Current sensor for cable partial discharge monitoring

Abstract

The invention relates to the technical field of cable detection, and provides a current sensor for cable partial discharge monitoring, and the current sensor comprises a box body which is of a hollow structure and comprises two semi-ring device boxes with the same structure, and the two semi-ring device boxes are divided into a first semi-ring device box and a second semi-ring device box; the magnetic part is arranged in the inner cavity of the box body, and a coil is wound on the magnetic part; the diamagnetic ring is arranged on the inner wall of the inner cavity of the box body, and the diamagnetic ring is located on the periphery of the magnetic part; a plurality of hexagonal grooves are formed in the surfaces of the inner ring wall and the outer ring wall of the diamagnetic ring, the hexagonal grooves are distributed at equal intervals in an array mode, the multiple hexagonal grooves form a honeycomb topological structure in the mode that adjacent edges are connected together, and the diamagnetic ring is made of permalloy materials. When the current sensor is used, stepped attenuation, reduction and shielding are carried out on electromagnetic interference by using the diamagnetic ring, so that the current sensor can still accurately detect the partial discharge condition of the cable under continuous electromagnetic interference in a transformer area.

Description

Technical Field

[0001] The present invention relates to the technical field of cable detection, and more specifically, to a current sensor for cable partial discharge monitoring. Background Art

[0002] The current sensor for cable partial discharge monitoring works based on the principle of electromagnetic induction. When partial discharge occurs inside the cable, a high-frequency current signal will be generated. The current signal propagates along the grounding wire or shielding layer of the cable. The coil inside the sensor can sense the high-frequency current signal and convert it into a voltage signal for output. By analyzing the output voltage signal, it is judged whether there is a partial discharge phenomenon in the cable.

[0003] When performing cable partial discharge detection, if the cable is located in the transformer area, the strong electromagnetic interference generated during the operation of the transformer will seriously affect the working state of the internal coil of the current sensor, resulting in disorder of the detection signal. Although the existing method suppresses the interference through an electromagnetic shielding layer, due to the continuous electromagnetic interference, some electromagnetic waves will still penetrate the weak band of the electromagnetic shielding layer, enabling the interference signal to invade the sensor, ultimately having an adverse impact on the accuracy of the sensor for detecting cable partial discharge and its normal operation.

[0004] Therefore, this application proposes a current sensor for cable partial discharge monitoring to solve the above problems. Summary of the Invention

[0005] Technical Problem to be Solved: Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a current sensor for cable partial discharge monitoring, which solves the problem that the continuous electromagnetic interference in the transformer area penetrates the shielding layer of the current sensor, thereby affecting the accuracy of its detection of cable partial discharge.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A current sensor for cable partial discharge monitoring, comprising: a box body, which is provided with a hollow structure inside, and the box body includes two semi-ring boxes with the same structure, namely semi-ring box one and semi-ring box two; a magnetic member, which is arranged in the inner cavity of the box body, and a coil is wound around the magnetic member; an anti-magnetic ring, which is arranged on the inner wall of the inner cavity of the box body, and the anti-magnetic ring is located outside the magnetic member; a plurality of hexagonal grooves are formed on both the inner and outer ring walls of the anti-magnetic ring, and the hexagonal grooves are arranged in an array at equal intervals. The plurality of hexagonal grooves form a honeycomb topological structure in a manner that adjacent sides are connected together. The anti-magnetic ring is made of permalloy material; a plurality of grooves are also arranged at equal intervals in a circular shape on the outer ring wall of the anti-magnetic ring. A copper mesh ring and a conductive foam ring are respectively arranged on the outer layer and the inner layer of the anti-magnetic ring; an inner adhesive ring plate is arranged on the outer ring inner wall of the box body, and the inner adhesive ring plate and the box body are of an integrated structure; a plurality of uniformly distributed rigid bristles are arranged on the inner wall surface of the inner adhesive ring plate. A plurality of convex columns are installed at equal intervals in a circular shape on the inner wall of the inner adhesive ring plate, and the size of the convex columns is the same as that of the grooves. A filling colloid is filled between the inner adhesive ring plate and the anti-magnetic ring.

