Current sensing measurement device and method, storage medium and electronic equipment

Abstract

The invention discloses a current sensing measurement device and method, a storage medium and electronic equipment, and the device comprises an AC detection module which is used for sensing an AC current and outputting an AC current analog signal; the direct-current compensation module is used for acquiring magnetic induction intensity generated by a direct-current component of the detected current and outputting a differential voltage analog signal; the compensation module is used for outputting compensation current which is equal to the direct-current component in size but opposite to the direct-current component in direction based on the compensation control signal output by the signal processing module so as to offset direct-current magnetic flux generated by the direct-current component; and the signal processing module is used for calculating a direct current component, a compensation current and an alternating current based on the alternating current analog signal and the differential voltage analog signal, and outputting the compensation control signal based on the direct current component. According to the invention, direct current interference can be effectively suppressed, air gap nonlinear errors can be compensated, influences caused by environmental changes and equipment aging can be adapted, high precision and high reliability of a measurement system can be maintained during long-term operation, and the requirement of high-precision field calibration can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of current measurement and detection, and more particularly, to a current sensing measurement device, method, storage medium and electronic device. BACKGROUND

[0002] The offline verification of conventional electromagnetic transformers usually relies on on-site disassembly, power-off operation, or requires access to standard transformers and external test circuits. Not only is the process cumbersome, but the test window is short, and there is a high risk of electric shock and misoperation, making it difficult to meet the requirements of modern power systems for uninterrupted power supply and high efficiency. Especially in post-disaster reconstruction or complex environments, the traditional method not only consumes time and effort, but also easily affects the accuracy of the verification due to limited conditions.

[0003] Conventional electromagnetic core current transformers (CT) have good low-frequency measurement stability and high magnetic flux density due to their ferromagnetic closed-loop structure, which can effectively achieve large-current isolation measurement. Based on this principle, the clamp CT further considers the advantages of detachable structure and high measurement accuracy. Without damaging the measured main loop, it can be flexibly clamped on any conductor or busbar, especially suitable for emergency detection, live testing and temporary wiring scenarios. The clamp structure makes it convenient to plug and play, greatly reducing maintenance downtime, effectively reducing the labor intensity of maintenance personnel and the safety risk on site, and avoiding economic losses and scheduling complexity caused by traditional shutdown verification.

[0004] However, this structure is sensitive to core saturation, residual magnetism and nonlinear magnetization characteristics, and is prone to hysteresis distortion and response delay, which affects measurement accuracy. In addition, the air gap at the closed clamp will disrupt the continuity of the magnetic circuit, causing magnetic flux leakage and increased magnetic resistance, resulting in transformer ratio error and phase error. Especially in high-precision measurement, the nonlinear magnetic flux disturbance caused by the air gap not only reduces the measurement sensitivity, but also may cause zero drift or short-term fluctuations due to unstable magnetic flux, affecting the repeatability and reliability of the measurement system. The air gap is difficult to accurately determine by conventional methods, and relies on manual visual or experience for clamping adjustment, which is neither intuitive nor prone to human error. Therefore, how to achieve quantitative perception and calibration of the closed state of the core has become a key technical bottleneck for improving the measurement accuracy and field adaptability of the clamp CT.

[0005] In addition, the traditional clamp CT is difficult to accurately measure the current containing direct current components. When the current contains direct current components, the core will be affected by the direct current, causing the magnetic flux to be biased, and then the core enters a saturated state, resulting in distortion, and even unable to provide effective measurement. Therefore, there will be a large error when processing alternating current containing direct current components.

[0006] Therefore, it is necessary to overcome the problems of the non-linear error caused by the air gap of the clamp-type mutual inductor and the distortion and failure when measuring the current containing the DC component, and to solve the problems of the existing clamp-type CT in terms of precision and stability. Therefore, a current sensing measurement device is needed. SUMMARY

[0007] The application provides a current sensing measurement device, method, storage medium and electronic equipment to solve the problem of how to efficiently and accurately measure the current.

[0008] In order to solve the above problems, according to one aspect of the application, a current sensing measurement device is provided, the device comprising: an alternating current detection module, a direct current compensation module and a signal processing module; wherein,

[0009] The alternating current detection module is configured to sense an alternating current and output an alternating current analog signal.

[0010] The direct current compensation module is configured to obtain a magnetic induction intensity generated by a direct current component of a measured current and output a differential voltage analog signal; and output a compensation current equal in size but opposite in direction to the direct current component based on a compensation control signal output by the signal processing module, so as to offset a direct current magnetic flux generated by the direct current component.

[0011] The signal processing module is configured to calculate the direct current component, the compensation current and the alternating current based on the alternating current analog signal and the differential voltage analog signal, and output the compensation control signal based on the direct current component.

[0012] Preferably, the alternating current detection module comprises a clamp-shaped iron core and a detection coil arranged on the clamp-shaped iron core.

[0013] Preferably, the direct current compensation module comprises a direct current detection unit and a direct current compensation unit; wherein,

[0014] The direct current detection unit comprises a tunnel magnetoresistance sensor (TMR) array and an amplification circuit; the TMR array is configured to sense a magnetic induction intensity generated by the direct current component of the measured current in the clamp-shaped iron core and output the differential analog voltage signal; and the amplification circuit is configured to amplify the differential analog voltage signal.

