Method and system for improving disturbance rejection of open-close Rogowski coil current sensor

Abstract

The invention provides a method and a system for improving the immunity of an open-close type Rogowski coil current sensor, and aims to design a compensation structure for reducing or eliminating a large error caused by a gap of the open-close type Rogowski coil current sensor. A plurality of layers of Archimedes spiral lines printed on the flexible PCB are connected with two winding ends of the Rogowski coil, and the winding directions are the same; the parameter size of the Archimedes spiral is determined according to the structure and the notch of the Rogowski coil, errors caused by the notch are greatly compensated or eliminated, the applicability is high, the influence of an external electromagnetic field on the errors of the Rogowski coil can be remarkably reduced, the opening and closing type Rogowski coil can more accurately measure a measured current signal in a complex electromagnetic environment, and the measurement accuracy is improved. And the measurement precision and reliability are improved. The method is convenient to calculate, easy to program for calculation and high in calculation precision. The whole structure of the Rogowski coil does not need to be transformed on a large scale, the manufacturing process is simple, cost is low, and engineering implementation is easy.

Description

Technical Field

[0001] This invention belongs to the field of current sensor technology, specifically relating to a method and system for improving the anti-interference capability of an open-close Rogowski coil current sensor. Background Technology

[0002] Rogowski coil current sensors, with their numerous advantages such as non-invasiveness, high bandwidth, and high accuracy, have been widely used in various fields including power systems, new energy vehicles, and industrial automation. However, the unique notch structure of the open-close Rogowski coil current sensor presents a significant problem in practical applications: it is susceptible to interference in complex electromagnetic environments. Stray magnetic fields generated by other electrical equipment operating near the Rogowski coil, or interference sources such as electromagnetic radiation in the space, can induce additional electromotive force in the Rogowski coil. This electromotive force superimposed on the signal generated by the measured current, leading to measurement deviations. Such deviations can cause errors in current measurement and may even trigger malfunctions in subsequent control systems, posing potential risks to equipment operation and safety.

[0003] The stability of the mutual inductance between the Rogowski coil current sensor and the current-carrying conductor affects the error of the current sensor. When the Rogowski coil current sensor has no notch (non-open / closed type), the mutual inductance between the Rogowski coil and the current-carrying conductor does not change with the position of the measured conductor passing through the coil, nor is it affected by the position of the external current-carrying conductor. However, the notch in the open / closed Rogowski coil current sensor easily introduces errors. Changes in the position of the measured conductor passing through the coil and the position of the external conductor will affect the measurement error of the open / closed Rogowski coil current sensor with the notch. Furthermore, the special structure of the Rogowski coil (thin and dense winding, thousands of turns) makes it difficult to calculate using electromagnetic simulation software, heavily relying on theoretical derivation and numerical calculation. The size of the anti-interference compensation structure is determined by the size of the Rogowski coil, the number of turns, and the size of the notch. Therefore, there is an urgent need for a new compensation structure and a rapid calculation design method that can effectively improve the anti-interference performance of the Rogowski coil without affecting its original advantages. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for improving the anti-interference capability of an open-type Rogowski coil current sensor, so as to improve the strong anti-interference capability of the current sensor.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a method for improving the anti-interference capability of an openable Rogowski coil current sensor, comprising the following steps: S1: Calculate the dimensions of the multilayer Archimedean spiral coil used for disturbance rejection compensation based on the structural dimensions of the open / closed Rogowski coil; the specific steps are as follows: S11: Calculate the mutual inductance between the switchable Rogowski coil and the conductor being measured; S12: Construct the spatial parameter equations of the Archimedes spiral coil located at the notch position of the open-close Rogowski coil; S13: Calculate the mutual inductance between each turn of the Rogowski coil and the conductor under test; S14: Calculate the mutual inductance between the open-close Rogowski coil with multiple layers of Archimedes spiral coil and the conductor under test, and adjust the size and number of turns of the Archimedes spiral coil to minimize the difference in mutual inductance between the conductor under test located at the notch and the center of the open-close Rogowski coil. S2: Fabricate flexible PCBs with even and odd number of turns of multi-layered Archimedes spiral coils that are consistent with the winding direction of the open-loop Rogowski coil and have the same shape as the winding skeleton, and connect them to the open-loop Rogowski coil.