[0007] In a new embodiment, the same side of the semi-ring box one and the semi-ring box two is connected by a cylindrical hinge; on the other side of the semi-ring box one and the semi-ring box two, a lock block is installed respectively. A keyhole is formed in the middle of each lock block, and the two lock blocks are connected by bolts.

[0008] In a new embodiment, the shells of the semi-ring box one and the semi-ring box two are made of engineering plastics, and an insulating layer is provided on the semi-ring box one, the semi-ring box two, the cylindrical hinge, the lock block and the bolts.

[0009] In a new embodiment, inner concave meshes are also arranged at equal intervals on the copper mesh ring, and the positions of the inner concave meshes correspond one by one to the positions of the grooves on the anti-magnetic ring.

[0010] In a new embodiment, a plurality of convex cotton points are arranged at equal intervals in an array on the outer ring of the conductive foam ring. The number of the convex cotton points is the same as the number of the hexagonal grooves. The gaps between the convex cotton points and the hexagonal grooves are supplemented with a filling colloid, and the conductive foam ring is connected to the anti-magnetic ring through the convex cotton points.

[0011] In a new embodiment, semi-ring cover plates are detachably installed at the front parts of the semi-ring box one and the semi-ring box two; honeycomb magnetic ring plates are installed on the inner walls of the semi-ring cover plates through a filling colloid, and the honeycomb magnetic ring plates are made of the same material as the anti-magnetic ring; honeycomb magnetic ring plates are also installed on the rear walls of the semi-ring box one and the semi-ring box two.

[0012] In a new embodiment, the filling colloid adopts a graphene-silver nanowire composite colloid.

[0013] In a new embodiment, a signal output terminal is arranged at the rear part of the semi-ring box one.

[0014] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows: 1. By installing a multi-layer composite anti-magnetic ring structure inside the current sensor box body, hierarchical shielding of high and low frequency electromagnetic interference is achieved. The outer copper mesh ring preferentially attenuates high frequency interference, and the middle permalloy uses its high magnetic permeability characteristic to construct a closed magnetic circuit to lock the low frequency magnetic field. The hexagonal honeycomb grooves on its surface optimize the eddy current path to improve the insertion loss. The inner conductive foam ring shields the low frequency electric field through a nickel-plated carbon fiber network, thereby attenuating, reducing, and shielding electromagnetic interference in a stepped manner. Even under continuous electromagnetic interference in the transformer area, the current sensor can still accurately detect the partial discharge situation of the cable.

[0015] 2. The precise assembly of the anti-magnetic ring is realized through the built-in integrated inner bonding ring plate structure inside the box body. The convex posts are used to position the grooves of the anti-magnetic ring to complete the interlock. The rigid filaments and the nano-level filling colloid cooperate to form an interface strengthening layer, which not only realizes the structural stability but also constructs a continuous electromagnetic shielding interface, significantly improving the integrity of the outer anti-magnetic layer.

[0016] 3. Through the topological interlock design of the convex cotton points and the hexagonal grooves, the coupling of the conductive foam ring and the anti-magnetic ring is realized. The maximum contact area is used to suppress electromagnetic leakage, and at the same time, the filling colloid is combined to form a seismic reinforcement interface. Its positioning and self-calibration characteristics reduce the assembly error, ensuring the uniformity and long-term stability of the shielding effectiveness.

[0017] 4. The electromagnetic compatibility is optimized through the split magnetic shielding cavity design. The front detachable half-ring cover plate and the rear wall honeycomb magnetic ring plate adopt the same homogeneous honeycomb topology structure. When the split parts are closed, a fully enclosed shielding cavity with continuous magnetic permeability is formed to eliminate the magnetic leakage at the seams. Combined with the side wall anti-magnetic rings, a multi-directional magnetic barrier is formed to effectively suppress the radial interference such as the front-back, side, and geomagnetism of the transformer. The filling colloid simultaneously realizes the structural sealing and electromagnetic protection. After disassembly and assembly, injecting glue can restore the shielding integrity. Brief Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the split structure of the box body of the present invention.

[0019] Figure 2 It is a schematic diagram of the position structure of the signal output end of the present invention.

