Anti-interference magneto-dependent current sensor calibration device and calibration calculation method

Abstract

The invention provides an anti-interference magnetic-sensing current sensor calibration device and a calibration calculation method, and the calibration device controls a reference waveform channel in control connection through a main control unit, collects reference waveform data at the two ends of a switchable standard resistor, and inputs the reference waveform data to a calculation unit. A connected to-be-measured waveform channel is controlled to collect to-be-measured waveform data of a to-be-measured sensor and input the to-be-measured waveform data into the calculation unit, and then the calculation unit extracts the reference waveform data and a coincident interval of a Fourier transform stable interval of the to-be-measured waveform data to obtain frequency-jitter-free reference waveform data and frequency-jitter-free to-be-measured waveform data; furthermore, the amplitude error, the phase error and the fundamental frequency of the to-be-measured sensor are calculated based on the non-frequency jitter reference waveform data and the non-frequency jitter to-be-measured waveform data, so that the problem that the measurement calculation is influenced by the frequency jitter of the current source is avoided.

Description

Technical Field

[0001] The invention relates to the field of sensor calibration, and in particular to an anti-interference magnetic sensitive current sensor calibration device and a calibration calculation method. Background Art

[0002] Magnetic current sensors have the characteristics of high sensitivity, low power consumption and low noise, and have been widely used in automotive electronics and industrial control. For magnetic current sensors used in power systems, the measurement characteristics are related not only to the amplitude error but also to the phase error. At present, the calibration of magnetic current sensors often uses standard current transformers as a reference to compare and calibrate the amplitude and phase errors of magnetic current sensors. However, standard current transformers are mainly used to measure large industrial frequency currents and cannot be used as a calibration benchmark for measuring broadband and small amplitude currents.

[0003] In response to this problem, the prior art proposes to use a shunt to obtain the original current to be measured and convert it into a voltage waveform for calibration. For example, CN 202122614857.0 discloses a device for detecting the wide-band measurement performance of an AC / DC current sensor. The scheme mentions extracting the standard signal of the current to be measured through a shunt, comparing it with the output of the sensor, and obtaining the amplitude error and phase error. However, the existing schemes usually have large errors when measuring broadband and small-amplitude currents. On the one hand, when the current is small, the original current obtained by the shunt is small, and the signal-to-noise ratio is poor. On the other hand, the current source is prone to frequency jitter within a wide frequency range, resulting in excessive phase measurement deviation.

[0004] Therefore, it is of great significance to solve the problem in the prior art that the signal-to-noise ratio is poor and the measurement calculation is affected by frequency jitter. Summary of the invention

[0005] In order to solve the problem in the prior art that the signal-to-noise ratio is poor and the measurement calculation is affected by frequency jitter, the present invention proposes an anti-interference magnetic sensitive current sensor calibration device and a calibration calculation method.

[0006] In a first aspect, the present invention provides an anti-interference magnetic sensitive current sensor calibration device, comprising:

[0007] A main control unit and a current generator connected to the main control unit, a switchable standard resistor, a reference waveform channel, a waveform channel to be measured, and a calculation unit;

[0008] One end of the waveform channel to be measured is connected to the sensor to be measured and then connected to the current generator, and the other end of the waveform channel to be measured is connected to the calculation unit;

[0009] One end of the reference waveform channel is connected to the current generator via a switchable standard resistor, and the other end of the reference waveform channel is connected to the calculation unit;

[0010] The main control unit is used to control the current generator to output the current to be measured; it is also used to control the switchable standard resistor to input the rated resistance so that the amplitude of the reference waveform data meets the preset measurement conditions; it is also used to control the reference waveform channel to collect the reference waveform data at both ends of the switchable standard resistor and input it to the calculation unit; it is also used to control the waveform channel to be measured to collect the waveform data of the sensor to be measured and input it to the calculation unit;

[0011] The calculation unit is used to extract the overlapping interval of the Fourier transform stable interval of the reference waveform data and the waveform data to be measured, obtain the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter, and calculate the amplitude error, phase error and fundamental frequency of the sensor to be measured based on the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter.

