A core-ring array multi-ring magnetic sensitive current sensor and current measurement method

Abstract

The present invention discloses a core-ring array multi-ring magnetic sensitive current sensor and a current measurement method, including: using a first ring structure to obtain a feedback current signal generated by a first magnetic field signal generated by a primary side current; using a second ring structure to measure a second magnetic field signal generated by the current of a conductor in a coil; using a digital processing unit to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current. The present invention uses a double air gap core as the first ring structure, and a coreless ring array with multiple magnetic sensitive chips installed as the second ring structure. A closed-loop feedback structure is designed based on the zero magnetic flux principle, and the current size is determined by combining digital signal processing with two-way measurement results. The current sensor combines the advantages of the core structure and the coreless structure, and can effectively reduce the influence of errors such as eccentricity and crosstalk, and realizes high-accuracy current measurement based on the tunnel magnetoresistance element.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical measurement, and more specifically, to a core-ring array multi-ring magnetic sensitive current sensor and a current measurement method. Background Art

[0002] In response to the current measurement needs that are prevalent in power systems, traditional iron core current sensors have been widely used, but their poor linearity and temperature stability will affect the measurement results, and they are not suitable for wide range requirements such as protection. Magnetic sensor arrays are an effective way to replace magnetic sensors with magnetic cores, and are an effective solution to problems such as spatial interference and core saturation. With the development and cost reduction of magnetic sensors such as tunnel magnetoresistance (TMR), it has become possible to form an array of multiple magnetoresistance sensors for non-contact current measurement. Its basic principle is based on Ampere's current loop law, using multiple TMR sensors around the current-carrying conductor to measure the magnetic field, and the sum of the magnetic sensors is approximately a closed loop. The use of annular magnetic sensor arrays to measure current has the following advantages: the annular magnetic sensor array uses a coreless structure, there is no saturation problem, greatly improves transient performance, and can be widely used in various types of protection fault measurements. However, due to the influence of factors such as crosstalk noise, the accuracy of the annular array current sensor still needs to be improved.

[0003] Prior art 1 Magnetic sensor array based on discrete Fourier transform (DFT) In order to reduce the influence of crosstalk error, a digital signal processing unit is added to the output part of the annular array sensor, and a signal processing algorithm based on DFT is designed in combination with the sensor output signal. The principle of the proposed algorithm is the Fourier expansion of the magnetic field around the conductor under test. The analytical expression of the Fourier coefficient is obtained in the presence of a uniform field when the magnetic field is generated by a current perpendicular to the array plane. The annular magnetic sensor array maps the magnetic field around the conductor under test to realize the spatial discrete Fourier transform of the sensor data. The measured current value is given by the inversion of the nonlinear system. The disadvantage is that the magnetic sensor array model based on discrete Fourier transform (DFT) only considers the case of circular cross-section conductors, but the magnetic field generated by the DC current flowing in the rectangular cross-section conductor does not have radial symmetry, resulting in the inability of the sensor of the circular array centered on the busbar to measure the same magnetic field value. If the sensor data is processed by the DFT algorithm, spatial harmonics of the magnetic field with an order of magnitude greater than zero will appear. Non-zero harmonics can also be attributed to the crosstalk field, making it difficult to distinguish the contribution of the current inside the array from the contribution of the external current. The annular array sensor loses the magnetic field gathering effect of the iron core and its accuracy is insufficient. The annular array sensor improved by the DFT algorithm has limited improvement in the accuracy of current measurement.

[0004] The second prior art dual Hall element magnetic sensitive current sensor. When the position of the measured current conductor in the sensor's annular magnetic circuit changes, the output signal of the sensor changes greatly, that is, the position error is large. To address this problem, a double air gap is opened in the magnetic circuit of the magnetic sensitive current sensor, and a Hall element is installed in each air gap and appropriate signal processing components are added to make a dual Hall element magnetic sensitive current sensor. The unequal Hall voltages generated by the different magnetic fields at the two Hall elements due to the different positions of the measured current conductors are connected in parallel by a circuit and synthesized according to the equivalent circuit of the parallel capacitor. The output value of the sensor is the arithmetic mean of the output values ​​of the two Hall elements. This achieves complete compensation for the position error. The disadvantages are: 1. The core structure is saturated, and its nonlinear error will affect the range and accuracy of the current measurement. In addition, its temperature stability will also affect the long-term use of the sensor; 2. The Hall sensor has inherent defects, namely low sensitivity, high power consumption and poor linearity. Summary of the invention

[0005] The present invention provides a core-ring array multi-ring magnetic sensitive current sensor and a current measurement method to solve the problem of how to measure current and reduce measurement errors.

