A current detection apparatus, method, device, system, and medium

Abstract

The application discloses a current detection device, method, equipment, system and medium, and relates to the technical field of detection. The device is characterized in that: a plurality of H-bridge driving excitations are connected with a coil; a first end of a sampling resistor is connected with a first winding end of the coil, and a second end of the sampling resistor is connected with a second winding end of the coil, so as to collect an excitation voltage signal to be detected; an input end of a DSP is connected with the first end of the sampling resistor and the second end of the sampling resistor; a comparator is connected with an output end of the DSP, and is used for detecting and determining the type of a B-type current corresponding to the excitation voltage signal to be detected according to direct-current characteristic values and alternating-current characteristic values generated by the DSP. Through the plurality of H-bridge driving excitations and the coil, the detection of direct-current currents and alternating-current currents is integrated, and the direct-current characteristic values and the alternating-current characteristic values obtained through the sampling resistor, the DSP and the comparator are used for detecting and determining the type of the B-type current corresponding to the excitation voltage signal to be detected, so that the type of the B-type current can be comprehensively detected.

Description

Technical Field

[0001] This application relates to the field of detection technology, and in particular to a current detection device, method, equipment, system and medium. Background Technology

[0002] With the continuous development of modern industrial science and technology, the level of automation and electrification is constantly improving, and electricity is being used more and more widely in various fields. At the same time, the probability of electric shock accidents is also increasing, and for many years, electrical fires have consistently ranked first among all types of fires in my country. Electric shock and electrical fire accidents cause enormous losses to the lives and property of the nation and its people. Safe and scientific use of electricity is essential for the harmonious development of society. Due to the increased use of nonlinear electrical equipment, the residual current waveform is no longer a single-frequency sine wave, but a complex waveform containing multiple AC and DC components, as well as a smooth DC waveform. AC residual current is extremely harmful to the human body; 50mA / s can cause ventricular fibrillation. Currently, DC power is widely used, including DC charging piles and household microwave ovens and washing machines. These products mostly use Type B and higher specifications of residual current. According to the leakage current detection standard GB / T22794-2017, Type B residual current includes seven categories: sinusoidal AC, pulsating DC, composite residual current, pulsating DC superimposed with smooth DC, sinusoidal AC below 1kHz, AC residual current superimposed with smooth DC, and smooth DC. Existing methods for detecting residual current include the Hall effect method and the magneto-optical effect method. The Hall effect method converts the magnetic field signal of a current into an electrical signal using the Hall effect, enabling AC / DC current measurement. Its current measurement range can reach several thousand amperes, with a detection bandwidth of 0–200 kHz. However, it is easily affected by large external current magnetic fields, leading to significant measurement errors. Furthermore, Hall sensors exhibit significant temperature drift and zero-point offset. Therefore, Hall current sensors are unsuitable for AC / DC residual current measurement. In addition, optical current sensors in the magneto-optical effect method have no magnetic core, eliminating magnetic saturation problems. They offer advantages such as small size, wide frequency response, and easy interfacing with digital devices, attracting widespread attention from scholars both domestically and internationally. However, their measurement accuracy is relatively low, they are easily affected by ambient temperature and vibration, and they suffer from the inherent linear birefringence problem of optical fibers. Therefore, optical current sensors are also unsuitable for measuring smoothed DC residual current.

[0003] Given the aforementioned problems, finding a way to comprehensively detect the types of B-type current is a problem that those skilled in the art are striving to solve. Summary of the Invention

[0004] The purpose of this application is to provide a current detection device, method, equipment, system, and medium for comprehensively detecting the types of type B current.

[0005] To solve the above-mentioned technical problems, this application provides a current detection device, including: multiple H-bridge drive excitations, coils, sampling resistors, DSP, and comparators;

[0006] Multiple H-bridge drive excitations are connected to the coil to transmit the excitation voltage signals output by the multiple H-bridge drive excitations to the coil. The excitation voltage signals include positive voltage signals and negative voltage signals. The positive voltage signals are used to make the coil work in the positive magnetic saturation region, and the negative voltage signals are used to make the coil work in the negative magnetic saturation region.