[0012] Preferably, the waveform channel to be measured comprises a first analog-to-digital conversion module and a first queue buffer connected to each other; the first analog-to-digital conversion module is connected to the sensor to be measured; the first queue buffer is connected to the calculation unit;

[0013] The first analog-to-digital conversion module is used to collect the voltage signal of the sensor to be tested based on the control of the main control unit, discretize the voltage signal into waveform data to be tested, and transmit the waveform data to be tested to the first queue buffer;

[0014] The first queue buffer is used to store the waveform data to be tested.

[0015] Preferably, the reference waveform channel comprises a second analog-to-digital conversion module and a second queue buffer connected to each other; the second analog-to-digital conversion module is connected to the switchable standard resistor; the second queue buffer is connected to the calculation unit;

[0016] The second analog-to-digital conversion module is used to collect the voltage signal at both ends of the switchable standard resistor based on the control of the main control unit, discretize the voltage signal into reference waveform data, and transmit the reference waveform data to the second queue buffer;

[0017] The second queue buffer is used to store the reference waveform data.

[0018] Preferably, the switchable standard resistor includes:

[0019] A plurality of branches connected in parallel to each other, each branch comprising a standard resistor and a switchable resistor switch connected in series;

[0020] The switchable resistance switch is used to close and open the switch based on the control of the main control unit to control the input of the rated resistance.

[0021] Preferably, the main control unit controls the output current to adjust the output amplitude from milliampere level to hundred ampere level and the output frequency from low frequency in hertz level to tens of kilohertz level.

[0022] In a second aspect, the present invention provides a calibration calculation method for an anti-interference magnetic sensitive current sensor, comprising:

[0023] Applying a Hanning window to the extracted waveform data to be measured and the reference waveform data, respectively, and calculating the Fourier transforms corresponding to the waveform data to be measured and the reference waveform data within the Hanning window, respectively;

[0024] Determine whether the Hanning window traverses all of the waveform data to be measured and the reference waveform data;

[0025] If not, move the Hanning window to the next interval, and calculate the Fourier transform of the waveform data to be measured and the reference waveform data in the next interval;

[0026] If yes, determine the overlap interval of the Fourier transform stable interval of the waveform data to be measured and the reference waveform data, and use the Fourier waveform data of the waveform data to be measured in the overlap interval as the sensor waveform data to be measured without frequency jitter, and use the Fourier transform data of the reference waveform data in the overlap interval as the reference waveform data without frequency jitter;

[0027] The amplitude error, phase error and fundamental frequency of the sensor to be tested are calculated based on the reference waveform data without frequency jitter and the waveform data of the sensor to be tested without frequency jitter.

[0028] In another aspect, the present application further provides an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0029] The memory is used to store one or more programs;

[0030] When the one or more programs are executed by the at least one processor, the above-mentioned anti-interference magnetic sensitive current sensor calibration calculation method is implemented.

[0031] On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the calibration calculation method for an anti-interference magnetic-sensitive current sensor as described above is implemented.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides an anti-interference magnetic sensitive current sensor calibration device and a calibration calculation method. The calibration device controls a connected current generator to output a current to be measured through a main control unit, controls a connected switchable standard resistor to input a rated resistor so that the amplitude of reference waveform data meets a preset measurement condition, controls a connected reference waveform channel to collect reference waveform data at both ends of the switchable standard resistor and inputs the data into a calculation unit, controls a connected waveform channel to be measured to collect waveform data of a sensor to be measured and inputs the data into the calculation unit, and then extracts the overlap interval of the reference waveform data and the Fourier transform stable interval of the waveform data to be measured through the calculation unit to obtain frequency jitter-free reference waveform data and frequency jitter-free waveform data to be measured, further calculates the amplitude error, phase error and fundamental frequency of the sensor to be measured based on the frequency jitter-free reference waveform data and the frequency jitter-free waveform data to be measured, and changes the resistance value of the switching resistor so that the reference waveform data has a good signal-to-noise ratio in both a small current interval and a large current interval. At the same time, the calculation unit extracts the reference waveform data and the frequency jitter-free interval in the waveform data to be measured to avoid the problem that the current source frequency jitter affects the measurement calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of a calibration device for an anti-interference magnetic sensitive current sensor of the present invention;

