Method and storage medium for measuring phase current of three-core cable based on tweezer-shaped Hall array

Abstract

The present invention discloses a method and a storage medium for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array. The method includes: setting six measurement points on the surface and periphery of the three-core cable to establish a theoretical magnetic field sensing model of the three-core cable; according to the theoretical magnetic field sensing model of the three-core cable, using Ampere's circuital law to deduce the transfer function between the phase current of the three-core cable and the magnetic induction intensities at the six measurement points, and obtaining a non-linear overdetermined system of equations; acquiring the magnetic induction intensity measurement data at the six measurement points, and constructing an objective function based on the magnetic induction intensity measurement data and the non-linear overdetermined system of equations; using a differential evolution algorithm to perform optimization calculation on the objective function to obtain the phase current values of each phase of the three-core cable. The present invention can achieve accurate measurement of the phase current of the three-core cable through the tweezer-shaped Hall array and the differential evolution algorithm.

Description

Technical Field

[0001] The present invention relates to the technical field of phase current detection, and in particular to a method and a storage medium for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array. Background Art

[0002] The 10 kV three-core cable is the backbone of the urban distribution network. The mixed operation of overhead lines and cables is widespread. It still takes a long time to change the grounding method of the transformer neutral point from through an arc suppression coil to through a small resistor, etc. More than 70% of the faults of distribution network cables are single-phase grounding, and cable channel fires caused thereby often occur.

[0003] With the increase in the usage of three-core cables, the failure rate of the cables will also continuously increase. When searching for a fault point of a 10 kV three-core cable, it is necessary to remove the three-core cable joint of the faulty circuit in the medium-voltage switchgear and inject electromagnetic pulse signals phase by phase, but on-site operation is not easy. Phase current can distinguish the normal and abnormal states of the cable and can be used for fault diagnosis and topology verification. Therefore, the detection of the phase current of the three-core cable is very meaningful. However, when the three-core cable is in steady-state operation, the zero-sequence current is zero, and the traditional zero-sequence current transformer cannot detect the phase currents of the three-core cable. Since when current flows through a wire, a circular magnetic field proportional to the current and inversely proportional to the distance will be generated, and the accurate measurement of the magnetic field can achieve the accurate measurement of the cable phase current. Therefore, a method for inverting the phase current of a three-core cable by measuring the magnetic field on the surface of the three-core cable is needed. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this purpose, the first object of the present invention is to provide a method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array, and through this method, the accurate measurement of the phase current of the three-core cable can be achieved.

[0005] The second object of the present invention is to provide a computer-readable storage medium.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] A method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array includes:

[0008] Step S1: Six measurement points are set on the surface and around the three-core cable to establish a theoretical magnetic field sensing model of the three-core cable;

[0009] Step S2: According to the theoretical magnetic field sensing model of the three-core cable, the transfer function between the phase current of the three-core cable and the magnetic induction intensity at the six measurement points is deduced by using Ampere's circuital law, and a non-linear overdetermined system of equations is obtained;

[0010] Step S3: Obtain the magnetic induction intensity measurement data of six measurement points, and construct an objective function according to the magnetic induction intensity measurement data and the non-linear overdetermined equations;

[0011] Step S4: Use the differential evolution algorithm to perform optimization calculation on the objective function to obtain the phase current values of the three-core cable.

[0012] Optionally, the step S1 includes:

[0013] Step S11: Establish a rectangular coordinate system with the center of the cross-section of the three-core cable as the origin. The rectangular coordinate system divides the circular cross-section of the three-core cable into four parts, and the four parts correspond to the four quadrants of the rectangular coordinate system. Among them, the vertical axis of the rectangular coordinate system passes through the center of the circle of the first core cable in the three-core cable;

[0014] Step S12: Set a first measurement point at the midpoint position of the arc segment in the first quadrant part of the circular cross-section, and set a second measurement point at the midpoint position of the arc segment in the second quadrant part of the circular cross-section;

[0015] Step S13: Make a first tangent at the first measurement point, and the first tangent intersects the positive semi-vertical axis to obtain an intersection point. Set the third measurement point and the fourth measurement point equidistantly along the first tangent between the intersection point and the first tangent point. And make a second tangent at the second measurement point, the second tangent passes through the intersection point, and set the fifth measurement point and the sixth measurement point equidistantly along the second tangent between the intersection point and the second tangent point.

[0016] Optionally, the magnetic induction intensity at the six measurement points in the step S2 is specifically the magnetic induction intensity measured by the six measurement points respectively along the horizontal axis direction of the rectangular coordinate system.

