A plug-in core type roebel coil current transformer

Abstract

The application discloses a plug-in plate type Rogowski coil current transformer with a magnetic core and relates to the technical field of current transformers, which comprises a PCB, a magnetic core, a forward winding coil and a reverse winding coil, a first circular ring and a second circular ring on the PCB are embeddedly fixed to an inner side plate and an outer side plate, a group of insertion slots on the outer side of the first circular ring and the second circular ring are used for fixing a signal acquisition plate, adjacent forward winding structures in the forward winding coil are connected in a head-to-tail mode, the end point of a previous forward winding structure is used as the starting point of a next forward winding structure, adjacent reverse winding structures in the reverse winding coil are connected in a head-to-tail mode, the end point of a previous reverse winding structure is used as the starting point of a next reverse winding structure, the forward winding coil and the reverse winding coil are used for generating an induced electromotive force, and the induced electromotive force is used for detecting the current of a to-be-detected conductor. The first circular ring and the second circular ring are used for winding the winding in a space isolation mode, the stray capacitance is reduced, and the bandwidth of the current transformer is improved.

Description

Technical Field

[0001] This invention belongs to the field of current transformer technology, and specifically relates to a PCB-mounted Rogowski coil current transformer with a magnetic core. Background Technology

[0002] Pulse current measurement and calibration technology is widely used in power system lightning protection and power equipment performance testing. Its measurement accuracy directly affects the evaluation results of power equipment's lightning protection performance and is crucial to the safe and stable operation of the power system. The pulse high-current measurement device is the core of establishing a standard measurement system. The measurement device includes a pulse high-current conversion device and measuring instruments. Currently, commonly used pulse current measuring instruments include shunts and Rogowski coils.

[0003] With the widespread application of pulsed high-current testing technology in power system lightning protection and grounding, and the continuous development of pulsed high-current technology in the defense science and technology field, higher current amplitude, faster response speed, and higher measurement accuracy are now required for pulsed high-current measurement technology. Traditional Rogowski coils with magnetic cores are difficult to wind densely using manual winding processes. To eliminate interference from vertical magnetic fields, a return line is needed, but its position requires precise calculation and is not necessarily centered; furthermore, the presence of the magnetic core restricts its location. To improve the waveform of the output induced signal under high-frequency, high-current conditions, suitable resistors and other electronic components need to be added, but traditional connection methods increase parasitic capacitance and make it difficult to ensure the uniformity and symmetry of the overall structure. Due to these limitations, traditional Rogowski coils with magnetic cores cannot achieve accurate measurement of high-frequency, high-current signals. Therefore, it is urgent to solve existing problems related to current transformers, high-frequency, high-current measurement, and the uniform placement of damping resistors. Summary of the Invention

[0004] To address the shortcomings and improvement needs of existing technologies, this invention provides a plug-in Rogowski coil current transformer with a magnetic core. Its purpose is to reduce stray capacitance and thus improve the bandwidth of the current transformer by using a double-ring design with the positive and negative winding coils staggered into upper and lower layers.

[0005] To achieve the above objectives, according to one aspect of the present invention, a plug-in Rogowski coil current transformer with a magnetic core is provided, comprising: a PCB board, a magnetic core, a forward winding coil and a reverse winding coil. The PCB board includes a first ring, a second ring, an outer side plate, an inner side plate, a ground plane, and a signal acquisition board. The inner and outer diameters of the first and second rings are equal and located in different planes, with their centers on the same axis. 2N+1 sets of slots are provided on the outer sides of the first and second rings, and 2N sets of slots are provided on the inner sides of the first and second rings for embedding and fixing the inner and outer side plates. The signal acquisition board is fixed in one set of slots on the outer sides of the first and second rings. The outer side plate includes a grounding plate slot for installing a grounding plate, which is electrically connected to ground through the grounding plate slot on the signal acquisition board; The magnetic core is fixed between the bottom of the first ring and the top of the second ring by an inner side plate and an outer side plate. The forward winding coil includes N forward winding structures, with adjacent forward winding structures connected end-to-end. The end point of the previous forward winding structure is the starting point of the next forward winding structure, and so on. The reverse winding coil includes N reverse winding structures, with adjacent reverse winding structures connected end-to-end. The end point of the previous reverse winding structure is the starting point of the next reverse winding structure, and so on. The end point of the Nth forward winding structure is connected to the starting point of the first reverse winding structure. The starting point of the first forward winding structure is connected to the positive terminal of the signal acquisition board, and the end point of the Nth reverse winding structure is connected to the negative terminal of the signal acquisition board. The forward and reverse winding coils are used to generate induced electromotive force, which is used to detect the current in the conductor under test.

