Symmetric differential multi-range distance magnetic sensing current detection device and method

Abstract

This invention discloses a symmetrical differential multi-range magnetic sensing current detection device and method. The device includes a current-carrying conductor, multiple sets of magnetic sensor pairs, a printed circuit board, a signal conditioning and acquisition circuit, and input / output interfaces. The current-carrying conductor is a straight metal conductor with a circular cross-section, and its axis is defined as the Z-axis, used to carry the current to be measured, I. The printed circuit board serves as a mounting substrate and electrical connection carrier, and is provided with component mounting positions and electrical traces. The multiple sets of magnetic sensor pairs are arranged on the printed circuit board in a radial plane perpendicular to the Z-axis. The signal conditioning and acquisition circuit includes a differential amplification module, a multi-channel analog selection switch, and a control and processing unit. The symmetrical differential multi-range magnetic sensing current detection device and method disclosed in this invention achieves a balance between wide range, high precision, strong anti-interference, and low cost.

Description

Technical Field

[0001] This invention belongs to the field of current detection technology, specifically relating to a symmetrical differential multi-range magnetic sensing current detection device and method. Background Technology

[0002] In the field of current detection, magnetic sensors such as Hall effect sensors are widely used due to their non-contact and high-precision characteristics. While various multi-sensor current detection schemes exist in the current sensing technology, all have significant shortcomings.

[0003] Asahi Kasei's CN201480049303.0 solution uses two U-shaped current paths to symmetrically arrange magnetic sensors to achieve dual-channel current detection and mutual interference cancellation. However, it is only suitable for independent dual-channel detection and cannot achieve single-channel wide-range measurement. In addition, the structure is complex and lacks automatic range switching function.

[0004] The dot matrix Hall current sensor solution (CN200810046761.5) uses multiple Hall elements evenly distributed in a ring around a wire to improve accuracy through signal accumulation. However, since all sensors are at the same distance, multi-range measurement cannot be achieved, there is no automatic switching mechanism, the dynamic range is limited, and the ability to suppress non-uniform external magnetic fields is insufficient.

[0005] Traditional multi-range solutions (such as CN200810161221.1) use Hall effect chips with different ranges connected in parallel. The output is selected by choosing the smallest range chip that has not exceeded the range. This solution requires the purchase of chips of different specifications, which is costly, has complex circuit matching, and the difference in chip performance will affect the measurement consistency.

[0006] In summary, existing technologies generally suffer from problems such as a contradiction between measurement range and accuracy, limited anti-interference capability, complex structure, or high cost. Therefore, there is an urgent need for a current detection scheme that is simple in structure, low in cost, and combines wide measurement range, high accuracy, and strong anti-interference capability. Summary of the Invention

[0007] The main objective of this invention is to provide a symmetrical differential multi-range magnetic sensing current detection device and method, achieving a balance between wide range, high precision, strong anti-interference, and low cost.

[0008] Another objective of this invention is to provide a symmetrical differential multi-range magnetic sensing current detection device and method. This involves symmetrically arranging multiple sets of identical magnetic sensors on both sides of a single current-carrying conductor, utilizing the different distances between the sensors and the conductor to construct multiple overlapping or continuous measurement ranges. By suppressing common-mode interference through differential amplification and combining it with automatic saturation detection and intelligent switching algorithms, the optimal measurement channel can be adaptively selected over an ultra-wide current range, thus achieving a good balance between wide range and high precision, strong anti-interference and low cost.

