Adaptive wire current anti-interference measurement method and system, and storage medium

Abstract

The present invention discloses an adaptive conductor current anti-interference measurement method and system, and a storage medium. The method is implemented based on three collinear TMR magnetoresistive chips and includes: obtaining distances x1, x2, and x3 between the three collinear TMR magnetoresistive chips and the conductor; when the distances x1, x2, and x3 change relative to preset calibration values, obtaining multiple magnetic field signals within a preset frequency range based on the frequency domain, calculating the variance of the multiple magnetic field signals, adaptively adjusting the Gaussian standard deviation of a Gaussian low-pass filter based on the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and using the adaptively adjusted Gaussian low-pass filter to perform low-pass Gaussian filtering on the magnetic field signals detected by the three collinear TMR magnetoresistive chips; further, performing high-pulse filtering on the magnetic field signal after the low-pass Gaussian filtering, and finally calculating the conductor current based on the magnetic field signal after the high-pulse filtering.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to an adaptive conductor current anti-interference measurement method and system, and a storage medium. Background Art

[0002] Accurate current sensing in power systems is the basis for transient information monitoring, accident warning, status analysis, and decision-making in power grids. In substations, lightning arrester leakage current, transformer core grounding current, high-frequency local current, etc. are important parameters for fault warning of equipment such as lightning arresters, transformers, and power cables. Currently, magnetic field sensors are usually installed on the ground wire to calculate the conductor current based on the surrounding magnetic field inversion, thereby monitoring the operating status of the substation equipment. For example, the prior art of the patent document with authorization announcement number CN109283380B discloses a method, device, equipment, and storage medium for measuring line current in a power system. In this prior art, it is only necessary to obtain the first magnetic induction intensity, second magnetic induction intensity, and third magnetic induction intensity generated by the current-carrying conductor in the magnetic sensitive direction of three single-axis magnetic sensors and the relative distance between the three single-axis magnetic sensors to calculate the current value of the current-carrying conductor and realize the measurement of the current of the current-carrying conductor. Meanwhile, for the three uniaxial magnetic sensors, as long as they are located on the same straight line, the straight line is not coplanar with the current-carrying conductor, and the magnetic sensitivity directions of the three uniaxial magnetic sensors are in the same direction and parallel to the straight line. However, substations present a complex electromagnetic environment. In particular, localized discharges such as corona discharge and creeping discharge in substation equipment can generate high-frequency electromagnetic signal interference, thereby affecting the detection results of magnetic field sensors and even causing serious accidents such as false alarms or missed alarms of substation equipment failures. The prior art with authorization publication number CN109283380B does not address the treatment of electromagnetic signal interference.

[0003] In order to suppress the interference of high-frequency electromagnetic signals, software and hardware methods are currently commonly used to filter and reduce noise on the signals collected by sensors. The technical principles and existing technical problems are as follows:

[0004] One method is to design hardware anti-interference circuits to suppress interference. For example, a study designed a differential balance circuit, which uses an interfering magnetic field to form two current signals with the same amplitude and opposite directions to perform common-mode differential interference suppression. However, due to the diversity of on-site interference and different propagation paths, the input signals at both ends of the differential cannot be completely symmetrical, resulting in poor interference suppression effect.

[0005] Another method is to denoise the signal through software algorithms. For example, the time domain signal is converted into the frequency domain through Fourier transform, and the interference signal is eliminated according to the threshold. However, this method is also difficult to select the optimal threshold when the interference on site is diverse, and it is easy to mistakenly eliminate the harmonic signal.

[0006] In summary, it is urgent to propose a technical solution that can better suppress the interference of high-frequency electromagnetic signals. Summary of the Invention

[0007] The purpose of the present invention is to provide an adaptive wire current anti-interference measurement method and system, and a storage medium to solve the above technical problems and achieve better suppression of interference from high-frequency electromagnetic signals.

