magnetic reluctance is larger, and the effective permeability is somewhat reduced, but the linear operating range of the core is greatly increased, and the dynamic measurement range of the current transformer is thus expanded. Furthermore, when the two limiting plates approach each other axially, the first arc-shaped strip moves radially inward, and the second arc-shaped strip moves radially outward, making the first and second mating surfaces fit more tightly. This reduces the possibility of excessive increase in magnetic reluctance due to excessive gaps between the breaks, resulting in a smaller increase in magnetic reluctance. This expands the dynamic measurement range of the current transformer and reduces variations in its measurement accuracy.

[0018] Optionally, reinforcing ribs are integrally formed between the outer peripheral surface of the reinforcing cylinder and the surface of the intermediate plate.

[0019] The above technical solution can enhance the structural strength of the reinforcing cylinder, thereby reducing the occurrence of excessive deformation in the middle caused by axial pressure on the shell.

[0020] Optionally, the protective shell has an annular second receiving cavity located outside the first receiving cavity, and a compensating reactor is fixed inside the second receiving cavity.

[0021] The above technical solution makes the wiring of the iron core integrated compensation reactor more convenient.

[0022] This application provides a current transformer coil, which is implemented using the following technical solution.

[0023] A current transformer coil includes a current transformer core and an electromagnetic wire wound around the current transformer core.

[0024] This application provides a current transformer, which is implemented using the following technical solution.

[0025] A current transformer includes a current transformer body and a transformer coil.

[0026] The beneficial effects of this application are:

[0027] 1. By setting an elastic structure and two limiting plates, the elastic force of the elastic structure is used to force the two limiting plates to rotate circumferentially relative to the protective shell. The elastic force of the elastic structure is transformed into a force that forces the two limiting plates to move axially closer together through the engagement between the second triangular tooth and the first triangular tooth. The two limiting plates together clamp the core, thereby improving the installation stability of the core. Furthermore, when the protective shell is subjected to axial assembly pressure, the protective shell deforms under pressure. This pressure is transformed into a force that forces the two limiting plates to rotate circumferentially relative to the protective shell through the engagement between the second triangular tooth and the first triangular tooth, thereby forcing the elastic structure to deform elastically. That is, the elastic structure buffers the assembly pressure, thereby reducing the pressure on the core.

[0028] 2. By setting rubber limiting plates and limiting sleeves, the core can be fixed. When the shell is subjected to axial assembly pressure, the pressure will be converted into a force that compels the two limiting plates to rotate circumferentially relative to the shell through the cooperation between the second triangular teeth and the first triangular teeth. This forces the rubber rope to deform elastically. Since there is a large friction between the second triangular teeth and the first triangular teeth, friction heat is generated during the reciprocating sliding process between the second triangular teeth and the first triangular teeth, which converts the impact kinetic energy into heat energy, thereby playing a shock absorption role.

[0029] 3. Before the current transformer coil is assembled into the current transformer, the casing is heated. When the temperature of the elastic rod is at its deformation temperature, the deformation force of the elastic rod drives the limiting plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are in clearance engagement. In this state, the two limiting plates are not in direct contact with the inner top wall and the inner bottom wall, respectively, and the core is not clamped. Therefore, when axial assembly pressure is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core, thereby avoiding damage to the core due to pressure. After the casing is assembled, and during use, when the casing is below its deformation temperature, the elastic force of the elastic rod is converted into a force that forces the two limiting plates to move axially closer through the engagement between the second triangular tooth and the first triangular tooth. The limiting plates clamp the core to ensure the positional stability of the core. Attached Figure Description

[0030] Figure 1 is an exploded view of the transformer core of Example 1.

[0031] Figure 2 is a top view of the transformer core of Embodiment 1.

[0032] Figure 3 is a cross-sectional view along the AA direction in Figure 2.

[0033] Figure 4 is a partial cross-sectional view of the protective shell of Embodiment 1.

[0034] Figure 5 is a cross-sectional view along the BB direction in Figure 2.

[0035] Figure 6 is a cross-sectional view along the CC direction in Figure 3.

[0036] Figure 7 is a schematic diagram of the relative positional relationship between the limiting plate and the limiting sleeve in Embodiment 1.

[0037] Figure 8 is a schematic diagram of the state changes of the limiting plate from not clamping the core to clamping the core in Example 1.

[0038] Figure 9 is a schematic diagram of the state change of the engagement relationship between the second triangular tooth of the limiting plate located above the core and the first triangular tooth of the cover plate in Embodiment 1.

[0039] Figure 10 is a schematic diagram of the state change of the engagement relationship between the second triangular tooth of the limiting plate located above the core and the first triangular tooth of the cover plate during assembly, according to Embodiment 1.