[0006] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects: This invention utilizes spatially isolated winding coils wound on a first and second circular ring, and designs forward and reverse winding coils to ensure that noise voltages are of the same magnitude but opposite in direction, thus canceling out the noise voltages. This solves the problem of needing to design a return line to cancel out interfering magnetic fields when using single-layer circular winding coils in existing technologies. The double-layer circular ring design, with the forward and reverse winding coils staggered into upper and lower layers, reduces stray capacitance, thereby increasing the bandwidth of the current transformer.

[0007] Furthermore, the plug-in type grounding plate allows for easier placement of damping resistors. By designing damping resistors, oscillations caused by stray capacitance are effectively suppressed, improving the transmission stability of high-frequency signals from the current transformer and thus enhancing measurement accuracy. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0009] Figure 2 This is a cross-sectional schematic diagram of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0010] Figure 3 This is an equivalent circuit diagram of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0011] Figure 4 This is a schematic diagram of the wiring of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention on a PCB board.

[0012] Figure 5 This is a schematic diagram of the port on the first ring of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0013] Figure 6 This is a schematic diagram of the port on the second ring of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0014] Figure 7 This is a schematic diagram of the outer plate, inner plate, and information acquisition board of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0015] Figure 8 This is a schematic diagram of the ground plane of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention.

[0016] In the figure, 1 is the first ring, 2 is the second ring, 3 is the outer side plate, 4 is the inner side plate, 5 is the ground plane, 6 is the signal acquisition board, 7 is the distributed resistor, 8 is the damping resistor, 9 is the inter-turn capacitor, 10 is the distributed capacitor, 11 is the single-turn winding, 12 is the outer side plate slot, 13 is the inner side plate slot, 14 is the ground plane slot, 15 is the impedance matching resistor, 16 is the signal output terminal, 17 is the damping resistor connection point, 18 is the winding connection pad, 19 is the ground plane connection point, 20 is the ground connection pad, 21 is the positive and negative winding connection point, 22 is the cross-section, 23 is the distributed winding, and 24 is the magnetic core. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0018] In this invention, the terms "first," "second," etc. (if present) in the invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0019] Example 1: This invention discloses a plug-in Rogowski coil current transformer with a magnetic core, wherein the current transformer includes: a PCB board, a magnetic core, a forward winding coil, and a reverse winding coil.

