Device current distribution detection method and apparatus based on double-layer rogowski coil

Abstract

The application relates to the technical field of power electronic devices, and discloses a device current distribution detection method and device based on a double-layer Rogowski coil, wherein the method comprises the following steps: acquiring a first mutual inductance measurement value and a first mutual inductance calculation value of a segmented sub-coil corresponding test current, and determining a correction parameter; determining a second mutual inductance calculation value of each segmented sub-coil, and correcting the second mutual inductance calculation value according to the correction parameter; acquiring a first output voltage of each segmented sub-coil, and determining a second mutual inductance measurement value of each segmented sub-coil; determining a three-dimensional current distribution point of a device to be measured, and inversely solving a current distribution value of the three-dimensional current distribution point. Through the matrix layout of the double-layer Rogowski coil, in combination with multi-dimensional mutual inductance data and a regularization inversion algorithm, the application not only improves the spatial coverage of the periphery of the device to be measured, reduces a detection blind area, but also can significantly improve the detection accuracy and reliability of the internal current distribution of a crimping type device.

Description

Technical Field

[0001] This application relates to the field of power electronic device technology, and in particular to a method and apparatus for detecting device current distribution based on a double-layer Rogowski coil. Background Technology

[0002] Press-pack devices (PP devices) are widely used in high-voltage direct current transmission systems due to their advantages such as high current capacity and double-sided heat dissipation. However, due to factors such as uneven pressure and device aging, uneven current distribution can easily occur in the parallel chips inside press-pack devices, leading to localized overheating or even performance failure.

[0003] In related technologies, there are two main detection methods for the internal current distribution of crimped devices: invasive and non-invasive. Invasive detection methods require destroying the original structure of the crimped device. In contrast, non-invasive detection methods can be performed without damaging the device package. However, the coverage of non-invasive detection devices for crimped devices is limited, resulting in certain detection blind spots, and the internal current distribution of the device cannot be accurately assessed. Summary of the Invention

[0004] This application provides a device current distribution detection method and apparatus based on double-layer Rogowski coils. By using a matrix layout of double-layer Rogowski coils, combined with multi-dimensional mutual inductance data and a regularized inversion algorithm, it achieves multi-dimensional analysis and quantitative processing of current density distribution, dynamic change trends, and other detection results. This not only improves the spatial coverage of the device under test and reduces the detection blind zone, but also significantly improves the detection accuracy and reliability of the internal current distribution of press-fit devices.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a method for detecting device current distribution based on a double-layer Rogowski coil, wherein the double-layer Rogowski coil is sleeved around the device under test, and the double-layer Rogowski coil includes several segmented sub-coils; the method includes: A test current is input to the device under test, and the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to the test current of each segmented sub-coil are obtained. The correction parameters of each segmented sub-coil are determined based on the first mutual inductance measurement value and the first mutual inductance calculation value. When the device under test is powered on, the total current flowing through the device under test is obtained, and the second mutual inductance calculation value corresponding to different current-carrying points on the device under test for each segmented sub-coil is determined based on the total current. The second mutual inductance calculation value is then corrected based on the correction parameter. Obtain the first output voltage of each segmented sub-coil, and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage; The three-dimensional current distribution points of the device under test are determined based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value. The current distribution values ​​of the three-dimensional current distribution points are then solved by inversion based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the solution results.

[0006] The device current distribution detection method proposed in this application utilizes a double-layer Rogowski coil, composed of several segmented sub-coils, surrounding the device under test (DUT). Compared to traditional single-layer coil structures, this method can comprehensively collect mutual inductance information related to the DUT without damaging the device package, improving the detection coverage around the DUT. This provides a precise data foundation for inverting and solving the current distribution value of the DUT. Furthermore, through inverting and solving based on the mutual inductance information and output voltage of the double-layer Rogowski coil, the quantitative calculation of the current distribution of the DUT is achieved, significantly improving the resolution and accuracy of current distribution detection. In addition, the number of segmented sub-coils in the double-layer Rogowski coil can be flexibly increased or decreased according to actual needs, enhancing adaptability to different application scenarios.

[0007] Optionally, in some embodiments of this application, the double-layer Rogowski coil includes a first Rogowski coil and a second Rogowski coil, wherein the first Rogowski coil and the second Rogowski coil each include a plurality of the segmented sub-coils, and the segmented sub-coils are arc-shaped; In this configuration, the segmented sub-coils of the first Rogowski coil correspond one-to-one with the segmented sub-coils of the second Rogowski coil, and the segmented sub-coils of the first Rogowski coil and the corresponding segmented sub-coils of the second Rogowski coil are offset by a preset angle.

[0008] The dual-layer structure of the first and second Rogowski coils enables the detection of the device under test in three dimensions, whereas traditional single-layer coils can only achieve two-dimensional detection. In addition, the arc-shaped segmented sub-coils can better fit the outer shape of the device under test and are set at a preset angle to increase the coverage of the outer space of the device and make up for possible detection blind spots. Therefore, it is conducive to more comprehensive and accurate acquisition of multi-dimensional mutual inductance information.

[0009] Optionally, in some embodiments of this application, the first Rogowski coil and the second Rogowski coil each include 12 segmented sub-coils, each segmented sub-coil having a central angle of 30° and a preset angle of 15°.

[0010] In this embodiment, the central angle of each segmented sub-coil is precisely determined to be 30°. On the one hand, this makes the sensing range of each segmented sub-coil for changes in the magnetic field more accurate and uniform. On the other hand, by evenly distributing 12 segmented sub-coils with a central angle of 30°, the circumferential space around the device is effectively and reasonably covered. At the same time, the segmented sub-coils of the first Rogowski coil and the second Rogowski coil are staggered by a preset angle of 15°, so that the two layers of coils form a staggered monitoring layout in space, further reducing the detection blind zone and comprehensively improving the ability to capture magnetic field information around the device, making the quantitative calculation of the current distribution of the device under test more accurate.