[0006] In order to solve the above problems, according to one aspect of the present invention, a core-ring array multi-ring magnetic sensitive current sensor is provided, the sensor comprising: a first ring structure, a second ring structure and a digital processing unit, wherein:

[0007] The first ring structure is sleeved on the conductor and connected to the digital processing unit, and is used to obtain a feedback current signal generated according to the first magnetic field signal generated by the primary side current, and output the feedback current signal to the digital processing unit;

[0008] The second ring structure is sleeved on the conductor and connected to the digital processing unit, and is used to measure the second magnetic field signal generated by the current of the conductor in the coil, and output the second magnetic field signal to the digital processing unit;

[0009] The digital processing unit is used to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current.

[0010] Preferably, the first ring structure comprises: an iron core, a feedback current acquisition circuit and a compensation winding; wherein,

[0011] The iron core is an open iron core with double air gaps symmetrically opened, and a first tunnel magnetoresistance TMR sensor chip is arranged at each air gap, and the first TMR sensor chip is used to measure the first magnetic field signal;

[0012] The feedback current acquisition circuit is used to obtain a first magnetic field average signal by averaging the first magnetic field signals measured by the two first TMR sensor chips, generate a feedback current signal through an amplifier based on the first magnetic field average signal, and output the feedback current signal to the compensation winding and the digital processing unit;

[0013] The compensation winding is evenly wound on the iron core and is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal to control the sensor to maintain a zero flux state.

[0014] Preferably, the second ring structure comprises: four second TMR sensor chips, which are connected in parallel and symmetrically arranged in the annular hollow housing at equal distances, and the second TMR sensor chips are used to obtain the second magnetic field signal.

[0015] Preferably, a double metal shielding layer is arranged outside the annular hollow shell.

[0016] Preferably, the digital processing unit comprises: an analog-to-digital conversion module, a digital processing module and a digital-to-analog conversion module;

[0017] The analog-to-digital conversion module is connected to the digital processing module and is used to convert the feedback current signal and the second magnetic field signal from analog quantities to digital quantities;

[0018] The digital processing module is connected to the digital-to-analog conversion module and is used to calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into a digital quantity;

[0019] The digital-to-analog conversion module is used to convert the characteristic quantity characterizing the wire current from a digital quantity to an analog quantity, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity.

[0020] Preferably, the sensor further comprises:

[0021] A power supply unit is used to supply power to the first TMR sensor chip and the second TMR sensor chip.

[0022] According to another aspect of the present invention, there is provided a current measurement method based on the core-ring array multi-ring magnetic sensitive current sensor as described above, the method comprising:

[0023] Acquire a feedback current signal generated by a first magnetic field signal generated by a primary-side current using a first ring structure, and output the feedback current signal to the digital processing unit;

[0024] measuring a second magnetic field signal generated by the current of the conductor in the coil using a second loop structure, and outputting the second magnetic field signal to the digital processing unit;

[0025] A digital processing unit is used to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current.

[0026] Preferably, the step of obtaining a feedback current signal generated by a first magnetic field signal generated by the primary side current using the first ring structure includes:

[0027] Measuring the first magnetic field signal by using a first TMR sensor chip arranged at an air gap of an open core with double air gaps symmetrically formed;

[0028] A first magnetic field signal measured by two first TMR sensor chips is averaged by a feedback current acquisition circuit to obtain a first magnetic field average signal, a feedback current signal is generated through an amplifier based on the first magnetic field average signal, and the feedback current signal is output to the compensation winding and the digital processing unit;

[0029] A compensation winding wound on the iron core is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal, and the sensor is controlled to maintain a zero magnetic flux state.