[0007] The first end of the sampling resistor is connected to the first winding end of the coil, and the second end of the sampling resistor is connected to the second winding end of the coil, which is used to acquire the excitation voltage signal to be detected.

[0008] The DSP's input terminal is connected to both the first and second terminals of the sampling resistor to generate DC and AC characteristic values.

[0009] The comparator is connected to the output of the DSP and is used to detect and determine the type of B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value.

[0010] Preferably, it further includes: a signal conditioning sampling circuit;

[0011] The first input terminal of the signal conditioning and sampling circuit is connected to the first terminal of the sampling resistor, the second input terminal of the signal conditioning and sampling circuit is connected to the second terminal of the sampling resistor, and the output terminal of the signal conditioning and sampling circuit is connected to the input terminal of the DSP. This circuit is used to generate an accurate excitation voltage signal to be detected and to transmit the excitation voltage signal to be detected to the DSP.

[0012] Preferably, the signal conditioning sampling circuit includes: an ADC and a fully differential amplifier circuit;

[0013] The first input terminal of the fully differential amplifier circuit serves as the first input terminal of the signal conditioning and sampling circuit, the second input terminal of the fully differential amplifier circuit serves as the second input terminal of the signal conditioning and sampling circuit, the output terminal of the fully differential amplifier circuit is connected to the input terminal of the ADC, and the output terminal of the ADC serves as the output terminal of the signal conditioning and sampling circuit.

[0014] Preferably, the fully differential amplifier circuit includes: a first input resistor, a second input resistor, a differential amplifier, a first fully differential resistor, and a second fully differential resistor;

[0015] The first end of the first input resistor serves as the first input terminal of the fully differential amplifier circuit, and the first end of the second input resistor serves as the second input terminal of the fully differential amplifier circuit. The second end of the first input resistor is connected to a common terminal formed by the first end of the first fully differential resistor and the non-inverting input terminal of the differential amplifier. The second end of the second input resistor is connected to a common terminal formed by the first end of the second fully differential resistor and the inverting input terminal of the differential amplifier. The common terminal formed by the output terminal of the differential amplifier, the second end of the first fully differential resistor, and the second end of the second fully differential resistor serves as the output terminal of the fully differential amplifier circuit.

[0016] To address the aforementioned technical problems, this application also provides a current detection method, comprising:

[0017] The control of multiple H-bridge drives outputs excitation voltage signals, which include positive and negative voltage signals. The positive voltage signal is used to make the coil work in the positive magnetic saturation region, and the negative voltage signal is used to make the coil work in the negative magnetic saturation region.

[0018] The excitation voltage signal to be detected is acquired and transmitted to the DSP through a sampling resistor;

[0019] Obtain the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected;

[0020] The type of B-current corresponding to the excitation voltage signal to be detected is determined based on the DC and AC characteristic values.

[0021] Preferably, obtaining the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected includes:

[0022] Multiple positive voltage values ​​corresponding to the excitation voltage signal are extracted in the positive magnetic linear region, and multiple negative voltage values ​​corresponding to the excitation voltage signal are extracted in the negative magnetic linear region.

[0023] Multiple positive voltage values ​​are used as a first sequence, and a first average value of the first sequence is determined. Multiple negative voltage values ​​are used as a second sequence, and a second average value of the second sequence is determined. The number of first average values ​​and second average values ​​is equal to the number of H-bridge drive excitations.

[0024] The first and second averages are differentially processed to obtain all difference values, and all difference values ​​are merged to form a difference sequence.

[0025] By inverting the odd-numbered sequence, we obtain the odd-numbered sequence and the even-numbered sequence;

[0026] The basic sequence is sampled based on a preset sampling length to obtain a sampled sequence, wherein the basic sequence consists of an odd sequence and an even sequence.