[0011] Optionally, in some embodiments of this application, the step of inputting a test current to the device under test, obtaining a first mutual inductance measurement value and a first mutual inductance calculation value corresponding to the test current for each of the segmented sub-coils, and determining the correction parameters for each of the segmented sub-coils based on the first mutual inductance measurement value and the first mutual inductance calculation value includes: Determine the center current-passing point of the device under test so that the test current flows through the center current-passing point; Obtain the second output voltage of each segmented sub-coil in response to the test current, and determine the first mutual inductance measurement value corresponding to each segmented sub-coil based on the ratio of the second output voltage to the test current; Obtain the first distance vector between the central current-carrying point and each segmented sub-coil, and determine the first mutual inductance value corresponding to each segmented sub-coil based on the test current and the first distance vector; The correction parameter is determined based on the ratio of the first mutual inductance measurement value to the first mutual inductance calculation value.

[0012] This application embodiment utilizes a test current to conduct current through the center of the device under test (DUT) in order to determine the error between the measured and calculated mutual inductance values ​​in the test scenario, and to determine the corresponding correction parameters to effectively calibrate the deviation between the actual measurement and the theoretical calculation. This achieves measurement error correction for each segmented sub-coil, which helps to improve the accuracy of subsequent second mutual inductance calculation value correction and provides more accurate data for determining the three-dimensional current distribution point of the DUT and inverting the current distribution value.

[0013] Optionally, in some embodiments of this application, determining the calculated second mutual inductance value of each segmented sub-coil corresponding to different current-carrying points on the device under test based on the total current includes: Determine the second distance vector between each current-carrying point on the device under test and each segmented sub-coil, and determine the second mutual inductance value based on the total current and the second distance vector.

[0014] Optionally, in some embodiments of this application, the step of correcting the second mutual inductance calculation value according to the correction parameter includes: Multiply the second mutual inductance calculation value by the correction parameter, and determine the corrected second mutual inductance calculation value based on the multiplication result.

[0015] By correcting the calculated second mutual inductance of each segmented sub-coil using correction parameters, the error between the measured value and the theoretical value is eliminated, further providing a more accurate data basis for determining the three-dimensional current distribution points of the device under test and for inverting the current distribution value.

[0016] Optionally, in some embodiments of this application, determining the second mutual inductance measurement value of each of the segmented sub-coils based on the total current and the first output voltage includes: The second mutual inductance measurement value is determined based on the ratio of the first output voltage to the total current.

[0017] Optionally, in some embodiments of this application, determining the three-dimensional current distribution point of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value includes: The measured value of the second mutual inductance corresponding to each segmented sub-coil is matched with the corrected calculated value of the second mutual inductance, and the equal value marking line of the mutual inductance corresponding to each segmented sub-coil is determined according to the current flow point corresponding to the matched calculated value of the second mutual inductance. Determine the intersection points between the mutual inductance equivalent marking lines corresponding to all the segmented sub-coils, and determine the three-dimensional current distribution points based on the intersection points.

[0018] By accurately matching the second mutual inductance measurement value and the second mutual inductance calculation value, the current-carrying position on the device under test (DUT) that causes the segmented sub-coils to generate the corresponding second mutual inductance measurement value can be determined. Based on these current-carrying positions, the equivalent mutual inductance marking lines corresponding to each segmented sub-coil can be determined. Furthermore, the intersection points between the equivalent mutual inductance marking lines corresponding to all segmented sub-coils can accurately reflect the current distribution in the three-dimensional space of the DUT. Compared with the traditional method of using a single-layer coil for detection, the embodiments of this application can more comprehensively and accurately detect the three-dimensional current distribution state, providing accurate three-dimensional position information for inverting and solving the current distribution value, and making the quantitative calculation of the current distribution of the DUT more accurate and comprehensive.

[0019] Optionally, in some embodiments of this application, the step of inverting the current distribution values ​​of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, and determining the current distribution of the device under test based on the solution result, includes: The rate of change of current at each of the three-dimensional current distribution points is taken as the variable to be solved, and the Tikhonov regularization objective function is determined based on the linear relationship between the second mutual inductance measurement value, the first output voltage and the variable to be solved. Determine the first derivative of the Tikhonov regularization objective function, and solve for the rate of change of current based on the extrema of the first derivative function; The rate of change of current is integrated and the current distribution value corresponding to each of the three-dimensional current distribution points is obtained based on the calculation result, so as to determine the current distribution of the device under test based on the current distribution value.

[0020] In this embodiment, the rate of change of current at each three-dimensional current distribution point is set as the variable to be solved. Based on the linear relationship between the rate of change of current and the second mutual inductance measurement value and the first output voltage, a Tikhonov regularization objective function is determined, thus establishing an effective mathematical model for accurately solving the current distribution value. Furthermore, the Tikhonov regularization method can handle the ill-posedness of the inverse problem caused by the number of mutual inductance measurements being less than the number of internal currents in the device to be solved, and effectively suppress noise interference from current coupling in the device connectors, making the solution process more stable and reliable. Finally, the current distribution value is obtained by integrating the inverted rate of change, achieving precise quantification of the current distribution value, thereby accurately reflecting the current distribution with specific numerical values.