[0020] Figure 1 This is a schematic diagram of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. Figure 2 This is a cross-sectional schematic diagram of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. Figure 4 This is a schematic diagram of the winding coil routing on a PCB board for a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. Figure 5 This is a schematic diagram of the port on the first ring of the PCB board in a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. Figure 6 This is a schematic diagram of the port of the second ring on the PCB board in a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. The following will be combined with... Figure 1 , Figure 2 , Figures 4-6 Describe the structural relationships between the various components in a current transformer and the routing of the winding coils. For example... Figure 1 As shown, the PCB board includes a first ring 1, a second ring 2, an outer side plate 3, an inner side plate 4, a ground plane 5, and a signal acquisition board 6. The inner and outer diameters of the first ring 1 and the second ring 2 are equal, located on different planes, and their centers are on the same axis. 2N+1 sets of slots are set on the outer sides of the first ring 1 and the second ring 2, and 2N sets of slots are set on the inner sides of the first ring 1 and the second ring 2. The slots on the outer sides of the first ring and the second ring are used to fix 2N outer side plates and 1 signal acquisition board. In other words, slots located on the first ring 1 and the second ring 2 respectively, and slots on the same vertical axis are called a set of slots. Here, the vertical axis refers to the slots on the first ring 1 and the second ring 2 that are on the same vertical axis when the current transformer is placed horizontally. Similarly, in the 2N sets of slots set on the inner sides of the first ring and the second ring, each set of slots is on the same vertical axis and consists of two slots located on the inner sides of the first ring and the second ring respectively. A set of slots on the outer side fixes an outer side plate, and a set of slots on the inner side fixes an inner side plate. The current transformer disclosed in this invention includes 2N outer side plates, 2N inner side plates, and 1 signal acquisition board, where N is a natural number. The slots are embedded to fix the inner side plates and outer side plates, and the set of slots on the outer side of the first ring and the second ring fixes the signal acquisition board.

[0021] Furthermore, the outer side plate 3 also includes a grounding plate slot for mounting a grounding plate 5, which is electrically connected to the ground via the grounding plate slot on the signal acquisition board.

[0022] Secondly, the magnetic core 22 is fixed between the bottom of the first ring 1 and the top of the second ring 2 by the outer side plate 3 and the inner side plate 4. Here, the magnetic core fills the entire space formed by the first ring 1, the second ring 2, the outer side plate 3 and the inner side plate 4, and is not limited to a fixed size.

[0023] In one embodiment of the present invention, the winding coil is wound on the first ring 1 and the second ring 2 via 2N sets of outer and inner plates. Specifically, the coil wound on the top layer of the first ring 1 and the second ring 2 is called the forward winding coil. Here, the top layer refers to the front side of the ring when the current transformer is placed horizontally, and the back side is the bottom layer. To better understand the winding method of the winding coil in the present invention, the forward winding coil is divided into N forward winding structures. Adjacent forward winding structures are connected end to end, and the end point of the previous forward winding structure is the starting point of the next forward winding structure, and so on. Similarly, the coil wound on the first ring and the second ring 2... The coil at the bottom of the two-ring structure is called the reverse winding coil. The reverse winding coil includes N reverse winding structures. Adjacent reverse winding structures are connected end to end. The end point of the previous reverse winding structure is the starting point of the next reverse winding structure, and so on. The end point of the Nth forward winding structure is connected to the starting point of the first reverse winding structure. The starting point of the first forward winding structure is connected to the positive terminal of the signal acquisition board. The end point of the Nth reverse winding structure is connected to the negative terminal of the signal acquisition board. When the current transformer is used to measure the current of the conductor, the forward winding coil and the reverse winding coil are used to generate an induced electromotive force. The induced electromotive force is used to detect the current of the conductor under test.

[0024] like Figure 4 As shown in Figure (a), the red line represents the forward winding coil, and the blue arrow indicates the direction of the winding coil. Viewed from top to bottom, the forward winding coil is wound clockwise from top to bottom. The starting point of the forward winding coil is the contact point on the signal acquisition board 6 with the outer side of the first ring, referred to as the first positive endpoint. The winding coil traces along the outline of the first ring from the first positive endpoint. The forward winding coil trace will combine... Figure 4 (a) Figure Figure 5 Figure (a) and Figure 6 Description (a) in the text, where Figure 4 Figure (a) is a three-dimensional view. Figure 5 Figure (a) is a plan view of the top layer of the first ring. Figure 6 (a) is a plan view of the top layer of the second ring. Figure 5As shown in Figure (a), the red markings 1-5 represent the five endpoints of the forward winding structure. The first positive endpoint of the first forward winding structure is located on the signal acquisition board, which is the starting point of the forward winding. The second and fifth positive endpoints are located on the inner and outer plates of the top of the first ring, respectively, and are in the same radial direction. The third and fourth positive endpoints are located on the inner and outer plates of the top of the second ring, respectively, and are in the same radial direction. The third and second positive endpoints are in the same axial direction, and the fourth and fifth positive endpoints are in the same axial direction. There is a slot between the first and fifth positive endpoints. In each forward winding structure, the winding coil winds clockwise from the first positive endpoint along the outline of the first ring to the second positive endpoint. The winding coil winds axially from the second positive endpoint to the third positive endpoint. The winding coil winds radially from the third positive endpoint to the fourth positive endpoint. The winding coil continues to wind axially to the fifth positive endpoint. The fifth positive endpoint is the starting point of the adjacent forward winding structure, and the winding direction of the adjacent winding structure is similar.