[0030] Preferably, the step of measuring the second magnetic field signal generated by the current of the conductor in the coil by using the second loop structure comprises:

[0031] The second magnetic field signal is acquired by using four second TMR sensor chips; wherein the four second TMR sensor chips are connected in parallel and symmetrically arranged in an annular hollow housing at equal distances.

[0032] Preferably, a double metal shielding layer is arranged outside the annular hollow shell.

[0033] Preferably, the step of calculating a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal using a digital processing unit comprises:

[0034] Convert the feedback current signal and the second magnetic field signal from analog to digital using an analog-to-digital conversion module;

[0035] Calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module;

[0036] The characteristic quantity characterizing the wire current is converted from a digital quantity to an analog quantity by using a digital-to-analog conversion module, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity.

[0037] Preferably, the step of calculating the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module comprises:

[0038] Within a first preset range, based on the second magnetic field signal, the feedback current signal is corrected for an eccentricity error to obtain the characteristic quantity characterizing the conductor current;

[0039] Within a second preset range, correcting the crosstalk error of the feedback current signal based on the second magnetic field signal to obtain the characteristic value characterizing the conductor current;

[0040] In the application scenario of transient response, an arithmetic mean value is calculated based on the second magnetic field signal to obtain the characteristic quantity characterizing the conductor current.

[0041] Preferably, the method further comprises:

[0042] The power supply unit is used to supply power to the first TMR sensor chip and the second TMR sensor chip.

[0043] The present invention provides a core-ring array multi-ring magnetic sensitive current sensor and a current measurement method, comprising: using a first ring structure to obtain a feedback current signal generated by a first magnetic field signal generated by a primary side current; using a second ring structure to measure a second magnetic field signal generated by the current of a conductor in a coil; using a digital processing unit to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current. The present invention can be used for current measurement scenarios of power systems such as DC distribution networks and DC charging piles for electric vehicles. Based on a magnetic sensitive element that uses tunnel magnetoresistance sensing technology to sense the magnetic field generated by the current to be measured, a double air gap core is used as the first ring structure, and a coreless ring array with multiple magnetic sensitive chips installed is used as the second ring structure. A closed-loop feedback structure is designed based on the zero flux principle, and the current size is determined by combining two measurement results through digital signal processing. The current sensor of the present invention combines the advantages of the core structure and the coreless structure, can effectively reduce the influence of errors such as eccentricity and crosstalk, expand the scope of application, and realize high-accuracy current measurement based on the tunnel magnetoresistance element. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0045] Figure 1 Schematic diagram of the structure of a core-ring array multi-ring magnetic sensitive current sensor 100 according to an embodiment of the present invention;

[0046] Figure 2It is a composition structure diagram of a core-ring array multi-ring magnetic sensitive current sensor according to an embodiment of the present invention;

[0047] Figure 3 is a circuit schematic diagram of a first ring structure according to an embodiment of the present invention;

[0048] Figure 4 4 is a flow chart of a current measurement method 400 based on a core-ring array multi-ring magnetic sensitive current sensor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0050] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0051] Figure 1 FIG. 1 is a schematic diagram of the structure of a core-ring array multi-ring magnetic sensitive current sensor 100 according to an embodiment of the present invention. Figure 1 As shown, the core-ring array multi-ring magnetic sensitive current sensor provided by the embodiment of the present invention can be used for current measurement scenarios of power systems such as DC distribution networks and DC charging piles for electric vehicles. It is based on the magnetic sensitive element that uses tunnel magnetoresistance sensing technology to sense the magnetic field generated by the current to be measured, with a double air gap core as the first ring structure, and a coreless ring array with multiple magnetic sensitive chips installed as the second ring structure. The closed-loop feedback structure is designed based on the zero magnetic flux principle, and the current size is determined by combining digital signal processing with two measurement results. The current sensor of the present invention combines the advantages of the core structure and the coreless structure, can effectively reduce the influence of errors such as eccentricity and crosstalk, expand the scope of application, and realize high-accuracy current measurement based on tunnel magnetoresistance elements. The core-ring array multi-ring magnetic sensitive current sensor 100 provided by the embodiment of the present invention includes: a first ring structure 101, a second ring structure 102 and a digital processing unit 103.