[0008] To achieve the above objectives, the present invention proposes an adaptive wire current anti-interference measurement method based on three collinear TMR magnetoresistive chips. The method comprises:

[0009] Obtaining distances x1, x2, and x3 between the three collinear TMR magnetoresistive chips and the conductive wires;

[0010] When any one of the distances x1, x2, and x3 changes relative to a preset calibration value, a plurality of magnetic field signals within a preset frequency range are acquired based on the frequency domain, and variance calculation is performed on the plurality of magnetic field signals, the Gaussian standard deviation of the Gaussian low-pass filter is adaptively adjusted according to the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and the magnetic field signals detected by the three collinear TMR magnetoresistive chips are subjected to low-pass Gaussian filtering using the adaptively adjusted Gaussian low-pass filter;

[0011] Calculating a signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, comparing the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminating signals having a signal-to-noise ratio less than the preset signal-to-noise ratio threshold based on the comparison result to achieve high-pulse filtering;

[0012] The conductor current is calculated based on the magnetic field signal after high pulse filtering.

[0013] Preferably, the method comprises:

[0014] When the distances x1, x2 and x3 do not change relative to the preset calibration values, the conductor current is directly calculated based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips.

[0015] Preferably, the Gaussian low-pass filter is represented by the following function:

[0016]

[0017]

[0018] Where H(s) is the transfer function of the Gaussian low-pass filter, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, s0 is the center frequency of the frequency range of the effective signal, σ is the Gaussian standard deviation, and δ(s) is the step function.

[0019] Preferably, the adaptive adjustment of the Gaussian low-pass filter is: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

[0020] Preferably, the adaptive adjustment of the Gaussian low-pass filter is shown in the following function:

[0021]

[0022] Wherein, T(s) is a preset constant, D(s) is the calculated variance, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, and σ is the Gaussian standard deviation.

[0023] Preferably, the signal-to-noise ratio of the magnetic field signal is calculated in the following manner:

[0024] Based on the time domain, m magnetic field signals after low-pass Gaussian filtering are obtained, and the magnetic field signal with the largest signal amplitude among the m magnetic field signals is determined. The signal-to-noise ratio of each magnetic field signal is calculated according to the following formula:

[0025]

[0026] Among them, K i is the signal-to-noise ratio of the i-th magnetic field signal among the m magnetic field signals, |w max | is the signal amplitude of the magnetic field signal with the largest signal value among the m magnetic field signals, w i is the signal amplitude of the i-th magnetic field signal among the m magnetic field signals.

[0027] To achieve the above object, the present invention further proposes an adaptive wire current anti-interference measurement system based on three collinear TMR magnetoresistive chips, characterized in that the system comprises:

[0028] A distance monitoring unit, configured to obtain distances x1, x2, and x3 between the three collinear TMR magnetoresistive chips and the conductors;

[0029] a low-pass Gaussian filtering unit, configured to, when any one of the distances x1, x2, and x3 changes relative to a preset calibration value, acquire multiple magnetic field signals within a preset frequency range based on the frequency domain, calculate the variance of the multiple magnetic field signals, adaptively adjust the Gaussian standard deviation of the Gaussian low-pass filter based on the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and use the adaptively adjusted Gaussian low-pass filter to perform low-pass Gaussian filtering on the magnetic field signals detected by the three collinear TMR magnetoresistive chips;

[0030] a high-pulse filtering unit, configured to calculate a signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, compare the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminate signals having a signal-to-noise ratio less than the preset signal-to-noise ratio threshold based on the comparison result to achieve high-pulse filtering;

[0031] The current calculation unit is used to calculate the conductor current according to the magnetic field signal after passing through the high pulse filtering.

[0032] Preferably, the current calculation unit is further configured to calculate the conductor current directly based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips when the distances x1, x2 and x3 do not change relative to preset calibration values.

[0033] Preferably, the adaptive adjustment of the Gaussian low-pass filter is: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

[0034] To achieve the above object, the present invention further proposes a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above-mentioned adaptive wire current anti-interference measurement method when executed by a processor.