[0040] Figure 11 is a partial cross-sectional view of the protective shell of Embodiment 2.

[0041] Figure 12 is a cross-sectional view of the protective shell of Embodiment 3.

[0042] Figure 13 is a magnified view of part D in Figure 9.

[0043] Figure 14 is a schematic diagram of the state change of the elastic rod from heating deformation to restoring its deformation state in Example 3.

[0044] Figure 15 is a top view of the core of Example 4.

[0045] Figure 16 is a partial cross-sectional view of Embodiment 4 illustrating the interaction between the first guide block and the first arc-shaped strip.

[0046] Figure 17 is a partial cross-sectional view of Embodiment 4 illustrating the interaction between the second guide block and the second arc-shaped strip.

[0047] Explanation of reference numerals in the attached drawings: 10. Core; 101. First arc-shaped strip; 1011. First guide surface; 1012. First mating surface; 102. Second arc-shaped strip; 1021. Second guide surface; 1022. Second mating surface; 11. Cover plate; 111. Second outer ring cylinder; 1111. Second bayonet; 112. Through hole; 12. Base plate; 121. Inner ring cylinder; 1211. Third triangular tooth; 122. First outer ring cylinder; 1221. First bayonet; 13. Intermediate plate; 131. Reinforcing cylinder; 132. Adding... 135. Reinforcing rib; 14. First triangular tooth; 15. Upper plate; 16. Lower plate; 17. Inner diameter cylinder; 18. Middle diameter cylinder; 19. Outer diameter cylinder; 20. Compensating reactor; 21. Limiting plate; 211. Second triangular tooth; 212. First guide block; 213. Second guide block; 22. Limiting sleeve; 221. Fourth triangular tooth; 23. Rubber rope; 251. Vertical plate; 252. Pressure plate; 253. Insert rod; 261. Bolt; 262. Groove; 263. Protrusion; 27. Elastic rod; 271. Slide groove. Detailed Implementation

[0048] The embodiments of this application are described in detail below, and examples of the embodiments are shown in Figures 1-17.

[0049] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Example 1

[0051] Example 1 discloses a current transformer core, as shown in Figures 1, 2 and 3. The current transformer core includes a protective shell, a core body 10 and a limiting assembly. The protective shell includes an annular cover plate 11, an annular base plate 12 and an annular intermediate plate 13.

[0052] As shown in Figures 3 and 4, the base plate 12 and the intermediate plate 13 are coaxially arranged. The base plate 12 is located on one side of the intermediate plate 13 along its axial direction, and the upper surface of the base plate 12 is attached to the lower surface of the intermediate plate 13. An annular reinforcing cylinder 131 is integrally formed in the middle of the intermediate plate 13. The reinforcing cylinder 131 is coaxially arranged with the intermediate plate 13. An annular inner ring cylinder 121 is integrally formed at the inner diameter of the base plate 12. The inner ring cylinder 121 is coaxially arranged with the base plate 12. An annular first outer ring cylinder 122 is integrally formed at the outer diameter of the base plate 12. The first outer ring cylinder 122 is coaxially arranged with the base plate 12. The axial length of the first outer ring cylinder 122 is equal to half the axial length of the inner ring cylinder 121. Furthermore, a reinforcing rib 132 is fixed between the outer circumferential surface of the reinforcing cylinder 131 and the surface of the intermediate plate 13 to strengthen the structural strength of the reinforcing cylinder 131, thereby reducing the occurrence of excessive deformation in the middle due to axial pressure on the shell.

[0053] The cover plate 11 and the intermediate plate 13 are coaxially arranged. The cover plate 11 is fixedly connected to the reinforcing cylinder 131. The fixed connection can be by bonding or welding. The outer diameter of the cover plate 11 is integrally formed with an annular second outer ring cylinder 111. The second outer ring cylinder 111 is coaxially arranged with the cover plate 11. The axial length of the second outer ring cylinder 111 is equal to half the axial length of the inner ring cylinder 121.

[0054] As shown in Figure 1, the first outer ring cylinder 122 is provided with a semi-circular first bayonet 1221, and the second outer ring cylinder 111 is provided with a semi-circular second bayonet 1111.

[0055] As shown in Figures 1 and 3, the cover plate 11, the reinforcing cylinder 131, the inner ring cylinder 121 and the intermediate plate 13 together form an annular first receiving cavity, and the cover plate 11, the reinforcing cylinder 131, the intermediate plate 13, the first outer ring cylinder 122 and the second outer ring cylinder 111 together form an annular second receiving cavity, which is located outside the first receiving cavity.