[0052] Preferably, the first ring structure 101 is sleeved on the conductor and connected to the digital processing unit, for obtaining a feedback current signal generated according to the first magnetic field signal generated by the primary side current, and outputting the feedback current signal to the digital processing unit.

[0053] Preferably, the first ring structure comprises: an iron core, a feedback current acquisition circuit and a compensation winding; wherein,

[0054] The iron core is an open iron core with double air gaps symmetrically opened, and a first tunnel magnetoresistance TMR sensor chip is arranged at each air gap, and the first TMR sensor chip is used to measure the first magnetic field signal;

[0055] The feedback current acquisition circuit is used to obtain a first magnetic field average signal by averaging the first magnetic field signals measured by the two first TMR sensor chips, generate a feedback current signal through an amplifier based on the first magnetic field average signal, and output the feedback current signal to the compensation winding and the digital processing unit;

[0056] The compensation winding is evenly wound on the iron core and is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal to control the sensor to maintain a zero flux state.

[0057] Preferably, the sensor further comprises:

[0058] A power supply unit is used to supply power to the first TMR sensor chip.

[0059] Combination Figure 2 As shown, in the present invention, the first ring structure includes an iron core, a feedback current acquisition circuit and a compensation winding. The iron core is an open iron core with double air gaps symmetrically opened, and a TMR chip is installed at each air gap, and each first TMR chip is used to measure the magnetic field generated by the primary side current. The first TMR chip is powered by a power supply unit (not shown in the figure). The feedback current acquisition circuit in the first ring structure averages the first magnetic field signals measured by the two first TMR chips through a parallel circuit, outputs the averaged result to the amplifier, generates a feedback current through the amplifier, and outputs the feedback current to the compensation winding and the digital signal processing unit. The compensation winding in the first ring structure is evenly wound on the iron core, and the compensation winding is used to receive the feedback current generated by the feedback current acquisition circuit to generate a compensation magnetic field, and superimpose it with the magnetic field generated by the primary side current, so that the sensor is maintained in a zero flux state.

[0060] The specific circuit of the first ring structure is as follows Figure 3As shown, the feedback current acquisition circuit in loop one first averages the measurement results of the two TMR chips through a parallel circuit, and then generates a feedback current through an operational amplifier and a feedback circuit, which is input into the compensation winding and the digital signal processing unit.

[0061] Preferably, the second ring structure 102 is sleeved on the conductor and connected to the digital processing unit, and is used to measure the second magnetic field signal generated by the current of the conductor in the coil, and output the second magnetic field signal to the digital processing unit.

[0062] Preferably, the second ring structure comprises: four second TMR sensor chips, which are connected in parallel and symmetrically arranged in the annular hollow housing at equal distances, and the second TMR sensor chips are used to obtain the second magnetic field signal.

[0063] Preferably, a double metal shielding layer is arranged outside the annular hollow shell.

[0064] Preferably, the sensor further comprises:

[0065] The power supply unit is used to supply power to the second TMR sensor chip.

[0066] Combination Figure 2 As shown, in the present invention, the second ring structure includes four second TMR sensor chips, which are equidistantly and symmetrically installed in an annular hollow shell, and a double-layer metal shielding layer is arranged on the outside of the annular hollow shell. The second ring structure uses four second TMR chips to measure the magnetic field generated by the current in the measuring coil, and outputs the acquired four second magnetic field signals to the digital signal processing unit. Among them, the second TMR chip is powered by a power supply unit (not shown in the figure).

[0067] Preferably, the digital processing unit 103 is used to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current.

[0068] Preferably, the digital processing unit comprises: an analog-to-digital conversion module, a digital processing module and a digital-to-analog conversion module;

[0069] The analog-to-digital conversion module is connected to the digital processing module and is used to convert the feedback current signal and the second magnetic field signal from analog quantities to digital quantities;

[0070] The digital processing module is connected to the digital-to-analog conversion module and is used to calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into a digital quantity;

[0071] The digital-to-analog conversion module is used to convert the characteristic quantity characterizing the wire current from a digital quantity to an analog quantity, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity.

