Intelligent measuring device based on tunnel magnetoresistance sensor

Abstract

The application discloses an intelligent measuring device based on a tunnel magnetoresistance sensor, comprising a TMR sensor module, a signal processing module, an intelligent control module, a communication module, an execution module and a temperature compensation module; three customized TMR sensors are used to construct a 120-degree surrounding wire differential array, so that the accurate measurement of a magnetic field signal is realized; in addition, through the processing and conversion of the magnetic field signal, it is determined whether there is a fault or an icing or other adverse condition on the corresponding line, so that the accurate regulation and control of the line are realized, and effective support is provided for the safe power supply of the line.

Description

Technical Field

[0001] This invention relates to the field of power system automation technology, and more specifically, to an intelligent measurement device based on a tunnel magnetoresistive sensor. Background Technology

[0002] In the fields of power systems and industrial power distribution, accurate current measurement and intelligent monitoring are fundamental to ensuring power supply security, improving power quality, and achieving efficient operation and maintenance. Traditional current measurement devices mainly use electromagnetic current transformers or Hall effect sensors. However, electromagnetic current transformers have the following inherent drawbacks: they are large and heavy, require direct contact with the line being measured, involve power-off operations during installation, and have a narrow frequency response range (typically only around 50Hz power frequency), making them unable to measure DC and high-frequency harmonic components. Under high current conditions, they are prone to magnetic saturation, leading to measurement distortion. While Hall effect sensors can measure DC, their sensitivity is low, temperature drift is severe, and power consumption is relatively high, making it difficult to meet the requirements of modern power Internet of Things (IoT) for miniaturization, low power consumption, and high precision.

[0003] On the other hand, existing intelligent measurement devices generally have limited functions, only realizing basic electrical parameter acquisition and remote transmission, lacking the ability to actively detect and locate line faults, as well as functions such as icing warning and automatic de-icing for mountain lines. Summary of the Invention

[0004] To address at least one of the aforementioned technical problems, the present invention aims to provide an intelligent measurement device based on a tunnel magnetoresistive sensor, which can actively detect and locate line faults and monitor in real time whether the line is covered with ice in low-temperature environments, thereby improving line safety.

[0005] This invention provides an intelligent measurement device based on a tunnel magnetoresistive sensor, comprising: TMR sensor module, signal processing module, intelligent control module, communication module, execution module and temperature compensation module; The TMR sensor module is used to acquire three-dimensional magnetic field signals generated by the current; The signal processing module is used to process the three-dimensional magnetic field signal to obtain a high-precision digital signal; The intelligent control module is used to process high-precision digital signals and generate control commands; The communication module is connected to the intelligent control module and is used to interact with the control commands of the intelligent control module with external devices or networks; The execution module is connected to the intelligent control module and is used to receive and execute corresponding physical actions according to the control instructions; The temperature compensation module is connected to the TMR sensor module and the signal processing module respectively. It is used to monitor the ambient temperature of the TMR sensor module in real time and correct the output signal of the TMR sensor module or the processing process of the signal processing module based on a preset temperature compensation algorithm, so as to eliminate the influence of temperature drift on measurement accuracy.

[0006] In this scheme, the TMR sensor module uses three customized TMR sensors, which are arranged in a differential array around the wire at a 120° angle; the distance between the TMR sensor and the wire is less than or equal to 5 mm.

[0007] In this solution, the step of processing high-precision digital signals to generate control commands includes: Extract the magnetic field strength output from three TMR sensors in the high-precision digital signal; Based on the magnetic field strength output by the three TMR sensors, determine the ratio of the corresponding magnetic field strength output by the three TMR sensors. Its formula is ,in The standard magnetic field strength calibrated when there is no icing. These represent the magnetic field strengths output by the three corresponding sensors; If the ratio of the magnetic field strength output by the three TMR sensors If the value is less than or equal to a preset first threshold, the corresponding duration is recorded and set as the first duration. The current ambient temperature value is obtained in real time based on the temperature sensor in the temperature compensation module; If the first duration is greater than a preset first time threshold and the current ambient temperature is lower than a preset first temperature threshold, then a line icing warning message is triggered. Based on the line icing warning information, an ice-melting command is generated.