[0015] The direct current compensation unit comprises a signal generation circuit and a compensation coil arranged on the clamp-shaped iron core; the signal generation circuit is configured to generate a compensation current equal in size but opposite in direction to the detected direct current component based on the compensation control signal output by the signal processing module, and inject the compensation current into the compensation coil, so as to generate a reverse magnetic flux in the clamp-shaped iron core to offset the direct current magnetic flux generated by the direct current component.

[0016] Preferably, the TMR array is composed of four groups of TMR chips, which are arranged at 0°, 90°, 180° and 270° positions outside the clamp core.

[0017] Preferably, the signal processing module comprises an analog-to-digital conversion unit and a digital signal processor; wherein,

[0018] The analog-to-digital conversion unit is configured to convert the alternating current analog signal and the differential voltage analog signal into alternating current digital signals and differential voltage digital signals.

[0019] The digital signal processor is configured to calculate a direct current component, a compensation current and an alternating current based on the alternating current analog signal and the differential voltage digital signal.

[0020] Preferably, the digital signal processor is further configured to:

[0021] Determine the air gap state of the clamp core of the current transformer based on the differential voltage analog signal, and if it is determined that the clamp core does not meet the closed requirement, generate a clamp core clamping prompt information.

[0022] Preferably, the signal processing module further comprises:

[0023] The display and storage unit is configured to display the direct current component, the compensation current and the alternating current in real time, and store them by using an SPI Flash memory.

[0024] Preferably, the device further comprises:

[0025] A self-calibration module is configured to output a start signal to the signal processing module to start a self-calibration process, output a direct current / alternating current standard voltage signal based on a calibration control signal output by the signal processing module when performing self-calibration, and obtain a first voltage signal and a second voltage signal based on the direct current / alternating current standard voltage signal.

[0026] The signal processing module is configured to output the calibration control signal based on the start signal when performing self-calibration, and perform self-calibration based on the first voltage signal and the second voltage signal to correct the compensation coefficient and the gain coefficient.

[0027] Preferably, the self-calibration module comprises a correction coil, a self-correction control switch, a signal generator, a V / I conversion unit and an I / V conversion unit; wherein,

[0028] The correction coil is wound on the surface of the clamp core, and the number of turns of the correction coil is the same as that of the detection coil.

[0029] The self-correction control switch is configured to control start and stop of the self-correction process, and when the self-correction control switch is turned on, the self-correction process is started, and a start signal is sent to the signal processing module.

[0030] The signal generator is configured to output a direct / alternating current standard voltage signal based on the calibration control signal.

[0031] The V / I conversion unit is configured to convert the direct / alternating current standard voltage signal into a standard current and inject the standard current into the correction coil.

[0032] The I / V conversion unit is configured to convert the standard current into a first voltage signal and convert a current induced by the detection coil into a second voltage signal.

[0033] According to another aspect of the present application, a measurement method based on the current sensing measurement device is provided, and the method comprises:

[0034] inducing an alternating current and outputting an alternating current analog signal;

[0035] obtaining a magnetic induction intensity generated by a direct current component of the measured current and outputting a differential voltage analog signal;

[0036] outputting the compensation control signal based on the direct current component;

[0037] outputting a compensation current equal in magnitude but opposite in direction to the direct current component based on the compensation control signal to offset a direct current magnetic flux generated by the direct current component;

[0038] calculating the direct current component, the compensation current and the alternating current based on the alternating current analog signal and the differential voltage analog signal.

[0039] Preferably, the method utilizes a clamp core and a detection coil arranged on the clamp core to induce the alternating current.

[0040] Preferably, the method further comprises:

[0041] utilizing a tunnel magnetoresistance sensor (TMR) array to induce a magnetic induction intensity generated by the direct current component of the measured current in the clamp core, output the differential analog voltage signal, and amplify the differential analog voltage signal through an amplification circuit;

[0042] generating a compensation current equal in magnitude but opposite in direction to the detected direct current component based on the compensation control signal and injecting the compensation current into a compensation coil arranged on the clamp core to generate a reverse magnetic flux in the clamp core to offset the direct current magnetic flux generated by the direct current component.

[0043] Preferably, the TMR array is composed of four groups of TMR chips, which are arranged at 0°, 90°, 180° and 270° positions outside the clamp core.

[0044] Preferably, the method further comprises:

[0045] converting the AC current analog signal and the differential voltage analog signal into AC current digital signal and differential voltage digital signal;

[0046] calculating DC component, compensation current and AC current based on the AC current analog signal and the differential voltage digital signal.

[0047] Preferably, the method further comprises:

[0048] judging the air gap state of the clamp core of the current transformer based on the differential voltage analog signal, and generating a clamp core clamping prompt information if it is determined that the clamp core does not meet the closed requirement.

[0049] Preferably, the method further comprises:

[0050] real-time displaying the DC component, compensation current and AC current, and storing them by using SPI Flash memory.

[0051] Preferably, the method further comprises:

[0052] outputting a start signal to start the self-calibration process;

[0053] outputting the calibration control signal based on the start signal when performing self-calibration;

[0054] outputting DC / AC standard voltage signal based on the calibration control signal output by the signal processing module when performing self-calibration, and obtaining first voltage signal and second voltage signal based on the DC / AC standard voltage signal;

[0055] performing self-calibration based on the first voltage signal and the second voltage signal, and correcting the compensation coefficient and the gain coefficient.

[0056] Preferably, the method further comprises:

[0057] The correction coil of the self-calibration module is wound on the surface of the clamp core, and the number of turns of the coil is the same as that of the detection coil.

