Magnetic array current sensor measurement error self-correction method, system and device

Abstract

The present invention relates to the field of magnetic array current sensors, and provides a method, system and device for self-correcting the measurement error of a magnetic array current sensor. The method for self-correcting the measurement error of a magnetic array current sensor includes: based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all magnetic field sensing units, using a principal component analysis method to calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all magnetic field sensing units; using the measurement error drift of all diamond NV color center quantum magnetic field sensing units as a correction amount to correct the measurement error drift of all magnetic field sensing units; calculating the difference between the magnetic field results of all magnetic field sensing units and the measurement error drift of all magnetic field sensing units after correction, and obtaining the result when no drift occurs. The present invention can realize the accurate measurement of the dynamic drift of the measurement error of conventional magnetic field sensing units.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic array current sensors, and in particular to a method, system and equipment for self-correcting measurement errors of magnetic array current sensors. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] The magnetic array current sensor is composed of multiple magnetic field sensing units. By measuring the magnetic field at multiple locations in the space around the measured current conductor, a mathematical equation group with sufficient redundancy is constructed. By solving the above equation group, the reverse calculation (i.e., measurement) of the measured current is realized. It has the characteristics of compact size and low insulation requirements, and has been widely used in distributed current measurement. However, since the working stability of conventional magnetic field sensing units (such as tunneling magnetoresistive sensors, Hall sensors, etc.) is easily affected by environmental factors (such as temperature, humidity, etc.), their measurement errors will drift to a certain extent, which will lead to reduced measurement accuracy and stability of the magnetic array current sensor.

[0004] The traditional calibration method based on the standard process of power outage and disassembly will consume a lot of manpower and material resources for large-scale and widely distributed magnetic array current sensors, which is obviously impractical. Summary of the invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a method, system and device for self-correcting the measurement error of a magnetic array current sensor. The present invention forms a hybrid magnetic array current sensor integrating the NV color center quantum magnetic field sensing unit and the conventional magnetic field sensing unit by adding one or more diamond NV color center (NV color center, nitrogen-vacancy center) quantum magnetic field sensing units to the magnetic array current sensor composed of conventional magnetic field sensing units; since the magnetic field measurement results of the NV color center quantum magnetic field sensing unit can be directly traced back to the basic physical constant (the magnetic gyroscopic ratio of the electron) and the frequency, and the current frequency measurement accuracy can reach 10 -18 Up to 10 -19 , so its magnetic field measurement results have quantum precision. By utilizing the highly accurate and very stable excellent performance of the diamond NV color center quantum magnetic field sensor unit, and combining the physical information correlation between the measured results of all magnetic field sensor units in the magnetic array current sensor, it is possible to accurately measure the dynamic drift of the measurement error of other conventional magnetic field sensor units, and then realize the online correction of the measurement error of the magnetic array current sensor, so as to ensure the long-term accuracy and reliability of its current measurement results.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides a method for self-correcting measurement errors of a magnetic array current sensor.

[0008] A magnetic array current sensor measurement error self-correction method, comprising:

[0009] Acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit;

[0010] Based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all magnetic field sensing units, the principal component analysis method is used to calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all magnetic field sensing units;

[0011] The measurement error drift of all diamond NV color center quantum magnetic field sensor units is used as a correction amount to correct the measurement error drift of all magnetic field sensor units;

[0012] The difference between the magnetic field results of all magnetic field sensing units and the corrected measurement error drift of all magnetic field sensing units is calculated to obtain the magnetic field results of all magnetic field sensing units when no drift occurs.

[0013] Furthermore, after the hybrid magnetic array current sensor is installed on the current line to be measured, an online or offline calibration is performed to determine the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

[0014] Furthermore, the online calibration method includes: establishing an equation relationship between the measured magnetic field and the measured current according to the Biot-Savart law, using multiple magnetic field sensing units to construct a group of equations; taking the measured current and the position coordinates of the current-carrying conductor as unknown variables, and taking the sensitivity coefficients and spatial geometric position coordinates of all magnetic field sensing units as known quantities, solving the group of equations and calculating the transfer coefficient matrix; based on the transfer coefficient matrix, determining the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

[0015] Furthermore, the offline calibration method includes: when the measured current line is out of power, injecting a standard current into the line, and calculating a transfer coefficient matrix based on the measured calibration current and the corresponding magnetic field to determine the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

[0016] Furthermore, after obtaining the magnetic field results of all the magnetic field sensing units, the method further includes: normalizing the magnetic field results of all the magnetic field sensing units.

[0017] Furthermore, after the normalization processing, the method includes: performing singular value decomposition on the magnetic field results of all the magnetic field sensing units after the normalization processing to obtain a principal element subspace and a residual subspace.