[0017] Optionally, the non-linear overdetermined equations in the step S2 are expressed as follows:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] Among them, B1 to B6 are the magnetic induction intensities at the six measurement points, I A 、IB and I C are the instantaneous values of the currents in each phase of a three-core cable, μ0 is the magnetic permeability of vacuum, π is the ratio of the circumference of a circle to its diameter, R is the radius of the three-core cable, r A , r B and r C are the distances from the origin of the rectangular coordinate system to the centers of the respective cores in the three-core cable, α is the angle between the negative semi-vertical axis and the positive semi-horizontal axis, sin is the sine function, and cos is the cosine function.

[0025] Optionally, the objective function is expressed as follows:

[0026]

[0027] where B S is the theoretically calculated value of the magnetic induction intensity at the S-th measurement point, is the measured value of the magnetic induction intensity at the S-th measurement point, S represents which measurement point, G represents the objective function, and ∑ represents the summation function.

[0028] Optionally, the constraint conditions corresponding to the objective function are:

[0029]

[0030] where I min is the lower limit value of the phase current, and I max is the upper limit value of the phase current.

[0031] Optionally, in step S4, the differential evolution algorithm is as follows:

[0032] Step S41: Initialize the population;

[0033] Step S42: Calculate the objective function value of each individual in the initial population, where the individual is the current in each phase, and the individual corresponding to the minimum objective function value is the best individual;

[0034] Step S43: Determine whether the termination condition is reached. If so, output the best individual at this time as the solution; otherwise, go to step S44;

[0035] Step S44: Perform mutation, crossover operations and boundary processing to obtain a temporary population;

[0036] Step S45: Substitute the temporary population into the objective function to calculate the function value, and perform a one-to-one selection operation on the temporary population and the original population to update and obtain a new population, and return to step S43.

[0037] Optionally, the step of obtaining the current value of each phase of the three-core cable in step S4 includes: performing curve fitting on the instantaneous current value corresponding to each preset time within an industrial frequency cycle obtained by using the differential evolution algorithm to extract the amplitude of each phase current.

[0038] Optionally, the method further includes: extracting the phase of each phase current by curve fitting.

[0039] To achieve the above-mentioned purpose, the second aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for measuring the phase current of a three-core cable based on a tweezers Hall array is implemented.

[0040] The present invention has at least the following technical effects:

[0041] In view of the fact that the zero-sequence current of the three-core cable is zero when it is running in a steady state, the traditional ferromagnetic current transformer cannot detect the current of each phase of the three-core cable. Considering the problem that the Hall sensor array is easy to install and implement, the present invention proposes a method for measuring the phase current of the three-core cable based on a tweezer-shaped Hall array. The method establishes a magnetic field sensing calculation model on the surface of the three-core cable, proposes to use a tweezer-shaped Hall sensor array composed of six Hall sensors to measure the magnetic induction intensity at six test points on the surface of the three-core cable, and derives the transfer function of the phase current and the magnetic induction intensity at the six measuring points, constructs a nonlinear overdetermined equation group composed of four unknown quantities and six equations, and then uses a differential evolution algorithm to transform the problem of solving the equation group into the problem of finding the extreme value of the function. Compared with directly finding an analytical solution, it greatly saves time. In addition, the present invention solves the problem that the traditional ferromagnetic current transformer cannot measure the phase current of the three-core cable, and the tweezer-shaped sensor array is used, which is more convenient to install.

[0042] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a flowchart of a method for measuring phase current of a three-core cable based on a tweezers Hall array according to an embodiment of the present invention.

[0044] Figure 2 Schematic diagram of a theoretical magnetic field sensing model of a three-core cable according to an embodiment of the present invention.

[0045] Figure 3 Flow chart of the differential evolution algorithm of an embodiment of the present invention.

[0046] Figure 4 Schematic diagram of a fitting curve of three-phase current according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The present embodiment will be described in detail below. Examples of the embodiment are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0048] A method and a storage medium for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to the present embodiment will be described below with reference to the accompanying drawings.

[0049] Figure 1 It is a flowchart of the method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to the embodiment of the present invention. As Figure 1 shown, the method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array includes:

[0050] Step S1: Six measurement points are set on the surface and periphery of the three-core cable to establish a theoretical magnetic field sensing model of the three-core cable.

[0051] Figure 2 It is a schematic diagram of the theoretical magnetic field sensing model of the three-core cable according to the embodiment of the present invention. Figure 2 The theoretical magnetic field sensing model of the three-core cable shown is established according to the following steps, that is, step S1 includes:

[0052] Step S11: A rectangular coordinate system is established with the center of the cross-section of the three-core cable as the origin. The rectangular coordinate system divides the circular cross-section of the three-core cable into four parts, and the four parts correspond to the four quadrants of the rectangular coordinate system. Among them, the vertical axis of the rectangular coordinate system passes through the center of the circle of the first core cable in the three-core cable, that is, point A.