[0006] According to the above scheme, the specific steps in step S11 are as follows: Establish a three-dimensional rectangular coordinate system with the geometric center of the Rogowski coil as the origin, such that the geometric center line is located at... xOy On the plane, the center of the coil notch is located at x On the axis; let The magnetic flux through the Rogowski coil is the magnetic field generated by the conductor being measured. I Calculate the mutual inductance between the switching Rogowski coil and the conductor being measured, given the current generated in the conductor being measured. M 0: .

[0007] Furthermore, in step S11, magnetic field B The angle between the normal vector of the coil section and the normal vector of the coil section, at any point on the coil section surface. P magnetic field B Projection on the normal vector of the line section for: ; set up R The radius of the geometric center line of the circular frame of the Rogowski coil is denoted as . r d is the radius of the circular tangent of the coil; z For discrete elements in the z-axis direction, l For point p to z The distance from the axis; then it lies at the angle. The first i Magnetic flux passing through each coil turn for: ; set up N This refers to the number of turns of the Rogowski coil winding. Located at the angle The first iMagnetic flux passing through each coil segment; angle The line connecting the center of the coil and the origin. x The included angle in the positive direction of the axis, when the coil distribution is uniform. The magnetic flux of the magnetic field generated by the conductor being measured through the open / closed Rogowski coil is... for: .

[0008] Furthermore, in step S11, let a, b, c, d, e, and f be the coordinates of the two ends A and B of the conductor being measured, i.e., A(a, b, c) and B(d, e, f), then: , .

[0009] Furthermore, in step S12, the specific steps are as follows: set up The polar angle is the parameter of the Archimedean curve; the Archimedean spiral coil is located at... xOz When the surface is flat, the spatial parametric equation of the Archimedes curve is: ; When the notch of the opening and closing Rogowski coil is at an angle At that time, the Archimedes spiral coil was located at... and In terms of location; Will be located x Archimedean spiral coil deflection angle of the axis Get located at The spatial parametric equation of the Archimedean spiral coil is: ; Will be located x Archimedean spiral coil deflection angle of the axis Get located at The spatial parametric equation of the Archimedean spiral coil is: ; When the conductor being measured passes perpendicularly through ( x 0, y When the coordinates are 0, 0, for ease of calculation, the wire is aligned with... z Coinciding axes are equivalent to translating the Archimedes coil by (-). x 0, - y 0, 0); then it is located at The spatial parametric equation of the Archimedean spiral coil is: .

[0010] Furthermore, in step S13, the specific steps are as follows: set up n To determine the number of turns of the Archimedes spiral, divide the Archimedes spiral into... N Divide into 1 equal parts, then the first i The angle corresponding to the center of each turn segment satisfy: ; No. i The coordinates of the beginning and end of each turn segment are: and ; z 1, z 2 are the conductors under test. z Axis coordinates, the first i The length of each coil is , No. i The distance from the center of each turn segment to the conductor being tested is D , No. i The angle between each coil segment and the conductor being measured The cosine is Then the first i The mutual inductance between the line segment and the conductor under test M i for: .

[0011] Furthermore, in step S13, No. i The length of each coil for: ; No. i Distance from the center of each coil segment to the conductor being measured D for: ; The unit vector of the conductor being measured is (0, 0, 1), and the first... i The unit vector of each line segment is: ( , No. i The angle between each coil segment and the conductor being measured cosine for: ; Then the first i The mutual inductance between the line segment and the conductor under test M i for:

[0012]

[0013] .

[0014] Furthermore, in step S14, the specific steps are as follows: Calculation located at The mutual inductance between the Archimedean spiral coil and the conductor being measured for: ; Calculation located at - The mutual inductance between the Archimedean spiral coil and the conductor being measured ; Calculate the mutual inductance between an open-close Rogowski coil with multiple Archimedean spiral coils and the conductor under test. M for: ; Adjust the size and number of turns of the multi-layer Archimedes spiral coil to minimize the difference in mutual inductance between the conductor being measured at the notch and the center of the open-close Rogowski coil.