[0035] Figure 2 A schematic diagram of switchable standard resistors of the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0036] Figure 3 It is a schematic diagram of the process of extracting data from a frequency jitter-free interval in a calculation unit of the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0037] Figure 4 A schematic diagram of the flow of calculating the amplitude error in the calculation unit of the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0038] Figure 5 It is a schematic diagram of the phase error calculation process in the calculation unit of the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0039] Figure 6 It is a schematic diagram of the frequency jitter-free interval extracted by the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0040] Figure 7 It is a schematic diagram of the amplitude error calculation result of the anti-interference magnetic sensitive current sensor calibration device of the present invention;

[0041] Figure 8 It is a flow chart of the calibration calculation method of the anti-interference magnetic sensitive current sensor of the present invention;

[0042] Fig. 9 The figure is a schematic diagram of the structure of an electronic device of the present invention. DETAILED DESCRIPTION

[0043] The present invention proposes an anti-interference magnetic sensitive current sensor calibration device and calibration calculation method, which uses a switchable resistor to replace the shunt, and changes the resistance value of the switchable standard resistor so that the reference waveform data has a good signal-to-noise ratio in both the small current range and the large current range. At the same time, the calculation unit adopts an anti-frequency jitter algorithm, which extracts the frequency jitter-free interval in the reference waveform data and the waveform data to be measured, avoiding excessive phase calculation errors of the sensor to be measured caused by the current source frequency jitter.

[0044] In order to better understand the present invention, the content of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] Embodiment 1:

[0046] A calibration device for an anti-interference magnetic sensitive current sensor, such as Figure 1 As shown, including:

[0047] A main control unit and a current generator connected to the main control unit, a switchable standard resistor, a reference waveform channel, a waveform channel to be measured, and a calculation unit;

[0048] One end of the waveform channel to be measured is connected to the sensor to be measured and then connected to the current generator, and the other end of the waveform channel to be measured is connected to the calculation unit;

[0049] One end of the reference waveform channel is connected to the current generator via a switchable standard resistor, and the other end of the reference waveform channel is connected to the calculation unit;

[0050] The main control unit is used to control the current generator to output the current to be measured; it is also used to control the switchable standard resistor to input the rated resistance so that the amplitude of the reference waveform data meets the preset measurement conditions; it is also used to control the reference waveform channel to collect the reference waveform data at both ends of the switchable standard resistor and input it to the calculation unit; it is also used to control the waveform channel to be measured to collect the waveform data of the sensor to be measured and input it to the calculation unit;

[0051] The calculation unit is used to extract the overlapping interval of the Fourier transform stable interval of the reference waveform data and the waveform data to be measured, obtain the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter, and calculate the amplitude error, phase error and fundamental frequency of the sensor to be measured based on the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter.

[0052] In this embodiment, the waveform channel to be measured includes a first analog-to-digital conversion module and a first queue cache which are interconnected; the first analog-to-digital conversion module is connected to the sensor to be measured; the first queue cache is connected to the calculation unit; the first analog-to-digital conversion module is used to collect the voltage signal of the sensor to be measured based on the control of the main control unit, discretize the voltage signal into waveform data to be measured, and transmit the waveform data to be measured to the first queue cache; the first queue cache is used to store the waveform data to be measured.

[0053] In this embodiment, the reference waveform channel includes a second analog-to-digital conversion module and a second queue cache connected to each other; the second analog-to-digital conversion module is connected to the switchable standard resistor; the second queue cache is connected to the calculation unit; the second analog-to-digital conversion module is used to collect the voltage signal across the switchable standard resistor based on the control of the main control unit, discretize the voltage signal into reference waveform data, and transmit the reference waveform data to the second queue cache; the second queue cache is used to store the reference waveform data.

[0054] In this embodiment, the switchable standard resistor includes multiple branches connected in parallel, each of which includes a standard resistor and a switchable resistor switch connected in series; the switchable resistor switch is used to close and open the switch based on the control of the main control unit to control the input of the rated resistance.

[0055] In one embodiment, Figure 2 A schematic diagram of a circuit including two standard resistors and two switching switches is shown; preferably, the standard resistors can be selected from BZ6 milliohm series and BZ3 hundred ohm series standard resistors.

[0056] In this embodiment, the main control unit controls the output current to adjust the output amplitude from milliampere level to hundred ampere level and the output frequency from low frequency in hertz level to ten kilohertz level.