[0009] To achieve the above objectives, the present invention provides a symmetrical differential multi-range magnetic sensing current detection device, including a current-carrying conductor, multiple magnetic sensor pairs, a printed circuit board, a signal conditioning and acquisition circuit, and an input / output interface. The current-carrying conductor is a straight metal conductor with a circular cross-section, and its axis is defined as the Z-axis, which is used to carry the current to be measured, I. The printed circuit board serves as a mounting substrate and electrical connection carrier, and is provided with component mounting positions and electrical traces. The multiple sets of magnetic sensor pairs are arranged on a printed circuit board in a radial plane perpendicular to the Z-axis; each set of magnetic sensor pairs includes a first magnetic sensor and a second magnetic sensor of identical model and specifications, and are arranged in a mirror-symmetrical manner with the central axis of the current-carrying conductor as the axis of symmetry, and the distance from the two sensors to the central axis is the characteristic distance of the set. ; The signal conditioning and acquisition circuit includes a differential amplifier module, a multiplex analog selection switch, and a control and processing unit, wherein: The differential amplifier module contains N differential amplifier units. The non-inverting input terminal of each differential amplifier unit is connected to the output terminal of the second magnetic sensor in the same group, and the inverting input terminal is connected to the output terminal of the first magnetic sensor in the same group. It outputs a differential voltage signal V_diff_i. The multiplex analog selection switch is an N-to-1 switch, with N input channels respectively connected to the output terminals of N differential amplifier units; The control and processing unit integrates an analog-to-digital converter, a non-volatile memory, and a control logic core. The input of the analog-to-digital converter is connected to the common output of a multiplex analog selection switch. The non-volatile memory stores the saturation voltage threshold V_sat_i and the distance correction coefficient K_di. The control logic core executes the measurement algorithm and outputs a channel selection signal. The input / output interface includes a current input terminal connected to both ends of the current-carrying conductor, and a signal output interface connected to the control and processing unit.

[0010] As a further preferred embodiment of the above technical solution, for magnetic sensors, the radial distance hierarchy is as follows: N sets of magnetic sensors are matched according to characteristic distance The sizes are arranged radially from near to far, and the characteristic distances of each group satisfy the following relationship: .

[0011] As a further preferred technical solution to the above technical solution, it also includes optional auxiliary components: a magnetic shielding cover and a temperature sensing element; the magnetic shielding cover is cylindrical or box-shaped, made of a high magnetic permeability material, and surrounds the current-carrying conductor and all magnetic sensors; The temperature sensing element is mounted on a printed circuit board to monitor the ambient temperature and provide temperature compensation data to the control and processing unit.

[0012] To achieve the above objectives, the present invention also provides a symmetrical differential multi-range magnetic sensing current detection method, comprising the following steps: Step S1: Magnetic field-to-voltage conversion and differential noise reduction: The current to be measured, I, flows through the current-carrying conductor and generates a ring magnetic field. The two sensors in each pair of magnetic sensors sense magnetic fields of equal magnitude and opposite direction, and output a voltage containing the useful signal, inherent offset voltage, and random noise. The corresponding differential amplifier unit performs differential operation on the voltage output by the two magnetic sensors to eliminate the common-mode inherent offset voltage, amplify the useful magnetic field signal, suppress common-mode environmental noise, and obtain the differential voltage signal V_diff_i. Step S2: Multi-distance range construction: Using magnetic induction intensity B i Proportional to current I and characteristic distance The inverse relationship allows magnetic sensor groups with different characteristic distances to correspond to different ranges; and by designing a sequence of characteristic distances, adjacent range groups can be connected or overlapped to construct a composite wide range. Due to magnetic induction intensity B i ∝I / d i Therefore, the differential output V_diff_i ∝ I / d i This means: For the first group with the smallest distance d1, its output V_diff_1 has the largest slope (highest sensitivity) with respect to the change in current I. With a small current I1, its output can reach the upper limit of the amplifier's linearity V_sat1, so its effective range is the smallest (e.g., 0-I1), but its resolution and accuracy are the highest within this range.

[0013] For distance d n The largest Nth group has the smallest slope (lowest sensitivity) for its output V_diff_N with respect to the change in current I. A very large current I_N is required to make its output reach V_sat_N, so it has the largest effective range (e.g., 0-I_N), but lower resolution in the low current range.

[0014] Through reasonable design This allows the upper limit of the range I_i of the i-th group to be well connected or partially overlapped with the lower limit of the range of the (i+1)-th group, thereby constructing a continuous and extended composite range from extremely high sensitivity (small current) to extremely high tolerance (large current).

[0015] Step S3: Intelligent range switching and optimal signal selection: Initialization and Default Channel: After the system starts, the multi-channel analog selection switch turns on the magnetic sensor group channel with the smallest characteristic distance as the initial measurement channel; Continuous monitoring and saturation early warning: The control and processing unit continuously reads the current channel differential voltage value V_diff_current through the analog-to-digital converter and compares it with the pre-stored saturation threshold V_sat_current; Upward switching: When V_diff_current≥V_sat_current, it is determined that the magnetic sensor of the current channel is about to enter the nonlinear region, and the channel is switched to the next set of magnetic sensor channels with a larger feature distance, and the current is calculated using the corresponding distance correction coefficient; Downward switching: Periodically check channels that are closer to the current channel and set a hysteresis threshold V_sat_(i-1)×H; if the differential voltage value is less than V_sat_(i-1)×H, switch back to that channel; Step S4: Current Calculation and Output: The current value is calculated, and temperature compensation is performed by combining the data from the temperature sensing element, or the output is smoothed through a digital filtering algorithm; the control and processing unit outputs the final current value I_out through the signal output interface.