[0008] In this solution, after generating the ice-melting command, the following steps are included: The voltage and current in the line are sampled in real time to obtain the line voltage sample value and the line current sample value; Determine the current line resistance estimate based on the current line voltage and line current sampling values; Get the time after the ice melt command is generated; The preset heat required for de-icing the current line is determined based on the time elapsed after the de-icing command is generated. Based on the preset heat required for current line de-icing and the current line resistance estimate, the de-icing current required for the next time node is revised to obtain the revised de-icing current, and the revised de-icing current application information is generated. The revised ice-melting current application information is sent to the preset dispatch center via the communication module to apply for ice-melting current.

[0009] This plan also includes: During line de-icing, the ratio of the magnetic field strength output from the three corresponding TMR sensors is periodically collected based on a preset first time. ; When the ratio of the magnetic field strength output by the three TMR sensors is greater than a preset second threshold, the set of magnetic field strength ratios output by the three TMR sensors is obtained based on a preset sliding time window and arranged in chronological order. The difference between adjacent magnetic field strength ratios is obtained by subtracting the magnetic field strength ratio of the next adjacent time node from the magnetic field strength ratio of the previous adjacent time node in the set of magnetic field strength ratios. If the difference between the ratios of adjacent magnetic field strengths is greater than zero, then the record for normal ice melting on the line at the corresponding adjacent time is incremented by one. By traversing the entire set of magnetic field strength ratios, the total number of normal ice melts on the line at adjacent time points is obtained. If the total number of normal line de-icing events in adjacent time periods is greater than the preset first threshold, it is determined that the ice has successfully detached and a stop de-icing instruction is generated. The preset second threshold is greater than the preset first threshold.

[0010] In this solution, the step of processing high-precision digital signals to generate control commands further includes: When the virtual geometric center formed by the environmental arrangement of the three TMR sensors coincides with the geometric center of the three-phase line under test, and the sensitive axis direction of each TMR sensor is perpendicular to the radial direction, Based on the preset conversion formula, the three-phase current values ​​in the three-phase circuit are determined according to the magnetic field strength output by the three TMR sensors in the high-precision digital signal. Based on the three-phase current values ​​in the three-phase circuit, determine the vector sum and current output of the three TMR sensors. Its formula is ,in , and These represent the three-phase current values ​​in a three-phase circuit; If the vector and current outputs of the three TMR sensors If the current exceeds the preset first current threshold, the corresponding duration is recorded and set as the second duration. If the second duration exceeds the preset second time threshold, a single-phase leakage fault warning message will be triggered, and a command message to cut off the power supply to the faulty circuit will be generated.

[0011] In this solution, after generating the power supply command information for cutting off the faulty circuit, the following is also included: Extract the vector and current outputs of this device and similar upstream and downstream devices that report leakage fault alerts. , respectively set as and ; Based on the vector and current outputs of this device and similar upstream and downstream devices that have reported leakage faults, determine the leakage current ratio. Its formula is ; The line distance L between this device and similar upstream and downstream devices that report leakage fault information; Set the distance from the fault point to this device as... Its formula is ; Based on the communication module, the distance from the fault point to this device is... Send a notification to the default management terminal.

[0012] This plan also includes: Before the fault is cleared and manually reset, the execution module injects a low-frequency AC signal into the line and measures the response current. Based on the intelligent control module, the line-to-ground insulation resistance is obtained according to the injected low-frequency AC signal and the measured response current. ; If the insulation resistance of the line to ground is greater than the preset resistance, record the corresponding duration and set it as the third duration. If the third duration exceeds the preset third time threshold, a remote or local power restoration command will be generated.

[0013] This plan also includes: If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit exceeds a preset first proportion threshold, it is determined to be an arc leakage, and a trip command message with a time shorter than a preset first reaction time is generated. If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit is lower than the preset second proportion threshold, it is determined to be resistive leakage, and a trip command message with a preset second reaction time delay is generated.