[0057] Embodiment 2:

[0058] The working principle of an anti-interference magnetic sensitive current sensor calibration device is described in detail below:

[0059] Configure the rated current of the sensor to be tested to be I N , the operating frequency range is f1~f2, then according to the calibration requirements of the sensor, select a point within 1%~100% of the rated range as the calibration point. For example, select 1%I N , 5%I N , 20%I N 、100%I N , 120%I N Five points are used as calibration points.

[0060] The main control unit controls the switching switch of the switchable resistor to switch on the resistor, wherein the resistance of the switched resistor should be such that the voltage generated by the current to be measured at both ends of the switchable resistor is within the 20% to 100% measurement range of the second analog-to-digital conversion module, that is, it is selected according to the following principles:

[0061]

[0062] Where V 模数转换 is the rated input voltage of the second analog-to-digital conversion module, I 标定点 Represents the calibration point current. Selecting this resistance value can ensure that the amplitude of the reference waveform data is within the 20% to 100% range of the second analog-to-digital conversion module. In this range, the signal-to-noise ratio is generally good and the subsequent system error can be reduced.

[0063] The main control unit controls the current generator to output the current at the calibration point to be measured. At this time, the sensor to be measured senses the current at the calibration point to be measured and generates an AC voltage:

[0064] V 待测传感器 (t) = V 待测电流产生的波形 (t)+n 噪声 (t)

[0065] Wherein, Vsensor to be tested (t) represents the AC voltage generated by the sensor to be tested at time t, Vwaveform generated by the current to be tested (t) represents the AC voltage waveform generated by the current to be tested at time t, and nnoise (t) represents the noise generated at time t.

[0066] Since the voltage signal-to-noise ratio generated by the current to be measured at both ends of the switchable resistor is relatively high, the following formula is valid:

[0067] V 可投切电阻 (t) = I 待测电流 ×R

[0068] Wherein, V switchable resistance (t) represents the AC voltage across the switchable standard resistor at time t, and R represents the resistance value of the switchable resistor.

[0069] Afterwards, the main control unit controls the first analog-to-digital conversion module to convert V 待测传感器 (t) is discretized and stored in the first queue buffer. The main control unit controls the second analog-to-digital conversion module to convert V 可投切电阻 (t) Discretize and store in the second queue cache.

[0070] Further, the main control unit controls the calculation unit to extract the waveform data of two channels (i.e., the aforementioned reference waveform channel and the waveform channel to be measured) stored in the first queue cache and the second queue cache, and notifies the calculation unit to calculate the amplitude and phase error characteristics of the magnetically sensitive current sensor to be measured (i.e., the aforementioned sensor to be measured).

[0071] The calculation unit calculates the amplitude error and the phase error. It first processes the reference waveform data and the waveform data of the sensor to be measured (i.e., the aforementioned waveform data to be measured), extracts the frequency jitter-free interval in the two data, and avoids the frequency jitter affecting the phase error measurement. The steps are as follows: Figure 3 As shown:

[0072] 1. Apply a Hanning window to the reference waveform data in the first queue buffer and the waveform data of the sensor to be tested in the second queue buffer.

[0073] 2 Calculate the Fourier transform of the reference waveform data and the waveform data of the sensor to be tested within the Hanning window.

[0074] 3. Determine whether the Hanning window has traversed the reference waveform and sensor waveform data. If not, return to step 1 to move the Hanning window and calculate the Fourier transform of the next interval. If all waveform data have been traversed, proceed to step 4.

[0075] 4 Analyze the Fourier transform calculated in step 2 as the Hanning window changes, and find the interval where the main frequency is stable in the Fourier transform of the reference waveform data and the Fourier transform of the waveform data of the sensor to be tested.

[0076] 5. Extract the overlapping interval of the Fourier transform stable interval of the reference waveform data and the sensor waveform data to be tested, obtain the reference waveform data without frequency jitter and the sensor waveform data to be tested without frequency jitter, and calculate the amplitude error and phase error respectively.

[0077] Through the above steps, the frequency jitter-free interval in the reference waveform and the sensor output waveform can be extracted, as shown in the schematic diagram. Figure 6 As shown in the figure, the waveform has frequency jitter in the intervals of 0-100ms and 400ms-500ms, and the frequency is stable in the interval of 100ms-400ms. If the complete waveform is directly used for phase calculation, there will be a large error. The above algorithm only extracts the interval of 100ms-400ms without frequency jitter for subsequent amplitude and phase error calculation, avoiding the calculation deviation of sensor measurement characteristics caused by frequency jitter caused by current source or interference.