[0058] When the self-correction control switch is closed, the self-calibration process is started, and a start signal is sent to the signal processing module;

[0059] outputting DC / AC standard voltage signal based on the calibration control signal;

[0060] convert the direct current / alternating current standard voltage signal into a standard current, and inject the standard current into a correction coil;

[0061] convert the standard current into a first voltage signal, and convert a current induced by a detection coil into a second voltage signal.

[0062] Based on another aspect of the present application, the present application provides a computer readable storage medium, which stores a computer program, the program being executed by a processor to implement the steps of any one of the measurement methods of the current sensing measurement device.

[0063] Based on another aspect of the present application, the present application provides an electronic device, comprising:

[0064] the computer readable storage medium described above; and

[0065] one or more processors for executing the program in the computer readable storage medium.

[0066] The present application provides a current sensing measurement device, method, storage medium and electronic device, comprising: an alternating current detection module for sensing an alternating current and outputting an alternating current analog signal; a direct current compensation module for obtaining a magnetic induction intensity generated by a direct current component of a measured current and outputting a differential voltage analog signal; a signal processing module for calculating the direct current component, a compensation current and the alternating current based on the alternating current analog signal and the differential voltage analog signal, and outputting a compensation control signal based on the direct current component, wherein the compensation current is equal in size but opposite in direction to the direct current component and is used to offset a direct current magnetic flux generated by the direct current component. The present application can effectively suppress direct current interference, compensate for air gap nonlinearity error, adapt to the influence of environmental changes and equipment aging, ensure the high precision and high reliability of the measurement system in long-term operation, and meet the demand of high-precision field verification. The device of the present application also integrates a self-calibration module, which can automatically calibrate the device regularly, compensate for errors caused by element aging or mechanical wear, and ensure the reliability and long-term precision of the device in complex field environments. BRIEF DESCRIPTION OF DRAWINGS

[0067] The exemplary embodiments of the present application can be more completely understood in reference to the following drawings:

[0068] Figure 1 a structural schematic diagram of a current sensing measurement device 100 according to an embodiment of the present application;

[0069] Figure 2 a connection structural diagram of a current sensing measurement device according to an embodiment of the present application;

[0070] Figure 3A schematic diagram of an array arrangement according to an embodiment of the application;

[0071] Figure 4 A schematic diagram of an open and closed state of a clamp core according to an embodiment of the application;

[0072] Figure 5 A flow chart of a current sensing measurement method 500 according to an embodiment of the application. DETAILED DESCRIPTION

[0073] Reference will now be made to the exemplary embodiments of the present application with reference to the accompanying drawings, however, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art. The terminology used in the description of the exemplary embodiments presented herein is not intended to be limiting. Identical elements / elements are denoted by identical reference numbers throughout the various figures.

[0074] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0075] Figure 1 A structural schematic diagram of a current sensing measurement device 100 according to an embodiment of the application. As shown, the current sensing measurement device provided by the embodiment of the application can effectively suppress DC interference, compensate for air gap non-linear error, adapt to the effects of environmental changes and equipment aging, ensure the high precision and high reliability of the measurement system in long-term operation, and meet the needs of high-precision field verification. Figure 1 Figure 1 As shown, the current sensing measurement device 100 provided by the embodiment of the application includes an AC detection module 101, a DC compensation module 102, and a signal processing module 103.

[0076] Preferably, the AC detection module 101 is configured to sense an AC current and output an AC current analog signal.

[0077] Preferably, the AC detection module 101 includes a clamp core and a detection coil disposed on the clamp core.

[0078] In combination with Figure 2 ​As shown, in the present application, the current sensing measurement device comprises: an alternating current detection module, a direct current compensation module and a signal processing module; the alternating current detection module comprises a clamp core and a detection coil arranged on the clamp core; the direct current compensation module comprises a direct current detection unit and a direct current compensation unit; and the signal processing module comprises an analog-to-digital conversion unit AD, a digital signal processor DSP and a display and storage unit.

[0079] In the present application, the alternating current detection module is used for measuring alternating current. Through the principle of electromagnetic induction, the alternating current I flowing through the primary winding is inducted to generate an alternating magnetic field in the core, and a voltage or current signal proportional to the current is inducted. AC The alternating current detection unit provides high precision and high stability in the measurement of alternating current, and can process measurement in a large current range.

[0080] The clamp core of the present application is made of microcrystalline material, which can improve the magnetic performance and stability.

[0081] Preferably, the direct current compensation module 102 is used for obtaining the magnetic induction intensity generated by the direct current component of the measured current and outputting a differential voltage analog signal; and is used for outputting a compensation current equal in size but opposite in direction to the direct current component based on a compensation control signal output by the signal processing module, so as to offset the direct current magnetic flux generated by the direct current component.

[0082] Preferably, the direct current compensation module 102 comprises a direct current detection unit and a direct current compensation unit; wherein,

[0083] The direct current detection unit comprises a tunnel magnetoresistance sensor TMR array and an amplification circuit; the TMR array is used for inducting the magnetic induction intensity generated by the direct current component of the measured current in the clamp core and outputting the differential analog voltage signal; and the amplification circuit is used for amplifying the differential analog voltage signal.

[0084] The direct current compensation unit comprises a signal generating circuit and a compensation coil arranged on the clamp core; the signal generating circuit is used for generating a compensation current equal in size but opposite in direction to the detected direct current component based on a compensation control signal output by the signal processing module, and injecting the compensation current into the compensation coil, so as to generate a reverse magnetic flux in the clamp core to offset the direct current magnetic flux generated by the direct current component.