[0053] Step S12: A first measurement point, that is, M6, is set at the midpoint position of the arc segment in the first quadrant part of the circular cross-section, and a second measurement point, that is, M3, is set at the midpoint position of the arc segment in the second quadrant part of the circular cross-section.

[0054] Step S13: A first tangent is made at the first measurement point M6, and the first tangent intersects the positive semi-vertical axis to obtain an intersection point. Along the first tangent, a third measurement point M4 and a fourth measurement point M5 are equidistantly arranged between the intersection point and the first tangent point M6. And a second tangent is made at the second measurement point M3, and the second tangent passes through the intersection point. Along the second tangent, a fifth measurement point M1 and a sixth measurement point M2 are equidistantly arranged between the intersection point and the second tangent point M3. Thus, a Hall sensor array can be designed, and a theoretical magnetic field sensing model of the three-core cable can be established. It should be noted that this Hall sensor array is a tweezer-shaped Hall sensor array different from the Hall sensor array in the prior art. In this embodiment, the phase currents of the three-core cable are mainly measured through this tweezer-shaped Hall sensor array and its corresponding measurement method.

[0055] Specifically, a Hall sensor array can be designed. For example, six magnetic field measurement points can be designed on the surface and around a three-core cable, and six Hall sensors are used to measure the magnetic field. The specific design of the Hall sensor positions is as shown in Figure 2 M1 to M6 in the figure. Among them, point O is the center of the three-core cable and also the origin of the rectangular coordinate system. Points A, B, and C are the centers of the three-phase cores, that is, the centers of the first core cable to the third core cable. The distances from point O to the centers of each core are r A , r B , r C , respectively. The radius of the three-core cable is R. The angles between OA, OB, and OC and the positive x-axis (horizontal axis) are α, β, and γ, respectively. Therefore, the coordinates of point A are (r A cosα, r A sinα), the coordinates of point B are (r B cosβ, r B sinβ), and the coordinates of point C are (r C cosγ, r C sinγ), where the angles α, β, and γ differ by 120° from each other. In addition, the coordinates of the positions M1 to M6 of the tweezer-shaped Hall sensor array designed in the figure are In the figure is perpendicular to the direction. The Hall sensor measures the magnetic induction intensity along the direction, that is, the horizontal axis direction, where represents the vector in the vertical axis direction, and represents the vector in the horizontal axis direction.

[0056] Step S2: According to the magnetic field theoretical sensing model of the three-core cable, use Ampere's circuital law to deduce the transfer function between the phase currents of the three-core cable and the magnetic induction intensities at the six measurement points, and obtain a non-linear overdetermined system of equations.

[0057] In this embodiment, Ampere's circuital law can be used to obtain the transfer functions of the phase currents and the magnetic induction intensities along the direction at the measurement points M1 to M6, and the non-linear overdetermined system of equations is obtained by combining them. The non-linear overdetermined system of equations is expressed as follows:

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] Among them, B1 to B6 are the magnetic induction intensities at six measurement points, and I A , I B and I C are the instantaneous values of the phase currents of a three-core cable, μ0 is the magnetic permeability of vacuum, π is the ratio of the circumference of a circle to its diameter, R is the radius of the three-core cable, and r A , r B and r C are the distances from the origin of the rectangular coordinate system to the centers of the respective cores in the three-core cable, α is the angle between the negative semi-vertical axis and the positive semi-horizontal axis, that is, the angle between OA and the positive horizontal axis, sin is the sine function, and cos is the cosine function.

[0065] Since I A , I B and I C , as well as the included angle α are unknowns, the others are known quantities, and there is a sine term about the included angle α in the system of equations. Additionally, the number of unknowns in the system of equations is less than the number of equations. Therefore, this system of equations is a non-linear overdetermined system of equations.

[0066] Step S3: Obtain the magnetic induction intensity measurement data of six measurement points, and construct an objective function based on the magnetic induction intensity measurement data and the non-linear overdetermined system of equations.

[0067] Among them, the objective function is expressed as follows:

[0068]

[0069] Among them, B S is the theoretical calculated value of the magnetic induction intensity at the S-th measurement point, is the measured value of the magnetic induction intensity at the S-th measurement point, S represents which measurement point, G represents the objective function, and ∑ represents the summation function.

[0070] Further, the constraint conditions corresponding to the objective function can be determined as:

[0071]

[0072] Among them, I min is the lower limit value of the phase current, and I max is the upper limit value of the phase current.