[0021] Secondly, embodiments of this application provide a device for detecting device current distribution based on a double-layer Rogowski coil. The double-layer Rogowski coil is sleeved around the device under test, and the double-layer Rogowski coil includes several segmented sub-coils. The device includes: The calibration preparation module is used to input a test current into the device under test, obtain the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to the test current for each segmented sub-coil, and determine the calibration parameters for each segmented sub-coil based on the first mutual inductance measurement value and the first mutual inductance calculation value. The calibration execution module is used to acquire the total current flowing through the device under test when the device under test is powered on, determine the second mutual inductance calculation value of each segmented sub-coil corresponding to different current-carrying points on the device under test based on the total current, and correct the second mutual inductance calculation value according to the calibration parameters. The measurement module is used to acquire the first output voltage of each segmented sub-coil and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage. The inversion solution module is used to determine the three-dimensional current distribution points of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value, and to perform inversion solution on the current distribution value of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the solution result.

[0022] The device current distribution detection device proposed in this application utilizes a double-layer Rogowski coil, composed of several segmented sub-coils, surrounding the device under test (DUT). Compared to traditional single-layer coil structures, this device can comprehensively collect mutual inductance information related to the DUT without damaging the device package, improving the detection coverage around the DUT. This provides a precise data foundation for inverting and solving the current distribution value of the DUT. Furthermore, through inverting and solving based on the mutual inductance information and output voltage of the double-layer Rogowski coil, a quantitative calculation of the current distribution of the DUT is achieved, significantly improving the resolution and accuracy of current distribution detection. In addition, the number of segmented sub-coils in the double-layer Rogowski coil can be flexibly increased or decreased according to actual needs, enhancing adaptability to different application scenarios. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic flowchart of a device current distribution detection method based on a double-layer Rogowski coil proposed in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the double-layer Rogowski coil proposed in the embodiments of this application; Figure 3 This is a schematic diagram illustrating the generation of magnetic induction intensity in each segmented sub-coil in the embodiments of this application; Figure 4 This is a schematic diagram of the mutual inductance equivalence marking lines proposed in the embodiments of this application; Figure 5 This is a schematic diagram of a device current distribution detection device based on a double-layer Rogowski coil, as proposed in an embodiment of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Press-fit devices are widely used power electronic components in high-voltage, high-current applications, such as press-fit insulated-gate bipolar transistors (IGBTs), integrated gate-commutated thyristors (IGCTs), and diode modules. These devices use mechanical pressing to connect the chip to the electrodes, rather than traditional soldering, resulting in double-sided heat dissipation, higher current capacity, and better thermal cycling resistance. Their structure typically consists of multiple layers of semiconductor chips connected in parallel, with external pressure ensuring reliable electrical contact. They are suitable for applications with stringent power density and reliability requirements, such as high-voltage direct current transmission and industrial frequency converters. However, during long-term operation, due to uneven pressure and device aging, the parallel chips in press-fit devices are prone to uneven current distribution, leading to localized overheating and even performance failure.

[0027] In related technologies, there are two main detection methods for the internal current distribution of crimped devices: invasive and non-invasive. Invasive detection methods require destroying the original structure of the crimped device, while non-invasive detection methods can be performed without damaging the device package. Generally, a single-layer coil is used to measure the change of the external magnetic field of the crimped device. When the internal current of the device passes through, the single-layer coil will sense magnetic field signals of different intensities and output corresponding voltages, thereby indirectly inverting its internal current distribution.

[0028] However, single-layer coils used for non-invasive testing have limited coverage of crimped devices, resulting in certain detection blind spots and low-dimensional magnetic field data, making it impossible to accurately assess the internal current distribution of the device. In addition, related technologies are limited by the ill-conditioned nature of the inverse problem, and can only invert the location of the current eccentricity point through limited data, unable to specifically quantify the current distribution. Therefore, it is difficult to assess the health status of the device from multiple dimensions such as current density distribution and dynamic change trends.

[0029] According to an embodiment of this application, a method for detecting device current distribution based on a double-layer Rogowski coil is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0030] This embodiment provides a device current distribution detection method based on a double-layer Rogowski coil, wherein the double-layer Rogowski coil is sleeved around the device under test, and the double-layer Rogowski coil includes several segmented sub-coils. Figure 1 This is a flowchart of a device current distribution detection method according to an embodiment of this application, such as... Figure 1 As shown, the process includes the following steps: Step S1: Input test current into the device under test, obtain the first mutual inductance measurement value and the first mutual inductance calculation value of the test current corresponding to each segment sub-coil, and determine the correction parameters of each segment sub-coil based on the first mutual inductance measurement value and the first mutual inductance calculation value.

[0031] Specifically, the mutual inductance characteristics between the double-layer Rogowski coil and the device under test (DUT) are accurately measured and corrected. A test current, which is a known excitation signal, is input to the DUT. Under the action of the test current, each segmented sub-coil will generate a mutual inductance phenomenon corresponding to the test current. The first mutual inductance measurement value of each segmented sub-coil corresponding to this test current is obtained through measurement methods. At the same time, the relative position information of the segmented sub-coil and the location through which the test current flows is determined, and the first mutual inductance calculation value of each segmented sub-coil corresponding to the test current is calculated based on the Biot-Savart law. However, due to various interferences and non-ideal factors in actual situations, there are often deviations. Therefore, corresponding correction parameters are determined based on the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to each segmented coil. These parameters are used to correct the relevant mutual inductance calculation values ​​in subsequent measurements, thereby reducing the error between theoretical calculations and actual measurements and improving the accuracy of the measurements.

[0032] Step S3: With the device under test powered on, obtain the total current flowing through the device under test, determine the second mutual inductance calculation value of each segment sub-coil corresponding to different current-carrying points on the device under test based on the total current, and correct the second mutual inductance calculation value according to the correction parameters.

[0033] Specifically, during the operation of the device under test (DUT), the total current flowing through the DUT is the sum of the currents flowing through each parallel chip. Combining information such as the spatial relationship between the segmented sub-coils and different current-carrying points on the DUT, the second mutual inductance calculation value for each segmented sub-coil corresponding to different current-carrying points on the DUT is determined based on the Biot-Savart law. This second mutual inductance calculation value theoretically characterizes the mutual inductance relationship between different current-carrying points and the segmented sub-coils under a given total current. Subsequently, the second mutual inductance calculation value is corrected for errors based on the correction parameters determined in step S1 to eliminate the error between the measured value and the theoretical value.