[0014] One or more technical solutions proposed in this application have at least the following technical effects: 1. The use of tunnel magnetoresistive (TMR) sensors with three TMR sensors arranged in a 120° ring tangential configuration improves the accuracy of magnetic field signal measurement. Furthermore, the three-phase current value is accurately restored through a preset conversion formula. The system does not require contact with the circuit under test, making installation and maintenance convenient and without damaging the original electrical connections. 2. For lines in low-temperature environments, the icing status is determined by the change in the ratio of magnetic field strength, the de-icing process is automatically initiated, and the current is safely carried out under the correction of line impedance. After the ice is removed, the power supply is restored autonomously, which effectively improves the safety of lines in low-temperature environments. 3. It can locate the fault point by using the ratio of upstream and downstream leakage current, and also has the functions of insulation resistance monitoring and fault type identification (resistive leakage / arc leakage), which significantly improves the level of personal safety protection.

[0015] In summary, this invention has been optimized from multiple dimensions, including measurement accuracy, functional integration, and environmental adaptability, effectively improving line safety. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0017] Figure 1 A flowchart of an intelligent measurement device based on a tunnel magnetoresistive sensor according to the present invention is shown; Figure 2 A schematic diagram of the TMR sensor array layout of the present invention is shown. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0019] Figure 1 A flowchart of an intelligent measurement device based on a tunnel magnetoresistive sensor according to the present invention is shown.

[0020] like Figure 1 As shown, this invention discloses an intelligent measurement device based on a tunnel magnetoresistive sensor, comprising: TMR sensor module, signal processing module, intelligent control module, communication module, execution module and temperature compensation module; The TMR sensor module is used to acquire three-dimensional magnetic field signals generated by the current; The signal processing module is used to process the three-dimensional magnetic field signal to obtain a high-precision digital signal; The intelligent control module is used to process high-precision digital signals and generate control commands; The communication module is connected to the intelligent control module and is used to interact with the control commands of the intelligent control module with external devices or networks; The execution module is connected to the intelligent control module and is used to receive and execute corresponding physical actions according to the control instructions; The temperature compensation module is connected to the TMR sensor module and the signal processing module respectively. It is used to monitor the ambient temperature of the TMR sensor module in real time and correct the output signal of the TMR sensor module or the processing process of the signal processing module based on a preset temperature compensation algorithm, so as to eliminate the influence of temperature drift on measurement accuracy.

[0021] According to an embodiment of the present invention, the TMR sensor module employs three customized TMR sensors arranged in a differential array around a conductor at a 120° angle, combined with a high-permeability alloy shield (completely covering the array), achieving a magnetic field detection sensitivity ≤5nT and adapting to a wide operating temperature range of -40℃ to 85℃. The signal processing module is equipped with a high common-mode rejection ratio instrumentation amplifier (CMRR≥100dB), a second-order active low-pass filter (cutoff frequency 1kHz), and a 24-bit high-precision ADC chip to amplify, filter, and analog-to-digitalize weak signals at the mV level. The conversion, combined with a neural network adaptive algorithm, dynamically adjusts the gain and filtering parameters to cancel signal noise; the intelligent control module is based on a mid-to-high-end Cortex-M series processor, and the execution module includes a relay and an intelligent circuit breaker. The circuit breaker has a rated current of 10A~630A, a breaking capacity of ≥50kA, and a mechanical life of ≥60,000 cycles. It adopts a graded action strategy, with a severe short circuit protection execution time of ≤15ms and a general short circuit protection execution time of ≤25ms; the temperature compensation module integrates a Class B platinum resistance temperature sensor, uses a three-wire connection, and has a temperature measurement accuracy of ±0.5℃.

[0022] Furthermore, the ADC chip of the signal processing module has a sampling rate of 10kHz and a resolution of ≤0.0003%, providing hardware support for a full-range measurement accuracy of 0.2.