[0085] Preferably, the TMR array is composed of four groups of TMR chips, and the four groups of TMR chips are uniformly arranged at positions of 0°, 90°, 180° and 270° outside the clamp core.

[0086] In combination with Figure 2As shown, in the present application, the direct current detection unit is composed of a tunnel magnetoresistance sensor TMR array and its peripheral amplification circuit. The TMR array is used to sense the magnetic induction intensity generated by the direct current component of the measured current in the iron core and output a corresponding differential voltage signal; the peripheral amplification circuit amplifies the differential voltage signal and outputs a voltage signal U representing the size of the measured direct current component out . The voltage signal has a high linearity relationship (I DC = K1*U DC -K2, where K1 and K2 are constants) with the measured direct current component I out . The TMR array is composed of four groups of TMR chips, which are arranged in specific stacking positions to optimize the detection sensitivity and uniformity of the direct current magnetic field. The TMR, as a new type of magnetic field detection technology, has the characteristics of high sensitivity, low temperature drift, wide linear range and excellent stability, and can provide a lower detection lower limit and better anti-interference ability. As shown in Figure 3 , the TMR array detection module is composed of four groups of TMR sensors, which are uniformly arranged at 0°, 90°, 180° and 270° positions outside the CT iron core to form a TMR array sensor module. The TMR, as a new type of magnetic field detection technology, has the characteristics of high sensitivity, low temperature drift, wide linear range and excellent stability, and can provide a lower detection lower limit and better anti-interference ability.

[0087] In the present application, the direct current compensation unit generates a compensation current I comp ≈-I DC based on the real-time calculation of the signal processing module DSP according to the voltage output by the direct current detection unit, controls the direct current signal generation circuit to generate a corresponding current and injects it into the compensation coil, so that the total magnetic flux of the iron core tends to zero to offset the direct current magnetic flux bias. Specifically, the direct current compensation unit includes a direct current signal generation circuit (such as a digital controlled adjustable signal generator + V / I conversion) and a compensation coil arranged on the iron core. The direct current detection unit can control the direct current signal generation circuit to generate a compensation current (I comp ≈-I DC ) with the same size and opposite direction as the detected direct current component I DC . The compensation current is injected into the compensation coil to generate a reverse magnetic flux in the iron core, which is used to offset the direct current magnetic flux generated by the measured direct current component, so that the total amount of the iron core magnetic flux is close to zero, thereby avoiding the saturation of the iron core and ensuring that the alternating current detection module can accurately measure the alternating current component.

[0088] Preferably, the signal processing module 103 is configured to calculate the direct current component, the compensation current and the alternating current based on the alternating current analog signal and the differential voltage analog signal, and output the compensation control signal based on the direct current component.

[0089] Preferably, the signal processing module 103 includes: an analog-to-digital converter and a digital signal processor; wherein,

[0090] The analog-to-digital conversion unit is used to convert the AC current analog signal and the differential voltage analog signal into AC current digital signal and differential voltage digital signal;

[0091] The digital signal processor is used to calculate the DC component, compensation current, and AC current based on the AC current analog signal and the differential voltage digital signal.

[0092] Preferably, the digital signal processor is further configured to:

[0093] Based on the differential voltage analog signal, the air gap state of the clamp core of the current transformer is determined. If it is determined that the clamp core is not fully closed, a clamp core clamping prompt message is generated.

[0094] Preferably, the signal processing module 103 further includes:

[0095] The display and storage unit is used to display the DC component, compensation current and AC current in real time, and to store them using an SPI Flash memory.

[0096] Combination Figure 2 As shown, in this invention, the signal processing module includes an analog-to-digital converter (AD), a digital signal processor (DSP), and a display unit.

[0097] The analog-to-digital converter (AD) module is used to convert analog signals acquired from the AC detection unit and the TMR array sensor into digital signals. The AD module uses a 16-bit Σ-Δ ADC (such as ADS8681) for synchronous sampling. Through AD conversion, AC and DC signals are converted into digital signals for further processing by the DSP control module.

[0098] The digital signal processor (DSP) is the core control unit, responsible for processing the digital signals acquired from the analog-to-digital converter (AD). The DSP calculates the DC current I in real time. DC Compensation current I comp and alternating current I AC The system performs data processing, compensation control, and self-calibration. The DSP control module is also responsible for real-time monitoring of the compensation current and DC current values ​​to ensure the system's accuracy and safety during operation. Furthermore, the DSP is used to analyze and judge the sensor signals of the TMR array, and to identify the closed state of the clamp-on transformer in real time, such as its open / closed state. Figure 4When the air gap anomaly or the magnetic flux distribution asymmetry is detected, or the set closing threshold is not met, the system will generate a prompt information to guide the user to re-clamp the core joint to reduce the influence of air gap error on the measurement accuracy, and to realize the verification and calibration of the closed state of the core.