[0027] The third average value determined based on the sampling sequence is used as the DC characteristic value;

[0028] Based on DFT, AC eigenvalues ​​are determined from the sampled sequence.

[0029] Preferably, detecting and determining the type of type B current corresponding to the excitation voltage signal to be detected based on DC and AC characteristic values ​​includes:

[0030] Determine whether the value of each element in the sampled sequence is greater than the first threshold;

[0031] If so, then summarize the elements that are greater than the first threshold and obtain the first subsequence;

[0032] If not, then summarize the elements that are not greater than the first threshold and obtain the second subsequence;

[0033] The type of B-type current is determined based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the criteria for pulsating DC. The criteria for pulsating DC is that the number of sampling points with signal values ​​of 0 and / or signal values ​​not exceeding 6mA within one cycle is greater than 40% of the total number of sampling points.

[0034] Preferably, before determining whether the value of each element in the sampling sequence is greater than the first threshold, the method further includes:

[0035] Determine whether the DC characteristic value exceeds the second threshold;

[0036] If so, then the excitation voltage signal contains DC current.

[0037] If not, then the excitation voltage signal contains alternating current.

[0038] Preferably, determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the criteria for pulsating DC current, includes:

[0039] When the number of elements in the first subsequence is greater than the number of elements in the second subsequence and the first subsequence meets the standard that the type of B current is pulsating DC, determine whether the first subsequence contains negative numbers.

[0040] If the first subsequence contains negative numbers, then the type of B current is determined to be negative pulsating DC superimposed with positive polarity DC;

[0041] If the first subsequence does not contain negative numbers, then the type of B current is determined to be positive pulsating DC superimposed with positive polarity DC;

[0042] When the number of elements in the second subsequence is greater than the number of elements in the first subsequence and the second subsequence meets the standard that the type of B current is pulsating DC, determine whether the second subsequence contains positive numbers.

[0043] If the second subsequence contains positive numbers, then the type of B current is determined to be positive pulsating DC superimposed with negative polarity DC;

[0044] If the second subsequence does not contain positive numbers, then the type of B current is determined to be negative pulsating DC superimposed with negative polarity DC.

[0045] Preferably, after determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of B-type current is pulsating DC, the method further includes:

[0046] The sampling sequence DC value that characterizes whether there is pulsating DC is determined based on the type of B current;

[0047] Determine whether the DC value of the sampled sequence exceeds the standard for pulsating DC;

[0048] If so, then pulsating DC current is confirmed to exist;

[0049] If not, then it is determined that there is no pulsating DC.

[0050] Preferably, detecting and determining the type of type B current corresponding to the voltage signal to be detected based on the DC characteristic value and the AC 50Hz characteristic value includes:

[0051] The excitation voltage signal acquired across the sampling resistor is filtered using a signal conditioning sampling circuit.

[0052] Set a windowing function for the filtered excitation voltage signal;

[0053] Given a spectral resolution of 50Hz, the FFT amplitude of the excitation voltage signal is determined based on FFT.

[0054] The type of B current is determined based on the FFT amplitude.

[0055] Preferably, after determining the sampling sequence DC value representing whether pulsating DC current is present based on the type of type B current, the method further includes:

[0056] When it is determined that the excitation voltage signal contains DC current and that there is pulsating DC current, determine the absolute value of the difference between the maximum and minimum values ​​among the multiple elements contained in the sampling sequence.

[0057] Determine if the difference exceeds 6mA;

[0058] If the difference does not exceed 6mA, then the type of current B is determined to be smoothed DC, and the DC characteristic value is determined to be the amplitude of smoothed DC.

[0059] If the difference exceeds 6mA, then determine whether the difference exceeds the third threshold;

[0060] If the difference exceeds the third threshold, the type of B current is determined to be pulsating DC superimposed with smooth DC, and the amplitude of pulsating DC superimposed with smooth DC is determined according to the DC characteristic value and AC characteristic value.

