A transformer core, a transformer coil and a current transformer

Abstract

The present application discloses a transformer core, a transformer coil and a current transformer, belonging to the technical field of current transformers. A transformer core includes a protective shell, a core body and a limit assembly, the protective shell has an annular first accommodating cavity, the core body is located in the first accommodating cavity, the inner top wall and the inner bottom wall of the first accommodating cavity are both protrudingly constructed with a plurality of first triangular teeth evenly arranged circumferentially, the limit assembly includes an elastic structure and two annular limit plates, the two limit plates are respectively located on both axial sides of the core body, the surface of the limit plate is protrudingly constructed with a plurality of second triangular teeth evenly arranged circumferentially, the inclined surface of the second triangular tooth is in contact with the inclined surface of the first triangular tooth, the elastic force of the elastic structure is used to force the two limit plates to rotate circumferentially relative to the protective shell, the inclined surface of the second triangular tooth is partially in contact with the inclined surface of the first triangular tooth, so that there is an axial gap between the tooth top of the second triangular tooth and the tooth root of the first triangular tooth. The present application can improve the structural stability and position stability of the core body.

Description

Technical Field

[0001] The present application belongs to the technical field of current transformers, and relates to a transformer core, a transformer coil and a current transformer. Background Art

[0002] The 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 protective shell and a core body arranged in the protective shell. The protective shell has a cover plate. After the core body is placed in the accommodating cavity of the protective shell, the accommodating cavity is covered with the cover plate to complete the installation of the core.

[0003] In order to reduce the shaking and collision of the core body in the protective shell, the surface of the core body is arranged to fit with the inner wall of the accommodating cavity, so as to achieve stable positioning of the core body. However, during the process of assembling the current transformer coil into the current transformer, it is necessary to apply assembly pressure in the axial direction to the current transformer coil. When the assembly pressure is too large, the assembly pressure will be transmitted to the core body through the protective shell, which can easily cause the core body to be compressed and the magnetic permeability to be reduced. Summary of the invention

[0004] In order to ensure the installation stability of the core and reduce the pressure on the core, a transformer core, a transformer coil and a current transformer are provided.

[0005] The present application provides a transformer core, which is specifically implemented by the following technical solutions:

[0006] A transformer core, comprising a protective shell, a core body and a limiting assembly, wherein the protective shell has an annular first accommodating cavity, the core body is located in the first accommodating cavity, the inner top wall and the inner bottom wall of the first accommodating cavity are both protrudingly constructed with a plurality of first triangular teeth uniformly arranged in a circumference, the length direction of the first triangular teeth is extended radially along the protective shell, and the cross-sectional profile of the first triangular teeth is triangular, the limiting assembly comprises an elastic structure and two annular limiting plates, the two limiting plates are respectively located on both axial sides of the core body, the surface of the limiting plates is protrudingly constructed with a plurality of second triangular teeth uniformly arranged in a circumference, the length direction of the second triangular teeth is extended radially along the protective shell, and the second triangular teeth are protrudingly constructed on the surface of the limiting plates. The cross-sectional profile of the triangular tooth is triangular; the elastic force of the elastic structure is used to force the two limit plates to rotate circumferentially relative to the protective shell, so that the inclined surface of the second triangular tooth fits with the inclined surface of the first triangular tooth, and the second triangular tooth drives the limit plate to move axially in the direction close to the core body under the guidance of the inclined surface of the first triangular tooth. When the two limit plates are fitted to the core body, the inclined surface of the second triangular tooth partially fits with the inclined surface of the first triangular tooth, so that there is an axial gap between the tooth top 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 middle plate, the surface of the bottom plate fits with the middle plate, and the middle plate An annular reinforcement cylinder is integrally formed in the middle part, an annular inner ring cylinder is integrally formed at the inner diameter of the base plate, an annular first outer ring cylinder is integrally formed at the outer diameter of the base plate, the cover plate is fixedly connected to the reinforcement cylinder, and an annular second outer ring cylinder is integrally formed at the outer diameter of the cover plate; the cover plate, the reinforcement cylinder, the inner ring cylinder and the middle plate are enclosed to form the first accommodating cavity, and the surface of the cover plate and the surface of the middle plate are respectively the inner top wall and the inner bottom wall of the first accommodating cavity; the first outer ring cylinder is provided with a first bayonet, and the second outer ring cylinder is provided with a second bayonet; the limiting assembly also includes a fixing structure and a limiting sleeve, the limiting sleeve The limiting plate and the limiting sleeve are both made of rubber material, the limiting sleeve is coaxially arranged with the inner ring tube, the outer circumferential surface of the inner ring tube is protrudingly constructed with a plurality of third triangular teeth evenly arranged circumferentially, the inner circumferential surface of the limiting sleeve is protrudingly constructed with a plurality of fourth triangular teeth evenly arranged circumferentially, the inclined surface of the fourth triangular teeth is in contact with the inclined surface of the third triangular teeth, the elastic structure is a rubber rope, the two ends of the rubber rope are respectively connected to the limiting plate and the limiting sleeve; the outer circumferential surface of the limiting sleeve is in contact with the inner circumferential surface of the core body, and there is a gap between the outer circumferential surface of the core body and the inner circumferential surface of the reinforcing tube; the fixing structure is located in the first bayonet and the second bayonet and is used to fix the first outer ring tube and the second outer ring tube.