[0099] The display and storage module is used for real-time display of measurement results and storage of historical data. The display module is a 2.8" TFT LCD (resolution 320x240) for real-time display of I DC 、 I AC and I comp . The storage module adopts SPI Flash (capacity ≥ 2MB) for saving the last 1000 measurement records, and adding a timestamp to each record for easy tracing and analysis. The module supports automatic timing recording and event triggered recording mechanism, and has basic data statistics and analysis functions such as mean, maximum, minimum and standard deviation calculation, which facilitates the user to quickly evaluate the volatility of measurement data. The system can set an early warning threshold, and automatically mark the record and prompt an alarm when detecting abnormal current or persistent bias. The module also provides a USB interface and an SD card slot, supports exporting historical data to external devices, and facilitates generating reports or uploading to the upper system; in addition, a serial communication interface is reserved for system-level data integration and remote communication expansion.

[0100] Preferably, wherein the device further comprises:

[0101] a self-calibration module for outputting a start signal to the signal processing module to start the self-calibration process; for outputting a direct current / alternating current standard voltage signal based on the calibration control signal output by the signal processing module when self-calibration is performed, and obtaining the first voltage signal and the second voltage signal based on the direct current / alternating current standard voltage signal;

[0102] a signal processing module for outputting the calibration control signal based on the start signal when self-calibration is performed; for self-calibration based on the first voltage signal and the second voltage signal to correct the compensation coefficient and the gain coefficient.

[0103] Preferably, wherein the self-calibration module comprises a correction coil, a self-correction control switch, a signal generator, a V / I conversion unit, and an I / V conversion unit; wherein,

[0104] The correction coil is wound on the surface of the clamp-shaped iron core, and the number of turns of the coil is the same as that of the detection coil.

[0105] The self-correction control switch is used to control the start and stop of the self-calibration process. When the self-correction control switch is closed, the self-calibration process is started, and a start signal is sent to the signal processing module;

[0106] The signal generator is used for outputting a direct current / alternating current standard voltage signal based on the calibration control signal.

[0107] The V / I conversion unit is used for converting the direct current / alternating current standard voltage signal into a standard current and injecting the standard current into a correction coil.

[0108] The I / V conversion unit is used for converting the standard current into a first voltage signal and converting a current induced by a detection coil into a second voltage signal.

[0109] In combination Figure 2 In the present application, the measuring device further comprises a self-calibration module, which is used for periodically injecting a known standard signal into the correction coil and synchronously collecting an output of the detection coil to perform self-calibration and calculate and update compensation coefficients and gain correction coefficients. By periodically calibrating the compensation coefficients and the gain correction coefficients in the system, long-term stability of the measuring precision can be ensured.

[0110] In the present application, the self-calibration module comprises a correction coil, a self-calibration control switch, a signal generator, a V / I conversion unit and an I / V conversion unit. The correction coil is wound on a surface of an iron core and has the same number of turns as the detection coil. This design ensures that the detection coil can induce a current signal with a theoretical value when the standard current passes through the correction coil, thereby eliminating system errors caused by the difference in the number of turns. The self-calibration control switch is a physical button switch, which directly controls start and stop of the self-calibration circuit. When the switch is closed, a start signal is sent to a digital signal processor (DSP) to trigger the entire self-calibration process. The signal generator is a high-precision signal source programmed by the DSP, which can generate a direct current / alternating current standard voltage signal in the order of millivolts to volts, thereby providing a traceable calibration reference. The V / I conversion unit is connected to an output end of the signal generator and linearly converts the standard voltage signal into a standard current I std . The core of the V / I conversion unit is a precision operational amplifier circuit, which ensures that the current output precision is better than ±0.05%. The double-path I / V conversion unit converts the standard current I std into a voltage signal V1, and the second path converts a current I sense induced by the detection coil into a voltage signal V2. The parameters of the two paths are completely symmetrical, thereby avoiding introduction of deviation by signal conversion.

[0111] The device of the present application can periodically perform automatic calibration on the equipment by integrating the self-calibration module, compensate errors caused by factors such as aging of components or mechanical wear, and ensure reliability and long-term precision of the device in a complex field environment.

[0112] In the present application, before use, the TMR array is installed at four opposite positions of the outer ring of the openable clamp-type transformer core, near 0°, 90°, 180° and 270° respectively, to form magnetically symmetrical measurement channels. Since the core has an opening and closing feature, its actual closed state directly affects the integrity of the magnetic flux path. Only when the core is well closed, the core magnetic circuit can form a complete loop, and the distribution of magnetic flux at each TMR sensing point has symmetry, and the static output of each channel tends to be consistent. If there are structural abnormalities such as air gap, poor clamping or offset during closing, it will cause leakage or local distortion of magnetic flux at the closed joint, and then cause asymmetric deviation of the output of each TMR channel. The system compares and analyzes the static initial output of each TMR channel through the DSP control module before the device is powered on or started, and if the output difference exceeds the set tolerance threshold, it is judged that the core is not closed well. At this time, the system will prompt the user to re-clamp the jaws through the display interface, and ensure that a continuous and symmetrical magnetic circuit is formed before entering the normal measurement process.