[0078] After that, the amplitude error is calculated through the following steps. The flowchart is as follows: Figure 4 As shown:

[0079] 1 Calculate the effective value V of the reference waveform data without frequency jitter 无频率抖动参考波形 ;

[0080] 2 Calculate the effective value of the current to be measured

[0081]

[0082] Where V无频率抖动参考波形 is the effective value of the reference waveform data without frequency jitter, R 可投切标准电阻 is the resistance value of the standard resistor, I 待测电流 is the effective value of the current to be measured;

[0083] 3 Calculate the theoretical output of the sensor to be tested

[0084] V 理论输出 =I 待测电流 ×S+B

[0085] Where V 理论输出 It represents the theoretical output voltage of the sensor to be tested, S is the AC nominal sensitivity of the sensor to be tested, and B is the AC nominal zero offset of the sensor to be tested.

[0086] 4 Calculate the amplitude error of the sensor to be tested

[0087]

[0088] Where δ is the amplitude error, V 无频率抖动传感器输出波形 This is the effective value of the sensor waveform data without frequency jitter.

[0089] The phase error is calculated by the following steps: Figure 5 As shown:

[0090] 1. Calculate Fourier transform of the waveform data of the sensor to be tested without frequency jitter and the reference waveform data without frequency jitter respectively;

[0091] 2. Obtain amplitude-frequency data and phase-frequency data through Fourier transform results, and find the index value of the maximum amplitude-frequency data;

[0092] 5. Obtain the fundamental frequency of the signal to be measured (i.e., the fundamental frequency of the sensor to be measured) according to the sampling rate of the first analog-to-digital conversion module, the index value of the maximum value of the amplitude-frequency data, and the length of the waveform data to be measured;

[0093]

[0094] Where f 基波 is the fundamental frequency of the signal to be measured, F s is the sampling rate, N is the waveform data length, and i is the index value of the maximum amplitude and frequency data.

[0095] 6. Obtain the phase of the waveform of the sensor to be tested and the phase of the reference waveform according to the index value and the phase-frequency data;

[0096] 7 The phase error of the sensor to be tested is obtained by subtracting the phase of the reference waveform from the phase of the sensor waveform to be tested.

[0097] Figure 7Table 1 is an example of the advantages of using the above algorithm. The sensor transfer function is set to produce a phase shift of -0.2°, the current source output frequency is set to 550Hz output, and a 1Hz frequency jitter is artificially generated at 0.1 seconds. If the phase difference between the reference full waveform and the sensor output full waveform is directly calculated, due to the influence of frequency jitter, the 10 groups of results are shown in Table 1 "Full Waveform Calculation", and the average value is -0.08°, which is larger than the sensor phase shift of -0.2°. If the above algorithm is used to extract the frequency jitter-free interval and then calculate the sensor phase difference, the average value is -0.19°, which is close to the sensor phase shift of -0.2°.

[0098] Table 1

[0099] Set phase difference (°) Calculation result of frequency jitter-free interval (°) Full waveform calculation results (°) -0.20 -0.17 -0.10 -0.20 -0.21 -0.12 -0.20 -0.20 -0.06 -0.20 -0.20 -0.05 -0.20 -0.20 -0.08 -0.20 -0.11 -0.12 -0.20 -0.15 -0.09 -0.20 -0.21 -0.10 -0.20 -0.19 -0.05 average value -0.19 -0.08

[0100] Embodiment 3:

[0101] The present invention based on the same inventive concept also provides a calibration calculation method for an anti-interference magnetic sensitive current sensor, such as Figure 8 As shown, including:

[0102] Step 1: applying a Hanning window to the extracted waveform data to be measured and the reference waveform data, respectively, and calculating the Fourier transform corresponding to the waveform data to be measured and the reference waveform data in the Hanning window, respectively;

[0103] Step 2: Determine whether the Hanning window traverses all of the waveform data to be tested and the reference waveform data;

[0104] Step 3: If not, move the Hanning window to the next interval, and calculate the Fourier change of the waveform data to be measured and the reference waveform data in the next interval;

[0105] Step 4: If yes, determine the overlap interval of the Fourier transform stable interval of the waveform data to be measured and the reference waveform data, and use the Fourier waveform data of the waveform data to be measured in the overlap interval as the sensor waveform data to be measured without frequency jitter, and use the Fourier transform data of the reference waveform data in the overlap interval as the reference waveform data without frequency jitter;

[0106] Step 5: Calculate the amplitude error, phase error and fundamental frequency of the sensor to be tested based on the reference waveform data without frequency jitter and the waveform data of the sensor to be tested without frequency jitter.