[0007] When installing the core body, first put the core body, the limit plate, the rubber rope and the limit sleeve on the middle plate, and then fix the cover plate on the reinforcing cylinder. At this time, the rubber rope is in a relaxed state, and the first triangular tooth and the second triangular tooth are gap-matched. Then the bottom plate and the middle plate are matched, and the bottom plate can rotate relative to the middle plate, the third triangular tooth and the fourth triangular tooth are matched, and the first bayonet and the second bayonet are misaligned; then the cover plate and the middle plate are kept stationary, and the bottom plate drives the inner ring cylinder to rotate a certain angle relative to the middle plate, so that the first bayonet of the first outer ring cylinder is aligned with the second bayonet of the second outer ring cylinder. In this process, the inner ring cylinder first drives the limit sleeve to rotate circumferentially by a certain angle, and the rubber rope is stretched. The elastic force of the rubber rope is converted into a force forcing the two limit plates to approach axially through the cooperation between the second triangular tooth and the first triangular tooth. The two limit plates jointly clamp the core body. At this time, the first bayonet is aligned with the second bayonet, and finally the first outer ring cylinder and the second outer ring cylinder are fixed by the fixing structure.

[0008] In this way, by setting the limit plate and limit sleeve made of rubber material, the core body can be fixed, and when the protective shell is subjected to axial assembly pressure, the pressure will be converted into forcing the two limit plates to rotate circumferentially relative to the protective shell through the cooperation between the second triangular teeth and the first triangular teeth, thereby forcing the rubber rope to deform elastically. Since there is a large friction force between the second triangular teeth and the first triangular teeth, friction generates heat during the relative reciprocating sliding process between the second triangular teeth and the first triangular teeth, and the impact kinetic energy is converted into heat energy, thereby playing a shock-absorbing role. In addition, the initial cooperation position of the inner ring tube and the limit sleeve can be adjusted, that is, the rotation angle of the bottom plate can be adjusted, so as to control and adjust the final elastic force of the rubber rope to adjust the clamping force of the core body, so as to be suitable for different use environments and core bodies with different material properties.

[0009] Optionally, the fixing structure includes a vertical plate, pressure plates are fixed at both ends of the vertical plate, an insertion rod is fixed in the middle of the vertical plate, the insertion rod passes through the first bayonet and the second bayonet at the same time, and the two pressure plates are elastically pressed on 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 bayonet and the second bayonet at the same time to limit the protective shell circumferentially, and the protective shell is limited axially through the elastic pressure of the pressure plate, thereby ensuring the installation stability of the protective shell.

[0011] Optionally, the fixing structure includes a bolt, the screw head of the bolt has a groove, and the outer peripheral surfaces of the first outer ring tube and the second outer ring tube are fixed with protrusions. When the first bayonet and the second bayonet are aligned, the bolt passes through the first bayonet and the second bayonet at the same time, the bolt is threadedly connected to the reinforcing tube, and the groove cooperates with the two protrusions at the same time.

[0012] Through the above technical solution, the bolt passes through the first bayonet and the second bayonet at the same time to limit the shell circumferentially, and the shell is limited axially through the cooperation of the groove and the protrusion, thereby ensuring the installation stability of the shell.

[0013] The present application also provides a transformer core, which is specifically implemented by the following technical solutions:

[0014] A transformer core comprises a protective shell, a core body and a limiting assembly, wherein the protective shell has an annular first accommodating cavity, the core body is located in the first accommodating cavity, the inner top wall and the inner bottom wall of the first accommodating cavity are both protrudingly constructed with a plurality of first triangular teeth uniformly arranged in a circumference, the length direction of the first triangular teeth is extended radially along the protective shell, and the cross-sectional profile of the first triangular teeth is triangular, the limiting assembly comprises an elastic structure and two annular limiting plates, the two limiting plates are respectively located on both axial sides of the core body, the surfaces of the limiting plates are protrudingly constructed with a plurality of second triangular teeth uniformly arranged in a circumference, the length direction of the second triangular teeth is extended radially along the protective shell, and the cross-sectional profile of the second triangular teeth is triangular; the elastic force of the elastic structure is used to force the two limiting plates to rotate circumferentially relative to the protective shell, so that the inclined surface of the second triangular teeth is fitted with the inclined surface of the first triangular teeth, and the second triangular teeth drive the limiting plates to move axially in the direction close to the core body under the guidance of the inclined surface of the first triangular teeth, when the two limiting plates are fitted to the core body, the inclined surface of the second triangular teeth is partially fitted with the inclined surface of the first triangular teeth, so that The tooth top of the second triangular tooth and the tooth root of the first triangular tooth have an axial gap; the protective shell includes a lower plate and an upper plate, the inner diameter of the lower plate is integrally formed with an annular inner diameter cylinder, the middle part of the lower plate is integrally formed with a middle diameter cylinder, the outer diameter of the lower plate is integrally formed with an outer diameter cylinder, the lower plate, the upper plate, the middle diameter cylinder and the inner diameter cylinder are surrounded to form the first accommodating 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 accommodating cavity, the elastic structure is two groups of elastic rods, the elastic rods are memory alloys, and the two An axially extending slide groove is provided at the inner diameter of the limit plate, one end of the two sets of elastic rods is fixedly connected to the inner diameter tube, and the other ends of the two sets of elastic rods are respectively extended into the slide grooves of the two limit plates and slideably cooperate with the slide 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 forcing the two limit plates to be axially close to each other through the cooperation 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 limit plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are gap-matched.