[0020] Figure 3 It is a schematic diagram of the connection state of the anti-magnetic ring and the inner bonding ring plate of the present invention.

[0021] Figure 4 It is a schematic diagram of the structure of the inner bonding ring plate of the present invention.

[0022] Figure 5 It is a schematic diagram of the position structure of the rigid filaments of the present invention.

[0023] Figure 6 It is a schematic diagram of the groove distribution structure of the anti-magnetic ring of the present invention.

[0024] Figure 7 This is a schematic diagram of the position structure of the conductive foam ring of the present invention.

[0025] Figure 8 This is a schematic diagram of the distribution structure of the hexagonal grooves of the present invention.

[0026] Figure 9 This is a schematic diagram of the hexagonal groove structure of the present invention.

[0027] Figure 10 This is a schematic diagram of the copper mesh ring structure of the present invention.

[0028] Figure 11 This is a schematic diagram of the conductive foam ring structure of the present invention.

[0029] Figure 12 This is a schematic diagram of the honeycomb magnetic ring plate structure of the present invention.

[0030] In the figure, the reference numerals are: 1, box body; 101, half-ring device box one; 102, half-ring device box two; 103, cylindrical hinge; 104, lock block; 2, magnetic part; 3, anti-magnetic ring; 4, hexagonal groove; 5, groove; 6, copper mesh ring; 61, concave mesh; 7, conductive foam ring; 71, convex cotton point; 8, inner adhesive ring plate; 9, rigid hair; 10, convex column; 11, filling colloid; 12, half-ring cover plate; 13, honeycomb magnetic ring plate; 14, signal output end. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] The embodiment of the present application provides a current sensor for cable partial discharge monitoring, which solves the problem that the continuous electromagnetic interference in the transformer area penetrates the shielding layer of the current sensor, thereby affecting the accuracy of detecting the partial discharge of the cable. When in use, the anti-magnetic ring is used to attenuate, eliminate and shield the electromagnetic interference in a stepped manner, so that the current sensor can still accurately detect the partial discharge situation of the cable under the continuous electromagnetic interference in the transformer area.

[0033] The technical solution in the embodiment of the present application is to solve the above technical problem, and the general idea is as follows.

[0034] Embodiment 1 Please refer to Figures 1-12, a current sensor for cable partial discharge monitoring, comprising: a box body 1, which is provided with a hollow structure inside, and the box body 1 includes two semi-ring boxes with the same structure, namely a semi-ring box one 101 and a semi-ring box two 102; a magnetic member 2, which is arranged in the inner cavity of the box body 1, and a coil is wound around the magnetic member 2; an anti-magnetic ring 3, which is arranged on the inner wall of the inner cavity of the box body 1, and the anti-magnetic ring 3 is located outside the magnetic member 2; a plurality of hexagonal grooves 4 are formed on both the inner and outer ring walls of the anti-magnetic ring 3, and the hexagonal grooves 4 are arranged in an array at equal intervals. The plurality of hexagonal grooves 4 form a honeycomb topological structure in a way that adjacent sides are connected together. The anti-magnetic ring 3 is made of permalloy material; a plurality of grooves 5 are also arranged in an equidistant circular shape on the outer ring wall of the anti-magnetic ring 3. A copper mesh ring 6 and a conductive foam ring 7 are respectively arranged on the outer layer and the inner layer of the anti-magnetic ring 3; an inner adhesive ring plate 8 is arranged on the outer ring inner wall of the box body 1, and the inner adhesive ring plate 8 and the box body 1 are of an integrated structure; a plurality of uniformly distributed rigid filaments 9 are arranged on the inner wall surface of the inner adhesive ring plate 8. A plurality of convex columns 10 are installed on the inner wall of the inner adhesive ring plate 8 at equal intervals in a circular shape, and the sizes of the convex columns 10 are the same as those of the grooves 5. A filling colloid 11 is filled between the inner adhesive ring plate 8 and the anti-magnetic ring 3.