[0072] Preferably, the step of calculating the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module comprises:

[0073] Within a first preset range, based on the second magnetic field signal, the feedback current signal is corrected for an eccentricity error to obtain the characteristic quantity characterizing the conductor current;

[0074] Within a second preset range, correcting the crosstalk error of the feedback current signal based on the second magnetic field signal to obtain the characteristic value characterizing the conductor current;

[0075] In the application scenario of transient response, an arithmetic mean value is calculated based on the second magnetic field signal to obtain the characteristic quantity characterizing the conductor current.

[0076] In the present invention, the digital signal processing unit 103 includes: an analog-to-digital conversion module, a digital signal processing module and a digital-to-analog conversion module. The analog-to-digital conversion module uses an on-chip 12-bit A / D converter to perform high-speed sampling on the signals (feedback current signal and four second magnetic field signals) measured by the dual loops, and converts the sampled data into digital signals and inputs them into the digital signal processing module, so that the digital signal processing module calculates and outputs the characteristic quantity representing the conductor current.

[0077] In the present invention, when the characteristic quantity characterizing the conductor current is calculated by the digital signal processing module, the low-end range part is based on the first ring structure and corrected by the second ring structure, the high-end range part is based on the second ring structure and corrected by the first ring structure, and the transient sensing function is realized by the second ring structure. The digital signal processing module can realize the following functions: within the low-end range, the measurement result of the first ring structure is mainly used, and the eccentricity error is corrected by the measurement results of the four TMR chips of the second ring structure; within the high-end range, the measurement result of the second ring structure is mainly used, and the crosstalk error is corrected by the measurement result of the first ring structure; in the application scenario of transient response, the measurement results of the four TMR chips of the second ring structure are directly calculated and output.

[0078] In the present invention, after the digital-to-analog conversion module in the digital signal processing unit receives the characteristic quantity representing the conductor current output by the digital signal processing module, it is converted into an analog voltage signal output by the digital-to-analog conversion module as the final output of the sensor. The current size on the measured conductor can be determined by the analog voltage signal output by the sensor.

[0079] The core-ring array multi-ring magnetic sensitive current sensor of the present invention has a first ring structure of a double air-gap open core with a compensation winding, which measures the superimposed magnetic field generated by the primary current and the feedback current to achieve a sensing function; the second ring structure is a magnetic sensor ring array, which achieves fast measurement and reduces eccentricity errors; the digital signal processing unit combines the measurement results of the two rings to achieve the purpose of correcting errors and expanding the measurement range for different application scenarios. The present invention can be used to develop high-precision current sensors suitable for a wide range of fields such as power system metering and protection.

[0080] Figure 4 FIG. 4 is a flow chart of a current measurement method 400 based on a core-ring array multi-ring magnetic sensitive current sensor according to an embodiment of the present invention. Figure 4 As shown, the current measurement method 400 based on the core-ring array multi-ring magnetic sensitive current sensor as described above provided in an embodiment of the present invention includes:

[0081] Step 401 : using a first ring structure to obtain a feedback current signal generated according to a first magnetic field signal generated by a primary-side current, and outputting the feedback current signal to the digital processing unit.

[0082] Preferably, the step of obtaining a feedback current signal generated by a first magnetic field signal generated by the primary side current using the first ring structure includes:

[0083] Measuring the first magnetic field signal by using a first TMR sensor chip arranged at an air gap of an open core with double air gaps symmetrically formed;

[0084] A first magnetic field signal measured by two first TMR sensor chips is averaged by a feedback current acquisition circuit to obtain a first magnetic field average signal, a feedback current signal is generated through an amplifier based on the first magnetic field average signal, and the feedback current signal is output to the compensation winding and the digital processing unit;

[0085] A compensation winding wound on the iron core is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal, and the sensor is controlled to maintain a zero magnetic flux state.