[0025] Similarly, the reverse winding coil direction is as follows: Figure 4 As shown in Figure (b), the blue line represents the reverse winding coil, and the red arrow indicates the direction of the winding coil. Viewed from bottom to top, the reverse winding coil is wound counter-clockwise. The starting point of the reverse winding coil is the ending point of the forward winding coil. The reverse winding coil routing will combine... Figure 4 Chinese (b) map Figure 5 Figure (b) in the middle and Figure 6 Description (b) in the text, where Figure 4 Figure (b) is a three-dimensional view. Figure 5 Figure (b) is a plan view of the bottom layer of the first ring. Figure 6 (b) is a plan view of the bottom layer of the second ring. Figure 5As shown in Figure (b), blue markings 1-5 represent the five endpoints of the reverse winding structure, located at the bottom of the first and second rings respectively. The first reverse endpoint of the first reverse winding structure is connected to the fifth positive endpoint of the Nth forward winding structure, which is also the end point of the forward winding coil. The first, fourth, and fifth reverse endpoints are located on the outer plate, while the second and third reverse endpoints are located on the inner plate. The first and second reverse endpoints are in the same radial direction, the second and third reverse endpoints are in the same axial direction, and the fourth and fifth reverse endpoints are in the same axial direction. Above, a slot is spaced between the first and fifth reverse winding endpoints. In each reverse winding structure, the winding coil is wound counterclockwise, following the bottom layer of the first and second rings. The winding coil starts from the first reverse endpoint and winds counterclockwise along the outline of the first ring to the second reverse endpoint. From the second reverse endpoint, the winding coil winds axially to the third reverse endpoint. The winding coil winds along the bottom of the second ring from the third reverse endpoint to the fourth reverse endpoint. The coil continues axially to the fifth reverse endpoint, where the fifth reverse endpoint is the starting point of the adjacent reverse winding structure. The winding paths of adjacent winding structures follow the same pattern. It should be noted that... Figure 5 and Figure 6 In the diagram, 11(a) represents a forward winding coil, and 11(b) represents a reverse winding coil.

[0026] By winding the forward and reverse windings in the above manner, the values ​​of inter-turn capacitance 9 and distributed capacitance 10 are reduced, thereby effectively improving the bandwidth of the current transformer. (Reference) Figure 3 The inter-turn capacitance 9 and distributed capacitance 10 in the equivalent circuit diagram of a medium current transformer.

[0027] Furthermore, such as Figure 1-4As shown, the current transformer also includes: distributed resistor 7, damping resistor 8, inter-turn capacitance 9, distributed capacitance 10, single-turn winding 11, outer plate slot 12, inner plate slot 13, ground plane slot 14, impedance matching resistor 15, signal output terminal 16, damping resistor connection point 17, winding connection pad 18, ground plane connection point 19, ground connection pad 20, positive and negative winding connection 21, cross-section 22, distributed winding 23, and magnetic core 24. The inner plate 4, outer plate 3, and signal acquisition board 6 contact the first ring 1 and the second ring 2 respectively at the winding connection pads 18, which are used to connect the winding coils passing through the first ring, the second ring, the inner plate, and the outer plate. Furthermore, the distributed resistor 7 is divided into forward distributed resistor and reverse distributed resistor. The forward distributed resistor is used to collect the voltage between adjacent forward winding structures at the top layer of the first ring, and the reverse distributed resistor is used to collect the voltage between adjacent reverse winding structures at the bottom layer of the second ring. The voltage on each forward distributed resistor and the voltage on each reverse distributed resistor are superimposed to obtain the induced electromotive force of the conductor under test. The induced electromotive force is output from the signal output terminal 16 of the signal acquisition board 6.