[0061] If the difference does not exceed the third threshold, the type of B current is determined to be pulsating DC, and the AC characteristic value is determined to be the amplitude of pulsating DC.

[0062] When it is determined that the excitation voltage signal contains DC current and that there is no pulsating DC current, the type of B current is determined to be AC ​​residual current superimposed with smoothed DC, and the amplitude of AC residual current superimposed with smoothed DC is determined according to the DC characteristic value and AC characteristic value.

[0063] When it is determined that the excitation voltage signal contains AC current and that there is pulsating DC current, it is determined whether the difference exceeds the third threshold.

[0064] If the difference exceeds the third threshold, the type of B current is determined to be pulsating DC superimposed with smooth DC.

[0065] If the difference does not exceed the third threshold, then the type of B current is determined to be pulsating DC.

[0066] Preferably, determining the type of B-type current based on the FFT amplitude includes:

[0067] When it is determined that the excitation voltage signal contains AC current and there is no pulsating DC current, the type of B current is determined according to the relationship between the AC characteristic value and the fourth threshold and the relationship between the FFT amplitude and the preset number.

[0068] When the AC characteristic value exceeds the fourth threshold and the FFT amplitude equals the preset number, the type of B current is determined to be sinusoidal AC; where the preset number is the number of FFT amplitudes that exceed the fifth threshold representing the preset value of FFT.

[0069] When the AC characteristic value exceeds the fourth threshold and the FFT amplitude is greater than the preset number, the type of B current is determined to be composite residual current.

[0070] When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is equal to the preset number, the type of B current is determined to be a sinusoidal AC signal below 1kHz.

[0071] When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is greater than the preset number, the type of B current is determined to be composite residual current.

[0072] To address the aforementioned technical problems, this application also provides a current detection device, comprising:

[0073] The control module is used to control multiple H-bridge drive excitations to output excitation voltage signals. The excitation voltage signals include positive voltage signals and negative voltage signals. The positive voltage signal is used to make the coil work in the positive magnetic saturation region, and the negative voltage signal is used to make the coil work in the negative magnetic saturation region.

[0074] The acquisition and transmission module is used to acquire and transmit the excitation voltage signal to be detected to the DSP through the sampling resistor;

[0075] The acquisition module is used to acquire the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected.

[0076] The detection and determination module is used to detect and determine the type of type B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value.

[0077] In addition, the device also includes the following modules:

[0078] Preferably, obtaining the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected includes:

[0079] The extraction module is used to extract multiple positive voltage values ​​corresponding to the excitation voltage signal in the positive magnetic linear region and multiple negative voltage values ​​corresponding to the excitation voltage signal in the negative magnetic linear region.

[0080] The first determining module is used to take multiple positive voltage values ​​as a first sequence and determine the first average value of the first sequence, take multiple negative voltage values ​​as a second sequence and determine the second average value of the second sequence, wherein the number of the first average value and the number of the second average value are both equal to the number of H-bridge drive excitations;

[0081] The difference processing module is used to process the first average and the second average to obtain all difference values, and then merge all difference values ​​into a difference sequence.

[0082] The odd-number inversion module is used to invert the difference sequence by odd numbers, resulting in odd and even sequences.

[0083] The sampling module is used to sample the basic sequence based on a preset sampling length to obtain a sampled sequence, wherein the basic sequence consists of an odd sequence and an even sequence.

[0084] The second determining module is used to take the third average value determined according to the sampling sequence as the DC characteristic value;

[0085] The third determination module is used to determine the AC characteristic value based on the DFT and the sampled sequence.

[0086] Preferably, detecting and determining the type of type B current corresponding to the excitation voltage signal to be detected based on DC and AC characteristic values ​​includes:

[0087] The first judgment module is used to determine whether the value of each element in the sampled sequence is greater than the first threshold.

[0088] If so, the first induction module is triggered to inductively summarize elements greater than the first threshold and obtain the first subsequence.

[0089] If not, the second induction module is triggered to inductively summarize elements that are not greater than the first threshold and obtain the second subsequence.