[0034] Step S5: Obtain the first output voltage of each segmented sub-coil, and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage.

[0035] Specifically, during the operation of the device under test (DUT), the total current flowing through the DUT causes a change in the magnetic field around each segmented sub-coil, thereby generating an induced electromotive force (EMF) in the segmented sub-coil. This induced EMF is the first output voltage of each segmented sub-coil. Based on the total current flowing through the DUT and the aforementioned first output voltage, the second mutual inductance measurement value is determined. This second mutual inductance measurement value characterizes the actual mutual inductance between the segmented sub-coil and the DUT, providing important actual measurement data for subsequent determination of the current distribution.

[0036] Step S7: Determine the three-dimensional current distribution points of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value, and perform inverse calculation on the current distribution values ​​of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the calculation results.

[0037] Specifically, a second mutual inductance calculation value, consistent with the second mutual inductance measurement value, is determined for each segmented sub-coil. Based on the correspondence between the second mutual inductance calculation value and the current-carrying points on the device under test (DUT), the three-dimensional current distribution points of the DUT are determined. These three-dimensional current distribution points characterize the possible distribution positions of the current in the three-dimensional space inside the device. Then, an inversion algorithm is used to solve the ill-posed inverse problem by reversing the current distribution values ​​at the three-dimensional current distribution points. Based on the solved current distribution values, the current distribution of the DUT is comprehensively and accurately determined.

[0038] Therefore, the device current distribution detection method proposed in this application utilizes a double-layer Rogowski coil, consisting of several segmented sub-coils, surrounding the device under test (DUT). Compared to the traditional single-layer coil structure, this method can comprehensively collect mutual inductance information related to the DUT without damaging the device package, improving the detection coverage around the DUT. This provides a precise data foundation for inverting and solving the current distribution value of the DUT. Furthermore, by inverting and solving based on the mutual inductance information and output voltage of the double-layer Rogowski coil, a quantitative calculation of the current distribution of the DUT is achieved, significantly improving the resolution and accuracy of current distribution detection. In addition, the number of segmented sub-coils in the double-layer Rogowski coil can be flexibly increased or decreased according to actual needs, enhancing adaptability to different application scenarios.

[0039] Figure 2 The diagram shows a schematic of the structure of a double-layer Rogowski coil in an embodiment of this application. The double-layer Rogowski coil includes a first Rogowski coil 10 and a second Rogowski coil 20. The first Rogowski coil 10 and the second Rogowski coil 20 each include a plurality of segmented sub-coils, and the segmented sub-coils are arc-shaped.

[0040] In this configuration, the segmented sub-coils of the first Rogowski coil 10 correspond one-to-one with the segmented sub-coils of the second Rogowski coil 20, and the segmented sub-coils of the first Rogowski coil 10 and the corresponding segmented sub-coils of the second Rogowski coil 20 are offset by a preset angle.

[0041] Specifically, such as Figure 2 As shown, the first Rogowski coil 10 and the second Rogowski coil 20 are arranged parallel to each other along the cross-section of the device under test 30, with the first Rogowski coil 10 positioned parallel above the second Rogowski coil 20. The direction of the current flowing through the device under test 30 is perpendicular to the aforementioned cross-section, that is, the current direction is perpendicular to the plane containing the first Rogowski coil 10 and the second Rogowski coil 20.

[0042] Therefore, compared with traditional single-layer coils, the double-layer Rogowski coil, composed of a first Rogowski coil 10 and a second Rogowski coil 20, can detect the device under test 30 in three dimensions, while traditional single-layer coils can only acquire mutual inductance information in two dimensions. Thus, the embodiments of this application achieve multi-dimensional detection of mutual inductance information, thereby greatly increasing the amount of data in the mutual inductance measurement values ​​and improving the resolution and accuracy of current distribution detection.

[0043] Meanwhile, the arc-shaped segmented sub-coil can better fit the outer shape of the device under test 30 and is set at a preset angle to increase the coverage of the outer space of the device and make up for possible detection blind spots. Therefore, it is conducive to more comprehensive and accurate acquisition of multi-dimensional mutual inductance information.

[0044] Furthermore, both the first Rogowski coil 10 and the second Rogowski coil 20 are composed of several segmented sub-coils. Therefore, according to actual needs, such as for devices under test 30 with different peripheral dimensions, the number of segmented sub-coils in the double-layer Rogowski coil can be flexibly increased or decreased to adapt to the detection requirements of different devices under test 30. This not only ensures comprehensive and accurate acquisition of multi-dimensional mutual inductance information, but also greatly improves the flexibility of detection.

[0045] Furthermore, as a preferred example, the first Rogowski coil and the second Rogowski coil each include 12 segmented sub-coils, each segmented sub-coil having a central angle of 30° and the aforementioned preset angle of 15°.

[0046] Specifically, the sum of the central angles of the 12 segmented sub-coils is 360°, which is one lap around the outer perimeter of the device under test 30. For example... Figure 2 As shown, taking a segmented sub-coil 10-1 in the first Rogowski coil 10 and a corresponding segmented sub-coil 20-1 in the second Rogowski coil 20 as examples, the central angles of both segmented sub-coil 10-1 and segmented sub-coil 20-1 are 30°, and segmented sub-coil 10-1 and segmented sub-coil 20-1 are offset by a preset angle. This preset angle is proportional to and smaller than the aforementioned central angle. In a preferred example, segmented sub-coil 10-1 and segmented sub-coil 20-1 have an offset angle of 15°, that is, the aforementioned preset angle is half of the aforementioned central angle, thereby ensuring that the periphery of the device under test 30 can be completely covered by the segmented sub-coil.