[0056] As shown in Figures 4 and 5, the annular core 10 is located in the first receiving cavity. The opposite surfaces of the cover plate 11 and the intermediate plate 13 are each provided with a plurality of first triangular teeth 135 (the opposite surfaces of the cover plate 11 and the intermediate plate 13 refer to the lower surface of the cover plate 11 and the upper surface of the intermediate plate 13). The first triangular teeth 135 are located in the first receiving cavity. The length direction of the first triangular teeth 135 extends radially along the protective shell, and each first triangular tooth 135 is evenly distributed around its circumference. The cross-sectional profile of the first triangular tooth 135 is triangular.

[0057] As shown in Figures 4, 5, and 6 (the arrow in Figure 5 indicates the direction in which the elastic structure forces the limiting plate 21 to move circumferentially), the limiting component includes an elastic structure, a fixing structure, two annular limiting plates 21, and a limiting sleeve 22. In this embodiment, both the limiting plates 21 and the limiting sleeve 22 are made of rubber. In other embodiments, the limiting plates 21 and the limiting sleeve 22 can be made of thin plastic. Both the limiting plates 21 and the limiting sleeve 22 are coaxially arranged with the protective shell. The two limiting plates 21 are located on both sides of the axial direction of the core 10. The surface of the limiting plate 21 has a protruding structure with a plurality of circumferentially evenly arranged second triangular teeth 211. The length direction of the second triangular teeth 211 extends radially along the protective shell. The cross-sectional profile of the second triangular teeth 211 is triangular, and the inclined surface of the second triangular teeth 211 is in contact with the inclined surface of the first triangular teeth 135.

[0058] As shown in Figures 4, 5, and 6 (the arrow in Figure 6 indicates the rotation direction of the inner ring cylinder 121), the limiting sleeve 22 is coaxially arranged with the inner ring cylinder 121. The limiting sleeve 22 is fitted onto the outer side of the inner ring cylinder 121. The inner circumferential surface of the limiting sleeve 22 has a protruding structure with multiple circumferentially evenly arranged fourth triangular teeth 221. The length direction of the fourth triangular teeth 221 extends along the axial direction of the limiting sleeve 22, and the cross-sectional profile of the fourth triangular teeth 221 is triangular. The outer circumferential surface of the inner ring cylinder 121 has a protruding structure with multiple circumferentially evenly arranged third triangular teeth 1211. The length direction of the third triangular teeth 1211 extends along the axial direction of the inner ring cylinder 121, and the cross-sectional profile of the third triangular teeth 1211 is triangular. The inclined surface of the fourth triangular teeth 221 fits against the inclined surface of the third triangular teeth 1211.

[0059] As shown in Figure 7, the elastic force of the elastic structure is used to force the two limiting plates 21 to rotate circumferentially relative to the protective shell. Specifically, the elastic structure is a rubber rope 23, and multiple rubber ropes 23 are provided. The two ends of the rubber rope 23 are integrally formed and connected to the limiting plate 21 and the limiting sleeve 22, respectively.

[0060] As shown in Figure 4, the fixing structure includes a vertical plate 251, with pressure plates 252 fixed at both ends of the vertical plate 251, and a plug rod 253 fixed in the middle of the vertical plate 251.

[0061] When installing the core 10, first place the core 10, limiting plate 21, rubber rope 23, and limiting sleeve 22 onto the intermediate plate 13. Specifically, referring to Figure 7, the two limiting plates 21 are located on the upper and lower sides of the core 10, respectively, and the limiting sleeve 22 is located on the inner side of the core 10. Then, fix the cover plate 11 onto the reinforcing cylinder 131. The fixing method can be adhesive or welding, that is, the cover plate 11, reinforcing cylinder 131, and intermediate plate 13 are relatively fixed. At this time, the mating relationship of the first triangular tooth 135 and the second triangular tooth 211 is as follows: Referring to the first state diagram in Figures 8 and 9, the second triangular teeth 211 of the two limiting plates 21 are simultaneously in clearance engagement with the two sets of first triangular teeth 135. At this time, there is no direct contact between the limiting plate 21 above the core 10 and the cover plate 11, and the axial distance between the limiting plate 21 below the core 10 and the intermediate plate 13 is small. It can be concluded that the core 10 is not subjected to the axial pressure of the limiting plate 21, the core 10 is in a loose state, and the rubber rope 23 is in a slack state (no tension is generated).

[0062] Then, the base plate 12 is fitted with the middle plate 13. Specifically, the upper surface of the base plate 12 is attached to the lower surface of the middle plate 13, the inner ring cylinder 121 of the base plate 12 is located inside the limiting sleeve 22, and the third triangular tooth 1211 of the inner ring cylinder 121 is located in the gap of the fourth triangular tooth 221 of the limiting sleeve 22. At this time, the first latch 1221 and the second latch 1111 are misaligned.