[0113] In use, the detection coil in the clamp-type transformer senses the alternating current signal by electromagnetic induction principle and outputs an analog voltage; at the same time, the TMR array installed at the 0°, 90°, 180° and 270° positions of the core axis is used to detect the magnetic flux bias caused by the direct current component and output a differential voltage signal, which is sent to the analog-to-digital conversion module AD after pre-amplification. The AD module synchronously collects the alternating and direct current analog signals and converts them into digital signals, which are transmitted to the DSP controller. The DSP calculates I DC 、 I AC and I comp , where I DC is from the TMR array, and I comp is its reverse compensation. If the system detects significant direct current magnetic flux, the DSP will control the direct current signal generator and the V / I conversion unit to generate an equivalent reverse compensation current I comp to inject into the compensation coil to eliminate the core magnetic flux bias and ensure that the CT remains in the linear operating region. At the same time, the DSP sends the real-time measurement value to the display module (LCD screen) for display and records it in the internal SPIFlash. The system is provided with a self-calibration module, which is automatically triggered at each power-on or at a set period: the DSP controls the digital signal source to output a standard voltage, which is injected into the correction coil after V / I conversion, while the standard current I std and the detection coil sensing value are collected, and the gain and compensation parameters are corrected by comparing the two I / V conversion values to ensure long-term measurement accuracy. Users can export measurement records and calibration logs through USB or SD card interface for data analysis and traceability. The entire process does not require power-off or disconnection, and can realize fast, accurate and stable on-line verification of the transformer on site.

[0114] The current sensing measurement device provided by the application, by integrating four TMR sensors uniformly distributed in the CT core outer ring, is used for detecting the direct current component in the current, and through a direct current compensation unit, the direct current bias of the CT core is corrected in real time, so that the core saturation distortion is avoided, and the accuracy of the alternating current measurement is ensured. Further, by injecting a reverse current through the compensation coil, the direct current magnetic flux bias in the core is offset, ensuring the accuracy of the measurement of the alternating current. In addition, the device also integrates a self-calibration module, which can periodically automatically calibrate the equipment, compensate for errors caused by factors such as component aging or mechanical wear, and ensure the reliability and long-term accuracy of the device in complex field environments. Further, in order to eliminate the air gap error caused by the poor closure of the core, when in use, the TMR array is used to detect the change of the magnetic induction intensity in the closed area, to judge the air gap state of the clamp-type mutual inductor, and the closure degree is judged through the DSP control module. When insufficient closure is detected, the system automatically prompts the user to re-tighten the core joint, so as to reduce the influence of the air gap on the measurement result, thereby realizing the identification and calibration of the air gap error.

[0115] The current sensing measurement device provided by the application has the following effects:

[0116] 1) The clamp coil and the TMR array cooperate to measure, realizing high-precision detection of alternating current and direct current mixed current. The clamp coil ensures the stability and accuracy in the alternating current measurement, and the TMR array sensor has the advantages of high sensitivity, low temperature drift and wide linear range, solving the problem that the traditional mutual inductor cannot detect the direct current component, thereby improving the overall measurement capability.

[0117] 2) Direct current bias saturation error elimination. Through the compensation mechanism, the magnetic flux bias caused by the direct current is offset, the distortion problem of the alternating current measurement caused by the core saturation is avoided, and the accurate measurement under complex current waveforms is ensured.

[0118] 3) Good long-term stability. By integrating the online self-calibration function, automatic verification and compensation can be performed periodically during the operation of the device, errors caused by environmental changes and component aging are actively corrected, the stability and reliability of the system during long-term operation are improved. The maintenance cost of the device is reduced, and the long-term stability and reliability of the device are improved.

[0119] 4) Strong anti-interference and high reliability. The differential TMR array + electromagnetic shield design is adopted, the anti-interference ability of the system in a strong electromagnetic interference environment is improved, and the stable measurement performance of the device in complex field conditions is ensured.

[0120] 5) Simplify the operation and maintenance process. The overall structure is compact and convenient. The on-line calibration function of the mutual inductor in the live state is supported, the operation and maintenance efficiency is improved. Through automatic calibration and compensation, subsequent frequent repeated calibration is not required, the complexity of maintenance and calibration and manual intervention in operation and maintenance are reduced,

[0121] 6) Intelligent recognition of air gap closure state. The device uses the TMR array channel arranged on the core to perceive the magnetic induction intensity distribution at the closure, to determine whether the air gap meets the set closure threshold. When detecting poor closure, the system automatically prompts the user to re-clamp the mutual inductor core, to avoid measurement drift or ratio difference deviation caused by air gap error, to realize closure quality evaluation and calibration, and to improve overall measurement reliability.

[0122] Figure 5 A flowchart of the current sensing measurement method 500 according to an embodiment of the present application. As shown in Figure 5 The measurement method 500 based on the current sensing measurement device as described above according to an embodiment of the present application starts from step 501, in which an alternating current is induced, and an alternating current analog signal is output.

[0123] Preferably, the method induces the alternating current using a split core and a detection coil arranged on the split core.

[0124] In step 502, the magnetic induction intensity generated by the direct current component of the measured current is obtained, and a differential voltage analog signal is output.

[0125] In step 503, the compensation control signal is output based on the direct current component.

[0126] In step 504, a compensation current equal in magnitude but opposite in direction to the direct current component is output based on the compensation control signal, to cancel the direct current magnetic flux generated by the direct current component.

[0127] Preferably, the method further comprises:

[0128] The tunnel magnetoresistance sensor TMR array is used to induce the magnetic induction intensity generated by the direct current component of the measured current in the split core, to output the differential analog voltage signal, and to amplify the differential analog voltage signal through an amplification circuit;

[0129] A compensation current equal in magnitude but opposite in direction to the detected direct current component is generated based on the compensation control signal, and is injected into a compensation coil arranged on the split core, to generate an opposite magnetic flux in the split core, to cancel the direct current magnetic flux generated by the direct current component.

[0130] In step 505, the direct current component, the compensation current, and the alternating current are calculated based on the alternating current analog signal and the differential voltage analog signal.