[0047] Therefore, on the one hand, it makes the sensing range of each segmented sub-coil more accurate and uniform in response to changes in the magnetic field. On the other hand, the 12 segmented sub-coils with a central angle of 30° are evenly distributed, effectively and reasonably covering the circumferential space around the device. At the same time, the segmented sub-coils of the first Rogowski coil and the second Rogowski coil are staggered at a preset angle of 15°, so that the two layers of coils form a staggered monitoring layout in space, further reducing the detection blind zone and comprehensively improving the ability to capture magnetic field information around the device, making the quantitative calculation of the current distribution of the device under test more accurate.

[0048] In some embodiments of this application, step S1 further includes: Step S11: Determine the center current-passing point of the device under test so that the test current flows through the center current-passing point.

[0049] Specifically, the aforementioned central current-passing point is the center of the cross-section of the device under test (DUT). For example, if the cross-section of the DUT is circular, then the central current-passing point is the center of that circle. In this embodiment of the application, current is passed through the center of the DUT during the test scenario, while no current is passed through other locations, in order to reduce signal interference and ensure the accuracy of the calibration parameters.

[0050] Step S12: Obtain the second output voltage of each segment sub-coil in response to the test current, so as to determine the first mutual inductance measurement value corresponding to each segment sub-coil based on the ratio of the second output voltage to the test current.

[0051] Specifically, the second output voltage of the nth segmented sub-coil at time t in response to the test current is: Then the first mutual inductance measurement value corresponding to the nth segment sub-coil The calculation formula is shown in formula (1) below: In the formula, Let t be the test current at time t.

[0052] Step S13: Obtain the first distance vector between the center current-carrying point and each segment sub-coil, and determine the first mutual inductance calculation value corresponding to each segment sub-coil based on the test current and the first distance vector.

[0053] Specifically, Figure 3 The nth segment sub-coil is shown in the test current. A schematic diagram illustrating the magnetic induction intensity generated under the action of , as shown below. Figure 3 As shown, the test current The direction is perpendicular to the busbar current direction of the device under test. The first distance vector between the center current-carrying point and the nth segment sub-coil is R. The magnetic induction intensity corresponding to the nth segment sub-coil is determined based on the Biot-Savart law. The magnetic induction intensity is shown in formula (2): In the formula, The magnetic flux density corresponds to the nth segment sub-coil. air permeability, A vector of unit length for the current path. for The distance vector to a point P on the nth segment coil.

[0054] like Figure 3 As shown, Let be the normal vector of the cross-section of the i-th turn of the segmented sub-coil. To calculate the magnetic flux through the segmented sub-coil, we need to... To conduct for Directional decomposition yields the magnetic field strength perpendicular to the cross-section of the nth segmented sub-coil. As shown in the following formula (3): Then the magnetic flux through the i-th turn of the n-th segmented sub-coil As shown in the following formula (4): In the formula, h is the height of the segmented sub-coil, R0 is the distance between the inner side of the segmented sub-coil and the current path, d is the width of the segmented sub-coil, dr is the differential component of the width of the segmented sub-coil, and dz is the differential component of the height of the segmented sub-coil.

[0055] This allows us to obtain the total magnetic flux passing through the nth segmented sub-coil. As shown in the following formula (5): In the formula, k is the total number of turns of the nth segment sub-coil.

[0056] Finally, the calculated value of the first mutual inductance corresponding to the nth segment sub-coil is obtained based on the following formula (6). for: Step S14: Determine the correction parameter based on the ratio of the first mutual inductance measurement value to the first mutual inductance calculation value.

[0057] Specifically, the correction parameters corresponding to the nth segment sub-coil are determined based on the following formula (7). for: Therefore, this embodiment of the application uses a test current to make the center of the device under test flow, so as to determine the error between the measured value and the calculated value of mutual inductance in the test scenario, and determine the corresponding correction parameters to effectively calibrate the deviation between the actual measurement and the theoretical calculation, thereby realizing the measurement error correction of each segmented sub-coil, which is beneficial to improving the accuracy of the subsequent second mutual inductance calculation value correction, and providing more accurate data for determining the three-dimensional current distribution point of the device under test and inverting the current distribution value.

[0058] In some embodiments of this application, step S3 further includes: Step S31: Determine the second distance vector between each current-carrying point on the device under test and each segmented sub-coil, and determine the second mutual inductance value based on the total current and the second distance vector.

[0059] Similarly, the second distance vector between each current-carrying point and the nth segmented sub-coil is... Based on the Biot-Savart law, the total current of the nth segment sub-coil is determined. The magnetic flux density generated under the influence of is shown in formula (8): In the formula, Let be the magnetic flux density at the current-carrying point corresponding to the nth segmented sub-coil. air permeability, This is the vector of the current path per unit length through the flow point. for The distance vector to a point on the nth segment coil.

[0060] Subsequently, The magnetic field strength perpendicular to the cross section of the nth segment sub-coil is obtained by decomposing the normal vector. Furthermore, based on the magnetic field strength Determine the magnetic flux through the i-th turn of the n-th segmented sub-coil, and calculate the sum of the magnetic flux and the total current of the k turns. The ratio is used to obtain the second mutual inductance calculation value. .

[0061] It should be noted that the above calculation process can be found in formulas (3) to (7), and will not be repeated here.

[0062] Step S32: Multiply the second mutual inductance calculation value with the correction parameter, and determine the corrected second mutual inductance calculation value based on the multiplication result.