[0028] It should be further explained that the signal acquisition board 6 is equipped with a BNC terminal for outputting the acquired signal; the damping resistor 8 can be distributed at the connection between the ground plane and the outer plate to improve the waveform of the measured signal; the inter-turn capacitance 9 refers to the parasitic capacitance generated between adjacent windings; the distributed capacitance 10 refers to the parasitic capacitance generated between the winding and the shell and the magnetic core; the single-turn winding 11 refers to a single-turn winding coil, and the signal on the single-turn winding is collected by the distributed resistor; the outer plate slot 12 is used to connect and fix the outer plate, the first ring and the second ring; the inner plate slot 13 is used to connect and fix the inner plate and the first ring and the second ring; the ground plane slot 14 is used to fix the ground plane; the impedance matching resistor 15 is used to maximize the power transmission of the output signal and reduce signal reflection; the signal... Output terminal 16 is connected to the BNC terminal for outputting the acquired signal; damping resistor connection point 17 is used to connect the damping resistor to the winding circuit; winding connection pad 18 is used to connect the winding lines in the first ring, the second ring, the inner plate, and the outer plate; ground plane connection point 19 is used to connect and conduct multiple sector rings that make up the ground plane; ground connection pad 20 is used to connect the ground plane to the ground potential on the signal acquisition board; positive and negative winding connection point 21 is the connection point between the positive winding coil and the negative winding coil, used to change the direction of the winding coil; section 22 shows a longitudinal cross-sectional view of the current transformer; distributed winding 23 represents an independent unit in the distributed winding; magnetic core 24 is fixed between the bottom of the first ring and the top of the second ring through the inner plate and the outer plate.

[0029] In an optional embodiment of the present invention, the ground plane 5 is annular in shape, and is fixed to the outer plate 3 and the signal acquisition board 6 via ground plane slots 14 on the outer plate 3 and signal acquisition board 6. To facilitate disassembly and installation, the ground plane 5 is composed of multiple segmented fan rings spliced ​​together to form an annulus. These fan rings can be of the same size or of different sizes.

[0030] To better understand the circuit structure corresponding to the current transformer disclosed in this invention Figure 3 An equivalent circuit diagram of a plug-in Rogowski coil current transformer with a magnetic core is shown. Figure 3 As shown, the equivalent circuit structure 23 of the winding structure is illustrated, where the winding structure includes a forward winding structure and a reverse winding structure. In the equivalent circuit diagram, the positive terminal represents the output terminal of the signal acquisition board, and the negative terminal represents the ground terminal of the forward acquisition board. The signal output terminal 16 outputs the sum of the voltages across all distributed resistors, which is used to calculate the current of the conductor to be detected.

[0031] Figure 7 This is a schematic diagram of the outer plate 3, inner plate 4, and information acquisition board 6 of a plug-in Rogowski coil current transformer with a magnetic core proposed in this invention. Figure 7 Figure (a) shows a schematic diagram of the outer side plate 3. The ground plane slot 14 in the outer side plate 3 is used to fix the ground plane 5. There is a damping resistor connection point 17 and a set of winding connection pads 18. The damping resistor connection point 17 is made of pads and is used to connect the damping resistor. The winding connection pads 18 are used to connect the winding coils passing through the first and second rings. Similarly... Figure 7 The components with the same labels in Figures (b) and (c) have the same purpose and will not be described again. The grounding connection pad 20 is connected to the ground plate 5 through the ground plate slot 14, connecting the BNC grounding terminal to the ground plate 5.