[0015] Through the above technical solution, the protective shell is heated before the current transformer coil is assembled to the current transformer. When the temperature of the elastic rod is at the deformation temperature, the deformation force of the elastic rod drives the limit plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are gap-matched. In this state, there is no direct contact between the two limit plates and the inner top wall and the inner bottom wall respectively, and the core body is not clamped. Therefore, when the assembly pressure in the axial direction is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core body, thereby avoiding the core body from being compressed and damaged; after the protective shell is assembled and during use, when the protective shell is lower than the deformation temperature, the elastic force of the elastic rod is converted into a force forcing the two limit plates to be axially close to each other through the cooperation between the second triangular tooth and the first triangular tooth, and the limit plates clamp the core body to ensure the position stability of the core body.

[0016] Optionally, the core body includes a plurality of first arc strips and a plurality of second arc strips, the first arc strips and the second arc strips are arranged circumferentially in an alternating manner, the two end surfaces of the first arc strip are set as first mating surfaces, the two end surfaces of the second arc strip are set as second mating surfaces, a first guide surface is provided at the outer diameter of the first arc strip, and a second guide surface is provided at the inner diameter of the second arc strip; a first guide block which is arranged in a one-to-one correspondence with the first arc strip is fixed at the outer diameter of the limiting plate, and a second guide block which is arranged in a one-to-one correspondence with the second arc strip is fixed at the inner diameter of the limiting plate; when the two limiting plates are axially close to each other, the first arc strip will be forced to move radially inward through the cooperation between the first guide block and the first guide surface, and when the two limiting plates are axially close to each other, the second arc strip will be forced to move radially outward through the cooperation between the second guide block and the second guide surface; when the second arc strip moves radially outward and the first arc strip moves radially inward, the first mating surface and the second mating surface fit together.

[0017] Through the above technical solution, firstly, the core is formed by splicing and combining a plurality of first arc strips and a plurality of second arc strips, that is, the core has a plurality of fractures. Compared with the core of a complete closed loop, the magnetic resistance is larger and the effective magnetic permeability is reduced, but the linear working range of the core is greatly increased, and the dynamic measurement range of the current transformer is expanded accordingly. Moreover, when the two limit plates are axially close to each other, the first arc strip moves radially inward and the second arc strip moves radially outward, so that the first mating surface and the second mating surface fit more closely, thereby reducing the excessive increase in magnetic resistance due to the excessive gap between the fractures, that is, the increase in magnetic resistance is smaller, which not only expands the dynamic measurement range of the current transformer, but also reduces the change in the measurement accuracy of the current transformer.

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

[0019] Through the above technical solution, the structural strength of the reinforcement tube can be enhanced, thereby reducing the axial pressure on the shell and causing excessive deformation in the middle part.

[0020] Optionally, the protective shell has an annular second accommodating cavity, the second accommodating cavity is located outside the first accommodating cavity, and a compensating inductor is fixed in the second accommodating cavity.

[0021] Through the above technical solution, the iron core is integrated with the compensating reactor, and the wiring is more convenient.

[0022] The present application provides a mutual inductor coil, which is specifically implemented by the following technical solution.

[0023] A mutual inductor coil comprises a mutual inductor core and an electromagnetic wire wound around the mutual inductor core.

[0024] The present application provides a current transformer, which is specifically implemented by the following technical solution.

[0025] A current transformer comprises 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 limit plates, the elastic force of the elastic structure is used to force the two limit plates to rotate circumferentially relative to the protective shell. The elastic force of the elastic structure is converted into a force forcing the two limit plates to approach axially through the cooperation between the second triangular tooth and the first triangular tooth. The two limit plates jointly clamp the core body, thereby improving the installation stability of the core body; and when the protective shell is subjected to axial assembly pressure, the protective shell is compressed and deformed. The pressure will be converted into a force forcing the two limit plates to rotate circumferentially relative to the protective shell through the cooperation 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 body;

[0028] 2. By setting a limit plate and a limit sleeve made of rubber material, the core body can be fixed, and when the protective shell is subjected to axial assembly pressure, the pressure will be converted through the cooperation between the second triangular teeth and the first triangular teeth to force the two limit plates to rotate circumferentially relative to the protective shell, thereby forcing the rubber rope to deform elastically. Since there is a large friction force between the second triangular teeth and the first triangular teeth, friction generates heat during the relative reciprocating sliding of the second triangular teeth and the first triangular teeth, and the impact kinetic energy is converted into heat energy, thereby playing a shock-absorbing role;

[0029] 3. Before the current transformer coil is assembled to the current transformer, the protective shell is heated. When the temperature of the elastic rod is at the deformation temperature, the deformation force of the elastic rod drives the limit plate to rotate circumferentially until the second triangular tooth and the first triangular tooth are gap-matched. In this state, the two limit plates have no direct contact with the inner top wall and the inner bottom wall respectively, and the core body is not clamped. Therefore, when the assembly pressure in the axial direction is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core body, thereby avoiding the core body from being compressed and damaged; after the protective shell is assembled and during use, when the protective shell is lower than the deformation temperature, the elastic force of the elastic rod is converted into a force that forces the two limit plates to be axially close to each other through the cooperation between the second triangular tooth and the first triangular tooth, and the limit plates clamp the core body to ensure the position stability of the core body. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0032] Figure 3 yes Figure 2 Cross-sectional view along the AA direction.

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

[0034] Figure 5 yes Figure 2 Cross-sectional view along the BB direction.

[0035] Figure 6 yes Figure 3 Cross-sectional view along CC direction.

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

[0037] Figure 8 This is a schematic diagram of Example 1 for showing the state change of the limiting plate from not clamping the core body to clamping the core body.

[0038] Fig. 9 It is a schematic diagram of the state change of Example 1 for showing the change of the matching relationship between the second triangular teeth of the limiting plate located above the core body and the first triangular teeth of the cover plate.