[0063] Specifically, the corrected second mutual inductance calculation value As shown in the following formula (9): This application embodiment corrects the calculated second mutual inductance value of each segmented sub-coil by using correction parameters, thereby eliminating the error between the measured value and the theoretical value, and further providing a more accurate data basis for determining the three-dimensional current distribution point of the device under test and the inversion calculation of the current distribution value.

[0064] In some embodiments of this application, step S5 above further includes: Step S51: Determine the second mutual inductance measurement value based on the ratio of the first output voltage to the total current.

[0065] Specifically, the second mutual inductance measurement value corresponding to the nth segment sub-coil As shown in the following formula (10): In the formula, The nth segment sub-coil responds to the total current The second output voltage.

[0066] In some embodiments of this application, step S7 further includes: Step S71: Match the second mutual inductance measurement value corresponding to each segmented sub-coil with the corrected second mutual inductance calculation value, and determine the mutual inductance equal value marking line corresponding to each segmented sub-coil based on the current flow point corresponding to the matched second mutual inductance calculation value.

[0067] Specifically, Figure 4 The corrected second mutual inductance calculation values ​​for each current-carrying point on the device under test corresponding to the nth segmented sub-coil are shown, and the current-carrying points corresponding to the equivalent second mutual inductance calculation values ​​are connected to obtain the mutual inductance equivalence marking lines. Figure 4 It can be seen that the calculated value of the second mutual inductance of each segmented sub-coil changes with the change of the current-carrying position, and generally shows the pattern of "larger closer and smaller farther away".

[0068] In this embodiment, the corrected second mutual inductance calculation value accurately characterizes the influence of current flowing through each current-carrying point on the mutual inductance of the nth segment sub-coil. Subsequently, the second mutual inductance measurement value is compared with the mutual inductance equivalence marking line to determine the possible distribution position of the current in the three-dimensional space inside the device.

[0069] Step S72: Determine the intersection points between the mutual inductance equivalent marking lines corresponding to all segmented sub-coils, and determine the three-dimensional current distribution points based on the intersection points.

[0070] Specifically, the intersection point between the mutual inductance equivalent marking lines corresponding to each segmented sub-coil is the aforementioned three-dimensional current distribution point. When the current flows through the three-dimensional current distribution point, the mutual inductance information generated by it for each segmented sub-coil conforms to the second mutual inductance calculation value. Therefore, the three-dimensional current distribution point can characterize the distribution of current in the three-dimensional space of the device under test.

[0071] Step S73: The rate of change of current at each three-dimensional current distribution point is taken as the variable to be solved, and the Tikhonov regularization objective function is determined based on the linear relationship between the second mutual inductance measurement value, the first output voltage and the variable to be solved.

[0072] Specifically, the second mutual inductance measurement value, the first output voltage, and the current distribution value flowing through the current-carrying point have a certain linear relationship. However, in the actual measurement and calculation process, the second mutual inductance measurement value, the first output voltage, and the current distribution value corresponding to each current-carrying point are actually matrix data. Furthermore, the device under test has multiple current paths, and the number of second mutual inductance measurement values ​​is limited by the number of segmented sub-coils. Therefore, the number of second mutual inductance measurement values ​​is much smaller than the number of currents flowing through the device under test that needs to be solved. This makes the solution to the inverse problem seriously ill-posed, that is, it is impossible to find a unique solution for the current distribution value based on a small number of second mutual inductance measurement values.

[0073] In this embodiment, constraints are introduced using the Tikhonov regularization objective function to minimize the norm of the solution, thereby transforming the ill-conditioned problem into a stable solution.

[0074] In this study, the rate of change of current at the three-dimensional current distribution points, di / dt, is taken as the variable to be solved, i.e., di / dt = Then the Tikhonov regularization objective function is shown in the following formula (11): In the formula, This represents the Tikhonov regularization objective function. The second mutual inductance measurement value corresponding to each segment sub-coil The matrix formed The first output voltage corresponding to each segmented sub-coil The matrix formed It is a regularization factor, and , It is a regular operator, and The identity matrix I is usually chosen.

[0075] Step S74: Determine the first derivative of the Tikhonov regularization objective function, and solve for the rate of change of current based on the extrema of the first derivative function.

[0076] Specifically, the first derivative of the above formula (11) is shown in the following formula (12): Then, the variable to be solved is obtained from formula (12). The current change rate is calculated as shown in the following formula (13): Step S75: Integrate the rate of change of current and obtain the current distribution value corresponding to each three-dimensional current distribution point based on the calculation result, so as to determine the current distribution of the device under test based on the current distribution value.

[0077] Specifically, by integrating the above formula (13), the current distribution value i is obtained as shown in the following formula (14): Therefore, it can be seen that the embodiments of this application realize the quantitative analysis of the current distribution in the three-dimensional space of the device under test through the Tikhonov regularization algorithm, so that the current distribution can be accurately evaluated according to the calculation results of formula (14).

[0078] Therefore, by accurately matching the second mutual inductance measurement value and the second mutual inductance calculation value, this embodiment of the application can determine the current-carrying position on the device under test that causes the segmented sub-coils to generate the corresponding second mutual inductance measurement value. Based on these current-carrying positions, the equivalent mutual inductance marking lines corresponding to each segmented sub-coil can be determined. Furthermore, the intersection points between the equivalent mutual inductance marking lines corresponding to all segmented sub-coils can accurately reflect the current distribution in the three-dimensional space of the device under test. Compared with the traditional method of using a single-layer coil for detection, this embodiment of the application can more comprehensively and accurately detect the three-dimensional current distribution state, providing accurate three-dimensional position information for inverting and solving the current distribution value, and making the quantitative calculation of the current distribution of the device under test more accurate and comprehensive.