[0063] Then, keeping the cover plate 11 and the intermediate plate 13 stationary, the operator can hold the cover plate 11 and the second outer ring cylinder 111 with one hand. The cover plate 11 remains stationary, while the intermediate plate 13 is fixedly connected to the cover plate 11, so the intermediate plate 13 remains stationary. With the other hand, the operator moves the bottom plate 12, which in turn rotates the inner ring cylinder 121 and the first outer ring cylinder 122 relative to the intermediate plate 13 by a certain angle (see the arrow direction in Figure 6), so that the first latch 1221 of the first outer ring cylinder 122 engages with the second outer ring cylinder 122. The second latch 1111 of the inner ring cylinder 111 is aligned. After the first latch 1221 and the second latch 1111 are aligned, the rotation stops. During this rotation, the inner ring cylinder 121 first drives the limiting sleeve 22 to rotate circumferentially by a certain angle. (Since the third triangular tooth 1211 of the inner ring cylinder 121 is located in the gap of the fourth triangular tooth 221 of the limiting sleeve 22, the movement of the third triangular tooth 1211 will push the fourth triangular tooth 221 and the limiting sleeve 22 to move. The arrow in Figure 6 indicates the movement of the inner ring cylinder 121.) When the limiting sleeve 22 moves, it will stretch the rubber rope 23. The movement of the limiting sleeve 22 will also drive the two limiting plates 21 to rotate a small angle relative to the first triangular tooth 135 through the rubber rope 23. At this time, the engagement relationship between the first triangular tooth 135 and the second triangular tooth 211 changes from the first state schematic diagram in Figures 8 and 9 to the second state schematic diagram. The solid arrow in Figure 9 indicates the direction of movement of the limiting plate 21. Since the middle plate 13 and the cover plate 11 are not moving, the first triangular tooth 135 remains stationary. The second triangular tooth 211 in Figure 9 moves downward under the guidance of the inclined surface of the first triangular tooth 135. That is, the limiting plate 21 above the core 10 moves downward, while the limiting plate 21 below the core 10 moves upward. The two limiting plates 21 together clamp the core 10 (at this time, the inclined surface of the second triangular tooth 211 only partially contacts the inclined surface of the first triangular tooth 135, which is called the incomplete engagement state). That is, the limiting plate 21 and the core 10 are fixed relative to the middle plate 13.

[0064] Finally, the first outer ring cylinder 122 and the second outer ring cylinder 111 are fixed by a fixing structure. Specifically, the insertion rod 253 passes through the circular hole formed by the first bayonet 1221 and the second bayonet 1111 to limit the circumferential position of the protective shell. The two pressure plates 252 are elastically pressed on the outer surface of the cover plate 11 and the outer surface of the bottom plate 12, respectively. That is, the elastic pressure of the pressure plates 252 is used to limit the axial position of the protective shell, thereby ensuring the stability of the installation of the protective shell.

[0065] Secondly, as shown in Figure 10, since the inclined surface of the second triangular tooth 211 only partially contacts the inclined surface of the first triangular tooth 135, the second triangular tooth 211 and the first triangular tooth 135 are not fully engaged (corresponding to the first state schematic diagram in Figure 10), which gives the core 10 and the limiting plate 21 a certain circumferential movement margin. When the protective shell is subjected to axial assembly pressure (the direction of the hollow arrow in Figure 10 is the direction of assembly pressure), the cover plate 11, the bottom plate 12, and the middle plate 13 have a tendency to undergo axial compression deformation. It can be understood that the first triangular teeth 135 of the cover plate 11 and the middle plate 13 approach each other axially. Therefore, the inclined surface of the first triangular tooth 135 presses against the inclined surface of the second triangular tooth 211. The first triangular tooth 135 will drive the two limiting plates 21 and the core 10 to rotate circumferentially by a certain angle (the direction of rotation is the direction of the solid arrow in Figure 10). At this time, the first triangular tooth 135 and the second triangular tooth 211 are fully engaged (corresponding to the second state schematic diagram in Figure 10). There is no axial clearance between the second triangular tooth 211 and the first triangular tooth 135. Furthermore, the rubber rope 23 is further elastically stretched, and the rubber rope will buffer the assembly pressure. Since there is a large friction between the second triangular tooth 211 and the first triangular tooth 135, friction heat is generated during the relative reciprocating sliding process of the second triangular tooth 211 and the first triangular tooth 135, which converts the impact kinetic energy into heat energy, thereby playing a buffering and shock absorption role, thereby reducing the pressure on the core 10.