[0032] Figure 8 This is a schematic diagram of the ground plane of a cored plug-in Rogowski coil current transformer proposed in this invention. Multiple damping resistors 8 are evenly distributed on the ground plane 5. The damping resistors 8 are connected between the pads of the outer plate slot and the ground of the ground plane, used to suppress high-frequency oscillations of the current transformer. The pads of the outer plate slot are connected to the winding coil. One end of the damping resistor 8 is connected to the damping resistor connection point 17 on the outer plate 3, and the other end is connected to the grounding wire on the ground plane. The grounding connection pad 20 is connected to the BNC grounding terminal pad on the signal acquisition board 6, i.e., the ground plane 5 is connected to the BNC grounding terminal. Multiple ground plane connection points 19 are provided on the ground plane 5. The number of ground plane connection points 19 is related to the number of sector rings into which the ground plane 5 is divided. The ground plane connection points 19 are used to connect and conduct multiple sector rings.

[0033] In summary, the winding coils are wound on spatially isolated first and second circular rings, and the design of forward and reverse winding coils ensures that the noise voltages are of the same magnitude but opposite in direction, thus canceling out the noise voltages. This solves the problem of needing to design a return line to cancel out the interfering magnetic field when using single-layer circular winding coils in existing technologies. Furthermore, the double-layer circular ring design, with the forward and reverse winding coils staggered into upper and lower layers, reduces stray capacitance, thereby increasing the bandwidth of the current transformer. In addition, the plug-in type ground plane allows for easier placement of damping resistors. By designing damping resistors, oscillations caused by stray capacitance are effectively suppressed, improving the transmission stability of high-frequency signals from the current transformer and thus improving measurement accuracy.

[0034] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A plug-in type Rogowski coil current transformer with a magnetic core, characterized in that, include: PCB board, magnetic core, forward winding coil and reverse winding coil, The PCB board includes a first ring, a second ring, an outer side plate, an inner side plate, a ground plane, and a signal acquisition board. The inner and outer diameters of the first and second rings are equal, located in different planes, and their centers are located on the same axis. 2N+1 sets of slots are provided on the outer sides of the first and second rings, and 2N sets of slots are provided on the inner sides of the first and second rings for embedding and fixing the inner and outer side plates. The signal acquisition board is fixed in one set of slots on the outer sides of the first and second rings. The outer side plate includes a grounding plate slot for installing a grounding plate, which is electrically connected to ground through the grounding plate slot on the signal acquisition board; The magnetic core is fixed between the bottom of the first ring and the top of the second ring by an inner side plate and an outer side plate. The inner side plate, outer side plate, and signal acquisition board each have winding connection pads at their contact points with the first and second rings. These winding connection pads are used to connect the winding coils that pass through the first ring, second ring, inner side plate, and outer side plate. The forward winding coil is wound on the top layer of the first and second rings, and the reverse winding coil is wound on the bottom layer of the first and second rings. Both the forward and reverse winding coils are routed between the first and second rings via the winding connection pads, through the inner and outer side plates. The forward winding coil includes N forward winding structures, with adjacent forward winding structures connected end-to-end. The end point of the previous forward winding structure is the starting point of the next forward winding structure, and so on. The reverse winding coil includes N reverse winding structures, with adjacent reverse winding structures connected end-to-end. The end point of the previous reverse winding structure is the starting point of the next reverse winding structure, and so on. The end point of the Nth forward winding structure is connected to the starting point of the first reverse winding structure. The starting point of the first forward winding structure is connected to the positive terminal of the signal acquisition board, and the end point of the Nth reverse winding structure is connected to the negative terminal of the signal acquisition board. The forward and reverse winding coils are used to generate induced electromotive force, which is used to detect the current in the conductor under test.