[0023] Furthermore, the communication module supports HPLC / HRF dual-mode communication with a communication rate of ≥500kbps. The RS485 interface supports DL / T 645, DL / T 698 series protocols and Modbus-RTU protocol, adapting to the communication needs of different power distribution network scenarios.

[0024] Furthermore, it also includes a power module that provides power to each system / module.

[0025] Figure 2 A schematic diagram of the TMR sensor array layout of the present invention is shown.

[0026] like Figure 2 As shown, the TMR sensor module uses three customized TMR sensors arranged in a differential array around the wire at a 120° angle; the distance between the TMR sensor and the wire is less than or equal to 5 mm.

[0027] It should be noted that the three TMR sensors are arranged in a 120° ring. This arrangement avoids the need to install three separate single-phase sensors, reducing volume and cost, while improving anti-interference capability by utilizing spatial symmetry. Each TMR sensor can measure the tangential magnetic field at its location. Since the magnetic fields generated by the three-phase lines are superimposed in space, the output of each TMR sensor is the vector sum of the magnetic fields of the three-phase currents.

[0028] According to an embodiment of the present invention, the step of processing high-precision digital signals to generate control commands includes: Extract the magnetic field strength output from three TMR sensors in the high-precision digital signal; Based on the magnetic field strength output by the three TMR sensors, determine the ratio of the corresponding magnetic field strength output by the three TMR sensors. Its formula is ,in The standard magnetic field strength calibrated when there is no icing. These represent the magnetic field strengths output by the three corresponding sensors; If the ratio of the magnetic field strength output by the three TMR sensors If the value is less than or equal to a preset first threshold, the corresponding duration is recorded and set as the first duration. The current ambient temperature value is obtained in real time based on the temperature sensor in the temperature compensation module; If the first duration is greater than a preset first time threshold and the current ambient temperature is lower than a preset first temperature threshold, then a line icing warning message is triggered. Based on the line icing warning information, an ice-melting command is generated.

[0029] It should be noted that when the line is covered with ice, the increased sag causes the conductor to drop, changing the relative distance between the conductor and the TMR sensor. This weakens the magnetic field acquired by the TMR sensor. For example, the preset first threshold can be set to 90% of the standard magnetic field strength calibrated when there is no ice, the preset first time threshold to be 30 minutes, and the preset first temperature threshold to be zero degrees Celsius. For example, when a 10kV line is normal... During the winter rime weather, the TMR sensor measured a total magnetic field of 88. And maintain for 40 minutes, then If the time exceeds 30 minutes, a line icing warning message will be triggered.

[0030] According to an embodiment of the present invention, after generating the ice-melting command, the process includes: The voltage and current in the line are sampled in real time to obtain the line voltage sample value and the line current sample value; Determine the current line resistance estimate based on the current line voltage and line current sampling values; Get the time after the ice melt command is generated; The preset heat required for de-icing the current line is determined based on the time elapsed after the de-icing command is generated. Based on the preset heat required for current line de-icing and the current line resistance estimate, the de-icing current required for the next time node is revised to obtain the revised de-icing current, and the revised de-icing current application information is generated. The revised ice-melting current application information is sent to the preset dispatch center via the communication module to apply for ice-melting current.

[0031] It should be noted that the voltage and current at the k-th sampling point are respectively set as and Then the estimated line resistance at the k-th sampling time is ,in The gain coefficient is used; during ice melting, different ice melting stages are divided according to the time length after the ice melting command is generated, and different ice melting heat is set for different stages. The ice melting heat is controlled by the ice melting current, based on the heat formula. By estimating the melting heat and current line resistance, the melting current at the next time point can be determined, thereby allowing for reasonable control of the melting current and reducing the waste and consumption of heat during melting.