[0035] Compared with the prior art, the present invention has at least the following advantages:

[0036] (1) The present invention is based on three collinear TMR magnetoresistive chips. The distance between the three TMR chips and the conductor is pre-calibrated. If the distance between the three TMR chips and the conductor changes, it indicates that there is magnetic field interference. When magnetic field interference exists, the present invention can dynamically adjust the Gaussian standard deviation of the low-pass Gaussian filter according to the frequency of the magnetic field signal, thereby realizing adaptive low-pass Gaussian filtering of the magnetic field signal, which can eliminate some high-frequency, low-amplitude interference;

[0037] (2) Adaptive Gaussian filtering can eliminate some high-frequency, low-amplitude interference, but it is difficult to eliminate high-pulse interference. Therefore, the present invention further constructs a signal-to-noise ratio by selecting the maximum amplitude of m signals in a small range, and filters out high-pulse signals based on the signal-to-noise ratio and a preset signal-to-noise ratio threshold to eliminate partial discharge interference of substation equipment.

[0038] Other features and advantages of the present invention will be set forth in the description that follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 Schematic diagram of the arrangement of three collinear TMR magnetoresistive chips and wires.

[0041] Figure 2 The figure is a flow chart of an adaptive wire current anti-interference measurement method according to an embodiment of the present invention.

[0042] Figure 3 The flowchart of an adaptive wire current anti-interference measurement method according to another embodiment of the present invention is shown.

[0043] Figure 4 FIG. 1 is a schematic structural diagram of an adaptive wire current anti-interference measurement system in one embodiment of the present invention. DETAILED DESCRIPTION

[0044] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. In addition, numerous specific details are provided in the following specific examples to better illustrate the present invention. Those skilled in the art will appreciate that the present invention can be practiced without certain specific details. In some instances, means well known to those skilled in the art are not described in detail in order to highlight the main points of the present invention.

[0045] One embodiment of the present invention provides an adaptive wire current anti-interference measurement method, which is implemented based on three collinear TMR magnetoresistive chips, including a first TMR magnetoresistive chip 1, a second TMR magnetoresistive chip 2 and a third TMR magnetoresistive chip 3. The arrangement of the three collinear TMR magnetoresistive chips is as follows: Figure 1 As shown, in Figure 1 Only the specific positional relationship between the first TMR magnetoresistance chip 1 and the current-carrying wire is drawn. It can be understood that the specific positional relationship between the second TMR magnetoresistance chip 2 and the current-carrying wire and the specific positional relationship between the third TMR magnetoresistance chip 3 and the current-carrying wire can be obtained by referring to the specific positional relationship between the first TMR magnetoresistance chip 1 and the current-carrying wire.

[0046] in, Figure 1 Where x1, x2, and x3 are the distances from the first TMR magnetoresistive chip 1, the second TMR magnetoresistive chip 2, and the third TMR magnetoresistive chip 3 to the current-carrying wire, respectively; θ1 is the complementary angle between the distance d between the current-carrying wire and the straight line where the three TMR magnetoresistive chips are located and x1, as shown in Figure 1As shown, similarly, θ2 and θ3 are the complementary angles of the angles formed by the distance between the current-carrying wire and the straight line where the three TMR magnetoresistive chips are located and x2 and x3. Figure 1 Not drawn; m is the distance between the first TMR magnetoresistive chip 1 and the second TMR magnetoresistive chip 2; n is the distance between the first TMR magnetoresistive chip 1 and the third TMR magnetoresistive chip 3, and α is the angle between the current-carrying wire and the "perpendicular line to the magnetic sensitive direction of the TMR magnetoresistive chip".

[0047] See Figure 2 The method of this embodiment specifically includes the following steps:

[0048] Step S1, obtaining the distances x1, x2 and x3 between the three collinear TMR magnetoresistive chips and the conductive wires;

[0049] Specifically, in this embodiment, three collinear TMR magnetoresistive chips are assembled in a sensor, and the sensor is fixed on the surface of a conductor. A known current I is passed through the current-carrying conductor. The distances x1, x2, and x3 between the three collinear TMR magnetoresistive chips and the conductor are calibrated in the absence of an interfering magnetic field. At this time, the magnetic induction intensities measured by the three TMR magnetoresistive chips are B1, B2, and B3, respectively. According to Figure 1 The following geometric relations exist:

[0050]

[0051] It can be calculated that:

[0052]

[0053] The derivation of the above formulas (1) to (2) is described in detail in the prior art of the patent document with the authorization announcement number CN109283380B. The prior art of the patent document with the authorization announcement number CN109283380B describes in detail that when there is no magnetic field interference in the environment, it is only necessary to know the magnetic induction intensity measured by the three TMR magnetoresistive chips and the relative distance between the three magnetoresistive TMR chips to obtain the current of the current-carrying conductor, and then the distances x1, x2 and x3 from the three TMR magnetoresistive chips to the long straight conductor can be solved according to the above formula (1). In this embodiment, this method can be used to solve the distances x1, x2 and x3 between the three collinear TMR magnetoresistive chips and the conductor. Of course, other methods can also be used. The present invention is not limited to this method, as long as the distances x1, x2 and x3 can be obtained.