[0015] According to the above scheme, in step S2, One end of the odd-numbered PCB winding connects to the Rogowski coil winding from the outermost layer of the helix, and the other end connects to the back winding from the geometric center of the PCB. A hole is drilled in the center of the even-numbered turns of the PCB, and one end of the winding is connected to the winding of the Rogowski coil from the outermost layer of the spiral, while the other end extends from the geometric center of the PCB. The return winding of the Rogowski coil passes through the hole in the geometric center of the PCB.

[0016] A system for improving the disturbance rejection capability of an openable Rogowski coil current sensor. The disturbance rejection calculation submodule is used to calculate the dimensions of the multilayer Archimedean spiral coil for disturbance rejection compensation based on the structural dimensions of the open-close Rogowski coil; The compensation fabrication submodule is used to fabricate flexible PCBs with even and odd number of turns of multilayer Archimedean spiral coils that are consistent with the winding direction of the open-loop Rogowski coil and have the same shape as the winding skeleton, and to connect the open-loop Rogowski coils.

[0017] The beneficial effects of this invention are as follows: 1. The present invention provides a method and system for improving the anti-interference capability of an openable Rogowski coil current sensor. A compensation structure is designed to reduce or eliminate the significant error caused by the notch in the openable Rogowski coil current sensor. Specifically, a multi-layered Archimedean spiral printed on a flexible PCB board is connected to both ends of the Rogowski coil winding, with the winding directions being the same. The size of the Archimedean spiral is determined according to the structure and notch of the Rogowski coil, significantly compensating for or eliminating the error caused by the notch, thereby achieving the function of improving the strong anti-interference capability of the current sensor.

[0018] 2. The strong anti-interference structure of this invention significantly reduces or eliminates the measurement error caused by the notch in the open-type Rogowski coil current sensor, making it highly applicable. It can significantly reduce the interference of external electromagnetic fields on the internal magnetic field distribution of the Rogowski coil, enabling the open-type Rogowski coil to more accurately measure the measured current signal in complex electromagnetic environments, thus improving measurement accuracy and reliability.

[0019] 3. The rapid parameter calculation and design method for compensation structures proposed in this invention verifies the anti-interference effect of the compensation structure through three aspects: theoretical formula derivation, programming calculation, and simulation design. It is convenient to calculate, requiring no additional calculation software such as finite element method; it is easy to program for calculation, saving design time; and it uses no empirical formulas, resulting in high calculation accuracy. It solves the problem that existing common electromagnetic simulation software cannot perform meshing parameter calculation and rapid design of finely wound sensors for high-density, fine-wire Rogowski coils, significantly improving the sensor's strong anti-interference capability and possessing broad practical application value.

[0020] 4. The strong anti-interference structure proposed in this invention only requires adding two flexible PCB boards with Archimedes spirals drawn on them at the gap of the Rogowski coil. It can significantly reduce or eliminate measurement errors without large-scale modification of the overall structure of the Rogowski coil. The manufacturing process is simple, the cost is low, and it is easy to implement in engineering.

[0021] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of an embodiment of the present invention.

[0024] Figure 2This is a schematic diagram of the structure of the opening and closing Rogowski coil according to an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of a Rogowski coil with an anti-interference structure according to an embodiment of the present invention.

[0026] Figure 4 This is an electromagnetic simulation model diagram of an embodiment of the present invention. Detailed Implementation

[0027] 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.

[0028] Example 1 See Figure 1 The specific steps of a method to improve the disturbance rejection capability of an openable Rogowski coil current sensor are as follows: S1: Based on the existing rapid calculation and design method for the structure dimensions and compensation structure of the open-close Rogowski coil with a notch, the dimensions of the multilayer Archimedean spiral coil that maximizes the anti-interference capability of the Rogowski coil are obtained; the specific steps are as follows: Establish a three-dimensional Cartesian coordinate system, with the geometric center of the coil located at the origin, and the geometric centerline of the coil located at... xOy On the plane, the center of the coil's notch is located at x On the axis, the mutual inductance between the Rogowski coil and the conductor being measured M The fast calculation method for 0 is as follows: ; In the above formula, It is the magnetic flux through the Rogowski coil of the magnetic field generated by the conductor being measured. I The current generated in the conductor being measured.