[0066] Furthermore, to improve integration, the following configuration can be made: a compensating reactor 20 is fixed in the second receiving cavity, and a through hole 112 can be opened in the cover plate 11. The through hole 112 is used for the lead wire of the compensating reactor 20 to pass through, and the lead wire can be connected to the electromagnetic wire wound around the iron core, which is more convenient.

[0067] This embodiment also discloses a current transformer coil, including the aforementioned current transformer core and an electromagnetic wire wound around the current transformer core.

[0068] This embodiment also discloses a current transformer, including a current transformer body and the aforementioned transformer coil.

[0069] Example 2

[0070] The difference between Embodiment 2 and Embodiment 1 is that, as shown in Figure 11, the fixing structure includes a bolt 261, the bolt head of which has a circular groove 262, and semi-annular protrusions 263 are fixed on the outer circumferential surfaces of the first outer ring cylinder 122 and the second outer ring cylinder 111.

[0071] When the core 10 is clamped and fixed by the two limiting plates 21 and the first bayonet 1221 and the second bayonet 1111 are aligned, the two semi-circular protrusions 263 combine to form a ring-shaped block. The bolt 261 passes through the circular hole formed by the first bayonet 1221 and the second bayonet 1111, so that the bolt 261 is threadedly connected to the reinforcing cylinder 131. During the screwing process of the bolt 261, the groove 262 of the bolt 261 cooperates with the two protrusions 263 at the same time, that is, the circular groove 262 cooperates with the ring-shaped block, thereby completing the axial and circumferential limiting of the protective shell.

[0072] Example 3

[0073] The difference between Embodiment 3 and Embodiment 1 is that, as shown in Figures 12 and 13, the protective shell includes an annular lower plate 15 and an annular upper plate 14. An annular inner diameter cylinder 151 is integrally formed at the inner diameter of the lower plate 15, a middle diameter cylinder 152 is integrally formed at the middle diameter of the lower plate 15, and an outer diameter cylinder 153 is integrally formed at the outer diameter of the lower plate 15. The lower plate 15, upper plate 14, middle diameter cylinder 152, and inner diameter cylinder 151 together form a first receiving cavity, i.e., two sets of first triangular teeth 135 are respectively arranged on the opposite surfaces of the upper plate 14 and the lower plate 15. The lower plate 15, upper plate 14, middle diameter cylinder 152, and outer diameter cylinder 153 together form a second receiving cavity. Furthermore, when the cover is fixed, the upper plate 14 can be fixedly connected to the inner diameter cylinder 151, middle diameter cylinder 152, or outer diameter cylinder 153 by welding or bonding.

[0074] Two sets of first triangular teeth 135 are respectively disposed on the lower surface of the upper plate 14 and the upper surface of the lower plate 15.

[0075] The elastic structure consists of two sets of elastic rods 27. The elastic rods 27 are made of shape memory alloy. The deformation temperature of the elastic rods 27 can be any temperature value between 40℃ and 70℃. In this embodiment, the deformation temperature of the elastic rods 27 is 65℃. Each set of elastic rods 27 includes multiple elastic rods 27 and is evenly arranged around the circumference of the protective shell. Both sets of elastic rods 27 are inclined and in opposite directions. The two sets of elastic rods 27 are symmetrically arranged about the axial direction of the protective shell.

[0076] Both limiting plates 21 have axially extending grooves 271 at their inner diameters. One end of each set of elastic rods 27 is fixedly connected to the inner diameter cylinder 151. The diameter of the elastic rods 27 is equal to the width of the grooves 271. The other ends of the two sets of elastic rods 27 extend into the grooves 271 of the two limiting plates 21 and slide with the grooves 271, thus allowing the limiting plates 21 to slide axially relative to the elastic rods 27.

[0077] Before the current transformer coil is assembled into the current transformer, the casing is heated. When the temperature of the elastic rod 27 is at the deformation temperature, the elastic rod 27 deforms circumferentially along the casing. Its deformation force drives the limiting plate 21 to rotate circumferentially by abutting against the groove wall of the slide groove 271 (the direction of rotation is referred to the direction of the solid arrow in the first state schematic diagram in Figure 14). The second triangular tooth 211 and the first triangular tooth 135 are in clearance fit. In this state, the two limiting plates 21 have no direct contact with the upper plate 14 and the lower plate 15 respectively, so that the core 10 is in an unclamped state. Therefore, when the axial assembly pressure is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core 10, thereby avoiding damage to the core 10 due to pressure.