[0016] As a further preferred technical solution to the above technical solution, in step S1, for those arranged at a distance... The i-th pair of magnetic sensors at location: The direction of the magnetic field sensed by the first sensor is recorded as positive, and its output voltage includes: the useful signal S·B i Inherent offset voltage Vos, random noise Vn1; Due to symmetry, the second sensor senses a magnetic field of equal magnitude but opposite direction, and its output voltage includes: useful signal - S·B i Inherent offset voltage Vos, random noise Vn2; The corresponding differential amplifier unit performs the operation: ; This represents the gain of the differential amplifier unit; At this point, in the differential output V_diff_i, the inherent offset voltage Vos of the common mode is completely eliminated, the magnetic field signal is amplified, and the common mode ambient noise is suppressed.

[0017] As a further preferred technical solution of the above technical solution, in step S4, the current value is calculated as follows: I_calc=K_di×V_diff_i, where K_di is the calibration coefficient of the i-th group, used to normalize the sensitivity difference caused by different distances.

[0018] The beneficial effects of this invention are as follows: 1. Achieve wide measurement range with the same model of sensor: There is no need to purchase and manage sensors with multiple ranges. By simply differentiating the physical distance, a sensor array with multiple ranges is equivalently obtained, which significantly reduces costs and supply chain complexity.

[0019] 2. Differential symmetrical layout suppresses interference: The symmetrical arrangement of sensors, combined with differential amplification, naturally cancels out common-mode offset and common-mode noise (such as temperature drift, power supply noise, and uniform external magnetic field), thus improving the signal-to-noise ratio and long-term stability.

[0020] 3. Adaptive Optimal Accuracy: The intelligent switching algorithm ensures that the system automatically operates in the channel that is "not saturated and closest to the current current (i.e., the highest accuracy)" at any time, so that it can maintain the best accuracy that can be achieved at the current point throughout the entire operating current range from the smallest to the largest.

[0021] 4. Simple and reliable structure: The entire device is built on a single straight conductor and a single PCB, which is compact, easy to industrialize and calibrate, and has high reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the device installation of the present invention.

[0023] Figure 2 This is a schematic diagram of the electrical signal chain of the present invention.

[0024] Figure 3 This is a flowchart of the method of the present invention.

[0025] The reference numerals in the attached figures include: 101, current-carrying conductor; 102, multiple magnetic sensor pairs; 102-Li, first magnetic sensor; 102-Ri, second magnetic sensor; 103, printed circuit board; 106, differential amplifier module; 107, control and processing unit; 202, signal output interface; 205, multi-channel analog selection switch. Detailed Implementation

[0026] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0027] In the preferred embodiments of the present invention, those skilled in the art should note that the host computer and the like involved in the present invention can be considered as prior art.

[0028] Preferred embodiment.