[0029] In the above formula: ; In the above formula, N The number of turns of the Rogowski coil winding. Located at the angle The first i The magnetic flux passing through each coil, angle The line connecting the center of the coil and the origin. x The included angle in the positive direction of the axis (if the coils are evenly distributed, ).

[0030] ; In the above formula, Any point on the tangent surface of the line turn P magnetic field BThe projection onto the normal vector of the line section. R Let be the radius of the geometric center line of the circular skeleton of the Rogowski coil. r The radius of the circular cross-section of the line is given.

[0031] ; In the above formula, The calculation method is as follows:

[0032] In the above formula, a, b, c, d, e, and f are the coordinates of the two ends A and B of the measured traverse, respectively, namely A(a, b, c) and B(d, e, f).

[0033] The compensation structure is located in xOz When the surface is flat, the spatial equation of the Archimedes curve on the compensation structure is: ; In the above formula, The polar angle is a parameter of the Archimedes curve. When the notch in the Rogowski coil is an angle... At that time, the compensation structures are located at respectively and In terms of location, it is situated at The spatial parameter equation of the compensation structure on can be obtained from the above equation located at... x Compensation structure on shaft get: ; Similarly located The spatial parameter equations of the compensation structure are: ; When the conductor being measured passes perpendicularly through ( x 0, y When the value is 0, 0, for ease of calculation, the wire is connected to... z When the axes coincide, this is equivalent to translating the Archimedes coil by (-). x 0, - y 0, 0). At this time, located at The spatial parameter equations of the compensation structure are as follows: ; The Archimedes spiral is divided into turns. N Divide into 1 equal parts, and divide the first part into 1 equal parts. i The angle corresponding to the center of the coil is: ; In the above formula, n This represents the number of turns of the string wound by Archimedes. i The coordinates of the first and last lines are: and Then the first i The formula for calculating the mutual inductance between a single line segment and the conductor being measured is: (3-7), ; In the above formula, z 1, z 2 are the conductors under test. z Axis coordinates For the first i The length of each coil, D For the first i Distance from the center of each turn segment to the conductor being measured: ; For the first i The angle between each coil segment and the conductor being tested The cosine of the measured traverse is (0, 0, 1), and the unit vector of the measured traverse is (0, 0, 1). i The unit vector of each small line segment is: ( ,

[0034]

[0035]

[0036] ; The method for calculating the mutual inductance between the compensation structure and the conductor under test is as follows: ; Similarly, the value located at - can be calculated. Mutual inductance between the compensation structure and the conductor under test Calculation method. Mutual inductance between a Rogowski coil with compensation and the conductor under test. M The calculation method is as follows: ; To reduce or eliminate the impact of the skeleton gap on the error, the size and number of turns of the compensation structure are continuously changed. When the difference between the mutual inductance of the tested conductor at the gap and the mutual inductance of the tested conductor at the center is minimized, the compensation structure has the optimal compensation structure size.

[0037] S2: Based on the obtained even-layer Archimedean spiral coil dimensions, fabricate an even-layer flexible PCB A with an even-layer Archimedean spiral coil that is aligned with the coil winding direction. The shape of the even-layer PCB A is consistent with the shape of the winding skeleton, and a hole is punched in the center of the PCB A. The two endpoints of the Archimedes curve of the multilayer flexible PCB A with an even number of Archimedes spiral coils are located on the outermost layer of each Archimedes winding. S3: Based on the obtained dimensions of the odd-layer Archimedean spiral coil, fabricate an odd-layer flexible PCB B with an odd-layer Archimedean spiral coil that is aligned with the coil winding direction. The shape of the odd-layer PCB B is consistent with the shape of the winding skeleton. One end of the winding of the odd-layer flexible PCB B is located at the outermost layer of the spiral, and the other end is located at the center of the PCB B. The two endpoints of the Archimedes curve of the multilayer flexible PCB B with an odd number of Archimedes spiral coils are located at the geometric center of the PCB and the outermost layer of the Archimedes winding, respectively. S4: Connect one end of the helical winding of the PCB B to the winding of the Rogowski coil, and connect the other end of the helical winding of the PCB B to one end of the return wire. S5: Connect one end of PCBA to the winding of the Rogowski coil, and pass the return wire of the Rogowski coil through the hole at the geometric center of PCBA.