[0039] Fig.10 It is a schematic diagram of the state change of Example 1 for demonstrating the change of the matching relationship between the second triangular teeth of the limit plate located above the core body and the first triangular teeth of the cover plate during assembly.

[0040] Fig.11It is a partial cross-sectional view of the protective shell of Example 2.

[0041] Fig.12 It is a cross-sectional view of the protective shell of Example 3.

[0042] Fig.13 yes Fig. 9 A partial enlarged view of point D in the middle.

[0043] Fig.14 This is a schematic diagram of Example 3 for showing the state change of the elastic rod from the heating deformation to the recovery deformation state.

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

[0045] Fig.16 It is a partial cross-sectional view of Example 4, which is used to reflect the cooperation between the first guide block and the first arc strip.

[0046] Fig.17 It is a partial cross-sectional view of Example 4, which is used to reflect the cooperation between the second guide block and the second arc strip.

[0047] Explanation of reference numerals: 10, core; 101, first arc strip; 1011, first guide surface; 1012, first mating surface; 102, second arc strip; 1021, second guide surface; 1022, second mating surface; 11, cover plate; 111, second outer ring tube; 1111, second bayonet; 112, through hole; 12, bottom plate; 121, inner ring tube; 1211, third triangular tooth; 122, first outer ring tube; 1221, first bayonet; 13, middle plate; 131, reinforcing tube; 132, reinforcing Reinforcement ribs; 135, first triangular teeth; 14, upper plate; 15, lower plate; 151, inner diameter tube; 152, middle diameter tube; 153, outer diameter tube; 20, compensation reactor; 21, limit plate; 211, second triangular teeth; 212, first guide block; 213, second guide block; 22, limit sleeve; 221, fourth triangular teeth; 23, rubber rope; 251, vertical plate; 252, pressure plate; 253, plug rod; 261, bolt; 262, groove; 263, protrusion; 27, elastic rod; 271, slide groove. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the attached Figure 1-Figure 17 Shown in.

[0049] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0050] Example 1

[0051] Embodiment 1 discloses a transformer core, such as Figure 1 , Figure 2 , Figure 3 As shown, the transformer core includes a protective shell, a core body 10 and a limit assembly. The protective shell includes an annular cover plate 11, an annular bottom plate 12 and an annular middle plate 13.

[0052] like Figure 3 , Figure 4 As shown, the bottom plate 12 is coaxially arranged with the middle plate 13, the bottom plate 12 is located on one side of the axial direction of the middle plate 13, and the upper surface of the bottom plate 12 is attached to the lower surface of the middle plate 13, and an annular reinforcing tube 131 is integrally formed in the middle part of the middle plate 13, and the reinforcing tube 131 is coaxially arranged with the middle plate 13, an annular inner ring tube 121 is integrally formed at the inner diameter of the bottom plate 12, and the inner ring tube 121 is coaxially arranged with the bottom plate 12, and an annular first outer ring tube 122 is integrally formed at the outer diameter of the bottom plate 12, and the first outer ring tube 122 is coaxially arranged with the bottom plate 12, and the axial length of the first outer ring tube 122 is equal to half of the axial length of the inner ring tube 121; and reinforcing ribs 132 are fixed between the outer circumferential surface of the reinforcing tube 131 and the surface of the middle plate 13 to strengthen the structural strength of the reinforcing tube 131, thereby reducing the occurrence of excessive deformation in the middle part caused by axial pressure on the shell.

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

[0054] like Figure 1 As shown, the first outer ring tube 122 is provided with a semicircular first bayonet 1221 , and the second outer ring tube 111 is provided with a semicircular second bayonet 1111 .

[0055] like Figure 1 , Figure 3As shown, the cover plate 11, the reinforcement tube 131, the inner ring tube 121 and the middle plate 13 together form an annular first accommodating chamber, and the cover plate 11, the reinforcement tube 131, the middle plate 13, the first outer ring tube 122 and the second outer ring tube 111 together form an annular second accommodating chamber, and the second accommodating chamber is located outside the first accommodating chamber.

[0056] like Figure 4 , Figure 5 As shown, the annular core body 10 is located in the first accommodating cavity, and the opposite surfaces of the cover plate 11 and the middle plate 13 are protrudingly constructed with a plurality of first triangular teeth 135 (the opposite surfaces of the cover plate 11 and the middle plate 13 refer to the lower surface of the cover plate 11 and the upper surface of the middle plate 13), the first triangular teeth 135 are located in the first accommodating cavity, the length direction of the first triangular teeth 135 is extended along the radial direction of the protective shell, and the first triangular teeth 135 are evenly arranged around the circumference, and the cross-sectional profile of the first triangular teeth 135 is triangular.

[0057] like Figure 4 , Figure 5 , Figure 6 As shown ( Figure 5 The direction of the arrow in the figure is the direction in which the elastic force of the elastic structure forces the limit plate 21 to move circumferentially), the limit assembly includes an elastic structure, a fixed structure, two annular limit plates 21 and a limit sleeve 22. In the present embodiment, the limit plate 21 and the limit sleeve 22 are both made of rubber. In other embodiments, the limit plate 21 and the limit sleeve 22 may be made of a thin plastic material; the limit plate 21 and the limit sleeve 22 are both coaxially arranged with the protective shell, and the two limit plates 21 are respectively located on both sides of the axial direction of the core body 10. The surface of the limit plate 21 is protrudingly structured with a plurality of second triangular teeth 211 evenly arranged circumferentially, and the length direction of the second triangular teeth 211 is extended 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 fits with the inclined surface of the first triangular teeth 135.