[0079] Furthermore, in this embodiment, the rate of change of current at each three-dimensional current distribution point is set as the variable to be solved, and the Tikhonov regularization objective function is determined based on the linear relationship between the rate of change of current and the second mutual inductance measurement value and the first output voltage, thus establishing an effective mathematical model for accurately solving the current distribution value. The Tikhonov regularization method can then handle the ill-posedness of the inverse problem caused by the number of mutual inductance measurements being less than the number of internal currents in the device to be solved, and effectively suppress noise interference from current coupling in the device connectors, making the solution process more stable and reliable. Finally, the current distribution value is obtained by integrating the inverted rate of change, achieving precise quantification of the current distribution value, thereby accurately reflecting the current distribution with specific numerical values.

[0080] Accordingly, please refer to Figure 5 This application provides a device for detecting device current distribution based on a double-layer Rogowski coil. The device 100 includes: The calibration preparation module 110 is used to input test current to the device under test, obtain the first mutual inductance measurement value and the first mutual inductance calculation value of the test current corresponding to each segment sub-coil, and determine the calibration parameters of each segment sub-coil based on the first mutual inductance measurement value and the first mutual inductance calculation value. For details, please refer to step S1.

[0081] The calibration execution module 120 is used to obtain the total current flowing through the device under test when the device under test is powered on, determine the second mutual inductance calculation value of each segment sub-coil corresponding to different current-carrying points on the device under test based on the total current, and correct the second mutual inductance calculation value according to the calibration parameters. For details, please refer to step S3.

[0082] The measurement module 130 is used to acquire the first output voltage of each segmented sub-coil and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage. For details, please refer to step S5.

[0083] The inversion solution module 140 is used to determine the three-dimensional current distribution points of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value, and to perform inversion solution on the current distribution value of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the solution result. For details, please refer to step S7.

[0084] The device current distribution detection device proposed in this application utilizes a double-layer Rogowski coil, composed of several segmented sub-coils, surrounding the device under test (DUT). Compared to traditional single-layer coil structures, this device can comprehensively collect mutual inductance information related to the DUT without damaging the device package, improving the detection coverage around the DUT. This provides a precise data foundation for inverting and solving the current distribution value of the DUT. Furthermore, through inverting and solving based on the mutual inductance information and output voltage of the double-layer Rogowski coil, the quantitative calculation of the current distribution of the DUT is achieved, significantly improving the resolution and accuracy of current distribution detection. In addition, the number of segmented sub-coils in the double-layer Rogowski coil can be flexibly increased or decreased according to actual needs, enhancing adaptability to different application scenarios.

[0085] In some embodiments of this application, the calibration preparation module 110 includes: The center current-passing unit 111 is used to determine the center current-passing point of the device under test so that the test current flows through the center current-passing point.

[0086] The first mutual inductance measurement unit 112 is used to acquire the second output voltage of each segment sub-coil in response to the test current, so as to determine the first mutual inductance measurement value corresponding to each segment sub-coil based on the ratio of the second output voltage to the test current.

[0087] The first mutual inductance calculation unit 113 is used to obtain the first distance vector between the center current-carrying point and each segment sub-coil, and to determine the first mutual inductance calculation value corresponding to each segment sub-coil based on the test current and the first distance vector.

[0088] The correction parameter generation unit 114 is used to determine the correction parameter based on the ratio of the first mutual inductance measurement value to the first mutual inductance calculation value.

[0089] In some embodiments of this application, the correction execution module 120 includes: The second mutual inductance calculation unit 121 is used to determine the second distance vector between each current-carrying point on the device under test and each segmented sub-coil, and to determine the second mutual inductance calculation value based on the total current and the second distance vector.

[0090] The mutual inductance correction unit 122 is used to multiply the second mutual inductance calculation value with the correction parameter, and determine the corrected second mutual inductance calculation value based on the multiplication result.

[0091] In some embodiments of this application, the measurement module 130 includes: The second mutual inductance measurement unit 132 is used to determine the second mutual inductance measurement value based on the ratio of the first output voltage to the total current.

[0092] In some embodiments of this application, the inversion solution module 140 includes: The mutual inductance matching unit 141 is used to match the second mutual inductance measurement value and the second mutual inductance calculation value corresponding to each segmented sub-coil, and to determine the mutual inductance equal value marking line corresponding to each segmented sub-coil based on the current flow point corresponding to the matched second mutual inductance calculation value.

[0093] The current distribution point determination unit 142 determines the intersection point between the mutual inductance equivalent marking lines corresponding to all segmented sub-coils, and determines the three-dimensional current distribution point based on the intersection point.

[0094] The inversion solution unit 143 is used to take the rate of change of current at each three-dimensional current distribution point as the variable to be solved, and determine the Tikhonov regularization objective function and the first derivative function of the Tikhonov regularization objective function based on the linear relationship between the second mutual inductance measurement value, the first output voltage and the variable to be solved. The current rate of change is then solved based on the extremum of the first derivative function. The current rate of change is integrated and calculated. Based on the calculation results, the current distribution value corresponding to each three-dimensional current distribution point is obtained, so as to determine the current distribution of the device under test based on the current distribution value.

[0095] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0096] In this embodiment, the device current distribution detection device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0097] This application provides a computer device comprising one or more processors, memory, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components are interconnected via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processor can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on an external input / output device (such as a display device coupled to the interface). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system).

[0098] The processor can be a central processing unit, a network processor, or a combination thereof. The processor may further include hardware chips. These hardware chips can be application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or combinations thereof. The programmable logic devices can be complex programmable logic devices (CLPs), field-programmable gate arrays (FPGAs), general-purpose array logic (GDAs), or any combination thereof.

[0099] The memory stores instructions executable by at least one processor to cause the at least one processor to perform the method shown in the above embodiments.

[0100] The memory may include a stored program area and a stored data area, wherein the stored program area may store the operating system and application programs required for at least one function; the stored data area may store data created based on the use of the computer device, etc. Furthermore, the memory may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0101] The memory may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 2 may also include a combination of the above types of memory.