[0038] This embodiment addresses the significant error caused by the notch in the open-type Rogowski coil current sensor by designing a compensation structure to reduce or eliminate this error. Specifically, a multi-layered Archimedean spiral printed on a flexible PCB board is connected to both ends of the Rogowski coil winding, with the winding directions being the same. The size of the Archimedean spiral is determined based on the structure and notch of the Rogowski coil, significantly compensating for or eliminating the error caused by the notch, thereby enhancing the current sensor's anti-interference capability.

[0039] Example 2 The steps in this embodiment are the same as in Embodiment 1, except that each step is applied to a specific instance. Specifically, it includes the following steps: In this embodiment of the invention, the diameter of the Rogowski coil bobbin is set to 4.5 mm, the number of turns to 55, the notch width to 18 mm, and the radius of the geometric center line of the bobbin to 64 mm. Figure 2 As shown. The installation location of the compensation structure is as follows: Figure 3 As shown, the method proposed in this invention will be described.

[0040] Substituting the dimensions of the Rogowski coil and the coordinates of the position of the fluid passing through the coil into the following formula, we obtain the mutual inductance between the conductor being measured and the Rogowski coil with compensation structure: ; By continuously changing the number of turns and parameters of Archimedes in the compensation structure, the mutual inductance of the measured fluid passing through the center of the coil and the wire being close to the coil notch are calculated respectively. When the error between the two is minimized, the modification of the compensation structure is stopped. Based on the optimal compensation structure, a multi-layer flexible PCB board printed with Archimedes is fabricated and connected to both ends of the notch of the Rogowski coil.

[0041] Table 1 shows the mutual inductance values ​​with and without interference suppression structures when the measured conductor is continuously varied in position inside the Rogowski coil. For example, inside the Rogowski coil, the mutual inductance values ​​are measured at the following locations: the conductor is located at the central axis, near the inner wall (40 mm from the central axis), and near the outer wall (40 mm from the central axis). Each measurement is repeated 5 times, and the average value is taken as the final result.

[0042] Table 1 Results of Internal Mutual Inductance Values

[0043] Table 1 illustrates that the compensation structure proposed in this invention can significantly reduce errors (from 8.8% to 0.9%). To evaluate the accuracy of the proposed rapid calculation design method, comparisons are made with calculation results based on Ansys electromagnetic simulation software (simulation modeling of Rogowski coils with compensation structure, as shown in Table 1). Figure 4 The results (shown in Table 2) are compared with the MATLAB calculation results derived from the theory proposed in this invention. Error analysis is performed by selecting the data of the conductor at the center and the mutual inductance value calculated numerically. The results show that the error is less than 5%, which further verifies the correctness of the fast calculation method proposed in this invention. Moreover, the calculation time is less than 1% of that of Ansys electromagnetic simulation software.

[0044] Table 2 Data Comparison

[0045] The rapid parameter calculation and design method for compensation structures proposed in this embodiment verifies the anti-interference effect of the compensation structure through three aspects: theoretical formula derivation, programming calculation, and simulation design. The calculation is convenient and does not require the use of other calculation software such as finite element method; it is easy to program for calculation, saving design time; there are no empirical formulas in the calculation process, and the calculation accuracy is high. It solves the problem that existing common electromagnetic simulation software cannot perform meshing parameter calculation and rapid design of finely wound sensors for high-density, fine-wire Rogowski coils, significantly improving the sensor's strong anti-interference capability and having broad practical application value.