[0035] In this embodiment, please refer to Figures 1-12 As shown, by setting the anti-magnetic ring 3, the hexagonal grooves 4, the grooves 5, the copper mesh ring 6 and the conductive foam ring 7, an anti-magnetic ring 3 is installed inside the box body 1 of the current sensor to accurately detect the partial discharge of a cable under electromagnetic interference. First, the copper mesh ring 6 on the outer layer of the anti-magnetic ring 3 is used to preferentially attenuate the high-frequency electromagnetic interference coming from conduction or radiation. The electromagnetic interference pre-treated by the copper mesh ring 6 then enters the anti-magnetic ring 3 body made of permalloy material in the middle layer. By using its high magnetic permeability characteristic, a closed magnetic circuit is formed to limit the low-frequency magnetic field within the ring. And the honeycomb-shaped hexagonal grooves 4 on the surface of the anti-magnetic ring 3 further improve the insertion loss of electromagnetic interference through the mechanism of extending the eddy current path and multiple reflections. Finally, the conductive foam ring 7 on the inner layer of the anti-magnetic ring 3 is used to shield the low-frequency electric field through a volume conduction network (the filler is nickel-plated carbon fiber), forming a complementary high-low shielding with the high-frequency eddy current shielding of the copper mesh ring 6.

[0036] Through the inner adhesive ring plate 8, the rigid filaments 9, the convex columns 10 and the filling colloid 11, by using the inner adhesive ring plate 8 and the rigid filaments 9, first, the inner adhesive ring plate 8 and the box body 1 are of an integrated structure. The convex columns 10 of the inner adhesive ring plate 8 are used as positioning points, so that the anti-magnetic ring 3 with grooves 5 can be stably placed inside the box body 1. Then, the filling colloid 11 is filled into the gap between the anti-magnetic ring 3 and the inner adhesive ring plate 8. The rigid filaments 9 provide better connection contacts for the filling colloid 11, so that the filling colloid 11 is not easily separated from the box body 1, and an outer anti-magnetic layer is also provided for the anti-magnetic ring 3 layer. Since the filling colloid 11 is made of nanoscale materials and has the ability to penetrate into micron-scale gaps, its filling rate is over 99%, thus effectively shielding electromagnetic interference.

[0037] In summary, through the three-layer structure of the copper mesh ring 6 (high-frequency eddy current shielding), the diamagnetic ring 3 body made of permalloy (low-frequency magnetic circuit limitation), and the conductive foam ring 7 (low-frequency electric field shielding), a stepped attenuation and shielding of electromagnetic interference transmitted into the current sensor from high frequency - medium and low frequencies - topological enhancement - low frequency is achieved. Additionally, with the outer diamagnetic layer formed by filling the colloid 11, while reducing the outer connection gap, it can also effectively resist external electromagnetic interference.

[0038] Please refer to Figure 1 and Figure 2 , on the same side of the half-ring box one 101 and the half-ring box two 102 are connected by a cylindrical hinge 103; on the other side of the half-ring box one 101 and the half-ring box two 102, lock blocks 104 are installed, and lock holes are provided in the middle of the lock blocks 104. The two lock blocks 104 are connected by bolts. By setting the cylindrical hinge 103, lock blocks 104, lock holes, and bolts, through the combination of the cylindrical hinge 103 and the lock blocks 104, the half-ring box one 101 and the half-ring box two 102 are convenient to disassemble and also convenient to replace the magnetic part 2 therein.

[0039] Please refer to Figure 1 and Figure 2 , the shells of the half-ring box one 101 and the half-ring box two 102 are made of engineering plastics, and insulating layers are provided on the half-ring box one 101, half-ring box two 102, cylindrical hinge 103, lock blocks 104, and bolts. The engineering plastic material used for the shells of the half-ring box one 101 and the half-ring box two 102 itself has certain insulation properties, and the additionally provided insulating layer further enhances this property. The insulating layer can effectively isolate the current, preventing short circuits or leakage between electrical components or between components and the external environment. During use and maintenance, the contact risk between staff and these components is reduced, thereby reducing the possibility of electric shock. Moreover, engineering plastics and insulating layers usually have good corrosion resistance and can resist the erosion of various chemical substances and humid environments.