[0102] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0103] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

[0104] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0105] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0106] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0107] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0108] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

[0109] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for detecting device current distribution based on a double-layer Rogowski coil, characterized in that, The double-layer Rogowski coil is sleeved around the device under test, and the double-layer Rogowski coil includes several segmented sub-coils. The method includes: A test current is input to the device under test, and the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to the test current of each segmented sub-coil are obtained. The correction parameters of each segmented sub-coil are determined based on the first mutual inductance measurement value and the first mutual inductance calculation value. When the device under test is powered on, the total current flowing through the device under test is obtained, and the second mutual inductance calculation value corresponding to different current-carrying points on the device under test for each segmented sub-coil is determined based on the total current. The second mutual inductance calculation value is then corrected based on the correction parameter. Obtain the first output voltage of each segmented sub-coil, and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage; The three-dimensional current distribution points of the device under test are determined based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value. The current distribution values ​​of the three-dimensional current distribution points are then solved by inversion based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the solution results. The double-layer Rogowski coil includes a first Rogowski coil and a second Rogowski coil, the first Rogowski coil and the second Rogowski coil each include a plurality of segmented sub-coils, and the segmented sub-coils are arc-shaped; In this configuration, the segmented sub-coils of the first Rogowski coil correspond one-to-one with the segmented sub-coils of the second Rogowski coil, and the segmented sub-coils of the first Rogowski coil and the corresponding segmented sub-coils of the second Rogowski coil are offset by a preset angle. The process of inputting a test current to the device under test, obtaining the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to the test current for each of the segmented sub-coils, and determining the correction parameters for each of the segmented sub-coils based on the first mutual inductance measurement value and the first mutual inductance calculation value includes: Determine the center current-passing point of the device under test so that the test current flows through the center current-passing point; Obtain the second output voltage of each segmented sub-coil in response to the test current, and determine the first mutual inductance measurement value corresponding to each segmented sub-coil based on the ratio of the second output voltage to the test current; Obtain the first distance vector between the central current-carrying point and each segmented sub-coil, and determine the first mutual inductance value corresponding to each segmented sub-coil based on the test current and the first distance vector; The correction parameter is determined based on the ratio of the first mutual inductance measurement value to the first mutual inductance calculation value; The step of determining the three-dimensional current distribution point of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value includes: The measured value of the second mutual inductance corresponding to each segmented sub-coil is matched with the corrected calculated value of the second mutual inductance, and the equal value marking line of the mutual inductance corresponding to each segmented sub-coil is determined according to the current flow point corresponding to the matched calculated value of the second mutual inductance. Determine the intersection points between the mutual inductance equivalent marking lines corresponding to all the segmented sub-coils, and determine the three-dimensional current distribution points based on the intersection points; The step of inverting and solving the current distribution values ​​of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, and determining the current distribution of the device under test based on the solution results, includes: The rate of change of current at each of the three-dimensional current distribution points is taken as the variable to be solved, and the Tikhonov regularization objective function is determined based on the linear relationship between the second mutual inductance measurement value, the first output voltage and the variable to be solved. Determine the first derivative of the Tikhonov regularization objective function, and solve for the rate of change of current based on the extrema of the first derivative function; The rate of change of current is integrated and the current distribution value corresponding to each of the three-dimensional current distribution points is obtained based on the calculation result, so as to determine the current distribution of the device under test based on the current distribution value.

2. The method according to claim 1, characterized in that, The first Rogowski coil and the second Rogowski coil each include 12 segmented sub-coils, each segmented sub-coil having a central angle of 30° and a preset angle of 15°.

3. The method according to claim 1, characterized in that, The step of determining the second mutual inductance calculation value of each segmented sub-coil corresponding to different current-carrying points on the device under test based on the total current includes: Determine the second distance vector between each current-carrying point on the device under test and each segmented sub-coil, and determine the second mutual inductance value based on the total current and the second distance vector.

4. The method according to claim 1, characterized in that, The step of correcting the second mutual inductance calculation value according to the correction parameters includes: Multiply the second mutual inductance calculation value by the correction parameter, and determine the corrected second mutual inductance calculation value based on the multiplication result.

5. The method according to claim 1, characterized in that, The step of determining the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage includes: The second mutual inductance measurement value is determined based on the ratio of the first output voltage to the total current.

6. A device for detecting device current distribution based on a double-layer Rogowski coil, characterized in that, The device current distribution detection device is suitable for applying the device current distribution detection method as described in any one of claims 1 to 5, wherein the double-layer Rogowski coil is sleeved around the device under test, and the double-layer Rogowski coil includes a plurality of segmented sub-coils, and the device includes: The calibration preparation module is used to input a test current into the device under test, obtain the first mutual inductance measurement value and the first mutual inductance calculation value corresponding to the test current for each segmented sub-coil, and determine the calibration parameters for each segmented sub-coil based on the first mutual inductance measurement value and the first mutual inductance calculation value. The calibration execution module is used to acquire the total current flowing through the device under test when the device under test is powered on, determine the second mutual inductance calculation value of each segmented sub-coil corresponding to different current-carrying points on the device under test based on the total current, and correct the second mutual inductance calculation value according to the calibration parameters. The measurement module is used to acquire the first output voltage of each segmented sub-coil and determine the second mutual inductance measurement value of each segmented sub-coil based on the total current and the first output voltage. The inversion solution module is used to determine the three-dimensional current distribution points of the device under test based on the second mutual inductance measurement value and the corrected second mutual inductance calculation value, and to perform inversion solution on the current distribution value of the three-dimensional current distribution points based on the second mutual inductance measurement value and the first output voltage, so as to determine the current distribution of the device under test based on the solution result.

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