[0054] If there is an interference signal in the substation during sensor operation, the relationship between the measured magnetic field of the three TMR chips in the sensor and the distance to the conductor does not satisfy equation (2). In this case, the interference magnetic field needs to be eliminated. Specifically, there are two types of interference signals in the substation: one is a periodic interference signal, which mainly comes from carriers and radio communications, and the frequency of this interference signal is usually 1-2 MHz; the other is a pulsed interference signal, which mainly comes from corona discharge interference of substation equipment, and the frequency of this type of interference signal is usually 5-20 MHz. In addition, the harmonics of the conductor will reflect the current operating status of the power grid and need to be retained. The frequency of the power grid power frequency harmonics is 100 Hz to 9 kHz. Although there are ultra-high harmonics (i.e., 150 kHz), the higher the frequency, the smaller the amplitude. Therefore, the embodiment of the present invention proposes a signal amplitude-frequency fusion analysis and filtering technology to eliminate external magnetic field interference while retaining the conductor current harmonic signal.

[0055] In this embodiment, the distance sensor can be directly used to obtain the relative distance between the three TMR magnetoresistive chips. Of course, using a distance sensor to measure the relative distance between the three TMR magnetoresistive chips is only a preferred method and does not represent the only method. In actual applications, the relative distance between the three TMR magnetoresistive chips can also be measured by a ruler, etc. The specific device used to measure the relative distance between the three TMR magnetoresistive chips is not limited by the present invention.

[0056] Furthermore, in this embodiment, the distances between the three TMR chips and the conductors are pre-calibrated, and the calibration values ​​are: 10 、x 20 and x 30 , and compare the distances x1, x2, and x3 obtained by the solution with the pre-calibrated distance x 10 、x 20 and x 30 Compare them one by one. If the distance between any of the three TMR chips and the wire changes, that is, x1 and x 10 The difference or error is greater than a preset small constant, or x2 and x 20 The difference or error is greater than a preset small constant, or x3 and x 30 If the distances between the three TMR chips and the wires do not change, it means there is no magnetic field interference.

[0057] Step S21: When the distances x1, x2, and x3 change relative to preset calibration values, multiple magnetic field signals within a preset frequency range are acquired based on the frequency domain, and variances of the multiple magnetic field signals are calculated; the Gaussian standard deviation of the Gaussian low-pass filter is adaptively adjusted according to the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter; and the magnetic field signals detected by the three collinear TMR magnetoresistive chips are subjected to low-pass Gaussian filtering using the adaptively adjusted Gaussian low-pass filter;

[0058] Specifically, when the distance between the three TMR chips and the wire changes, there is magnetic field interference, and filtering is required. In this embodiment, low-pass Gaussian filtering is first performed. It should be noted that the low-pass Gaussian filtering in this embodiment is different from other Gaussian filtering in the prior art, because the Gaussian low-pass filter in this embodiment can be adaptively adjusted. It should be understood that the selection of the value of the Gaussian standard deviation is the key to the signal filtering effect. If the degree of discreteness near the filtered signal point is large, it is necessary to increase the Gaussian standard deviation to make the filtering smoother. Otherwise, it is necessary to reduce the standard deviation. In this embodiment, n magnetic field signals (frequency domain signals) within a preset frequency range are obtained based on the frequency domain, and the variance of the n magnetic field signals is calculated, as follows:

[0059]

[0060] In the above formula, D(s) is the calculated variance, f(s) j is the signal amplitude (frequency domain) of the jth magnetic field signal among n magnetic field signals, is the mean value of the signal amplitudes of n magnetic field signals;

[0061] Based on the above formula, the variance D(s) can be calculated. In the embodiment of the present invention, an adaptive function between the variance D(s) and the Gaussian standard deviation σ is pre-established. Based on this adaptive function, the Gaussian standard deviation σ of the Gaussian low-pass filter can be adaptively adjusted according to the calculated variance D(s), thereby obtaining an adaptively adjusted Gaussian low-pass filter.