[0090] The fourth determining module is used to determine the type of type B current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard of pulsating DC for type B current. The standard of pulsating DC is that the number of sampling points of signal values ​​that are 0 and / or signal values ​​that do not exceed 6mA in one cycle is greater than 40% of the total number of sampling points.

[0091] Preferably, before determining whether the value of each element in the sampling sequence is greater than the first threshold, the method further includes:

[0092] The second judgment module is used to determine whether the DC characteristic value exceeds the second threshold.

[0093] If so, the fifth determination module is triggered to determine whether the excitation voltage signal contains DC current.

[0094] If not, the sixth determination module is triggered to determine whether the excitation voltage signal contains AC current.

[0095] Preferably, determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the criteria for pulsating DC current, includes:

[0096] The third judgment module is used to determine whether the first subsequence contains negative numbers when the number of elements in the first subsequence is greater than the number of elements in the second subsequence and the first subsequence meets the standard that the type of B current is pulsating DC.

[0097] The seventh determination module is used to determine the type of B-type current as negative pulsating DC superimposed with positive polarity DC if the first subsequence contains negative numbers.

[0098] The eighth determining module is used to determine the type of B-type current as positive pulsating DC superimposed with positive polarity DC if the first subsequence does not contain negative numbers.

[0099] The fourth judgment module is used to determine whether the second subsequence contains positive numbers when the number of elements in the second subsequence is greater than the number of elements in the first subsequence and the second subsequence meets the standard that the type of B current is pulsating DC.

[0100] The ninth determining module is used to determine the type of B-type current as positive pulsating DC superimposed with negative polarity DC if the second subsequence contains positive numbers.

[0101] The tenth determination module is used to determine the type of B-type current as negative pulsating DC superimposed with negative polarity DC if the second subsequence does not contain positive numbers.

[0102] Preferably, after determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of B-type current is pulsating DC, the method further includes:

[0103] The eleventh determination module is used to determine the DC value of the sampling sequence that indicates whether there is pulsating DC, based on the type of B current.

[0104] The fifth judgment module is used to determine whether the DC value of the sampling sequence exceeds the standard of pulsating DC.

[0105] If so, the twelfth determination module is triggered to determine the presence of pulsating DC.

[0106] If not, the thirteenth determination module is triggered to determine that there is no pulsating DC.

[0107] Preferably, detecting and determining the type of type B current corresponding to the voltage signal to be detected based on the DC characteristic value and the AC 50Hz characteristic value includes:

[0108] The filtering module is used to filter the excitation voltage signal collected across the sampling resistor using the signal conditioning sampling circuit;

[0109] The configuration module is used to set the windowing function for the filtered excitation voltage signal;

[0110] The fourteenth determination module is used to determine the FFT amplitude of the excitation voltage signal based on FFT, with a spectral resolution of 50Hz as the condition.

[0111] The fifteenth determination module is used to determine the type of B-type current based on the FFT amplitude.

[0112] Preferably, after determining the sampling sequence DC value representing whether pulsating DC current is present based on the type of type B current, the method further includes:

[0113] The sixteenth determination module is used to determine the absolute value of the difference between the maximum and minimum values ​​among multiple elements in the sampling sequence when it is determined that the excitation voltage signal contains DC current and that there is pulsating DC current.

[0114] The sixth judgment module is used to determine whether the difference exceeds 6mA;

[0115] The seventeenth determination module is used to determine the type of B current as smoothed DC if the difference does not exceed 6mA, and to determine the DC characteristic value as the amplitude of smoothed DC.

[0116] The seventh judgment module is used to determine whether the difference exceeds the third threshold if the difference exceeds 6mA.

[0117] The eighteenth determination module is used to determine the type of B current as pulsating DC superimposed with smooth DC if the difference exceeds the third threshold, and to determine the amplitude of pulsating DC superimposed with smooth DC based on the DC characteristic value and AC characteristic value.