[0018] Furthermore, the process of obtaining the pivot subspace includes: determining the number of pivots p, and determining the first P columns in the right matrix obtained by singular value decomposition as the pivot subspace.

[0019] Furthermore, the number of pivots p is determined using the following formula:

[0020] ;

[0021] in, σ i represents the value on the diagonal of the eigenvalue matrix of the magnetic field results of all magnetic field sensing units after normalization, λ is the control threshold of the number of principal elements, m is the total number of magnetic field sensing units.

[0022] Furthermore, the process of obtaining the residual subspace includes: transforming the right matrix p The matrix consisting of the +1 column to the last column is determined as the residual subspace.

[0023] Furthermore, after obtaining the principal component subspace and the residual subspace, the method includes: taking the magnetic field results of all magnetic field sensing units as test data and performing normalization processing; extracting the main components based on the normalized test data and the principal component subspace; extracting the residual components based on the normalized test data and the residual subspace; denormalizing the main components and the residual components to obtain the denormalized main components and residual components;

[0024] Based on the denormalized main components and residual components, combined with the magnetic field results measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, the relative errors of the main components relative to the magnetic field amplitude measured when the measurement errors of all magnetic field sensing units are in a normal state, as well as the relative errors of the magnetic field amplitude of the magnetic field sensing units with offset errors are calculated respectively.

[0025] Furthermore, the relative error of the main component relative to the magnetic field amplitude measured when the measurement error state of all magnetic field sensing units is normal is calculated using the following formula:

[0026] ;

[0027] in, It indicates the relative error of the main component relative to the magnetic field amplitude measured when the measurement error state of all magnetic field sensing units is normal. represents the main component after denormalization, DT It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

[0028] Furthermore, the relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset is calculated using the following formula:

[0029] ;

[0030] in, Indicates the relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset, represents the residual component after denormalization, D T It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

[0031] Furthermore, the magnetic field results of all magnetic field sensing units include a matrix consisting of amplitudes or phases.

[0032] A second aspect of the present invention provides a magnetic array current sensor measurement error self-correction system.

[0033] A magnetic array current sensor measurement error self-correction system, comprising:

[0034] A data acquisition module, which is configured to: acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit;

[0035] A principal component analysis module is configured to: calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all magnetic field sensing units using a principal component analysis method based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all magnetic field sensing units;

[0036] An error calculation module is configured to: use the measurement error drift of all diamond NV color center quantum magnetic field sensing units as a correction amount to correct the measurement error drift of all magnetic field sensing units;

[0037] The correction module is configured to calculate the difference between the magnetic field results of all magnetic field sensing units and the measurement error drift of all magnetic field sensing units after correction, and obtain the magnetic field results of all magnetic field sensing units when no drift occurs.

[0038] A third aspect of the present invention provides a magnetic array current sensor measurement error self-correction system.

[0039] A magnetic array current sensor comprises a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit. The magnetic field sensing units are error corrected by using the steps in the magnetic array current sensor measurement error self-correction method described in the first aspect.

[0040] A fourth aspect of the present invention provides a computer device.

[0041] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for self-correction of measurement errors of a magnetic array current sensor as described in the first aspect above are implemented.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention accurately measures the drift of the measurement error of the magnetic field sensing unit in the magnetic array current sensor in an online manner, aiming to ensure the accuracy and reliability of the measurement result of the magnetic array current sensor. Specifically, the present invention comprises: adding a small amount (at least 1) of NV color center quantum magnetic field sensing unit to the magnetic array current sensor composed of a plurality of conventional magnetic field sensing units to form a hybrid magnetic array current sensor integrating the quantum magnetic field sensing unit and the conventional magnetic field sensing unit; using the quantum magnetic field sensing unit as a reference to realize the measurement of the drift of the measurement error of the conventional magnetic field sensing unit; when the magnetic array current sensor is in normal operation, obtaining the amplitude or phase of the magnetic field measured by all the magnetic field sensing units as training data, and using the principal component analysis method to calculate the drift of the measurement error of the conventional magnetic field sensing unit. Determine the linear correlation between the magnetic field results measured by all magnetic field sensing units, and use the singular value decomposition method to separate the principal element subspace from the residual subspace; in the long-term operation of the magnetic array current sensor, use the magnetic field results measured by all magnetic field sensing units as test data, and combine the residual subspace to achieve the preliminary extraction of the measurement error drift of each magnetic field sensing unit; use the extracted measurement error drift of the quantum magnetic field sensing unit as the correction amount to correct the measurement error drift of each conventional magnetic field sensing unit; then use the corrected measurement error drift to perform error compensation on the magnetic field results measured by all conventional magnetic field sensing units, and then achieve self-correction of the measurement error of the magnetic array current sensor in an online manner. The present invention makes full use of the highly stable and accurate characteristics of the diamond NV color center quantum magnetic field sensing unit in measuring the magnetic field, as well as the linear correlation between the magnetic field results measured by all magnetic field sensing units, so as to more accurately extract the measurement error drift of the conventional magnetic field sensing unit from the measured magnetic field data, and then achieve online self-correction of the measurement error of the magnetic array current sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0045] Figure 1 It is a flow chart of a method for self-correcting measurement errors of a magnetic array current sensor according to the present invention;