[0062] Step S22, calculating the signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, comparing the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminating signals with a signal-to-noise ratio less than the preset signal-to-noise ratio threshold based on the comparison result to achieve high pulse filtering;

[0063] Step S23: Calculate the conductor current according to the magnetic field signal after high pulse filtering.

[0064] Specifically, as mentioned in the background art, the prior art document CN109283380B proposes a method for measuring the current in a long straight conductor using three uniaxial TMR chips. In step S23, based on the method proposed in this prior art, the current value of the current-carrying conductor can be calculated based on the magnetic field signal after high pulse filtering, namely, the first magnetic induction intensity B1, the second magnetic induction intensity B2, and the third magnetic induction intensity B3 generated by the current-carrying conductor in the magnetically sensitive directions of the three uniaxial TMR chips, as well as the relative distance between the three uniaxial TMR chips, thereby achieving measurement of the current in the current-carrying conductor. Therefore, the TMR chip in this embodiment is preferably a uniaxial TMR chip.

[0065] Based on the method of the above embodiment, see Figure 3 In a more specific embodiment, the method of the embodiment of the present invention further includes:

[0066] Step S3: When the distances x1, x2, and x3 do not change relative to the preset calibration values, the conductor current is directly calculated based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips.

[0067] Specifically, when the distances x1, x2 and x3 are respectively 10 、x 20 and x 30 When comparing one by one, if there is no change, that is: x1 and x 10 The same or the error is less than or equal to a preset small constant, or x2 and x 20 The same or the error is less than or equal to a preset small constant, or x3 and x 30 If they are the same or the error is less than or equal to a preset small constant, it means that there is no magnetic field interference. At this time, there is no need to perform low-pass Gaussian filtering and high-pulse filtering. The current value of the current-carrying conductor can be calculated directly based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips, that is, the first magnetic induction intensity B1, the second magnetic induction intensity B2, and the third magnetic induction intensity B3 generated by the current-carrying conductor in the magnetic sensitive direction of the three uniaxial TMR chips, and the relative distance between the three uniaxial TMR chips, thereby realizing the measurement of the current of the current-carrying conductor. The calculation principle is as described above, so it will not be repeated here.

[0068] Based on the method of the above embodiment, in a more specific implementation manner, the transfer function of the Gaussian low-pass filter is designed as follows:

[0069]

[0070]

[0071] Where H(s) is the transfer function of the Gaussian low-pass filter, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, s0 is the center frequency of the frequency range of the effective signal, σ is the Gaussian standard deviation, and δ(s) is the step function;

[0072] In which, it is assumed that the highest harmonic frequency of the signal is f max is 150kHz, the frequency range of the effective signal is 0~150kHz, so the center frequency is s0=f max / 2=75kHz.

[0073] Based on the method of the above embodiment, in a more specific implementation manner, the adaptive adjustment of the Gaussian low-pass filter is: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

[0074] Specifically, the adaptive adjustment design of the Gaussian low-pass filter in this embodiment is shown in the following function:

[0075]

[0076] Wherein, T(s) is a preset constant, D(s) is the calculated variance, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, and σ is the Gaussian standard deviation.

[0077] Based on the method of the above embodiment, in a more specific implementation manner, the signal-to-noise ratio of the magnetic field signal is calculated in the following manner:

[0078] Based on the time domain, m magnetic field signals (time domain signals) after low-pass Gaussian filtering are obtained, and the magnetic field signal with the largest signal amplitude among the m magnetic field signals is determined. The signal-to-noise ratio of each magnetic field signal is calculated according to the following formula:

[0079]

[0080] Among them, K i is the signal-to-noise ratio of the i-th magnetic field signal among the m magnetic field signals, |w max | is the signal amplitude of the magnetic field signal with the largest signal value among the m magnetic field signals, w i is the signal amplitude of the i-th magnetic field signal among the m magnetic field signals.