[0107] In this embodiment, the calculation of the amplitude error in step 5 includes: calculating the effective value of the voltage of the reference waveform without frequency jitter based on the reference waveform data without frequency jitter and a preset root mean square formula, and calculating the effective value of the current to be measured based on the ratio of the effective value of the voltage of the reference waveform without frequency jitter to the resistance value of the switchable standard resistor; calculating the theoretical output voltage of the sensor to be measured based on the effective value of the current to be measured and the basic configuration information of the sensor to be measured; calculating the difference between the effective value of the voltage of the reference waveform without frequency jitter and the theoretical output voltage of the sensor to be measured as the amplitude error of the sensor to be measured.

[0108] In this embodiment, the calculation of the phase error in step 5 includes: respectively calculating the Fourier transform of the waveform data to be measured without frequency jitter and the reference waveform data without frequency jitter, generating amplitude-frequency data and phase-frequency data corresponding to the waveform data to be measured without frequency jitter and the reference waveform data without frequency jitter, and finding the index value of the maximum value in the amplitude-frequency data; respectively calculating the phase corresponding to the waveform data to be measured and the phase corresponding to the reference waveform data based on the index value and the phase-frequency data; subtracting the phase corresponding to the reference waveform data from the phase corresponding to the waveform data to be measured to obtain the phase error of the sensor to be measured.

[0109] In this embodiment, the calculation of the fundamental frequency of the sensor to be tested in step 5 includes: multiplying the sampling rate corresponding to the first analog-to-digital conversion module by the ratio between the index value and the data length of the waveform data to be tested without frequency jitter to generate the fundamental frequency of the sensor signal to be tested.

[0110] Embodiment 4:

[0111] like Fig. 9 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0112] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of an anti-interference magnetic-sensitive current sensor calibration calculation method in the above embodiment.

[0113] Embodiment 5:

[0114] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in the electronic device for storing programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device and the extended storage medium supported by the electronic device. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of the anti-interference magnetic sensitive current sensor calibration calculation method in the above embodiment.

[0115] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0116] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0117] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0119] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A calibration device for an anti-interference magnetic sensitive current sensor, characterized in that: include: A main control unit and a current generator connected to the main control unit, a switchable standard resistor, a reference waveform channel, a waveform channel to be measured, and a calculation unit; One end of the waveform channel to be measured is connected to the sensor to be measured and then connected to the current generator, and the other end of the waveform channel to be measured is connected to the calculation unit; One end of the reference waveform channel is connected to the current generator via a switchable standard resistor, and the other end of the reference waveform channel is connected to the calculation unit; The main control unit is used to control the current generator to output the current to be measured; it is also used to control the switchable standard resistor to input the rated resistance so that the amplitude of the reference waveform data meets the preset measurement conditions; it is also used to control the reference waveform channel to collect the reference waveform data at both ends of the switchable standard resistor and input it to the calculation unit; it is also used to control the waveform channel to be measured to collect the waveform data of the sensor to be measured and input it to the calculation unit; The calculation unit is used to extract the overlapping interval of the Fourier transform stable interval of the reference waveform data and the waveform data to be measured, obtain the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter, and calculate the amplitude error, phase error and fundamental frequency of the sensor to be measured based on the reference waveform data without frequency jitter and the waveform data to be measured without frequency jitter.

2. The device according to claim 1, characterized in that The waveform channel to be tested includes a first analog-to-digital conversion module and a first queue buffer connected to each other; the first analog-to-digital conversion module is connected to the sensor to be tested; the first queue buffer is connected to the calculation unit; The first analog-to-digital conversion module is used to collect the voltage signal of the sensor to be tested based on the control of the main control unit, discretize the voltage signal into waveform data to be tested, and transmit the waveform data to be tested to the first queue buffer; The first queue buffer is used to store the waveform data to be tested.