2. The core-embedded plug-in Rogowski coil current transformer according to claim 1, characterized in that, Each forward winding structure includes five endpoints. The first positive endpoint of the first forward winding structure is located on the signal acquisition board, serving as the starting point of the first forward winding structure. The second and fifth positive endpoints are located on the inner and outer plates of the top of the first ring, respectively, with the second and fifth positive endpoints aligned radially. The third and fourth positive endpoints are located on the inner and outer plates of the top of the second ring, respectively, with the third and fourth positive endpoints aligned radially. The third and second positive endpoints are aligned axially, as are the fourth and fifth positive endpoints. There is a slot between the first and fifth positive endpoints. In each forward winding structure, the winding coil winds clockwise from the first positive endpoint along the outline of the first ring to the second positive endpoint. The winding coil winds axially from the second positive endpoint to the third positive endpoint. The winding coil winds radially from the third positive endpoint to the fourth positive endpoint. The winding coil continues axially to the fifth positive endpoint, where the fifth positive endpoint is the starting point of the adjacent forward winding structure. The winding directions of adjacent winding structures follow the same pattern.

3. The core-embedded plug-in Rogowski coil current transformer according to claim 2, characterized in that, Each reverse winding structure includes five endpoints located at the bottom of the first and second rings. The first reverse endpoint of the first reverse winding structure is connected to the fifth positive endpoint of the Nth positive winding structure. The first, fourth, and fifth reverse endpoints are located on the outer side plate, and the second and third reverse endpoints are located on the inner side plate. The first and second reverse endpoints are in the same radial direction, the second and third reverse endpoints are in the same axial direction, and the fourth and fifth reverse endpoints are in the same axial direction. There is a slot between the first and fifth reverse endpoints. In each reverse winding structure, the winding coil is wound counterclockwise along the bottom layer of the first and second rings. The winding coil starts from the first reverse endpoint and winds counterclockwise along the outline of the first ring to the second reverse endpoint. The winding coil winds from the second reverse endpoint along the axial direction to the third reverse endpoint. The winding coil winds along the bottom of the second ring from the third reverse endpoint to the fourth reverse endpoint. The coil continues to wind along the axial direction to the fifth reverse endpoint. The fifth reverse endpoint is the starting point of the adjacent reverse winding structure, and the winding direction of the adjacent winding structure follows the same pattern.

4. The core-embedded plug-in Rogowski coil current transformer according to claim 1, characterized in that, It also includes multiple forward distributed resistors and multiple reverse distributed resistors. The forward distributed resistors are used to collect the voltage between adjacent forward winding structures at the top layer of the first ring, and the reverse distributed resistors are used to collect the voltage between adjacent reverse winding structures at the bottom layer of the second ring. The voltage on each forward distributed resistor and the voltage on each reverse distributed resistor are superimposed to obtain the induced electromotive force of the conductor under test. The induced electromotive force is output from the signal output terminal of the signal acquisition board.

5. The core-embedded plug-in Rogowski coil current transformer according to claim 1, characterized in that, The grounding plate is circular in shape, and it is fixed to the outer plate and the signal acquisition board through grounding plate slots on the outer plate and the signal acquisition board.

6. The core-embedded plug-in Rogowski coil current transformer according to claim 5, characterized in that, The grounding plate consists of multiple detachable fan rings.

7. The core-embedded plug-in Rogowski coil current transformer according to claim 6, characterized in that, Multiple damping resistors are evenly distributed on the ground plane. The damping resistors are connected between the pads of the outer plate slot and the ground of the ground plane to suppress the high-frequency oscillation of the current transformer. The pads of the outer plate slot are connected to the winding coil.

8. The core-embedded plug-in Rogowski coil current transformer according to claim 4, characterized in that, The signal acquisition board includes an impedance matching resistor connected between the output terminal of the signal acquisition board and the starting point of the forward winding coil, which is used to improve the stability of the voltage signal transmission acquired on the forward distributed resistor and the reverse distributed resistor.

9. The core-embedded plug-in Rogowski coil current transformer according to claim 1, characterized in that, The second ring, the ground plate, and the first ring are placed from bottom to top.

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