[0058] like Figure 4 , Figure 5 , Figure 6 As shown ( Figure 6 The direction of the arrow in is the rotation direction of the inner ring tube 121), the limiting sleeve 22 is coaxially arranged with the inner ring tube 121, the limiting sleeve 22 is sleeved on the outer side of the inner ring tube 121, the inner circumferential surface of the limiting sleeve 22 is protruded with a plurality of circumferentially evenly arranged fourth triangular teeth 221, the length direction of the fourth triangular teeth 221 is extended 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 tube 121 is protruded with a plurality of circumferentially evenly arranged third triangular teeth 1211, the length direction of the third triangular teeth 1211 is extended along the axial direction of the inner ring tube 121, and the cross-sectional profile of the third triangular teeth 1211 is triangular, and the inclined surface of the fourth triangular tooth 221 is in contact with the inclined surface of the third triangular tooth 1211.

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

[0060] like Figure 4 As shown, the fixing structure includes a vertical plate 251 , pressure plates 252 are fixed to both ends of the vertical plate 251 , and an insertion rod 253 is fixed to the middle of the vertical plate 251 .

[0061] When installing the core 10, first place the core 10, the limiting plate 21, the rubber rope 23 and the limiting sleeve 22 on the middle plate 13. Figure 7 The two limiting plates 21 are respectively located on the upper and lower sides of the core body 10, and the limiting sleeve 22 is located on the inner side of the core body 10. Then, the cover plate 11 is fixed to the reinforcing cylinder 131. The fixing form can be bonding or welding, that is, the cover plate 11, the reinforcing cylinder 131 and the middle plate 13 are relatively fixed. At this time, the matching relationship between the first triangular tooth 135 and the second triangular tooth 211 is referenced Figure 8 and Fig. 9 In the first state diagram, the second triangular teeth 211 of the two limit plates 21 are clearance-matched with the two groups of first triangular teeth 135 at the same time. At this time, there is no direct contact between the limit plate 21 above the core body 10 and the cover plate 11, and the axial distance between the limit plate 21 below the core body 10 and the middle plate 13 is small. It can be concluded that the core body 10 is not subjected to the axial pressure of the limit plate 21, the core body 10 is in a loose state, and the rubber rope 23 is in a relaxed state (no tension is generated).

[0062] Then the bottom plate 12 is matched with the middle plate 13. Specifically, the upper surface of the bottom plate 12 fits the lower surface of the middle plate 13, the inner ring tube 121 of the bottom plate 12 is located on the inner side of the limiting sleeve 22, and the third triangular tooth 1211 of the inner ring tube 121 is located in the gap of the fourth triangular tooth 221 of the limiting sleeve 22. At this time, the first bayonet 1221 and the second bayonet 1111 are misaligned.

[0063] Then, the cover plate 11 and the middle plate 13 are kept stationary. The operator can hold the cover plate 11 and the second outer ring tube 111 with one hand. The cover plate 11 is stationary, and the middle plate 13 is fixedly connected to the cover plate 11, so the middle plate 13 is stationary. The operator moves the bottom plate 12 with the other hand, and drives the inner ring tube 121 and the first outer ring tube 122 to rotate relative to the middle plate 13 by a certain angle (see Figure 6The inner ring tube 121 first drives the limiting sleeve 22 to rotate circumferentially by a certain angle (because the third triangular tooth 1211 of the inner ring tube 121 is located in the gap of the fourth triangular tooth 221 of the limiting sleeve 22, the third triangular tooth 1211 will push the fourth triangular tooth 221 and the limiting sleeve 22 to move when the third triangular tooth 1211 moves). Figure 6 The arrow direction is the moving direction of the inner ring tube 121), the limiting sleeve 22 will stretch the rubber rope 23 when it moves, and the limiting sleeve 22 also drives 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 matching relationship between the first triangular tooth 135 and the second triangular tooth 211 is changed from Figure 8 and Fig. 9 The first state diagram in the figure becomes the second state diagram, Fig. 9 The solid arrow in the figure is the moving direction of the limit plate 21, and since the middle plate 13 and the cover plate 11 are stationary, the first triangular teeth 135 remain stationary. Fig. 9 The second triangular tooth 211 in the middle moves downward under the guidance of the inclined surface of the first triangular tooth 135, that is, the limit plate 21 located above the core body 10 moves downward, and the limit plate 21 located below the core body 10 moves upward, and the two limit plates 21 clamp the core body 10 together (at this time, the inclined surface of the second triangular tooth 211 is only partially in contact with the inclined surface of the first triangular tooth 135, which is called an incompletely meshed state), that is, the limit plate 21 and the core body 10 are fixed relative to the middle plate 13.

[0064] Finally, the first outer ring tube 122 and the second outer ring tube 111 are fixed by a fixing structure. Specifically, the insert rod 253 passes through the circular hole formed by the first bayonet 1221 and the second bayonet 1111 at the same time to limit the circumferential position of the shell, 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, that is, the elastic pressure of the pressure plate 252 is used to limit the axial position of the shell, thereby ensuring the installation stability of the shell.