[0131] Preferably, the TMR array is composed of four groups of TMR chips, which are uniformly arranged at 0°, 90°, 180°, and 270° positions outside the split core.

[0132] Preferably, the method further comprises:

[0133] converting the alternating current analog signal and the differential voltage analog signal into alternating current digital signal and differential voltage digital signal;

[0134] calculating direct current component, compensation current and alternating current based on the alternating current analog signal and the differential voltage digital signal.

[0135] Preferably, the method further comprises:

[0136] judging the air gap state of the clamp core of the current transformer based on the differential voltage analog signal, and if it is determined that the clamp core does not meet the closed requirement, generating a clamp core clamping prompt information.

[0137] Preferably, the method further comprises:

[0138] real-time displaying the direct current component, the compensation current and the alternating current, and storing them by using SPI Flash memory.

[0139] Preferably, the method further comprises:

[0140] outputting a start signal to start the self-calibration process;

[0141] outputting the calibration control signal based on the start signal when performing self-calibration;

[0142] outputting a direct current / alternating current standard voltage signal based on the calibration control signal output by the signal processing module when performing self-calibration, and obtaining a first voltage signal and a second voltage signal based on the direct current / alternating current standard voltage signal;

[0143] performing self-calibration based on the first voltage signal and the second voltage signal, and correcting the compensation coefficient and the gain coefficient.

[0144] Preferably, the method further comprises:

[0145] setting the correction coil of the self-calibration module to be wound on the surface of the clamp core, wherein the number of turns of the correction coil is the same as that of the detection coil;

[0146] when the self-correction control switch is closed, starting the self-calibration process and sending a start signal to the signal processing module;

[0147] outputting a direct current / alternating current standard voltage signal based on the calibration control signal;

[0148] converting the direct current / alternating current standard voltage signal into a standard current and injecting it into the correction coil;

[0149] The standard current is converted into a first voltage signal, and the current induced by the detection coil is converted into a second voltage signal.

[0150] The current sensing measurement method 500 of the embodiment of the present application corresponds to the current sensing measurement device 100 of another embodiment of the present application, which will not be described herein again.

[0151] Based on another aspect of the present application, the present application provides a computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, implements the steps of any one of the measurement methods of the current sensing measurement device.

[0152] Based on another aspect of the present application, the present application provides an electronic device, comprising:

[0153] The computer readable storage medium described above; and

[0154] One or more processors for executing the program in the computer readable storage medium.

[0155] The present application has been described by reference to a few embodiments. However, one of ordinary skill in the art will readily recognize that other embodiments, in addition to those explicitly described, are equally within the scope of the present application.

[0156] Generally, all terms used in the present application are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a" or "an" means "at least one" unless otherwise clearly indicated by the context of the disclosure. The steps of any methods disclosed herein need not be performed in the exact order disclosed, unless explicitly stated.

[0157] Those skilled in the art will appreciate that embodiments of the present application can be devised for use with three-dimensional (3D) imaging devices, as well as two-dimensional (2D) imaging devices. Accordingly, the term "imaging device" should be interpreted in accordance with the broadest possible interpretation of the principles described herein. Embodiments of the present application can be provided as a method, a system or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer readable storage media (including, but not limited to, disk memory, CD-ROMs, optical storage devices, etc.) embodying computer readable program code thereon for use by or in connection with an instruction execution system. Such a system can be a computer based system, an electronic system, a processor based system, or the like.

[0158] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0159] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0160] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0161] Finally, it should be noted that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application, but not limit the technical solutions of the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be covered in the protection scope of the present application.

Claims

1. A current sensing and measuring device, characterized in that, The device includes: an AC detection module, a DC compensation module, and a signal processing module; wherein... The AC detection module is used to sense AC current and output an AC current analog signal; The DC compensation module is used to acquire the magnetic flux density generated by the DC component of the measured current and output a differential voltage analog signal; it is also used to output a compensation current that is equal in magnitude but opposite in direction to the DC component based on the compensation control signal output by the signal processing module, so as to cancel the DC magnetic flux generated by the DC component. The signal processing module is used to calculate the DC component, compensation current, and AC current based on the AC current analog signal and the differential voltage analog signal, and output the compensation control signal based on the DC component.

2. The apparatus according to claim 1, characterized in that, The AC detection module includes: a clamp-shaped iron core and a detection coil disposed on the clamp-shaped iron core.

3. The apparatus according to claim 2, characterized in that, The DC compensation module includes: a DC detection unit and a DC compensation unit; wherein, The DC detection unit includes: a tunnel magnetoresistive sensor (TMR) array and an amplifier circuit; the TMR array is used to sense the magnetic induction intensity generated by the DC component of the measured current in the clamp-shaped iron core and output the differential analog voltage signal; the amplifier circuit is used to amplify the differential analog voltage signal. The DC compensation unit includes: a signal generation circuit and a compensation coil disposed on the clamp-shaped iron core; the signal generation circuit is used to generate a compensation current that is equal in magnitude but opposite in direction to the detected DC component based on the compensation control signal output by the signal processing module, and inject it into the compensation coil to generate a reverse magnetic flux in the clamp-shaped iron core to cancel the DC magnetic flux generated by the DC component.

4. The apparatus according to claim 3, characterized in that, The TMR array consists of four groups of TMR chips, which are evenly arranged at 0°, 90°, 180° and 270° positions outside the clamp-shaped iron core.