[0029] like Figure 1-2 As shown, the present invention discloses a symmetrical differential multi-range magnetic sensing current detection device, characterized in that it includes a current-carrying conductor 101, multiple sets of magnetic sensor pairs 102, a printed circuit board 103, a signal conditioning and acquisition circuit, and an input / output interface. The current-carrying conductor 101 is a straight metal conductor with a circular cross-section, and its axis is defined as the Z-axis, which is used to carry the current to be measured I. The printed circuit board 103 serves as a mounting substrate and electrical connection carrier, and is provided with component mounting positions (for fixing subsequent components) and electrical traces. The multiple sets of magnetic sensor pairs 102 are arranged on the printed circuit board 103 in a radial plane (XY plane) perpendicular to the Z-axis (N≥2). Each set of magnetic sensor pairs includes a first magnetic sensor 102-Li and a second magnetic sensor 102-Ri with identical model and specifications, and are arranged in a mirror-symmetrical manner with the central axis of the current-carrying conductor 101 as the axis of symmetry. The distance from the two sensors to the central axis is the characteristic distance of the set. ; The signal conditioning and acquisition circuit includes a differential amplifier module 106, a multiplex analog selection switch 205, and a control and processing unit 107, wherein: The differential amplifier module 106 contains N differential amplifier units (1061-106N). The non-inverting input terminal of each differential amplifier unit is connected to the output terminal of the second magnetic sensor 102-Ri in the same group, and the inverting input terminal is connected to the output terminal of the first magnetic sensor 102-Li in the same group. It also outputs a differential voltage signal V_diff_i (which theoretically eliminates the inherent common-mode offset and common-mode environmental noise of the sensor). The multiplex analog selection switch 205 is an N-to-1 switch, with N input channels (CH1-CHN) respectively connected to the output terminals of N differential amplifier units (1061-106N); The control and processing unit 107 integrates an analog-to-digital converter, a non-volatile memory, and a control logic core. The input terminal of the analog-to-digital converter is connected to the common output terminal of the multiplex analog selection switch 205. The non-volatile memory stores the saturation voltage threshold V_sat_i and the distance correction coefficient K_di. The control logic core executes the measurement algorithm and outputs a channel selection signal. The input / output interface includes current input terminals connected to both ends of the current-carrying conductor 101, and signal output terminals 202 connected to the control and processing unit 107 (connected to the digital output bus of the control and processing unit 107, used to output the final processed digital current measurement value I_out to the host computer or control system; the interface type can be SPI, I...). 2 C, PWM or UART, etc.

[0030] Specifically, for magnetic sensors, the radial distance hierarchy is as follows: N sets of magnetic sensors are matched according to characteristic distance The sizes are arranged radially from near to far, and the characteristic distances of each group satisfy the following relationship: (The group closest to the magnetic field (i=1) is the most sensitive to the magnetic field, while the group furthest from the magnetic field (i=N) is the least sensitive to the magnetic field but has the strongest resistance to saturation.)

[0031] Furthermore, it also includes optional auxiliary components: a magnetic shield and a temperature sensing element; the magnetic shield is cylindrical or box-shaped and made of a high magnetic permeability material (such as permalloy or manganese zinc ferrite), surrounding the current-carrying conductor 101 and all magnetic sensors; The temperature sensing element is mounted on the printed circuit board 103 to monitor the ambient temperature and provide temperature compensation data to the control and processing unit 107.

[0032] In this invention, the current to be measured flows through conductor 101, generating a magnetic field. All magnetic sensors synchronously sense the magnetic field and output signals, which are converted into differential signals by the corresponding differential amplifier units. The control and processing unit 107 collects these differential signals either cyclically or at fixed points through the multiplexer switch 205, determines which set of signals should be used based on the built-in algorithm, performs calculations and compensation, and finally provides a precise current value through the signal output interface 202.