[0040] Please refer to Figure 6 and Figure 10 , the copper mesh ring 6 is also equidistantly provided with concave meshes 61, and the positions of the concave meshes 61 correspond one-to-one with the positions of the grooves 5 on the diamagnetic ring 3. Through the corresponding relationship between the concave meshes 61 and the grooves 5, the copper mesh ring 6 can be more closely attached to the surface of the diamagnetic ring 3, optimizing the contact area and shape between the copper mesh ring 6 and the diamagnetic ring 3, which can further improve the shielding ability of electromagnetic waves in a specific frequency range, and the connection between the copper mesh ring 6 and the diamagnetic ring 3 is also achieved by the filling effect of the filling colloid 11.

[0041] Please refer to Figures 7-11, a plurality of convex cotton points 71 are equidistantly distributed in the outer ring array of the conductive foam ring 7, and the number of the convex cotton points 71 is the same as that of the hexagonal grooves 4; the gaps between the convex cotton points 71 and the hexagonal grooves 4 are supplemented by filling colloids 11, and the conductive foam ring 7 is connected to the anti-magnetic ring 3 through the convex cotton points 71. Through the corresponding relationship between the convex cotton points 71 and the hexagonal grooves 4, it is ensured that the maximum contact area is achieved between the conductive foam ring 7 and the anti-magnetic ring 3, which helps to reduce the leakage of electromagnetic waves between the two, thereby improving the overall electromagnetic shielding efficiency. Moreover, the tight fit between the convex cotton points 71 and the hexagonal grooves 4, as well as the supplementation of the filling colloids 11, enhance the connection stability between the conductive foam ring 7 and the anti-magnetic ring 3. This stable connection helps to prevent the connection from loosening due to vibration or impact, thereby maintaining the continuity and reliability of the electromagnetic shielding effect. At the same time, since the number and position of the convex cotton points 71 correspond to those of the hexagonal grooves 4, the errors during the installation process can be greatly reduced, which helps to ensure the uniformity and consistency of the electromagnetic shielding effect.

[0042] Please refer to Figure 1 and Figure 12 , semi-ring boxes one 101 and semi-ring boxes two 102 are both detachably installed with semi-ring cover plates 12 at the front; honeycomb magnetic ring plates 13 are installed on the inner walls of the semi-ring cover plates 12 through filling colloids 11, and the honeycomb magnetic ring plates 13 are made of the same material as the anti-magnetic ring 3; honeycomb magnetic ring plates 13 are also installed on the rear walls of the semi-ring boxes one 101 and semi-ring boxes two 102.

[0043] By setting the front detachable semi-ring cover plates 12 and honeycomb magnetic ring plates 13 are installed on both the front and rear walls, a fully enclosed magnetic shielding cavity is formed when the sensor is split and closed, avoiding the magnetic field leakage caused by the sudden change of magnetic permeability at the joint of traditional split sensors.

[0044] The honeycomb magnetic ring plates 13 are made of the same material (Permalloy) as the anti-magnetic ring 3, and have the same honeycomb topology structure, ensuring the continuity of the magnetic circuit when split and closed, and reducing the signal distortion caused by magnetic resistance mismatch.

[0045] The honeycomb magnetic ring plates 13 on the front and rear walls and the anti-magnetic ring 3 on the side walls form a closed magnetic barrier, which is used to suppress multi-directional electromagnetic interference from the front and back, side directions of the nearby transformer, and radial direction (such as geomagnetic interference). Secondly, the filling colloid 11 has both bonding and sealing functions, and the anti-electromagnetic interference protection level can still be restored by re-injecting glue after the honeycomb magnetic ring plates 13 are disassembled.

[0046] Please refer to Figure 3 and Figure 4, the filling colloid 11 uses a graphene-silver nanowire composite colloid. The filling colloid 11 is made of a graphene-silver nanowire composite material, where the mass ratio of silver nanowires is 60%-80%, the graphene accounts for 5%-10%, and the balance is a polyurethane matrix. The filling colloid 11 forms a continuous and efficient conductive interface between the anti-magnetic ring 3 and the honeycomb magnetic ring plate 13, not only significantly reducing the electromagnetic leakage between the gaps, but also effectively improving the overall electromagnetic shielding efficiency, thereby enhancing the electromagnetic compatibility and anti-interference ability of the device.