5. The apparatus according to claim 1, characterized in that, The signal processing module includes: an analog-to-digital converter and a digital signal processor; wherein, The analog-to-digital conversion unit is used to convert the AC current analog signal and the differential voltage analog signal into AC current digital signal and differential voltage digital signal; The digital signal processor is used to calculate the DC component, compensation current, and AC current based on the AC current analog signal and the differential voltage digital signal.

6. The apparatus according to claim 5, characterized in that, The digital signal processor is also used for: Based on the differential voltage analog signal, the air gap state of the clamp core of the current transformer is determined. If it is determined that the clamp core is not fully closed, a clamp core clamping prompt message is generated.

7. The apparatus according to claim 5, characterized in that, The signal processing module further includes: The display and storage unit is used to display the DC component, compensation current and AC current in real time, and to store them using an SPIFlash memory.

8. The apparatus according to claim 2, characterized in that, The device further includes: The self-calibration module is used to output a start signal to the signal processing module to start the self-calibration process; it is also used to output a DC / AC standard voltage signal based on the calibration control signal output by the signal processing module during self-calibration, and to obtain a first voltage signal and a second voltage signal based on the DC / AC standard voltage signal. The signal processing module is used to output the calibration control signal based on the start signal during self-calibration; and to perform self-calibration based on the first voltage signal and the second voltage signal, correcting the compensation coefficient and gain coefficient.

9. The apparatus according to claim 8, characterized in that, The self-calibration module includes: a calibration coil, a self-calibration control switch, a signal generator, a V / I conversion unit, and an I / V conversion unit; wherein, The correction coil is wound on the surface of the clamp-shaped iron core, and the number of turns of the coil is the same as the number of turns of the detection coil. The self-calibration control switch is used to control the start and stop of the self-calibration process. When the self-calibration control switch is closed, the self-calibration process is started and a start signal is sent to the signal processing module. The signal generator is used to output a DC / AC standard voltage signal based on the calibration control signal; The V / I conversion unit is used to convert the DC / AC standard voltage signal into a standard current and inject it into the correction coil; The I / V conversion unit is used to convert the standard current into a first voltage signal and the current induced by the detection coil into a second voltage signal.

10. A measurement method based on the current sensing and measuring device according to any one of claims 1-9, characterized in that, The method includes: It senses alternating current and outputs an analog alternating current signal; The magnetic flux density generated by the DC component of the measured current is obtained, and a differential voltage analog signal is output. The compensation control signal is output based on the DC component; Based on the compensation control signal, a compensation current with the same magnitude but opposite direction as the DC component is output to counteract the DC magnetic flux generated by the DC component; The DC component, compensation current, and AC current are calculated based on the AC current analog signal and the differential voltage analog signal.

11. The method according to claim 10, characterized in that, The method utilizes a clamp-shaped iron core and a detection coil disposed on the clamp-shaped iron core to induce an alternating current.

12. The method according to claim 11, characterized in that, The method further includes: Using a tunnel magnetoresistive sensor (TMR) array, the magnetic induction intensity generated by the DC component of the measured current in the clamp-shaped iron core is sensed, the differential analog voltage signal is output, and the differential analog voltage signal is amplified by an amplifier circuit. Based on the compensation control signal, a compensation current equal in magnitude but opposite in direction to the detected DC component is generated and injected into the compensation coil set on the clamp-shaped iron core to generate a reverse magnetic flux in the clamp-shaped iron core, which cancels the DC magnetic flux generated by the DC component.

13. The method according to claim 12, characterized in that, The TMR array consists of four groups of TMR chips, which are evenly arranged at 0°, 90°, 180° and 270° positions outside the clamp-shaped iron core.

14. The method according to claim 10, characterized in that, The method further includes: The analog AC current signal and analog differential voltage signal are converted into digital AC current signal and digital differential voltage signal; The DC component, compensation current, and AC current are calculated based on the AC current analog signal and the differential voltage digital signal.

15. The method according to claim 14, characterized in that, The method further includes: Based on the differential voltage analog signal, the air gap state of the clamp core of the current transformer is determined. If it is determined that the clamp core is not fully closed, a clamp core clamping prompt message is generated.

16. The method according to claim 14, characterized in that, The method further includes: The DC component, compensation current, and AC current are displayed in real time and stored using an SPI Flash memory.

17. The method according to claim 11, characterized in that, The method further includes: Output a start signal to initiate the self-calibration process; During self-calibration, the calibration control signal is output based on the start signal; During self-calibration, a DC / AC standard voltage signal is output based on the calibration control signal output by the signal processing module, and a first voltage signal and a second voltage signal are obtained based on the DC / AC standard voltage signal. Self-calibration is performed based on the first and second voltage signals to correct the compensation coefficient and gain coefficient.

18. The method according to claim 17, characterized in that, The method further includes: The self-calibration module's correction coil is wound on the surface of a clamp-shaped iron core; the number of turns of the coil is the same as the number of turns of the detection coil. When the self-calibration control switch is closed, the self-calibration process is initiated by sending a start signal to the signal processing module. Based on the calibration control signal, output a DC / AC standard voltage signal; The DC / AC standard voltage signal is converted into a standard current and injected into the correction coil; The standard current is converted into a first voltage signal, and the current induced by the detection coil is converted into a second voltage signal.

19. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 10-18.

20. An electronic device, characterized in that, include: The computer-readable storage medium as described in claim 19; as well as One or more processors for executing a program in the computer-readable storage medium.

Images