[0033] like Figure 3 As shown, this invention also discloses a symmetrical differential multi-range magnetic sensing current detection method, comprising the following steps: Step S1: Magnetic field-to-voltage conversion and differential noise reduction: The current I to be measured flows through the current-carrying conductor 101, generating a ring-shaped magnetic field (at a distance d from the center axis of the conductor, the magnetic induction intensity B is directly proportional to the current I and inversely proportional to the distance d). The two sensors in each pair of magnetic sensors sense magnetic fields of equal magnitude and opposite direction, and output a voltage containing the useful signal, inherent offset voltage, and random noise. The corresponding differential amplifier unit performs differential operation on the voltages output by the two magnetic sensors to eliminate the common-mode inherent offset voltage, amplify the useful magnetic field signal, suppress common-mode environmental noise, and obtain the differential voltage signal V_diff_i. Step S2: Multi-distance range construction: Using magnetic induction intensity B i Proportional to current I and characteristic distance The inverse relationship allows magnetic sensor groups with different characteristic distances to correspond to different ranges; and by designing a sequence of characteristic distances, adjacent range groups can be connected or overlapped to construct a composite wide range. Step S3: Intelligent range switching and optimal signal selection (core control algorithm, the control and processing unit 107 runs a state machine or periodic task to implement the following intelligent switching logic): Initialization and default channel: After the system starts, the multi-channel analog selection switch 205 turns on the magnetic sensor group channel with the smallest characteristic distance (i.e., i=1, the closest distance and the highest accuracy), which is used as the initial measurement channel; Continuous monitoring and saturation warning: The control and processing unit 107 continuously reads the current channel differential voltage value V_diff_current through the analog-to-digital converter and compares it with the pre-stored saturation threshold V_sat_current (V_sat_current is usually set to 85%-95% of the linear output voltage range of the amplifier in this channel, as a saturation warning point). Upward switching (entering a larger current range): When V_diff_current ≥ V_sat_current, it is determined that the magnetic sensor of the current channel is about to enter the nonlinear region (continuing to use it will lead to a decrease in accuracy). The system switches to the next set of magnetic sensor channels with a larger characteristic distance and calculates the current using the corresponding distance correction coefficient (the control and processing unit 107 immediately outputs a control word, commanding the multiplexer analog selection switch 205 to switch to the next set of (i+1) signal channels. Subsequently, the system uses the distance correction coefficient K_d(i+1) corresponding to the new channel to calculate the current. This process is extremely fast (microsecond level), realizing automatic and seamless range expansion). Switch down (return to a higher precision range): periodically check channels that are closer to the current channel (such as channel i-1), and set a hysteresis threshold V_sat_(i-1)×H (H is a hysteresis coefficient of 0.6~0.8). If its differential voltage value (e.g., V_sat_(i-1)) is less than V_sat_(i-1)×H, then switch back to that channel (indicating that the closer channel is operating in the linear region and has sufficient margin. The control and processing unit 107 then automatically switches back to the (i-1)th channel to improve the measurement accuracy under the current current). Step S4: Current Calculation and Output: The current value is calculated, and temperature compensation is performed by combining the data from the temperature sensing element, or the output is smoothed through a digital filtering algorithm; the control and processing unit 107 outputs the final current value I_out through the signal output interface 202.

[0034] Specifically, in step S1, for those arranged at a distance The i-th pair of magnetic sensors at location: The direction of the magnetic field sensed by the first sensor 102-Li is recorded as positive, and its output voltage includes: useful signal S·B i Inherent offset voltage Vos, random noise Vn1; Due to symmetry, the magnetic fields sensed by the second sensor 102-Ri are equal in magnitude but opposite in direction, and its output voltage includes: useful signal - S·B i Inherent offset voltage Vos, random noise Vn2; The corresponding differential amplifier unit (106i) performs the operation: ; This represents the gain (i.e., amplification factor) of the differential amplifier unit. At this point, in the differential output V_diff_i, the inherent offset voltage Vos of the common mode is completely eliminated, the (useful) magnetic field signal is amplified (by 2 G·S times), and the common mode ambient noise is (significantly) suppressed.

[0035] More specifically, in step S4, the current value is calculated using the formula: I_calc=K_di×V_diff_i, where K_di is the calibration coefficient of the i-th group, used to normalize the sensitivity differences caused by different distances.

[0036] It is worth mentioning that the technical features such as the host computer involved in this patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0037] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A symmetrical differential multi-range magnetic sensing current detection device, characterized in that, It includes a current-carrying conductor, multiple magnetic sensor pairs, a printed circuit board, signal conditioning and acquisition circuitry, and input / output interfaces; The current-carrying conductor is a straight metal conductor with a circular cross-section, and its axis is defined as the Z-axis, which is used to carry the current to be measured, I. The printed circuit board serves as a mounting substrate and electrical connection carrier, and is provided with component mounting positions and electrical traces. The multiple sets of magnetic sensor pairs are arranged on a printed circuit board in a radial plane perpendicular to the Z-axis; each set of magnetic sensor pairs includes a first magnetic sensor and a second magnetic sensor of identical model and specifications, and are arranged in a mirror-symmetrical manner with the central axis of the current-carrying conductor as the axis of symmetry, and the distance from the two sensors to the central axis is the characteristic distance of the set. ; The signal conditioning and acquisition circuit includes a differential amplifier module, a multiplex analog selection switch, and a control and processing unit, wherein: The differential amplifier module contains N differential amplifier units. The non-inverting input terminal of each differential amplifier unit is connected to the output terminal of the second magnetic sensor in the same group, and the inverting input terminal is connected to the output terminal of the first magnetic sensor in the same group. It outputs a differential voltage signal V_diff_i. The multiplex analog selection switch is an N-to-1 switch, with N input channels respectively connected to the output terminals of N differential amplifier units; The control and processing unit integrates an analog-to-digital converter, a non-volatile memory, and a control logic core. The input of the analog-to-digital converter is connected to the common output of a multiplex analog selection switch. The non-volatile memory stores the saturation voltage threshold V_sat_i and the distance correction coefficient K_di. The control logic core executes the measurement algorithm and outputs a channel selection signal. The input / output interface includes a current input terminal connected to both ends of the current-carrying conductor, and a signal output interface connected to the control and processing unit.