[0047] Please refer to Figure 2 , a signal output terminal 14 is provided at the rear of the semi-ring box 101. The signal output terminal 14 can be internally provided with a standard pulse generator (not shown in the figure), which can regularly inject calibration signals to automatically correct the sensor sensitivity drift, and use the positioning signal channel of the signal output terminal 14 to send nanosecond-level pulses. Through the reflection waveform time delay analysis, the precise positioning of the partial discharge point is realized.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A current sensor for cable partial discharge monitoring, characterized in that: include: The box body (1) has a hollow structure inside, and the box body (1) includes two semi-circular boxes with the same structure, namely a semi-circular box one (101) and a semi-circular box two (102); A magnetic member (2) is arranged in the inner cavity of the box body (1), and a coil is wound around the magnetic member (2); An anti-magnetic ring (3) is arranged on the inner wall of the inner cavity of the box body (1), and the anti-magnetic ring (3) is located outside the magnetic member (2); The inner and outer ring wall surfaces of the anti-magnetic ring (3) are both provided with a plurality of hexagonal grooves (4), and the hexagonal grooves (4) are evenly distributed in an array, and the plurality of hexagonal grooves (4) are connected by adjacent edges to form a honeycomb topological structure, and the anti-magnetic ring (3) is made of Permalloy; The outer ring wall of the anti-magnetic ring (3) is also provided with a plurality of grooves (5) at equal intervals in an annular shape, and the outer layer and the inner layer of the anti-magnetic ring (3) are respectively provided with a copper mesh ring (6) and a conductive foam ring (7); An inner adhesive ring plate (8) is arranged on the inner wall of the outer ring of the box body (1), and the inner adhesive ring plate (8) and the box body (1) are an integrated structure; The inner wall surface of the inner adhesive ring plate (8) is provided with a plurality of uniformly distributed rigid hair threads (9), the inner wall of the inner adhesive ring plate (8) is provided with a plurality of convex columns (10) equidistantly annularly mounted, and the convex columns (10) are of the same size as the grooves (5), and a filling colloid (11) is filled between the inner adhesive ring plate (8) and the antimagnetic ring (3).

2. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The same side of the half ring box 1 (101) and the half ring box 2 (102) are connected via a column hinge (103); The other sides of the half ring box one (101) and the half ring box two (102) are both installed with locking blocks (104), the middle of each locking block (104) is provided with a keyhole, and the two locking blocks (104) are connected by bolts.

3. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The shells of the half ring box one (101) and the half ring box two (102) are made of engineering plastics, and an insulating layer is provided on the half ring box one (101), the half ring box two (102), the column hinge (103), the locking block (104) and the bolt.

4. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The copper mesh ring (6) is also provided with concave meshes (61) at equal intervals, and the positions of the concave meshes (61) correspond one to one with the positions of the grooves (5) on the anti-magnetic ring (3).

5. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The outer ring array of the conductive foam ring (7) has a plurality of convex foam points (71) distributed equidistantly, and the number of the convex foam points (71) is consistent with the number of the hexagonal grooves (4); The gap between the convex cotton point (71) and the hexagonal groove (4) is supplemented by filling the colloid (11), and the conductive foam ring (7) is connected to the antimagnetic ring (3) through the convex cotton point (71).

6. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: A semi-ring cover plate (12) is detachably mounted on the front of the semi-ring box one (101) and the semi-ring box two (102); The inner wall of the semi-ring cover plate (12) is provided with a honeycomb magnetic ring plate (13) by filling the colloid (11), and the honeycomb magnetic ring plate (13) is made of the same material as the anti-magnetic ring (3); The rear walls of the half ring box one (101) and the half ring box two (102) are also installed with honeycomb magnetic ring plates (13).

7. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The filling colloid (11) is a graphene-silver nanowire composite colloid.

8. The current sensor for cable partial discharge monitoring according to claim 1, characterized in that: The rear portion of the half ring box (101) is provided with a signal output terminal (14).

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