[0046] Figure 2 A schematic diagram of a magnetic array current sensor composed of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit for measuring line current according to an embodiment of the present invention;

[0047] Figure 3 The amplitude result of the magnetic field measured by 5 conventional magnetic field sensing units and 1 diamond NV color center quantum magnetic field sensing unit according to one embodiment of the present invention (only the measurement error of the #1 magnetic field sensing unit has drifted);

[0048] Figure 4 The phase result of the magnetic field measured by 5 conventional magnetic field sensing units and 1 diamond NV color center quantum magnetic field sensing unit according to one embodiment of the present invention (only the measurement error of the #1 magnetic field sensing unit has drifted);

[0049] Figure 5 is a setting value of the amplitude relative error drift of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit under the condition that only the measurement error of the #1 conventional magnetic field sensing unit drifts according to an embodiment of the present invention;

[0050] Figure 6 is a setting value of the phase error drift of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit under the condition that only the measurement error of the #1 conventional magnetic field sensing unit has drifted according to an embodiment of the present invention;

[0051] Figure 7 According to one embodiment of the present invention, under the condition that the measurement error of the #1 conventional magnetic field sensing unit drifts, the amplitude relative error drift of all magnetic field sensing units extracted by the principal component analysis method is obtained;

[0052] Figure 8 According to one embodiment of the present invention, when the measurement error of the conventional magnetic field sensing unit #1 drifts, the phase error drift of all magnetic field sensing units is extracted by using the principal component analysis method;

[0053] Fig. 9The drift of the amplitude relative error of all magnetic field sensing units extracted by combining the principal component analysis method and the error correction method under the condition that the measurement error of the #1 conventional magnetic field sensing unit drifts according to an embodiment of the present invention;

[0054] Fig.10 The drift of the phase errors of all magnetic field sensing units extracted by combining the principal component analysis method and the error correction method under the condition that the measurement error of the #1 conventional magnetic field sensing unit drifts according to an embodiment of the present invention;

[0055] Fig.11 is a setting value of the amplitude relative error drift of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit under the condition that the measurement errors of #1, #2 and #3, i.e., up to three conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0056] Fig.12 is a setting value of the phase error drift of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit under the condition that the measurement errors of #1, #2 and #3, i.e., up to three conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0057] Fig.13 The drift of the relative error of the amplitude of all magnetic field sensing units extracted by the principal component analysis method under the condition that the measurement errors of #1, #2 and #3, i.e., up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0058] Fig.14 The drift of the phase errors of all magnetic field sensing units extracted by the principal component analysis method under the condition that the measurement errors of #1, #2 and #3, i.e., up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0059] Fig.15 The drift of the amplitude relative error of all magnetic field sensing units extracted by combining the principal component analysis method and the error correction method under the condition that the measurement errors of #1, #2 and #3, i.e., up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0060] Fig.16 The drift of the phase errors of all magnetic field sensing units extracted by combining the principal component analysis method and the error correction method under the condition that the measurement errors of #1, #2 and #3, i.e., up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0061] Fig.17A schematic diagram of the relative error of the amplitude of the current measured by the magnetic array current sensor under the condition that the measurement errors of #1, #2 and #3, i.e., up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention;

[0062] Fig.18 The diagram is a schematic diagram of the phase error of the current measured by the magnetic array current sensor under the condition that the measurement errors of #1, #2 and #3, i.e. up to 3 conventional magnetic field sensing units, drift according to one embodiment of the present invention. DETAILED DESCRIPTION

[0063] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0064] Embodiment 1

[0065] like Figure 1 As shown, this embodiment provides a magnetic array current sensor measurement error self-correction method, comprising the following steps:

[0066] Acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit;

[0067] Based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all magnetic field sensing units, the principal component analysis method is used to calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all magnetic field sensing units;

[0068] The measurement error drift of all diamond NV color center quantum magnetic field sensor units is used as a correction amount to correct the measurement error drift of all magnetic field sensor units;

[0069] The difference between the magnetic field results of all magnetic field sensing units and the corrected measurement error drift of all magnetic field sensing units is calculated to obtain the magnetic field results of all magnetic field sensing units when no drift occurs.