[0078] After the protective shell is assembled and used without being heated, the shell is below its deformation temperature. The elastic rod 27 returns to its original shape, driving the limiting plate 21 to rotate circumferentially (the direction of rotation is indicated by the solid arrow in the second state diagram of Figure 14). Since the upper plate 14 and lower plate 15 are already assembled and fixed, the first triangular tooth 135 remains stationary. Therefore, the second triangular tooth 211 of the limiting plate 21 rotates relative to the first triangular tooth 135 of the upper plate 14 and lower plate 15. During this process, the second triangular tooth of the limiting plate 21 located above the core 10... 211 moves downward under the guidance of the inclined surface of the first triangular tooth 135, that is, the limiting plate 21 above the core 10 moves downward, while the limiting plate 21 below the core 10 moves upward. The two limiting plates 21 together clamp the core 10 (at this time, the inclined surface of the second triangular tooth 211 and the inclined surface of the first triangular tooth 135 are only partially in contact, which is called the incomplete engagement state). That is, the limiting plate 21 and the core 10 are fixed relative to the intermediate plate 13. After clamping the core 10, the elastic rod 27 is resisted, the elastic rod 27 stops deforming, and the limiting plate 21 stops rotating.

[0079] Example 4

[0080] The difference between Embodiment 4 and Embodiment 3 is that, as shown in Figure 15, the core 10 includes multiple first arc-shaped strips 101 and multiple second arc-shaped strips 102. The first arc-shaped strips 101 and the second arc-shaped strips 102 are arranged in an alternating circumferential pattern. The two end faces of the first arc-shaped strips 101 are designated as first mating surfaces 1012, and the two end faces of the second arc-shaped strips 102 are designated as second mating surfaces 1022. The limiting component is used to fix the core 10 while simultaneously ensuring that the first mating surfaces 1012 and the second mating surfaces 1022 are in contact to ensure the splicing stability of the core 10.

[0081] It can be understood that the core 10 is formed by splicing together multiple first arc-shaped strips 101 and multiple second arc-shaped strips 102. That is, the core 10 has multiple breaks. Compared with the complete closed-loop core 10, the magnetic resistance is larger and the effective magnetic permeability is reduced. However, the linear operating range of the core 10 is greatly increased, and the dynamic measurement range of the current transformer is expanded accordingly.

[0082] As shown in Figures 15, 16, and 17, a first guide surface 1011 is provided at the outer diameter of the first arc-shaped strip 101, and the first guide surface 1011 extends along the arc path of the first arc-shaped strip 101. A second guide surface 1021 is provided at the inner diameter of the second arc-shaped strip 102, and the second guide surface 1021 extends along the arc path of the second arc-shaped strip 102.

[0083] A first guide block 212, corresponding to the first arc-shaped strip 101, is fixed at the outer diameter of the limiting plate 21, and a second guide block 213, corresponding to the second arc-shaped strip 102, is fixed at the inner diameter of the limiting plate 21. The cross-sectional shape of the first guide block 212 and the second guide block 213 is a right triangle.

[0084] When not heated, the elastic force of the elastic rod 27 is applied to the two limiting plates 21. Through the engagement of the inclined surfaces of the first triangular tooth 135 and the second triangular tooth 211 (there is an axial gap between the limiting plates 21 and the core 10, meaning the limiting plates 21 and the core 10 are not in direct contact; only the first guide block 212 and the first guide surface 1011 remain in contact, and the second guide block 213 and the second guide surface 1021 remain in contact), the two limiting plates 21 are forced to move axially closer together. During this process, the engagement of the first guide block 212 and the first guide surface 1011 forces the first arc-shaped strip 101 to move radially inward. The movement of the first arc-shaped strip 101 is shown in the direction of the arrow in Figure 15. The second guide block 213 and the second guide surface 1021 cooperate to force the second arc-shaped strip 102 to move radially outward (the direction of movement of the second arc-shaped strip 102 is shown in the direction of the arrow in Figure 15). This makes the first mating surface 1012 and the second mating surface 1022 fit more tightly, thereby reducing the occurrence of excessive increase in magnetic resistance due to excessive gap. Even if the increase in magnetic resistance is small, it will both expand the dynamic measurement range of the current transformer and reduce the change in the measurement accuracy of the current transformer.