[0065] Secondly, if Fig.10 As shown, since the inclined surface of the second triangular tooth 211 is only partially in contact with the inclined surface of the first triangular tooth 135, the second triangular tooth 211 is not fully engaged with the first triangular tooth 135 (corresponding to Fig.10 The first state diagram in FIG. 1 is shown in FIG. 2 ), so that the core 10 and the limit plate 21 have a certain circumferential movement margin. When the shell is subjected to axial assembly pressure ( Fig.10The hollow arrow direction in the figure is the assembly pressure direction), the cover plate 11, the bottom plate 12 and the middle plate 13 have a tendency to axially compress and deform. It can be understood that the first triangular teeth 135 of the cover plate 11 and the middle plate 13 are axially close to each other. Therefore, the inclined surface of the first triangular tooth 135 is pressed against the inclined surface of the second triangular tooth 211, and the first triangular tooth 135 will drive the two limit plates 21 and the core body 10 to rotate circumferentially by a certain angle (the rotation direction is Fig.10 In the direction of the solid arrow in the middle), at this time, the first triangular tooth 135 and the second triangular tooth 211 are fully engaged (corresponding to Fig.10 As shown in the second state schematic diagram in FIG, there is no axial gap between the second triangular tooth 211 and the first triangular tooth 135, and the rubber rope 23 is further elastically stretched, and the rubber rope will buffer the assembly pressure. Since there is a large friction force between the second triangular tooth 211 and the first triangular tooth 135, friction generates heat during the relative reciprocating sliding of the second triangular tooth 211 and the first triangular tooth 135, and the impact kinetic energy is converted into heat energy, thereby playing a buffering and shock absorbing role, thereby reducing the pressure on the core 10.

[0066] Furthermore, in order to improve the integration, the following arrangement may be made: a compensating inductor 20 is fixed in the second accommodating cavity, and a through hole 112 may be provided in the cover plate 11 for allowing the lead of the compensating inductor 20 to pass through, and the lead may be connected to the electromagnetic wire wound around the iron core, which is more convenient.

[0067] This embodiment also discloses a mutual inductor coil, comprising the above-mentioned mutual inductor core and an electromagnetic wire wound around the mutual inductor core.

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

[0069] Example 2

[0070] The difference between Example 2 and Example 1 is that Fig.11 As shown, the fixing structure includes a bolt 261 , the screw head of the bolt 261 has a circular groove 262 , and the outer circumferential surfaces of the first outer cylinder 122 and the second outer cylinder 111 are both fixed with semi-annular protrusions 263 .

[0071] When the core body 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 semicircular protrusions 263 are combined to form an annular block, and the bolt 261 passes through the circular hole formed by the first bayonet 1221 and the second bayonet 1111 at the same time, so that the bolt 261 is threadedly connected with the reinforcement tube 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 annular block, thereby completing the axial and circumferential limitation of the shell.

[0072] Example 3

[0073] The difference between Example 3 and Example 1 is that Fig.12 , Fig.13 As shown, 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 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, the upper plate 14, the middle diameter cylinder 152 and the inner diameter cylinder 151 are surrounded to form a first accommodating cavity, that is, two groups 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, the upper plate 14, the middle diameter cylinder 152 and the outer diameter cylinder 153 are surrounded to form a second accommodating cavity. And when the upper plate 14 is covered and fixed, the upper plate 14 can be fixedly connected with the inner diameter cylinder 151, the middle diameter cylinder 152 or the outer diameter cylinder 153 by welding or bonding.

[0074] The two groups 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 is two groups of elastic rods 27, the elastic rods 27 are memory alloys, and the deformation temperature of the elastic rods 27 can be any temperature value between 40°C and 70°C. In this embodiment, the deformation temperature of the elastic rods 27 is 65°C. A single group of elastic rods 27 includes multiple elastic rods 27 and are evenly arranged around the circumference of the protective shell. The two groups of elastic rods 27 are both inclined and in opposite directions, and the two groups of elastic rods 27 are symmetrically arranged about the axis of the protective shell.

[0076] An axially extending slide groove 271 is provided at the inner diameter of the two limit plates 21. One end of the two groups of elastic rods 27 is fixedly connected to the inner diameter tube 151. The diameter of the elastic rod 27 is equal to the groove width of the slide groove 271. The other ends of the two groups of elastic rods 27 are respectively extended into the slide grooves 271 of the two limit plates 21 and slideably cooperate with the slide grooves 271, that is, the limit plates 21 are allowed to slide axially relative to the elastic rods 27.

[0077] Before the current transformer coil is assembled to the current transformer, the housing is heated. When the temperature of the elastic rod 27 is at the deformation temperature, the elastic rod 27 deforms along the circumferential direction of the housing. The deformation force abuts against the groove wall of the slide groove 271, thereby driving the limit plate 21 to rotate circumferentially (the rotation direction is referenced to Fig.14 In the solid arrow direction of the first state schematic diagram, the second triangular tooth 211 is loosely matched with the first triangular tooth 135. In this state, the two limit plates 21 have no direct contact with the upper plate 14 and the lower plate 15 respectively, so that the core 10 is in a non-clamped state. Therefore, when the assembly pressure in the axial direction is applied to the current transformer coil, the assembly pressure will not be directly transmitted to the core 10, thereby avoiding the core 10 from being damaged by pressure.

[0078] After the protective shell is assembled and used, the protective shell is not heated. At this time, the protective shell is below the deformation temperature, and the elastic rod 27 recovers its deformation. The elastic rod 27 drives the limit plate 21 to rotate circumferentially and reset (the rotation direction is referenced to Fig.14 The second state schematic diagram is in the direction of the solid arrow), since the upper plate 14 and the lower plate 15 are assembled and fixed, the first triangular tooth 135 remains stationary, and therefore the second triangular tooth 211 of the limit plate 21 rotates relative to the first triangular tooth 135 of the upper plate 14 and the lower plate 15. During this process, the second triangular tooth 211 of the limit plate 21 located above the core body 10 moves downward under the guidance of the inclined surface of the first triangular tooth 135, that is, the limit plate 21 located above the core body 10 moves downward, while the limit plate 21 located below the core body 10 moves upward, and the two limit plates 21 jointly clamp the core body 10 (at this time, the inclined surface of the second triangular tooth 211 is only partially in contact with the inclined surface of the first triangular tooth 135, which is called an incompletely meshed state), that is, the limit plate 21 and the core body 10 are fixed relative to the middle plate 13. After clamping the core body 10, the elastic rod 27 is subjected to resistance, the elastic rod 27 stops deforming, and the limit plate 21 stops rotating.