[0046] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0047] Example 3 This embodiment is used to implement the principle of the above method embodiment to construct a system for improving the anti-interference capability of an open-type Rogowski coil current sensor, including an anti-interference calculation submodule and a compensation fabrication submodule.

[0048] The disturbance rejection calculation submodule is used to calculate the dimensions of the multilayer Archimedean spiral coil for disturbance rejection compensation based on the structural dimensions of the open-close Rogowski coil; The compensation fabrication submodule is used to fabricate flexible PCBs with even and odd number of turns of multilayer Archimedean spiral coils that are consistent with the winding direction of the open-loop Rogowski coil and have the same shape as the winding skeleton, and to connect the open-loop Rogowski coils.

[0049] Each submodule is mainly used to implement the various steps of the method implementation, which will not be elaborated here.

[0050] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0051] This embodiment also includes a processor, a communication interface, a memory, and a communication bus; wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; the memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of a method for improving the anti-interference capability of an open-close Rogowski coil current sensor.

[0052] This embodiment also provides a computer-readable storage medium storing executable instructions that, when executed by a processor, enable the processor to implement a method for improving the disturbance rejection capability of an open-close Rogowski coil current sensor.

[0053] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects.

[0054] Furthermore, this application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] This application is described with reference to the flowchart of the method and computer program product according to Embodiment 1 and the block diagram of the device (system) according to Embodiment 3. It should be understood that each step or block in the flowchart or block diagram, as well as combinations of steps or blocks in the flowchart or block diagram, can be implemented by computer program instructions.

[0056] These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which are executable by the processor of the computer or other programmable data processing device, produce instructions for implementing the process. Figure 1 One or more processes or boxes Figure 1 A system for improving the immunity of an openable Rogowski coil current sensor by specifying the functions in one or more boxes.

[0057] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes or boxes Figure 1 The function specified in one or more boxes.

[0058] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes or boxes Figure 1 The steps of a method for improving the immunity of an openable Rogowski coil current sensor are specified in one or more boxes.

[0059] The above embodiments are only used to illustrate the design concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications made based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A method of increasing the immunity of an open-close Rogowski coil current sensor, characterized by: It comprises the following steps: S1: calculating the size of the multi-layer Archimedes spiral coil for anti-interference compensation according to the structural size of the split Rogowski coil; the specific steps are: S11: calculating the mutual inductance between the split Rogowski coil and the measured conductor; S12: constructing the spatial parameter equation of the Archimedes spiral coil located at the notch position of the split Rogowski coil; S13: calculating the mutual inductance between each turn segment of the split Rogowski coil and the measured conductor; S14: calculating the mutual inductance between the split Rogowski coil with the multi-layer Archimedes spiral coil and the measured conductor, and adjusting the size and number of turns of the Archimedes spiral coil to minimize the difference in mutual inductance between the measured conductor at the notch and the center of the split Rogowski coil; S2: respectively manufacturing flexible PCBs with even and odd number of turns of multi-layer Archimedes spiral coils with the same winding direction and shape as the winding skeleton of the split Rogowski coil, and connecting the split Rogowski coil.

2. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 1, wherein: In the step S11, the specific steps are: Establish a three-dimensional rectangular coordinate system with the geometric center of the Rogowski coil as the origin, such that the geometric center line is located at... xOy On the plane, the center of the coil notch is located at x On the axis; let The magnetic flux through the Rogowski coil is the magnetic field generated by the conductor being measured. I Calculate the mutual inductance between the switching Rogowski coil and the conductor being measured, given the current generated in the conductor being measured. M 0: 。 3. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 2, wherein: The step S11, is the magnetic field B The angle between the normal vector of the cross section of the turn and the magnetic field at any point on the cross section of the turn P is the magnetic field B The projection of the magnetic field on the normal vector of the cross section of the turn is: ； Let R R be the radius of the geometric center line of the circular skeleton of the open / close type Roebel coil, r r be the radius of the circular cross section of the turns; d z be the discrete unit in the coordinate z direction, l be the distance from the point p to z the axis; then the magnetic flux passing through the first turn located at the angle i is: ​ ； set up N This refers to the number of turns of the Rogowski coil winding. Located at the angle The first i Magnetic flux passing through each coil segment; angle The line connecting the center of the coil and the origin. x The included angle in the positive direction of the axis, when the coil distribution is uniform. The magnetic flux of the magnetic field generated by the conductor being measured through the open / closed Rogowski coil is... for: 。 4. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 3, wherein: In the step S11, let a, b, c, d, e, f be the coordinates of the two ends A and B of the measured conductor, i.e. A(a, b, c) and B(d, e, f), then: ， 。 5. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 3, wherein: In the step S12, the specific steps are: Let be the polar angle of the Archimedean spiral; the spatial parametric equation of the Archimedean spiral is xOz when the Archimedean spiral is located on the plane ； When the gap of the split-roebel coil is an angle , the archimedes spiral coils are located at and positions, respectively; The axial x The Archimedean spiral coil deflection angle of the shaft The axial The spatial parameter equation of the Archimedean spiral coil is ； The axial x The axial The axial The spatial parameter equation of the axial ； When the measured conductor vertically passes through (0, 0, 0) x 0, y 0, 0), in order to facilitate the calculation of the wire coincides with the axis, which is equivalent to the Archimedes coil translation (0, 0, 0) z 0, x 0, y 0, 0); the space parameter equation of the Archimedes spiral coil located on the is: 。 6. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 5, wherein: In the step S13, the specific steps are: Let n be the number of turns of the Archimedean spiral, and divide the turns of the Archimedean spiral into N equal parts, then the center of the i th turn segment corresponds to an angle satisfying: ； No. i The coordinates of the beginning and end of each turn segment are and ; z 1, z 2 are the conductors under test. z Axis coordinates, the first i The length of each coil is , No. i The distance from the center of each turn segment to the conductor being tested is D , No. i The angle between each coil segment and the conductor being measured The cosine is Then the first i The mutual inductance between the coil segment and the conductor under test M i for: 。 7. The method of increasing the noise immunity of an open-close Rogowski coil current sensor according to claim 6, wherein: In the step S13, The length of the first coil is: i :​ ； The first i Distance of the center of the turn segment to the measured conductor D is: ； The unit vector of the conductor under test is (0, 0, 1), and the unit vector of the first i turn segment is: （ ， The cosine of the angle between the segment of the loop and the conductor under test is: i cos(θ) =​​ ； Then the first i M i is:​ 。 8. The method of increasing the noise immunity of an open-close Rogowski coil current sensor of claim 6, wherein: In the step S14, the specific steps are: The calculation is located The mutual inductance of an Archimedean spiral coil with a measured conductor is given by: ； The calculation is located at the mutual inductance of an archimedes spiral coil with a measured conductor ; Calculation of mutual inductance between open-close roebel coil with multi-layer archimedes spiral coil and measured conductor M is: ； Adjust the size and number of turns of the multi-layer Archimedes spiral coil to minimize the difference in mutual inductance between the measured conductor at the notch and the center of the split Rogowski coil.

9. The method of increasing the noise immunity of an open-close Rogowski coil current sensor of claim 1, wherein: In the step S2, One end of the winding of the odd-turn PCB is connected to the winding of the Rogowski coil from the outermost layer of the spiral coil, and the other end is connected to the return winding from the geometric center of the PCB; A hole is punched in the center of the even-turn PCB, and one end of the winding is connected to the winding of the Rogowski coil from the outermost layer of the spiral coil, and the other end is stretched from the geometric center of the PCB, and the return winding of the Rogowski coil passes through the hole in the geometric center of the PCB.

10. A system for improving the anti-interference of a split Rogowski coil current sensor, characterized in that: an anti-interference calculation sub-module for calculating the size of the multi-layer Archimedes spiral coil for anti-interference compensation according to the structural size of the split Rogowski coil; a compensation manufacturing sub-module for respectively manufacturing flexible PCBs with even and odd number of turns of multi-layer Archimedes spiral coils with the same winding direction and shape as the winding skeleton of the split Rogowski coil, and connecting the split Rogowski coil.

Images