[0086] Step 402: Use a second loop structure to measure a second magnetic field signal generated by the current of the conductor in the coil, and output the second magnetic field signal to the digital processing unit.

[0087] Preferably, the step of measuring the second magnetic field signal generated by the current of the conductor in the coil by using the second loop structure comprises:

[0088] The second magnetic field signal is acquired by using four second TMR sensor chips; wherein the four second TMR sensor chips are connected in parallel and symmetrically arranged in an annular hollow housing at equal distances.

[0089] Preferably, a double metal shielding layer is arranged outside the annular hollow shell.

[0090] Step 403: Utilize a digital processing unit to calculate a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the conductor according to the characteristic quantity characterizing the conductor current.

[0091] Preferably, the step of calculating a characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal using a digital processing unit comprises:

[0092] Convert the feedback current signal and the second magnetic field signal from analog to digital using an analog-to-digital conversion module;

[0093] Calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module;

[0094] The characteristic quantity characterizing the wire current is converted from a digital quantity to an analog quantity by using a digital-to-analog conversion module, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity.

[0095] Preferably, the step of calculating the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module comprises:

[0096] Within a first preset range, based on the second magnetic field signal, the feedback current signal is corrected for an eccentricity error to obtain the characteristic quantity characterizing the conductor current;

[0097] Within a second preset range, correcting the crosstalk error of the feedback current signal based on the second magnetic field signal to obtain the characteristic value characterizing the conductor current;

[0098] In the application scenario of transient response, an arithmetic mean value is calculated based on the second magnetic field signal to obtain the characteristic quantity characterizing the conductor current.

[0099] Preferably, the method further comprises:

[0100] The power supply unit is used to supply power to the first TMR sensor chip and the second TMR sensor chip.

[0101] The current measurement method 400 based on the core-ring array multi-ring magnetic sensitive current sensor of the embodiment of the present invention corresponds to the core-ring array multi-ring magnetic sensitive current sensor 100 based on another embodiment of the present invention, which will not be repeated here.

[0102] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0103] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0104] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0105] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0106] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A core-ring array multi-ring magnetic sensitive current sensor, characterized in that: The sensor comprises: a first ring structure, a second ring structure and a digital processing unit, wherein: The first ring structure is sleeved on the conductor and connected to the digital processing unit, and is used to obtain a feedback current signal generated according to the first magnetic field signal generated by the primary side current, and output the feedback current signal to the digital processing unit; The second ring structure is sleeved on the conductor and connected to the digital processing unit, and is used to measure the second magnetic field signal generated by the current of the conductor in the coil, and output the second magnetic field signal to the digital processing unit; The digital processing unit is used to calculate a characteristic quantity characterizing the wire current according to the feedback current signal and the second magnetic field signal, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current; Wherein, the digital processing unit includes: an analog-to-digital conversion module, a digital processing module and a digital-to-analog conversion module; The analog-to-digital conversion module is connected to the digital processing module and is used to convert the feedback current signal and the second magnetic field signal from analog quantities to digital quantities; The digital processing module is connected to the digital-to-analog conversion module and is used to calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into a digital quantity; The digital-to-analog conversion module is used to convert the characteristic quantity characterizing the wire current from a digital quantity to an analog quantity, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity; The step of calculating the characteristic quantity characterizing the conductor current according to the feedback current signal converted into a digital quantity and the second magnetic field signal comprises: Within a first preset range, based on the second magnetic field signal, the feedback current signal is corrected for an eccentricity error to obtain the characteristic quantity characterizing the conductor current; Within a second preset range, correcting the crosstalk error of the second magnetic field signal based on the feedback current signal to obtain the characteristic quantity characterizing the conductor current; In the application scenario of transient response, an arithmetic mean value is calculated based on the second magnetic field signal to obtain the characteristic quantity characterizing the conductor current.