[0032] According to an embodiment of the present invention, it further includes: During line de-icing, the ratio of the magnetic field strength output from the three corresponding TMR sensors is periodically collected based on a preset first time. ; When the ratio of the magnetic field strength output by the three TMR sensors is greater than a preset second threshold, the set of magnetic field strength ratios output by the three TMR sensors is obtained based on a preset sliding time window and arranged in chronological order. The difference between adjacent magnetic field strength ratios is obtained by subtracting the magnetic field strength ratio of the next adjacent time node from the magnetic field strength ratio of the previous adjacent time node in the set of magnetic field strength ratios. If the difference between the ratios of adjacent magnetic field strengths is greater than zero, then the record for normal ice melting on the line at the corresponding adjacent time is incremented by one. By traversing the entire set of magnetic field strength ratios, the total number of normal ice melts on the line at adjacent time points is obtained. If the total number of normal line de-icing events in adjacent time periods is greater than the preset first threshold, it is determined that the ice has successfully detached and a stop de-icing instruction is generated. The preset second threshold is greater than the preset first threshold.

[0033] It should be noted that, for example, the preset second threshold is set to 95% of the standard magnetic field strength calibrated when there is no icing; for example, based on the preset sliding time window of 10, after the ratio of the magnetic field strength output by the three TMR sensors is greater than the preset second threshold, the magnetic field strength ratio corresponding to 10 sampling time nodes is continuously taken, and the preset first quantity threshold is less than the value corresponding to the sliding time window, for example, set to 6.

[0034] According to an embodiment of the present invention, the step of processing the high-precision digital signal to generate control commands further includes: When the virtual geometric center formed by the environmental arrangement of the three TMR sensors coincides with the geometric center of the three-phase line under test, and the sensitive axis direction of each TMR sensor is perpendicular to the radial direction, Based on the preset conversion formula, the three-phase current values ​​in the three-phase circuit are determined according to the magnetic field strength output by the three TMR sensors in the high-precision digital signal. Based on the three-phase current values ​​in the three-phase circuit, determine the vector sum and current output of the three TMR sensors. Its formula is ,in , and These represent the three-phase current values ​​in a three-phase circuit; If the vector and current outputs of the three TMR sensors If the current exceeds the preset first current threshold, the corresponding duration is recorded and set as the second duration. If the second duration exceeds the preset second time threshold, a single-phase leakage fault warning message will be triggered, and a command message to cut off the power supply to the faulty circuit will be generated.

[0035] It should be noted that the preset conversion formula is as follows: ,in This represents the magnetic field strength output by the three TMR sensors in the high-precision digital signal. Where is the vacuum permeability, and r is the distance from the TMR sensor to the conductor. When the three-phase conductors (A, B, C) are arranged in a triangle or horizontally, the magnetic field measured at each position is the vector sum of the tangential components of the magnetic fields of the three-phase currents at that point. For example, the preset first current threshold is set to 30mA. The preset second time threshold can be set according to the actual situation, and the smaller the value, the more sensitive the corresponding TMR sensor will be. For example, the preset second time threshold can be set to 100ms.

[0036] According to an embodiment of the present invention, after generating the power supply command information for cutting off the fault circuit, the method further includes: Extract the vector and current outputs of this device and similar upstream and downstream devices that report leakage fault alerts. , respectively set as and ; Based on the vector and current outputs of this device and similar upstream and downstream devices that have reported leakage faults, determine the leakage current ratio. Its formula is ; The line distance L between this device and similar upstream and downstream devices that report leakage fault information; Set the distance from the fault point to this device as... Its formula is ; Based on the communication module, the distance from the fault point to this device is... Send a notification to the default management terminal.

[0037] It should be noted that the vector and current refer to the instantaneous absolute value of the leakage current. For example, if the line distance between this device and the upstream / downstream similar devices that reported the leakage fault is 500 meters, and when a leakage occurs, this device measures a leakage current of 50mA, while the corresponding upstream / downstream device measures a leakage current of 80mA, then... ; The distance from the fault point to the device is approximately 115 meters.