[0070] The present invention forms a hybrid magnetic array current sensor that integrates NV color center quantum magnetic field sensing units and conventional magnetic field sensing units by adding one or more diamond NV color center quantum magnetic field sensing units to the magnetic array current sensor composed of conventional magnetic field sensing units. The magnetic field measurement results of the NV color center quantum magnetic field sensing units can be directly traced back to the basic physical constants (magnetic gyrometry ratio of electrons) and frequency, and the current frequency measurement accuracy can reach 10 -18 Up to 10 -19, so its magnetic field measurement results have quantum precision. By utilizing the highly accurate and very stable excellent performance of the diamond NV color center quantum magnetic field sensor unit, and combining the physical information correlation between the measured results of all magnetic field sensor units in the magnetic array current sensor, it is possible to accurately measure the dynamic drift of the measurement error of other conventional magnetic field sensor units, and then realize the online correction of the measurement error of the magnetic array current sensor, so as to ensure the long-term accuracy and reliability of its current measurement results.

[0071] The following describes a method for online self-correction of measurement errors of a magnetic array current sensor according to an embodiment of the present invention with reference to the accompanying drawings, comprising:

[0072] After the magnetic array current sensor is installed on the current line to be measured, it can be calibrated offline or online to determine the matrix relationship between the magnetic field measured by all magnetic field sensing units and the measured current, specifically:

[0073] ; (1)

[0074] in, for J The column vector of the current on a current-carrying conductor at a certain moment, for m The column vector of the magnetic field measured by the magnetic field sensing units at a certain moment, and It is the transfer coefficient matrix that characterizes the mathematical relationship between the measured current and the measured magnetic field.

[0075] The online calibration method is to establish an equation relationship between the measured magnetic field and the measured current based on the Biot-Savart law, use multiple magnetic field sensing units, establish a sufficiently redundant set of equations, take the measured current and the position coordinates of the current-carrying conductor as unknown variables, and take the sensitivity coefficient and spatial geometric position coordinates of the magnetic field sensing unit as known quantities. By solving the above set of equations, the position coordinates of the current-carrying conductor can be solved, and then the transfer coefficient matrix can be calculated. The offline calibration method is to inject the calibration current into the line after the magnetic array current sensor is installed and the measured current line is powered off. The calibration current and the corresponding magnetic field are measured at the same time, and then the transfer coefficient matrix is ​​calculated by formula (1): , and finally complete the online calibration of the magnetic array current sensor.

[0076] In the subsequent long-term current measurement process, the above matrix relationship and the measured magnetic field are used to calculate (or measure) the measured current. In the initial operation stage of the magnetic array current sensor, its measurement accuracy meets the accuracy level requirements. Therefore, the magnetic field results measured in the initial operation stage are taken as training data, recorded as S n×m(S is a matrix consisting of the amplitude or phase of the magnetic field measured by all magnetic field sensing units, n The data length of the magnetic field measured by a single magnetic field sensing unit, m is the total number of magnetic field sensing units), for the convenience of calculation, S n×m Normalize it, that is:

[0077] ; (2)

[0078] in, is a column vector whose elements are all 1; It is the row vector consisting of the average value of each column of the matrix S; It is a diagonal matrix consisting of the standard deviation of each column of the matrix S.

[0079] right Do singular value decomposition, that is:

[0080] ; (3)

[0081] Among them, U and V are the left and right matrices respectively; Λ is the eigenvalue matrix, on its diagonal ( i , i ) is σ i , and the other values ​​are 0.

[0082] The following formula is used to determine the number of principal components: p ,Right now:

[0083] ; (4)

[0084] Among them, λ is the control threshold of the number of principal components. Specifically, λ = 0.85 can be selected.

[0085] The front of the matrix V p The columns are established as the principal element subspace P, and the matrix V p +1 column to m The column is established as the residual subspace Q. During the long-term operation of the magnetic array current sensor, the magnetic field results measured by all magnetic field sensing units are used as test data, denoted as D l×m , and normalize it, namely:

[0086] ; (5)

[0087] Combined with test data D l×mThe main components of the magnetic field results measured by all magnetic field sensing units are extracted by using the principal element subspace. The extracted main components include not only the magnetic field results measured when the magnetic field sensing unit is in a normal measurement error state, but also a part of the magnetic field increment introduced by the drift of the measurement error of the magnetic field sensing unit. The specific expression is:

[0088] ; (6)

[0089] Combined with test data D l×m And residual subspace, to extract the residual components of the magnetic field results measured by all magnetic field sensing units, that is:

[0090] ; (7)