2. The sensor according to claim 1, characterized in that The first ring structure includes: an iron core, a feedback current acquisition circuit and a compensation winding; wherein, The iron core is an open iron core with double air gaps symmetrically opened, and a first TMR sensor chip is arranged at each air gap, and the first TMR sensor chip is used to measure the first magnetic field signal; The feedback current acquisition circuit is used to obtain a first magnetic field average signal by averaging the first magnetic field signals measured by the two first TMR sensor chips, generate a feedback current signal through an amplifier based on the first magnetic field average signal, and output the feedback current signal to the compensation winding and the digital processing unit; The compensation winding is evenly wound on the iron core and is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal to control the sensor to maintain a zero flux state.

3. The sensor according to claim 2, characterized in that The second ring structure includes: four second TMR sensor chips, which are connected in parallel and symmetrically arranged in the annular hollow housing at equal distances, and the second TMR sensor chips are used to obtain the second magnetic field signal.

4. The sensor according to claim 3, characterized in that A double metal shielding layer is arranged outside the annular hollow shell.

5. The sensor according to claim 3, characterized in that The sensor also includes: A power supply unit is used to supply power to the first TMR sensor chip and the second TMR sensor chip.

6. A current measurement method based on the core-ring array multi-ring magnetic sensitive current sensor according to any one of claims 1 to 5, characterized in that: The method comprises: Acquire a feedback current signal generated by a first magnetic field signal generated by a primary-side current using a first ring structure, and output the feedback current signal to the digital processing unit; measuring a second magnetic field signal generated by the current of the conductor in the coil using a second loop structure, and outputting the second magnetic field signal to the digital processing unit; Calculating a characteristic quantity characterizing the wire current according to the feedback current signal and the second magnetic field signal using a digital processing unit, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current; The step of calculating the characteristic quantity representing the conductor current according to the feedback current signal and the second magnetic field signal by using a digital processing unit includes: Convert the feedback current signal and the second magnetic field signal from analog to digital using an analog-to-digital conversion module; Calculate the characteristic quantity characterizing the conductor current according to the feedback current signal and the second magnetic field signal converted into digital quantities by using a digital processing module; The characteristic quantity characterizing the wire current is converted from a digital quantity to an analog quantity by using a digital-to-analog conversion module, so as to determine the current on the wire according to the characteristic quantity characterizing the wire current converted into the analog quantity; The method of calculating the characteristic quantity characterizing the conductor current according to the feedback current signal converted into a digital quantity and the second magnetic field signal by using the digital processing module includes: Within a first preset range, based on the second magnetic field signal, the feedback current signal is corrected for an eccentricity error to obtain the characteristic quantity characterizing the conductor current; Within a second preset range, correcting the crosstalk error of the second magnetic field signal based on the feedback current signal to obtain the characteristic quantity characterizing the conductor current; In the application scenario of transient response, an arithmetic mean value is calculated based on the second magnetic field signal to obtain the characteristic quantity characterizing the conductor current.

7. The method according to claim 6, characterized in that The method of using the first ring structure to obtain a feedback current signal generated by a first magnetic field signal generated by the primary side current includes: Measuring the first magnetic field signal by using a first TMR sensor chip arranged at an air gap of an open core with double air gaps symmetrically formed; A first magnetic field signal measured by two first TMR sensor chips is averaged by a feedback current acquisition circuit to obtain a first magnetic field average signal, a feedback current signal is generated through an amplifier based on the first magnetic field average signal, and the feedback current signal is output to a compensation winding and a digital processing unit; A compensation winding wound on the iron core is used to generate a compensation magnetic field according to the feedback current signal, so that the compensation magnetic field is superimposed on the first magnetic field signal, and the sensor is controlled to maintain a zero magnetic flux state.

8. The method according to claim 7, characterized in that The method of measuring a second magnetic field signal generated by a current in a conductor in a coil by using a second loop structure comprises: The second magnetic field signal is acquired by using four second TMR sensor chips; wherein the four second TMR sensor chips are connected in parallel and symmetrically arranged in an annular hollow housing at equal distances.

9. The method according to claim 8, characterized in that A double metal shielding layer is arranged outside the annular hollow shell.

10. The method according to claim 8, characterized in that The method further comprises: The power supply unit is used to supply power to the first TMR sensor chip and the second TMR sensor chip.

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