[0118] The nineteenth determination module is used to determine the type of B current as pulsating DC if the difference does not exceed the third threshold, and to determine the AC characteristic value as the amplitude of pulsating DC.

[0119] The twentieth determination module is used to determine the type of type B current as AC residual current superimposed smoothed DC when it is determined that the excitation voltage signal contains DC current and that there is no pulsating DC current, and to determine the amplitude of AC residual current superimposed smoothed DC based on the DC characteristic value and AC characteristic value.

[0120] The eighth judgment module is used to determine whether the difference exceeds the third threshold when it is determined that the excitation voltage signal contains AC current and that there is pulsating DC current.

[0121] The twenty-first determination module is used to determine the type of B current as pulsating DC superimposed with smooth DC if the difference exceeds the third threshold.

[0122] The twenty-second determination module is used to determine the type of B current as pulsating DC if the difference does not exceed the third threshold.

[0123] Preferably, determining the type of B-type current based on the FFT amplitude includes:

[0124] The twenty-third determination module is used to determine the type of type B current based on the relationship between the AC characteristic value and the fourth threshold and the relationship between the FFT amplitude and the preset number when it is determined that the excitation voltage signal contains AC current and there is no pulsating DC current.

[0125] The twenty-fourth determination module is used to determine that the type of B current is sinusoidal AC when the AC characteristic value exceeds the fourth threshold and the FFT amplitude is equal to the preset number; wherein, the preset number is the number of FFT amplitudes that exceed the fifth threshold representing the preset value of FFT.

[0126] The twenty-fifth determination module is used to determine the type of B-type current as composite residual current when the AC characteristic value exceeds the fourth threshold and the FFT amplitude is greater than the preset number.

[0127] The twenty-sixth determination module is used to determine that the type of B current is a sinusoidal AC signal below 1kHz when the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is equal to the preset number.

[0128] The twenty-seventh determination module is used to determine the type of B-type current as composite residual current when the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is greater than the preset number.

[0129] To address the aforementioned technical problems, this application also provides a current detection system, comprising:

[0130] Memory, used to store computer programs;

[0131] A processor is used to direct computer programs to implement the steps of a current detection method.

[0132] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements all the steps of the aforementioned current detection method.

[0133] This application provides a current detection device, comprising: multiple H-bridge drive excitations, a coil, a sampling resistor, a DSP, and a comparator. The multiple H-bridge drive excitations are all connected to the coil, used to transmit the excitation voltage signals output by the multiple H-bridge drive excitations to the coil. The excitation voltage signals include positive and negative voltage signals; the positive voltage signal is used to make the coil operate in the positive magnetic saturation region, and the negative voltage signal is used to make the coil operate in the negative magnetic saturation region. The first end of the sampling resistor is connected to the first winding end of the coil, and the second end of the sampling resistor is connected to the second winding end of the coil, used to acquire the excitation voltage signal to be detected. The input terminal of the DSP is connected to both the first and second ends of the sampling resistor, used to generate DC and AC characteristic values. The comparator is connected to the output terminal of the DSP, used to detect and determine the type of B-current corresponding to the excitation voltage signal to be detected based on the DC and AC characteristic values. By using multiple H-bridges to drive excitation and coils, it can detect both DC and AC currents. Furthermore, it uses sampling resistors, DSPs, and comparators to further implement specific functions. By obtaining the DC and AC characteristic values, it can detect and determine the type of B-type current corresponding to the excitation voltage signal to be detected, thus enabling comprehensive detection of all types of B-type currents.

[0134] This application also provides a current detection method, device, system, and medium, with the same effect as above. Attached Figure Description

[0135] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0136] Figure 1 This is a structural diagram of a current detection device provided in an embodiment of this application;

[0137] Figure 2 This is a flowchart of a current detection method provided in an embodiment of this application;

[0138] Figure 3 This is a structural diagram of a current detection device provided in an embodiment of this application;

[0139] Figure 4 This is a structural diagram of a current detection system provided in an embodiment of this application.