[0085] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A current transformer core, characterized in that, The device includes a protective shell, a core (10), and a limiting assembly. The protective shell has an annular first receiving cavity, and the core (10) is located within the first receiving cavity. The inner top wall and inner bottom wall of the first receiving cavity are both convexly constructed with a plurality of circumferentially evenly arranged first triangular teeth (135). The length direction of the first triangular teeth (135) extends radially along the protective shell, and the cross-sectional profile of the first triangular teeth (135) is triangular. The limiting assembly includes an elastic structure and two annular limiting plates (21). The two limiting plates (21) are located on both sides of the axial direction of the core (10), and the surface of the limiting plates (21) is convexly constructed with a plurality of circular... The second triangular teeth (211) are evenly arranged around the periphery, and their length direction extends radially along the protective shell. The cross-sectional profile of the second triangular teeth (211) is triangular. The elastic force of the elastic structure is used to force the two limiting plates (21) to rotate circumferentially relative to the protective shell, so that the inclined surface of the second triangular teeth (211) is in contact with the inclined surface of the first triangular teeth (135). Under the guidance of the inclined surface of the first triangular teeth (135), the second triangular teeth (211) drive the limiting plates (21) to move axially in the direction close to the core (10). When the two limiting plates (21) are in contact with the core (10), the second... The inclined surface of the triangular tooth (211) is in contact with the inclined surface of the first triangular tooth (135), so that there is an axial gap between the tooth tip of the second triangular tooth (211) and the tooth root of the first triangular tooth (135); the protective shell includes an annular cover plate (11), an annular base plate (12) and an annular intermediate plate (13), the surface of the base plate (12) is in contact with the intermediate plate (13), an annular reinforcing cylinder (131) is integrally formed in the middle of the intermediate plate (13), an annular inner ring cylinder (121) is integrally formed in the inner diameter of the base plate (12), and an annular... The first outer ring cylinder (122) is fixedly connected to the cover plate (11) and the reinforcing cylinder (131). The outer diameter of the cover plate (11) is integrally formed with an annular second outer ring cylinder (111). The cover plate (11), the reinforcing cylinder (131), the inner ring cylinder (121) and the intermediate plate (13) together form the first receiving cavity. The surface of the cover plate (11) and the surface of the intermediate plate (13) are the inner top wall and the inner bottom wall of the first receiving cavity, respectively. The first outer ring cylinder (122) is provided with a first latch (1221), and the second outer ring cylinder (111) is provided with a second latch (1111).The limiting component also includes a fixing structure and a limiting sleeve (22). Both the limiting sleeve (22) and the limiting plate (21) are made of rubber. The limiting sleeve (22) is coaxially arranged with the inner ring cylinder (121). The outer circumferential surface of the inner ring cylinder (121) has a protruding structure with multiple circumferentially evenly arranged third triangular teeth (1211). The inner circumferential surface of the limiting sleeve (22) has a protruding structure with multiple circumferentially evenly arranged fourth triangular teeth (221). The inclined surface of the fourth triangular teeth (221) is parallel to the third triangular teeth (1211). The inclined surfaces of the core (10) are in contact with each other. The elastic structure is a rubber rope (23), and the two ends of the rubber rope (23) are connected to the limiting plate (21) and the limiting sleeve (22) respectively. The outer circumferential surface of the limiting sleeve (22) is in contact with the inner circumferential surface of the core (10), and there is a gap between the outer circumferential surface of the core (10) and the inner circumferential surface of the reinforcing cylinder (131). The fixing structure is located in the first bayonet (1221) and the second bayonet (1111) and is used to fix the first outer ring cylinder (122) and the second outer ring cylinder (111).

2. The transformer core according to claim 1, characterized in that, The fixing structure includes a vertical plate (251), with pressure plates (252) fixed at both ends of the vertical plate (251) and a plug rod (253) fixed in the middle of the vertical plate (251). The plug rod (253) passes through the first bayonet (1221) and the second bayonet (1111) at the same time, and the two pressure plates (252) are elastically pressed on the outer surface of the cover plate (11) and the outer surface of the bottom plate (12) respectively.

3. The transformer core according to claim 1, characterized in that, The fixing structure includes a bolt (261), the bolt (261) has a groove (262) at the head, and the outer circumferential surfaces of the first outer ring cylinder (122) and the second outer ring cylinder (111) are both fixed with protrusions (263). When the first bayonet (1221) and the second bayonet (1111) are aligned, the bolt (261) passes through the first bayonet (1221) and the second bayonet (1111) at the same time. The bolt (261) is threadedly connected to the reinforcing cylinder (131), and the groove (262) cooperates with the two protrusions (263) at the same time.