2. The symmetrical differential multi-range magnetic sensing current detection device according to claim 1, characterized in that, For magnetic sensors, the radial distance hierarchy is as follows: N sets of magnetic sensors are matched according to characteristic distance The sizes are arranged radially from near to far, and the characteristic distances of each group satisfy the following relationship: .

3. The symmetrical differential multi-range magnetic sensing current detection device according to claim 1, characterized in that, It also includes optional auxiliary components: a magnetic shield and a temperature sensing element; the magnetic shield is cylindrical or box-shaped, made of a high magnetic permeability material, and surrounds the current-carrying conductor and all magnetic sensors. The temperature sensing element is mounted on a printed circuit board to monitor the ambient temperature and provide temperature compensation data to the control and processing unit.

4. A symmetrical differential multi-range magnetic sensing current detection method, applied to the symmetrical differential multi-range magnetic sensing current detection device according to any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Magnetic field-to-voltage conversion and differential noise reduction: The current to be measured, I, flows through the current-carrying conductor and generates a ring magnetic field. The two sensors in each pair of magnetic sensors sense magnetic fields of equal magnitude and opposite direction, and output a voltage containing the useful signal, inherent offset voltage, and random noise. The corresponding differential amplifier unit performs differential operation on the voltage output by the two magnetic sensors to eliminate the common-mode inherent offset voltage, amplify the useful magnetic field signal, suppress common-mode environmental noise, and obtain the differential voltage signal V_diff_i. Step S2: Multi-distance range construction: Using magnetic induction intensity B i Proportional to current I and characteristic distance The inverse relationship allows magnetic sensor groups with different characteristic distances to correspond to different ranges; and by designing a sequence of characteristic distances, adjacent range groups can be connected or overlapped to construct a composite wide range. Step S3: Intelligent range switching and optimal signal selection: Initialization and Default Channel: After the system starts, the multi-channel analog selection switch turns on the magnetic sensor group channel with the smallest characteristic distance as the initial measurement channel; Continuous monitoring and saturation early warning: The control and processing unit continuously reads the current channel differential voltage value V_diff_current through the analog-to-digital converter and compares it with the pre-stored saturation threshold V_sat_current; Upward switching: When V_diff_current≥V_sat_current, it is determined that the magnetic sensor of the current channel is about to enter the nonlinear region, and the channel is switched to the next set of magnetic sensor channels with a larger feature distance, and the current is calculated using the corresponding distance correction coefficient; Downward switching: Periodically check channels that are closer to the current channel and set a hysteresis threshold V_sat_(i-1)×H; If its differential voltage value is less than V_sat_(i-1)×H, then switch back to this channel; Step S4: Current Calculation and Output: The current value is calculated, and temperature compensation is performed by combining the data from the temperature sensing element, or the output is smoothed through a digital filtering algorithm; the control and processing unit outputs the final current value I_out through the signal output interface.

5. The symmetrical differential multi-range magnetic sensing current detection method according to claim 4, characterized in that, In step S1, for those arranged at a distance The i-th pair of magnetic sensors at location: The direction of the magnetic field sensed by the first sensor is recorded as positive, and its output voltage includes: the useful signal S·B i Inherent offset voltage Vos, random noise Vn1; Due to symmetry, the second sensor senses a magnetic field of equal magnitude but opposite direction, and its output voltage includes: useful signal - S·B i Inherent offset voltage Vos, random noise Vn2; The corresponding differential amplifier unit performs the operation: ; This represents the gain of the differential amplifier unit; At this point, in the differential output V_diff_i, the inherent offset voltage Vos of the common mode is completely eliminated, the magnetic field signal is amplified, and the common mode ambient noise is suppressed.

6. The symmetrical differential multi-range magnetic sensing current detection method according to claim 5, characterized in that, In step S4, the current value is calculated using the formula: I_calc=K_di×V_diff_i, where K_di is the calibration coefficient of the i-th group, used to normalize the sensitivity differences caused by different distances.

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