[0091] It should be pointed out that the principal component analysis method alone cannot perfectly extract the magnetic field increment caused by the drift of the measurement error of the magnetic field sensor unit from the measured magnetic field result. That is, the main component calculated according to formula (6) is Compared with the magnetic field measured by all magnetic field sensing units in the normal measurement error state, there is a certain deviation; at the same time, according to formula (7) There is also a certain deviation from the magnetic field increment introduced by the drift of the magnetic field sensor unit measurement error. and Denormalization is performed separately, namely:

[0092] ; (8)

[0093] ; (9)

[0094] Furthermore, for the magnetic field amplitude, the following formula is used to calculate and When the measurement error of all magnetic field sensing units is in a normal state, the relative amplitude error of the measured magnetic field is and , the specific expression is as follows:

[0095] ; (10)

[0096] ; (11)

[0097] Among them, D T is the test data matrix D l×mThe magnetic field result measured when the measurement errors of all corresponding magnetic field sensing units are in a normal state is taken as the accurate value or theoretical value of the measured magnetic field result; the operator . / represents the division of the corresponding elements of the two matrices, and a matrix of the same size is obtained. Generally, the relative error is used to characterize the measurement accuracy of the magnetic field amplitude by the magnetic field sensing unit, and the absolute value of the phase error is directly used to characterize the measurement accuracy of the phase.

[0098] The use of formula (6) cannot perfectly extract the magnetic field increment introduced by the drift of the measurement error of the magnetic field sensor unit from the measured magnetic field data, that is, the extracted magnetic field increment will have a certain deviation from its accurate value; and the main components of the magnetic field results measured by all magnetic field sensor units calculated by formula (7) and the magnetic field results measured when the measurement errors of all magnetic field sensor units are in a normal state also have a certain deviation. Through simulation analysis, it is found that the value of the above deviation shows a certain regularity: when the relative error of the magnetic field amplitude of a magnetic field sensor unit has a drift of err, and the corresponding measurement errors of other magnetic field sensor units have not drifted, the magnitude of the relative error of the magnetic field amplitude of the magnetic field sensor unit with the offset error calculated by formula (11) is ( m -1) / m ×err, while the corresponding amplitude relative error of other magnetic field sensing units is -1 / m ×err; The relative error of the main components of each magnetic field sensor unit calculated by formula (10) relative to the measured magnetic field amplitude when the measurement error state of all magnetic field sensor units is normal is 1 / m ×err.

[0099] Based on the regularity of the measurement magnetic field error obtained by the above analysis and summary, the present invention introduces the diamond NV color center quantum magnetic field sensor unit into the magnetic array current sensor composed of conventional magnetic field sensor units, making full use of its intrinsic characteristics of highly stable measurement performance, that is, its measurement error will not drift over time. The measurement error drift of the diamond NV color center quantum magnetic field sensor unit calculated by the principal component analysis method is is the correction amount, that is:

[0100] ; (12)

[0101] in, for m Column vector The matrix formed.

[0102] Then, the measurement error drift of all magnetic field sensing units calculated by the principal component analysis method is corrected, that is:

[0103] ; (13)

[0104] in, It is the correction result of the measurement error of the magnetic field sensing unit.

[0105] The corrected measurement error drift is denormalized and subtracted from the magnetic field results measured by all magnetic field sensing units to obtain the magnetic field measurement results corresponding to when the measurement errors of all magnetic field sensing units do not drift. ,Right now:

[0106] ; (14)

[0107] in, Represents test data.

[0108] Then, the corrected magnetic field measurement result is substituted into equation (1) to accurately obtain the current measurement result, namely:

[0109] ; (15)

[0110] The relative error ε and phase error of the current amplitude measured by the magnetic array current sensor φ , to evaluate the effectiveness of the online self-correction method for the measurement error of the magnetic array current sensor proposed in the present invention, namely:

[0111] ; (16)

[0112] ; (17)

[0113] in, For the measured J The length of time on a current-carrying conductor is l The matrix composed of reference current phasor data; operation symbol It indicates the phase angle of the current phasor; Measured by magnetic array current sensor J The length of time on a current-carrying conductor is l The matrix composed of the current phasor data.

[0114] Now, in conjunction with an embodiment, the feasibility and effectiveness of the proposed online self-correction method for measurement errors of a magnetic array current sensor incorporating a diamond NV color center quantum magnetic field sensing unit are explained.

[0115] The proposed method is analyzed and verified by simulation.

[0116] Figure 2The figure is a schematic diagram of a magnetic array current sensor composed of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit according to one embodiment of the present invention, and using the same to measure conductor current. It can be seen that all magnetic field sensing units are evenly distributed around the current conductor being measured, and their magnetic sensitivity directions are approximately toward the direction of the magnetic field generated by the current.