[0081] Specifically, when performing high-pulse filtering, a time window can be designed. The time window determines the selection range of the time domain signal. That is, the step is to obtain m magnetic field signals in a time window to construct a signal-to-noise ratio calculation method within a small range. The size of the time window can be set according to technical requirements. No specific limitation is made in this embodiment. After completing the high-pulse filtering of the signal in the current time window, the high-pulse filtering of the signal in the next time window is continued.

[0082] Corresponding to the above embodiment method, another embodiment of the present invention further proposes an adaptive wire current anti-interference measurement system, which is implemented based on three collinear TMR magnetoresistive chips. The system of this embodiment can be used to perform the steps of the method of the above embodiment, see Figure 4 , the system comprising:

[0083] A distance monitoring unit 1 is used to obtain the distances x1, x2 and x3 between the three collinear TMR magnetoresistive chips and the conductor;

[0084] a low-pass Gaussian filtering unit 2, configured to obtain, based on the frequency domain, a plurality of magnetic field signals within a preset frequency range when any one of the distances x1, x2, and x3 changes relative to a preset calibration value, calculate the variance of the plurality of magnetic field signals, adaptively adjust the Gaussian standard deviation of the Gaussian low-pass filter according to the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and use the adaptively adjusted Gaussian low-pass filter to perform low-pass Gaussian filtering on the magnetic field signals detected by the three collinear TMR magnetoresistive chips;

[0085] a high pulse filtering unit 3, configured to calculate a signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, compare the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminate signals having a signal-to-noise ratio less than the preset signal-to-noise ratio threshold according to the comparison result to achieve high pulse filtering; and

[0086] The current calculation unit 4 is used to calculate the conductor current according to the magnetic field signal after high pulse filtering.

[0087] Based on the system of the above embodiment, in a more specific implementation, the current calculation unit 4 is also used to calculate the conductor current directly based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips when the distances x1, x2 and x3 have not changed relative to the preset calibration values.

[0088] Based on the system of the above embodiment, in a more specific implementation manner, the adaptive adjustment of the Gaussian low-pass filter is: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

[0089] Based on the system of the above embodiment, in a more specific implementation manner, the signal-to-noise ratio of the magnetic field signal is calculated in the following manner:

[0090] Based on the time domain, m magnetic field signals (time domain signals) after low-pass Gaussian filtering are obtained, and the magnetic field signal with the largest signal amplitude among the m magnetic field signals is determined. The signal-to-noise ratio of each magnetic field signal is calculated according to the following formula:

[0091]

[0092] Among them, K i is the signal-to-noise ratio of the i-th magnetic field signal among the m magnetic field signals, |w max | is the signal amplitude of the magnetic field signal with the largest signal value among the m magnetic field signals, w i is the signal amplitude of the i-th magnetic field signal among the m magnetic field signals.

[0093] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the objectives of this embodiment based on actual needs.

[0094] It should be noted that the system described in the above embodiment corresponds to the method described in the above embodiment. Therefore, the part of the system described in the above embodiment that is not described in detail can be obtained by referring to the content of the method described in the above embodiment, that is, the specific steps recorded in the method of the above embodiment can be understood as the functions that can be achieved by the system of this embodiment, and will not be repeated here.

[0095] Furthermore, if the adaptive wire current anti-interference measurement system described in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0096] Another embodiment 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 steps of the adaptive wire current anti-interference measurement method described in the above embodiment are implemented.

[0097] Specifically, the computer-readable storage medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0098] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An adaptive wire current anti-interference measurement method based on three collinear TMR magnetoresistive chips, characterized in that: The method comprises: Obtaining the magnetic induction intensities B1, B2, and B3 of the three collinear TMR magnetoresistive chips, and obtaining the distances x1, x2, and x3 between the three collinear TMR magnetoresistive chips and the wires according to the magnetic induction intensities of the three collinear TMR magnetoresistive chips; wherein, When any one of the distances x1, x2, and x3 changes relative to a preset calibration value, a plurality of magnetic field signals within a preset frequency range are acquired based on the frequency domain, and variance calculation is performed on the plurality of magnetic field signals, the Gaussian standard deviation of the Gaussian low-pass filter is adaptively adjusted according to the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and the magnetic field signals detected by the three collinear TMR magnetoresistive chips are subjected to low-pass Gaussian filtering using the adaptively adjusted Gaussian low-pass filter; Calculating a signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, comparing the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminating signals having a signal-to-noise ratio less than the preset signal-to-noise ratio threshold based on the comparison result to achieve high-pulse filtering; The conductor current is calculated based on the magnetic field signal after high pulse filtering.