[0079] Example 4

[0080] The difference between Example 4 and Example 3 is that Fig.15 As shown, the core body 10 includes a plurality of first arc-shaped strips 101 and a plurality of second arc-shaped strips 102, the first arc-shaped strips 101 and the second arc-shaped strips 102 are arranged alternately in a circle, the two end surfaces of the first arc-shaped strip 101 are set as first mating surfaces 1012, the two end surfaces of the second arc-shaped strip 102 are set as second mating surfaces 1022, and the limiting assembly is used to fix the core body 10 while making the first mating surfaces 1012 and the second mating surfaces 1022 fit together to ensure the splicing stability of the core body 10.

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

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

[0083] A first guide block 212 corresponding to the first arc strip 101 is fixed at the outer diameter of the limiting plate 21, and a second guide block 213 corresponding to the second arc 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 limit plates 21, and the two limit plates 21 are forced to approach axially through the cooperation of the inclined surface of the first triangular tooth 135 and the inclined surface of the second triangular tooth 211 (there is an axial gap between the limit plate 21 and the core body 10, that is, there is no direct contact between the limit plate 21 and the core body 10, only the first guide block 212 and the first guide surface 1011 are kept in contact, and the second guide block 213 and the second guide surface 1021 are kept in contact), and in this process, the first arc strip 101 is forced to move radially inward through the cooperation of the first guide block 212 and the first guide surface 1011 (the moving direction of the first arc strip 101 is shown in FIG. Fig.15 The second guide block 213 cooperates with the second guide surface 1021 to force the second arc strip 102 to move radially outward (the moving direction of the second arc strip 102 is shown in FIG. Fig.15 ), so that the first mating surface 1012 and the second mating surface 1022 are more closely fitted, thereby reducing the excessive increase in magnetic resistance due to an excessively large fracture gap, that is, the increase in magnetic resistance is small, which not only expands the dynamic measurement range of the current transformer, but also reduces the change in the measurement accuracy of the current transformer.

[0085] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A transformer core, characterized in that: The invention comprises a protective shell, a core body (10) and a limiting assembly, wherein the protective shell has an annular first accommodating cavity, the core body (10) is located in the first accommodating cavity, the inner top wall and the inner bottom wall of the first accommodating cavity are both protrudingly constructed with a plurality of first triangular teeth (135) evenly arranged in a circumference, the length direction of the first triangular teeth (135) is extended along the radial direction of the protective shell, and the cross-sectional profile of the first triangular teeth (135) is triangular, and the limiting assembly comprises an elastic structure and two annular limiting plates (21), the two limiting plates (21) are respectively located on both sides of the axial direction of the core body (10), and the surface of the limiting plates (21) is protrudingly constructed with a plurality of circular teeth. The second triangular teeth (211) are evenly arranged around the shell, the length direction of the second triangular teeth (211) is extended along the radial direction of the shell, and 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 relative to the shell in the circumferential direction, so that the inclined surface of the second triangular teeth (211) is in contact with the inclined surface of the first triangular teeth (135), and the second triangular teeth (211) drive the limiting plates (21) to move axially in a direction close to the core body (10) under the guidance of the inclined surface of the first triangular teeth (135). When the two limiting plates (21) are in contact with the core body (10), the second triangular teeth (211) The inclined surface of the triangular tooth (211) is partially fitted with the inclined surface of the first triangular tooth (135), so that an axial gap exists between the tooth top of the second triangular tooth (211) and the tooth root of the first triangular tooth (135); the protective shell comprises an annular cover plate (11), an annular bottom plate (12) and an annular middle plate (13); the surface of the bottom plate (12) is fitted with the middle plate (13); an annular reinforcing cylinder (131) is integrally formed in the middle of the middle plate (13); an annular inner ring cylinder (121) is integrally formed at the inner diameter of the bottom plate (12); and an annular A first outer ring tube (122), the cover plate (11) is fixedly connected to the reinforcing tube (131), and a second annular outer ring tube (111) is integrally formed at the outer diameter of the cover plate (11); the cover plate (11), the reinforcing tube (131), the inner ring tube (121) and the middle plate (13) together form the first accommodating cavity, and the surface of the cover plate (11) and the surface of the middle plate (13) are respectively the inner top wall and the inner bottom wall of the first accommodating cavity; the first outer ring tube (122) is provided with a first bayonet (1221), and the second outer ring tube (111) is provided with a second bayonet (1111);The limiting assembly further comprises a fixing structure and a limiting sleeve (22), the limiting sleeve (22) and the limiting plate (21) are both made of rubber, the limiting sleeve (22) is coaxially arranged with the inner ring tube (121), the outer circumferential surface of the inner ring tube (121) is protrudingly structured with a plurality of third triangular teeth (1211) evenly arranged in a circumference, the inner circumferential surface of the limiting sleeve (22) is protrudingly structured with a plurality of fourth triangular teeth (221) evenly arranged in a circumference, the inclined surface of the fourth triangular teeth (221) is in contact with the third triangular teeth (1211), and the inner circumferential surface of the limiting sleeve (22) is protrudingly structured with the inclined surface of the fourth triangular teeth (221). ) is fitted with the inclined surface of the core body (10), the elastic structure is a rubber rope (23), and the two ends of the rubber rope (23) are respectively connected to the limiting plate (21) and the limiting sleeve (22); the outer circumference of the limiting sleeve (22) is fitted with the inner circumference of the core body (10), and there is a gap between the outer circumference of the core body (10) and the inner circumference of the reinforcing tube (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 tube (122) and the second outer ring tube (111). ; 2. The transformer core according to claim 1, characterized in that: The fixing structure comprises a vertical plate (251), pressure plates (252) are fixed at both ends of the vertical plate (251), an insertion rod (253) is fixed in the middle of the vertical plate (251), the insertion 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 screw head of the bolt (261) has a groove (262), and the outer peripheral surfaces of the first outer ring tube (122) and the second outer ring tube (111) are 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, and the bolt (261) is threadedly connected to the reinforcing tube (131), and the groove (262) cooperates with the two protrusions (263) at the same time.