[0117] Figure 3 , Figure 4 Schematic diagram of the amplitude and phase of the magnetic field measured by five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit according to one embodiment of the present invention, from top to bottom respectively representing Figure 2 The results of the magnetic field measured by the magnetic field sensing units #1, #2, #3, #4, #5 and #6 are shown, Figures 5 to 16 The above sorting method is adopted; Figure 3 , Figure 4 In the figure, the first 100 data points are training data, corresponding to the results of the magnetic field measured when the measurement errors of all magnetic field sensing units are in a normal state; the last 400 data points are test data, corresponding to the magnetic field results measured after a certain drift of the measurement errors of one or more magnetic field sensing units. In the simulation calculation, white noise is used to simulate the fluctuation of the measured current, and the fluctuation range of the current amplitude is set to 0.9~1.1 of its rated value.

[0118] Figure 5 , Figure 6 The following are setting values ​​of the measurement error drift of five conventional magnetic field sensing units and one diamond NV color center quantum magnetic field sensing unit when the measurement error of the #1 conventional magnetic field sensing unit drifts according to one embodiment of the present invention.

[0119] The training data is normalized, and the principal component subspace and residual subspace P and Q are obtained through equations (3) and (4). Then, the residual subspace Q and the test data D are used, and the drift of the amplitude relative error of the magnetic field sensor unit is calculated through equations (7), (9) and (11). The calculation results are shown in Figure 7 , Figure 8 As shown in the left column, Figure 7 , Figure 8 The right column of is the extracted phase error drift. Figure 7 , Figure 8 It can be seen that the drift of the measurement error of the #1 magnetic field sensor unit extracted by principal component analysis is only 5 / 6 of its set value, while the measurement error drift detected on other magnetic field sensor units with normal measurement errors is -1 / 6 of the set error. It can be seen that the magnetic field increment introduced by the drift of the measurement error of the magnetic field sensor unit cannot be completely removed from the measured magnetic field data by only using the principal component analysis method.

[0120] In view of this, the present invention uses the measurement error drift extracted from the magnetic field measured by the diamond NV color center quantum magnetic field sensor unit as the correction amount, and compensates the measurement error drift detected in all magnetic field sensor units through formula (13), and then accurately obtains the measurement error drift of all magnetic field sensor units, see Fig. 9 , Fig.10 .Depend on Fig. 9 , Fig.10 It can be seen that the calculated drift of the relative error of the magnetic field amplitude and the phase error of all magnetic field sensing units are consistent with their set values.

[0121] Without loss of generality, when the measurement errors of multiple magnetic field sensing units (#1, #2 and #3) drift, such as Fig.11 , Fig.12 Then, only the principal component analysis method is used to extract the relative amplitude error and phase error drift of all magnetic field sensing units. The corresponding results are shown in Fig.13 , Fig.14 It can be seen that there is still a certain gap between the measured error drift calculated in this way and the set value; when the method combining principal component analysis and error drift correction proposed in the present invention is adopted, the amplitude relative error and phase error drift results of all magnetic field sensor units are extracted, as shown in detail. Fig.15 , Fig.16 As shown by Fig.15 , Fig.16 It can be seen that the error drift calculated in this way is basically consistent with its set value.

[0122] To set by Fig.11 , Fig.12 The magnetic field measured by the magnetic field sensor unit with the measured error drift is shown in Figure 1, and combined with equations (16) and (17), the amplitude relative error and phase error of the measured current are calculated respectively. The corresponding results are shown in Fig.17 , Fig.18 The first line; Fig.13 , Fig.14 The measurement error drift of the magnetic field sensing unit extracted as shown is used to compensate the magnetic field result measured by the magnetic field sensing unit, and the relative amplitude error and phase error of the measured current are calculated according to equations (16) and (17) respectively based on the compensated magnetic field result. The corresponding results are shown in Fig.17 , Fig.18 As shown in the second row; Fig.15 , Fig.16 The measurement error drift of the magnetic field sensing unit extracted as shown is used to compensate the magnetic field result measured by the magnetic field sensing unit, and the relative amplitude error and phase error of the measured current are calculated according to equations (16) and (17) respectively based on the compensated magnetic field result. The corresponding results are shown in Fig.17 , Fig.18 As shown in the third row. Fig.17 , Fig.18 It can be seen that the online self-correction method for measurement errors of magnetic array current sensors that incorporate diamond NV color center quantum magnetic field sensing units proposed in the present invention can ensure that the measurement errors of the magnetic array current sensors remain in a normal state, that is, will not exceed the tolerance, even when the measurement errors of multiple conventional magnetic field sensing units drift.