[0073] Thus, the problem of solving the original non-linear overdetermined system of equations can be transformed into a function optimization problem, that is, solving the objective function G under this constraint condition. When the objective function G takes the minimum value, at this time, the corresponding three-phase current values are the optimal solutions of the phase currents in the system of equations to be solved.

[0074] Step S4: Use the differential evolution algorithm to perform optimization calculation on the objective function to obtain the phase currents of the three-core cable.

[0075] In step S4, the differential evolution algorithm is as follows:

[0076] Step S41: Initialize the population.

[0077] Step S42: Calculate the objective function values of each individual in the initial population, where the individual is the phase current, and the individual corresponding to the minimum objective function value is the best individual.

[0078] Step S43: Determine whether the termination condition is reached. If so, output the best individual at this time as the solution; otherwise, go to step S44.

[0079] Step S44: Perform mutation, crossover operations and boundary processing to obtain a temporary population.

[0080] Step S45: Substitute the temporary population into the objective function to calculate the function value, and perform a one-to-one selection operation on the temporary population and the original population to update and obtain a new population, and then return to step S43.

[0081] Figure 3 This is the flowchart of the differential evolution algorithm according to the embodiment of the present invention. As Figure 3 shown, the population can be initialized and the control parameters of the differential evolution algorithm can be determined, and then the initial population is evaluated, the objective function values of each individual in the initial population are calculated, and then it is determined whether the termination condition is reached. If so, the best individual at this time is output as the solution; otherwise, the next operation is performed, that is, mutation, crossover operations and boundary condition processing are performed to obtain a temporary population, and then the temporary population is substituted into the objective function to calculate the function value, and a one-to-one selection operation is performed on the temporary population and the original population to obtain a new population, and then return to the step of determining whether the termination condition is reached.

[0082] Furthermore, the step of obtaining the phase currents of the three-core cable in step S4 includes curve fitting the current instantaneous values corresponding to each preset time (such as 1 millisecond) within a power frequency cycle obtained by using the differential evolution algorithm to extract the amplitudes and phases of the phase currents.

[0083] As a specific example, when the three-core cable is in steady-state operation, the instantaneous expression of the phase current can be set as:

[0084]

[0085] where, i a (t), i b (t) and i c(t) are the three-phase instantaneous currents respectively, w is the angular frequency, w = 100π, and t is the time.

[0086] The phasor expressions of the above three-phase instantaneous currents are respectively: and are the phasor parameters corresponding to the three phases respectively. Further, the parameters of the three-core cable can be set as R = 38.96 mm, r A = 17.61 mm, r B = 18.61 mm, r C = 19.61 mm, and the included angles α, β, γ are 270°, 150°, 30° respectively. In the simulation analysis, the magnetic induction intensity along the direction at six measurement points can be calculated using formulas (1) to (6), and then it is used as the simulated magnetic field measurement data and substituted into the objective function G. Then, the differential evolution algorithm is used for inverse deduction and solution to obtain the instantaneous current values at corresponding moments every 1 millisecond within a period. Then, the current instantaneous values are curve-fitted to obtain the amplitudes and phases of the phase currents.

[0087] In this example, the fitting curves of the three-phase currents obtained by inverse deduction are as shown in Figure 4 The phasor expressions of the phase currents finally obtained by inverse deduction are: The inverse deduction current error results are listed in Table 1 below:

[0088] Table 1 is the inverse deduction three-phase current error value

[0089]

[0090] As shown in Table 1, compared with the set true values of the three-phase currents, the absolute values of the amplitude errors of the ABC three-phase currents are 0.02 A (ampere), 0.06 A, and 0.06 A respectively, and the absolute values of the phase errors of the three-phase currents are 0.00° (degree), 0.01°, and 0.01° respectively. Obviously, the errors are very small, which can show the effectiveness of this method.

[0091] Further, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for measuring the phase currents of a three-core cable based on a tweezer-shaped Hall array as described above can be realized.

[0092] In summary, in view of the fact that the zero-sequence current of a three-core cable is zero during steady-state operation, and traditional ferromagnetic current transformers cannot detect the phase currents of a three-core cable. At the same time, considering the problem that the Hall sensing array is easy to install and implement, a method for measuring the phase currents of a three-core cable based on a tweezer-shaped Hall array is proposed. This method establishes a magnetic field sensing calculation model on the surface of the three-core cable, proposes to use a tweezer-shaped Hall sensing array composed of six Hall sensors to measure the magnetic induction intensities at six points to be measured on the surface of the three-core cable, and deduces the transfer function between the phase current and the magnetic induction intensities at the six measurement points, constructs a non-linear overdetermined system of equations composed of four unknowns and six equations, and then uses the differential evolution algorithm to transform the problem of solving the system of equations into the problem of finding the extreme value of a function. Compared with directly finding the analytical solution, it greatly saves time. In addition, this invention solves the problem that traditional ferromagnetic current transformers cannot measure the phase currents of a three-core cable, and the method of using a tweezer-shaped sensor array is more convenient for installation.