2. The method according to claim 1, wherein The method comprises: When the distances x1, x2 and x3 do not change relative to the preset calibration values, the conductor current is directly calculated based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips.

3. The method according to claim 1 or 2, wherein: The Gaussian low-pass filter is shown in the following function: Where H(s) is the transfer function of the Gaussian low-pass filter, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, s0 is the center frequency of the frequency range of the effective signal, σ is the Gaussian standard deviation, and δ(s) is the step function.

4. The method according to claim 1 or 2, wherein: The adaptive adjustment of the Gaussian low-pass filter is as follows: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

5. The method according to claim 1 or 2, wherein: The adaptive adjustment of the Gaussian low-pass filter is shown in the following function: Wherein, T(s) is a preset constant, D(s) is the calculated variance, G(s) is the Gaussian function of the Gaussian low-pass filter, s is the frequency of the magnetic field signal detected by the TMR magnetoresistive chip, and σ is the Gaussian standard deviation.

6. The method according to claim 1 or 2, wherein: in, The signal-to-noise ratio of the magnetic field signal is calculated as follows: Based on the time domain, m magnetic field signals after low-pass Gaussian filtering are obtained, and the magnetic field signal with the largest signal amplitude among the m magnetic field signals is determined. The signal-to-noise ratio of each magnetic field signal is calculated according to the following formula: Among them, K i is the signal-to-noise ratio of the i-th magnetic field signal among the m magnetic field signals, |w max | is the signal amplitude of the magnetic field signal with the largest signal value among the m magnetic field signals, w i is the signal amplitude of the i-th magnetic field signal among the m magnetic field signals.

7. An adaptive wire current anti-interference measurement system based on three collinear TMR magnetoresistive chips, characterized in that: The system comprises: A distance monitoring unit is used to obtain the magnetic induction intensities B1, B2 and B3 of the three collinear TMR magnetoresistive chips, and obtain the distances x1, x2 and x3 between the three collinear TMR magnetoresistive chips and the conductors according to the magnetic induction intensities of the three collinear TMR magnetoresistive chips; wherein, a low-pass Gaussian filtering unit, configured to, when any one of the distances x1, x2, and x3 changes relative to a preset calibration value, acquire multiple magnetic field signals within a preset frequency range based on the frequency domain, calculate the variance of the multiple magnetic field signals, adaptively adjust the Gaussian standard deviation of the Gaussian low-pass filter based on the calculated variance to obtain an adaptively adjusted Gaussian low-pass filter, and use the adaptively adjusted Gaussian low-pass filter to perform low-pass Gaussian filtering on the magnetic field signals detected by the three collinear TMR magnetoresistive chips; a high-pulse filtering unit, configured to calculate a signal-to-noise ratio of the magnetic field signal after low-pass Gaussian filtering, compare the calculated signal-to-noise ratio of the magnetic field signal with a preset signal-to-noise ratio threshold, and eliminate signals having a signal-to-noise ratio less than the preset signal-to-noise ratio threshold based on the comparison result to achieve high-pulse filtering; The current calculation unit is used to calculate the conductor current according to the magnetic field signal after passing through the high pulse filtering.

8. The system according to claim 7, wherein: The current calculation unit is further configured to calculate the conductor current directly based on the magnetic field signals detected by the three collinear TMR magnetoresistive chips when the distances x1, x2, and x3 do not change relative to preset calibration values.

9. The system according to claim 7 or 8, characterized in that The adaptive adjustment of the Gaussian low-pass filter is as follows: when the variance is larger, the standard deviation is larger, and when the variance is smaller, the standard deviation is smaller.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the adaptive wire current anti-interference measurement method according to any one of claims 1 to 6 are implemented.

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