[0123] To sum up, the online self-correction method of measurement error of the magnetic array current sensor incorporating the diamond NV color center quantum magnetic field sensing unit proposed in the present invention can realize the accurate calculation of the measurement error drift of the conventional magnetic field sensing unit, thereby ensuring that the magnetic array current sensor can operate accurately and reliably for a long time.

[0124] Embodiment 2

[0125] This embodiment provides a magnetic array current sensor measurement error self-correction system, including:

[0126] A data acquisition module, which is configured to: acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit;

[0127] A principal component analysis module is configured to: calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all magnetic field sensing units using a principal component analysis method based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all magnetic field sensing units;

[0128] An error calculation module is configured to: use the measurement error drift of all diamond NV color center quantum magnetic field sensing units as a correction amount to correct the measurement error drift of all magnetic field sensing units;

[0129] The correction module is configured to calculate the difference between the magnetic field results of all magnetic field sensing units and the measurement error drift of all magnetic field sensing units after correction, and obtain the magnetic field results of all magnetic field sensing units when no drift occurs.

[0130] In some embodiments, the system further includes a processing module, which is configured to: take the magnetic field results of all magnetic field sensing units as test data and perform normalization processing; extract the main components based on the normalized test data and the principal component subspace; extract the residual components based on the normalized test data and the residual subspace; denormalize the main components and the residual components to obtain the denormalized main components and residual components;

[0131] Based on the denormalized main components and residual components, combined with the magnetic field results measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, the relative errors of the main components relative to the magnetic field amplitude measured when the measurement errors of all magnetic field sensing units are in a normal state, as well as the relative errors of the magnetic field amplitude of the magnetic field sensing units with offset errors are calculated respectively.

[0132] Specifically, the relative error of the main component relative to the magnetic field amplitude measured when the measurement error state of all magnetic field sensing units is normal is calculated using the following formula:

[0133] ;

[0134] in, It indicates the relative error of the main component relative to the magnetic field amplitude measured when the measurement error state of all magnetic field sensing units is normal. represents the main component after denormalization, D T It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

[0135] Specifically, the relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset is calculated using the following formula:

[0136] ;

[0137] in, Indicates the relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset, represents the residual component after denormalization, D T It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

[0138] A third aspect of the present invention provides a magnetic array current sensor measurement error self-correction system.

[0139] A magnetic array current sensor comprises a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit. The magnetic field sensing units are error corrected by using the steps in the magnetic array current sensor measurement error self-correction method described in the first embodiment.

[0140] Embodiment 4

[0141] This embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for self-correction of measurement errors of a magnetic array current sensor as described in the first embodiment are implemented.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnetic array current sensor measurement error self-correction method, characterized in that: include: Acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit; Based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all conventional magnetic field sensing units, the principal component analysis method is used to calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all conventional magnetic field sensing units; After obtaining the magnetic field results of all magnetic field sensing units, it also includes: normalizing the magnetic field results of all magnetic field sensing units; after the normalization, it includes: performing singular value decomposition on the magnetic field results of all magnetic field sensing units after the normalization to obtain a principal component subspace and a residual subspace; after obtaining the principal component subspace and the residual subspace, it includes: taking the magnetic field results of all magnetic field sensing units as test data and performing normalization; extracting the main components based on the normalized test data and the principal component subspace; extracting the residual components based on the normalized test data and the residual subspace; denormalizing the main components and the residual components to obtain the denormalized main components and residual components; based on the denormalized main components and residual components, combined with the magnetic field results measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, respectively calculating the relative errors of the main components relative to the magnetic field amplitudes measured when the measurement errors of all magnetic field sensing units are in a normal state, and the relative errors of the magnetic field amplitudes of the magnetic field sensing units with offset errors; The measurement error drift of all diamond NV color center quantum magnetic field sensor units is used as a correction amount to correct the measurement error drift of all conventional magnetic field sensor units; The difference between the magnetic field results of all conventional magnetic field sensing units and the corrected measurement error drift of all conventional magnetic field sensing units is calculated to obtain the magnetic field results of all conventional magnetic field sensing units when no drift occurs.

2. The magnetic array current sensor measurement error self-correction method according to claim 1, characterized in that: After the hybrid magnetic array current sensor is installed on the current line to be measured, an online or offline calibration is performed to determine the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

3. The magnetic array current sensor measurement error self-correction method according to claim 2, characterized in that: The online calibration method includes: establishing an equation relationship between the measured magnetic field and the measured current according to the Biot-Savart law, using multiple magnetic field sensing units to construct an equation group; taking the measured current and the position coordinates of the current-carrying conductor as unknown variables, taking the sensitivity coefficients and the spatial geometric position coordinates of all magnetic field sensing units as known quantities, solving the equation group, and calculating the transfer coefficient matrix; based on the transfer coefficient matrix, determining the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

4. The magnetic array current sensor measurement error self-correction method according to claim 2, characterized in that: The offline calibration method includes: when the measured current line is out of power, injecting a standard current into the line, and calculating a transfer coefficient matrix based on the measured calibration current and the corresponding magnetic field to determine the matrix relationship between the magnetic field of all magnetic field sensing units and the measured current.