[0093] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0094] Although the content of the present invention has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array, characterized in that, Including: Step S1: Set six measurement points on the surface and periphery of a three-core cable to establish a theoretical sensing model of the three-core cable magnetic field. The step S1 includes: Step S11: Establish a rectangular coordinate system with the center of the cross-section of the three-core cable as the origin. The rectangular coordinate system divides the circular cross-section of the three-core cable into four parts, and the four parts correspond to the four quadrants of the rectangular coordinate system. Among them, the vertical axis of the rectangular coordinate system passes through the center of the circle of the first core cable in the three-core cable. Step S12: Set a first measurement point at the midpoint position of the arc segment in the first quadrant part of the circular cross-section, and set a second measurement point at the midpoint position of the arc segment in the second quadrant part of the circular cross-section. Step S13: Make a first tangent at the first measurement point. The first tangent intersects the positive semi-vertical axis to obtain an intersection point. Equally spaced set a third measurement point and a fourth measurement point between the intersection point and the first tangent point. And make a second tangent at the second measurement point. The second tangent passes through the intersection point. Equally spaced set a fifth measurement point and a sixth measurement point between the intersection point and the second tangent point. Step S2: According to the theoretical sensing model of the three-core cable magnetic field, use Ampere's loop theorem to deduce the transfer function between the phase currents of the three-core cable and the magnetic induction intensities at the six measurement points, and obtain a non-linear overdetermined system of equations. The non-linear overdetermined system of equations in the step S2 is expressed as follows: Among them, B1 to B6 are the magnetic induction intensities at six measurement points, and I A , I B , and I C are the instantaneous values of the currents in each phase of the three-core cable, μ0 is the magnetic permeability of vacuum, π is the ratio of the circumference of a circle to its diameter, R is the radius of the three-core cable, r A , r B , and r C are the distances from the origin of the rectangular coordinate system to the centers of the cores in the three-core cable respectively, α is the angle between the negative semi-vertical axis and the positive semi-horizontal axis, sin is the sine function, and cos is the cosine function; Step S3: Obtain the magnetic induction intensity measurement data of the six measurement points, and construct an objective function according to the magnetic induction intensity measurement data and the non-linear overdetermined system of equations. The objective function is expressed as follows: Among them, B S is the theoretically calculated value of the magnetic induction intensity at the S-th measurement point, is the measured value of the magnetic induction intensity at the S-th measurement point, S represents which measurement point, G represents the objective function, and ∑ represents the summation function; Step S4: Use the differential evolution algorithm to perform optimization calculation on the objective function to obtain the phase current values of the three-core cable.

2. The method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to claim 1, wherein, The magnetic induction intensities at the six measurement points in the step S2 are specifically the magnetic induction intensities measured by the six measurement points along the horizontal axis direction of the rectangular coordinate system.

3. The method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array as claimed in claim 1, wherein, The constraint conditions corresponding to the objective function are: Among them, I min is the lower limit value of the phase current, and I max is the upper limit value of the phase current.

4. The method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to claim 1, characterized in that, In the step S4, the differential evolution algorithm is: Step S41: Initialize the population. Step S42: Calculate the objective function values of each individual in the initial population, where the individual is the phase current, and the individual corresponding to the minimum objective function value is the best individual. Step S43: Judge whether the termination condition is reached. If so, output the best individual at this time as the solution. Otherwise, enter step S44. Step S44: Perform mutation, crossover operations and boundary processing to obtain a temporary population. Step S45: Substitute the temporary population into the objective function to calculate the function value, and perform a one-to-one selection operation on the temporary population and the original population to update and obtain a new population, and return to step S43.

5. The method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to claim 1, wherein The steps of obtaining the phase current values of the three-core cable in the step S4 include: Perform curve fitting on the current instantaneous values corresponding to each preset time interval within a power frequency cycle obtained by using the differential evolution algorithm to extract the amplitudes of the phase currents.

6. The method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array according to claim 5, wherein Also including: Extract the phases of the phase currents through curve fitting.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method for measuring the phase current of a three-core cable based on a tweezer-shaped Hall array as described in any one of claims 1-6.

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