4. A transformer core, characterized in that: The invention comprises a protective shell, a core body (10) and a limiting assembly, wherein the protective shell has an annular first accommodating cavity, the core body (10) is located in the first accommodating cavity, the inner top wall and the inner bottom wall of the first accommodating cavity are both protrudingly constructed with a plurality of first triangular teeth (135) evenly arranged in a circumference, the length direction of the first triangular teeth (135) is extended along the radial direction of the protective shell, and the cross-sectional profile of the first triangular teeth (135) is triangular, and the limiting assembly comprises an elastic structure and two annular limiting plates (21), the two limiting plates (21) are respectively located on both axial sides of the core body (10), the surface of the limiting plates (21) is protrudingly constructed with a plurality of second triangular teeth (211) evenly arranged in a circumference, and the length direction of the second triangular teeth (211) is The second triangular tooth (211) is radially extended along the protective shell, and the cross-sectional profile of the second triangular tooth (211) is triangular; the elastic force of the elastic structure is used to force the two limiting plates (21) to rotate relative to the protective shell in the circumferential direction, so that the inclined surface of the second triangular tooth (211) fits with the inclined surface of the first triangular tooth (135), and the second triangular tooth (211) drives the limiting plate (21) to move axially in the direction close to the core body (10) under the guidance of the inclined surface of the first triangular tooth (135); when the two limiting plates (21) fit on the core body (10), the inclined surface of the second triangular tooth (211) fits with the inclined surface of the first triangular tooth (135), so that there is a tooth top of the second triangular tooth (211) and a tooth root of the first triangular tooth (135). The protective shell comprises 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 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), the upper plate (14), the middle diameter cylinder (152) and the inner diameter cylinder (151) are enclosed to form the first accommodating 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 accommodating cavity; the elastic structure is two groups of elastic rods (27), the elastic rods (27) are memory alloys, and the inner diameters of the two limit plates (21) are both provided with axial The two sets of elastic rods (27) are fixedly connected to the inner diameter cylinder (151), and the other ends of the two sets of elastic rods (27) are respectively extended into the slide grooves (271) of the two limit plates (21) and slideably matched with the slide grooves (271); when the temperature of the elastic rods (27) is lower than the deformation temperature, the elastic force of the elastic rods (27) is converted into a force forcing the two limit plates (21) to approach axially through the cooperation between the second triangular teeth (211) and the first triangular teeth (135); when the temperature of the elastic rods (27) is at the deformation temperature, the deformation force of the elastic rods (27) drives the limit plates (21) to rotate circumferentially until the second triangular teeth (211) and the first triangular teeth (135) are clearance-matched.

5. The transformer core according to claim 1 or 4, characterized in that: The core body (10) comprises a plurality of first arc strips (101) and a plurality of second arc strips (102); the first arc strips (101) and the second arc strips (102) are arranged in a staggered manner in a circle; the two end surfaces of the first arc strip (101) are set as first matching surfaces (1012); the two end surfaces of the second arc strip (102) are set as second matching surfaces (1022); a first guide surface (1011) is provided at the outer diameter of the first arc strip (101); and a second guide surface (1021) is provided at the inner diameter of the second arc strip (102); a first guide block (212) which is arranged in a one-to-one correspondence with the first arc strip (101) is fixed at the outer diameter of the limiting plate (21); and the limiting plate (21) is provided with a plurality of first arc strips (101) and a plurality of second arc strips (102) are provided at the inner diameter of the second arc strip (102); 1) is fixed with a second guide block (213) arranged in one-to-one correspondence with the second arc strip (102); when the two limit plates (21) are axially close to each other, the first guide block (212) and the first guide surface (1011) are matched to force the first arc strip (101) to move radially inward; when the two limit plates (21) are axially close to each other, the second guide block (213) and the second guide surface (1021) are matched to force the second arc strip (102) to move radially outward; when the second arc strip (102) moves radially outward and the first arc strip (101) moves radially inward, the first matching surface (1012) and the second matching surface (1022) are in contact with each other.

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 accommodating cavity, the second accommodating cavity is located outside the first accommodating cavity, and a compensating reactor (20) is fixed in the second accommodating cavity.

8. A transformer coil, characterized in that: It comprises the transformer core as claimed in claim 1 or 4 and an electromagnetic wire wound around the transformer core.

9. A current transformer, characterized in that: It comprises a current transformer body and the transformer coil as claimed in claim 8.

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