5. The magnetic array current sensor measurement error self-correction method according to claim 1, characterized in that: The process of obtaining the pivot subspace includes: determining the number of pivots p, and determining the first p columns of the right matrix obtained by singular value decomposition as the pivot subspace.

6. The magnetic array current sensor measurement error self-correction method according to claim 5, characterized in that: To determine the number of principal components p, use the following formula: ； in, σ i represents the value on the diagonal of the eigenvalue matrix of the magnetic field results of all magnetic field sensing units after normalization, λ is the control threshold of the number of principal elements, m is the total number of magnetic field sensing units.

7. The magnetic array current sensor measurement error self-correction method according to claim 5, characterized in that: The process of obtaining the residual subspace includes: transforming the right matrix p The matrix consisting of the +1 column to the last column is determined as the residual subspace.

8. The magnetic array current sensor measurement error self-correction method according to claim 1, characterized in that: The relative error of the main component relative to the measured magnetic field amplitude when the measurement error state of all magnetic field sensing units is normal is calculated using the following formula: ； in, It indicates the relative error of the main component relative to the magnetic field amplitude measured when the measurement error state of all magnetic field sensing units is normal. represents the main component after denormalization, D T It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

9. The magnetic array current sensor measurement error self-correction method according to claim 1, characterized in that: The relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset is calculated using the following formula: ； in, Indicates the relative error of the magnetic field amplitude of the magnetic field sensing unit where the error is offset, represents the residual component after denormalization, D T It represents the magnetic field result measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, and . / represents the division of the corresponding elements of the two matrices.

10. The magnetic array current sensor measurement error self-correction method according to any one of claims 1 to 9, characterized in that: The magnetic field results of all magnetic field sensing units include a matrix consisting of amplitude or phase.

11. A magnetic array current sensor measurement error self-correction system, characterized in that: include: A data acquisition module, which is configured to: acquire magnetic field results of all magnetic field sensing units of a hybrid magnetic array current sensor, wherein the hybrid magnetic array current sensor includes a plurality of conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit; A principal component analysis module is configured to: calculate the measurement error drift of all diamond NV color center quantum magnetic field sensing units and the measurement error drift of all conventional magnetic field sensing units using a principal component analysis method based on the magnetic field results of all diamond NV color center quantum magnetic field sensing units and the magnetic field results of all conventional magnetic field sensing units; After obtaining the magnetic field results of all magnetic field sensing units, it also includes: normalizing the magnetic field results of all magnetic field sensing units; after the normalization, it includes: performing singular value decomposition on the magnetic field results of all magnetic field sensing units after the normalization to obtain a principal component subspace and a residual subspace; after obtaining the principal component subspace and the residual subspace, it includes: taking the magnetic field results of all magnetic field sensing units as test data and performing normalization; extracting the main components based on the normalized test data and the principal component subspace; extracting the residual components based on the normalized test data and the residual subspace; denormalizing the main components and the residual components to obtain the denormalized main components and residual components; based on the denormalized main components and residual components, combined with the magnetic field results measured when the measurement errors of all magnetic field sensing units corresponding to the test data are in a normal state, respectively calculating the relative errors of the main components relative to the magnetic field amplitudes measured when the measurement errors of all magnetic field sensing units are in a normal state, and the relative errors of the magnetic field amplitudes of the magnetic field sensing units with offset errors; An error calculation module is configured to: use the measurement error drift of all diamond NV color center quantum magnetic field sensing units as a correction amount to correct the measurement error drift of all conventional magnetic field sensing units; The correction module is configured to calculate the difference between the magnetic field results of all conventional magnetic field sensing units and the measurement error drift of all conventional magnetic field sensing units after correction, and obtain the magnetic field results of all conventional magnetic field sensing units when no drift occurs.

12. A magnetic array current sensor, characterized in that: It comprises several conventional magnetic field sensing units and at least one diamond NV color center quantum magnetic field sensing unit; the magnetic field sensing units are corrected for errors by using the steps in the magnetic array current sensor measurement error self-correction method described in any one of claims 1 to 10.

13. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps in the method for self-correcting measurement errors of a magnetic array current sensor as described in any one of claims 1 to 10 are implemented.

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