4. A current transformer core, characterized in that, The device includes a protective shell, a core (10), and a limiting assembly. The protective shell has an annular first receiving cavity, and the core (10) is located within the first receiving cavity. The inner top wall and inner bottom wall of the first receiving cavity are both protruding with a plurality of circumferentially evenly arranged first triangular teeth (135). The length direction of the first triangular teeth (135) extends radially along the protective shell, and the cross-sectional profile of the first triangular teeth (135) is triangular. The limiting assembly includes an elastic structure and two annular limiting plates (21). The two limiting plates (21) are located on the axial sides of the core (10), respectively. The surface of the limiting plates (21) is protruding with a plurality of circumferentially evenly arranged second triangular teeth (211). The length direction of the second triangular teeth (211) is... Extending radially along the protective shell, the second triangular tooth (211) has a triangular cross-sectional profile. The elastic force of the elastic structure forces the two limiting plates (21) to rotate circumferentially relative to the protective shell, causing the inclined surface of the second triangular tooth (211) to fit against the inclined surface of the first triangular tooth (135). Guided by the inclined surface of the first triangular tooth (135), the second triangular tooth (211) drives the limiting plates (21) to move axially towards the core (10). When the two limiting plates (21) fit against the core (10), the inclined surface of the second triangular tooth (211) partially fits against the inclined surface of the first triangular tooth (135), resulting in a gap between the tooth tip of the second triangular tooth (211) and the tooth root of the first triangular tooth (135). Axial clearance; the protective shell includes a lower plate (15) and an upper plate (14). An annular inner diameter cylinder (151) is integrally formed at the inner diameter of the lower plate (15). A middle diameter cylinder (152) is integrally formed at the middle diameter of the lower plate (15). An outer diameter cylinder (153) is integrally formed at the outer diameter of the lower plate (15). The lower plate (15), upper plate (14), middle diameter cylinder (152), and inner diameter cylinder (151) together form the first receiving cavity. The surface of the upper plate (14) and the surface of the lower plate (15) are respectively the inner top wall and the inner bottom wall of the first receiving cavity. The elastic structure consists of two sets of elastic rods (27). The elastic rods (27) are made of shape memory alloy. An axial clearance is provided at the inner diameter of both limiting plates (21). The extended groove (271) has one end of two sets of elastic rods (27) fixedly connected to the inner diameter cylinder (151), and the other ends of the two sets of elastic rods (27) respectively extend into the grooves (271) of the two limiting plates (21) and slide with the grooves (271); when the temperature of the elastic rod (27) is lower than the deformation temperature, the elastic force of the elastic rod (27) is converted into a force that forces the two limiting plates (21) to approach each other axially through the cooperation between the second triangular tooth (211) and the first triangular tooth (135); when the temperature of the elastic rod (27) is at the deformation temperature, the deformation force of the elastic rod (27) drives the limiting plate (21) to rotate circumferentially until the second triangular tooth (211) and the first triangular tooth (135) are in clearance cooperation.

5. The transformer core according to claim 1 or 4, characterized in that, The core (10) includes multiple first arc-shaped strips (101) and multiple second arc-shaped strips (102). The first arc-shaped strips (101) and the second arc-shaped strips (102) are arranged in an alternating pattern around their circumference. The two end faces of the first arc-shaped strips (101) are designated as first mating surfaces (1012), and the two end faces of the second arc-shaped strips (102) are designated as second mating surfaces (1022). The outer diameter of the first arc-shaped strips (101) is provided with a first guide surface (1011), and the inner diameter of the second arc-shaped strips (102) is provided with a second guide surface (1021). The outer diameter of the limiting plate (21) is fixed with a first guide block (212) that corresponds one-to-one with the first arc-shaped strips (101). 1) A second guide block (213) is fixed at the inner diameter of the first guide block (212) and is correspondingly arranged one-to-one with the second arc-shaped strip (102). When the two limiting plates (21) approach each other axially, the first arc-shaped strip (101) will be forced to move radially inward through the cooperation of the first guide block (212) and the first guide surface (1011). When the two limiting plates (21) approach each other axially, the second arc-shaped strip (102) will be forced to move radially outward through the cooperation of the second guide block (213) and the second guide surface (1021). When the second arc-shaped strip (102) moves radially outward and the first arc-shaped strip (101) moves radially inward, the first mating surface (1012) and the second mating surface (1022) fit together.

6. The transformer core according to claim 1, characterized in that, A reinforcing rib (132) is integrally formed between the outer peripheral surface of the reinforcing cylinder (131) and the surface of the intermediate plate (13).

7. The transformer core according to claim 1 or 4, characterized in that, The protective shell has an annular second receiving cavity, which is located outside the first receiving cavity, and a compensation reactor (20) is fixed inside the second receiving cavity.

8. A current transformer coil, characterized in that, It includes the current transformer core as described in claim 1 or 4 and the electromagnetic wire wound around the current transformer core.

9. A current transformer, characterized in that, It includes a current transformer body and a transformer coil as described in claim 8.

Images