3. The device according to claim 1, characterized in that The reference waveform channel includes a second analog-to-digital conversion module and a second queue buffer connected to each other; the second analog-to-digital conversion module is connected to the switchable standard resistor; the second queue buffer is connected to the calculation unit; The second analog-to-digital conversion module is used to collect the voltage signal at both ends of the switchable standard resistor based on the control of the main control unit, discretize the voltage signal into reference waveform data, and transmit the reference waveform data to the second queue buffer; The second queue buffer is used to store the reference waveform data.

4. The device according to claim 1, characterized in that The switchable standard resistor comprises: A plurality of branches connected in parallel to each other, each branch comprising a standard resistor and a switchable resistor switch connected in series; The switchable resistance switch is used to close and open the switch based on the control of the main control unit to control the input of the rated resistance.

5. The device according to claim 1, characterized in that The main control unit controls the output current to adjust the output amplitude from milliampere level to hundred ampere level and the output frequency from low frequency in hertz level to ten kilohertz level.

6. A calibration calculation method for an anti-interference magnetic sensitive current sensor, characterized in that: The calculation unit used in the calibration device of the anti-interference magnetic sensitive current sensor comprises: Applying a Hanning window to the extracted waveform data to be measured and the reference waveform data, respectively, and calculating the Fourier transforms corresponding to the waveform data to be measured and the reference waveform data within the Hanning window, respectively; Determine whether the Hanning window traverses all of the waveform data to be measured and the reference waveform data; If not, move the Hanning window to the next interval, and calculate the Fourier transform of the waveform data to be measured and the reference waveform data in the next interval; If yes, determine the overlap interval of the Fourier transform stable interval of the waveform data to be measured and the reference waveform data, and use the Fourier waveform data of the waveform data to be measured in the overlap interval as the sensor waveform data to be measured without frequency jitter, and use the Fourier transform data of the reference waveform data in the overlap interval as the reference waveform data without frequency jitter; The amplitude error, phase error and fundamental frequency of the sensor to be tested are calculated based on the reference waveform data without frequency jitter and the waveform data of the sensor to be tested without frequency jitter.

7. The method according to claim 6, characterized in that The calculation of the amplitude error includes: Calculating the effective value of the voltage of the reference waveform without frequency jitter based on the reference waveform data without frequency jitter and a preset root mean square formula, and calculating the effective value of the current to be measured based on the ratio of the effective value of the voltage of the reference waveform without frequency jitter to the resistance value of the switchable standard resistor; Calculating a theoretical output voltage of the sensor to be tested based on the effective value of the current to be tested and basic configuration information of the sensor to be tested; The difference between the voltage effective value of the reference waveform without frequency jitter and the theoretical output voltage of the sensor to be tested is calculated as the amplitude error of the sensor to be tested.

8. The method according to claim 6, characterized in that The calculation of the phase error includes: Calculate the Fourier transform of the waveform data to be tested without frequency jitter and the reference waveform data without frequency jitter respectively, generate amplitude-frequency data and phase-frequency data corresponding to the waveform data to be tested without frequency jitter and the reference waveform data without frequency jitter respectively, and find the index value of the maximum value in the amplitude-frequency data; Calculate the phase corresponding to the waveform data to be measured and the phase corresponding to the reference waveform data based on the index value and the phase-frequency data; The phase error of the sensor to be tested is obtained by subtracting the phase corresponding to the reference waveform data from the phase corresponding to the waveform data to be tested.

9. The method according to claim 8, characterized in that The calculation of the fundamental frequency of the sensor to be tested includes: The sampling rate corresponding to the first analog-to-digital conversion module is multiplied by the ratio between the index value and the data length of the waveform data to be measured without frequency jitter to generate the fundamental frequency of the sensor signal to be measured.

10. An electronic device, characterized in that: include: at least one processor and memory; The memory and the processor are connected via a bus; The memory is used to store one or more programs; When the one or more programs are executed by the at least one processor, the anti-interference magnetic-sensitive current sensor calibration calculation method according to any one of claims 6 to 9 is implemented.

11. A readable storage medium, characterized in that: An execution program is stored thereon, and when the execution program is executed, the calibration calculation method for the anti-interference magnetic sensitive current sensor as described in any one of claims 6 to 9 is implemented.

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