[0038] According to an embodiment of the present invention, it further includes: Before the fault is cleared and manually reset, the execution module injects a low-frequency AC signal into the line and measures the response current. Based on the intelligent control module, the line-to-ground insulation resistance is obtained according to the injected low-frequency AC signal and the measured response current. ; If the insulation resistance of the line to ground is greater than the preset resistance, record the corresponding duration and set it as the third duration. If the third duration exceeds the preset third time threshold, a remote or local power restoration command will be generated.

[0039] It should be noted that the formula for calculating the insulation resistance to ground of the aforementioned line is as follows: ,in The injected low-frequency AC voltage, for example, 10Hz and 10V; The detected response current, The rate of change of the injected low-frequency AC voltage; for example, setting the preset resistor to... Set the preset third time threshold to 10 minutes.

[0040] According to an embodiment of the present invention, it further includes: If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit exceeds a preset first proportion threshold, it is determined to be an arc leakage, and a trip command message with a time shorter than a preset first reaction time is generated. If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit is lower than the preset second proportion threshold, it is determined to be resistive leakage, and a trip command message with a preset second reaction time delay is generated.

[0041] It should be noted that the high-frequency component ranges from 1kHz to 100kHz, the preset first proportion threshold is greater than the preset second proportion threshold, and the preset second reaction time is greater than the preset first reaction time; for example, the preset first proportion threshold is set to 30%, the preset second proportion threshold is set to 5%, and the preset first reaction time is set to 50. The preset second reaction time is 200ms.

[0042] This invention discloses an intelligent measurement device based on a tunnel magnetoresistive sensor, comprising: a TMR sensor module, a signal processing module, an intelligent control module, a communication module, an execution module, and a temperature compensation module; it uses three customized TMR sensors to construct a differential array around a 120° conductor to achieve accurate measurement of magnetic field signals; in addition, by processing and converting the magnetic field signals, it determines whether there are faults or icing or other adverse conditions on the corresponding line, thereby achieving precise control of the line and providing effective support for the safe power supply of the line.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An intelligent measurement device based on a tunnel magnetoresistive sensor, characterized in that, include: TMR sensor module, signal processing module, intelligent control module, communication module, execution module and temperature compensation module; The TMR sensor module is used to acquire three-dimensional magnetic field signals generated by the current; The signal processing module is used to process the three-dimensional magnetic field signal to obtain a high-precision digital signal; The intelligent control module is used to process high-precision digital signals and generate control commands; The communication module is connected to the intelligent control module and is used to interact with the control commands of the intelligent control module with external devices or networks; The execution module is connected to the intelligent control module and is used to receive and execute corresponding physical actions according to the control instructions; The temperature compensation module is connected to the TMR sensor module and the signal processing module respectively. It is used to monitor the ambient temperature of the TMR sensor module in real time and correct the output signal of the TMR sensor module or the processing process of the signal processing module based on a preset temperature compensation algorithm, so as to eliminate the influence of temperature drift on measurement accuracy.

2. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 1, characterized in that, The TMR sensor module uses three customized TMR sensors arranged in a differential array around the conductor at a 120° angle; the distance between the TMR sensor and the conductor is less than or equal to 5 mm.

3. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 1, characterized in that, The step of processing high-precision digital signals to generate control commands includes: Extract the magnetic field strength output from three TMR sensors in the high-precision digital signal; Based on the magnetic field strength output by the three TMR sensors, determine the ratio of the corresponding magnetic field strength output by the three TMR sensors. Its formula is ,in The standard magnetic field strength calibrated when there is no icing. These represent the magnetic field strengths output by the three corresponding sensors; If the ratio of the magnetic field strength output by the three TMR sensors If the value is less than or equal to a preset first threshold, the corresponding duration is recorded and set as the first duration. The current ambient temperature value is obtained in real time based on the temperature sensor in the temperature compensation module; If the first duration is greater than a preset first time threshold and the current ambient temperature is lower than a preset first temperature threshold, then a line icing warning message is triggered. Based on the line icing warning information, an ice-melting command is generated.

4. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 3, characterized in that, After generating the ice-melting command, the following is included: The voltage and current in the line are sampled in real time to obtain the line voltage sample value and the line current sample value; Determine the current line resistance estimate based on the current line voltage and line current sampling values; Get the time after the ice melt command is generated; The preset heat required for de-icing the current line is determined based on the time elapsed after the de-icing command is generated. Based on the preset heat required for current line de-icing and the current line resistance estimate, the de-icing current required for the next time node is revised to obtain the revised de-icing current, and the revised de-icing current application information is generated. The revised ice-melting current application information is sent to the preset dispatch center via the communication module to apply for ice-melting current.

5. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 4, characterized in that, Also includes: During line de-icing, the ratio of the magnetic field strength output from the three corresponding TMR sensors is periodically collected based on a preset first time. ; When the ratio of the magnetic field strength output by the three TMR sensors is greater than a preset second threshold, the set of magnetic field strength ratios output by the three TMR sensors is obtained based on a preset sliding time window and arranged in chronological order. The difference between adjacent magnetic field strength ratios is obtained by subtracting the magnetic field strength ratio of the next adjacent time node from the magnetic field strength ratio of the previous adjacent time node in the set of magnetic field strength ratios. If the difference between the ratios of adjacent magnetic field strengths is greater than zero, then the record for normal ice melting on the line at the corresponding adjacent time is incremented by one. By traversing the entire set of magnetic field strength ratios, the total number of normal ice melts on the line at adjacent time points is obtained. If the total number of normal line de-icing events in adjacent time periods is greater than the preset first threshold, it is determined that the ice has successfully detached and a stop de-icing instruction is generated. The preset second threshold is greater than the preset first threshold.

6. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 1, characterized in that, The step of processing high-precision digital signals to generate control commands further includes: When the virtual geometric center formed by the environmental arrangement of the three TMR sensors coincides with the geometric center of the three-phase line under test, and the sensitive axis direction of each TMR sensor is perpendicular to the radial direction, Based on the preset conversion formula, the three-phase current values ​​in the three-phase circuit are determined according to the magnetic field strength output by the three TMR sensors in the high-precision digital signal. Based on the three-phase current values ​​in the three-phase circuit, determine the vector sum and current output of the three TMR sensors. Its formula is ,in , and These represent the three-phase current values ​​in a three-phase circuit; If the vector and current outputs of the three TMR sensors If the current exceeds the preset first current threshold, the corresponding duration is recorded and set as the second duration. If the second duration exceeds the preset second time threshold, a single-phase leakage fault warning message will be triggered, and a command message to cut off the power supply to the faulty circuit will be generated.

7. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 6, characterized in that, After generating the power supply command information for cutting off the faulty circuit, the method further includes: Extract the vector and current outputs of this device and similar upstream and downstream devices that report leakage fault alerts. , respectively set as and ; Based on the vector and current outputs of this device and similar upstream and downstream devices that have reported leakage faults, determine the leakage current ratio. Its formula is ; The line distance L between this device and similar upstream and downstream devices that report leakage fault information; Set the distance from the fault point to this device as... Its formula is ; Based on the communication module, the distance from the fault point to this device is... Send a notification to the default management terminal.

8. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 7, characterized in that, Also includes: Before the fault is cleared and manually reset, the execution module injects a low-frequency AC signal into the line and measures the response current. Based on the intelligent control module, the line-to-ground insulation resistance is obtained according to the injected low-frequency AC signal and the measured response current. ; If the insulation resistance of the line to ground is greater than the preset resistance, record the corresponding duration and set it as the third duration. If the third duration exceeds the preset third time threshold, a remote or local power restoration command will be generated.

9. The intelligent measurement device based on a tunnel magnetoresistive sensor according to claim 6, characterized in that, Also includes: If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit exceeds a preset first proportion threshold, it is determined to be an arc leakage, and a trip command message with a time shorter than a preset first reaction time is generated. If the vector and current outputs of the three TMR sensors If the proportion of high-frequency components in the circuit is lower than the preset second proportion threshold, it is determined to be resistive leakage, and a trip command message with a preset second reaction time delay is generated.

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