[0140] Among them, 10 is the H-bridge driver, 11 is the DSP, 12 is the comparator, 13 is the signal conditioning and sampling circuit, 14 is the ADC, and 15 is the fully differential amplifier circuit. Detailed Implementation

[0141] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0142] The core of this application is to provide a current detection device, method, equipment, system, and medium that can comprehensively detect the types of type B current.

[0143] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0144] Figure 1 This is a structural diagram of a current detection device provided in an embodiment of this application. Figure 1 As shown, the current detection device includes: multiple H-bridge drive excitations, a coil Rt, a sampling resistor Rs, a DSP, and a comparator. The multiple H-bridge drive excitations are all connected to the coil, used to transmit the excitation voltage signals output by the multiple H-bridge drive excitations to the coil. The excitation voltage signals include positive and negative voltage signals; the positive voltage signal is used to make the coil operate in the positive magnetic saturation region, and the negative voltage signal is used to make the coil operate in the negative magnetic saturation region. The first end of the sampling resistor is connected to the first winding end of the coil, and the second end of the sampling resistor is connected to the second winding end of the coil, used to acquire the excitation voltage signal to be detected. The input terminal of the DSP is connected to both the first and second ends of the sampling resistor, used to generate DC and AC characteristic values. The comparator is connected to the output terminal of the DSP, used to detect and determine the type of B-current corresponding to the excitation voltage signal to be detected based on the DC and AC characteristic values.

[0145] In addition, to improve the accuracy of the excitation voltage signal to be detected acquired across the sampling resistor, the device also includes a signal conditioning sampling circuit. The first input terminal of the signal conditioning sampling circuit is connected to the first terminal of the sampling resistor, the second input terminal is connected to the second terminal of the sampling resistor, and the output terminal is connected to the input terminal of the DSP. This circuit generates an accurate excitation voltage signal to be detected and transmits it to the DSP. The signal conditioning sampling circuit comprises an ADC and a fully differential amplifier circuit, and it is used to improve the accuracy of the excitation voltage signal to be detected. The first input terminal of the fully differential amplifier circuit serves as the first input terminal of the signal conditioning sampling circuit, the second input terminal serves as the second input terminal of the signal conditioning sampling circuit, and the output terminal of the fully differential amplifier circuit is connected to the input terminal of the ADC. The output terminal of the ADC serves as the output terminal of the signal conditioning sampling circuit.

[0146] It should also be noted that the fully differential amplifier circuit includes: a first input resistor Rin1, a second input resistor Rin2, a differential amplifier U1, a first fully differential resistor Rf1, and a second fully differential resistor Rf2. The first terminal of the first input resistor serves as the first input terminal of the fully differential amplifier circuit, and the first terminal of the second input resistor serves as the second input terminal. The second terminal of the first input resistor is connected to a common terminal formed by the first terminal of the first fully differential resistor and the non-inverting input terminal of the differential amplifier. The second terminal of the second input resistor is connected to a common terminal formed by the first terminal of the second fully differential resistor and the inverting input terminal of the differential amplifier. The common terminal formed by the output terminal of the differential amplifier, the second terminal of the first fully differential resistor, and the second terminal of the second fully differential resistor serves as the output terminal of the fully differential amplifier circuit. In this case, the fully differential operational amplifier circuit is used to adjust the amplification factor of the excitation voltage signal to be detected, i.e., the amplification factor of the differential amplifier. It inputs the voltage signal of the sampling resistor and outputs the amplified voltage signal. The digital signal is then input to the DSP via an ADC for filtering and related calculations. It should be noted that the DSP also integrates an anti-aliasing filter, which further improves the accuracy of the excitation voltage signal.

[0147] In this embodiment, it should be noted that the comparator is only used to compare the magnitude relationship between two values ​​and does not act as a controller. In this embodiment, a controller is additionally provided, and the function of the controller is consistent with the method corresponding to this device, as detailed in the following embodiments, and will not be repeated here. Furthermore, the coil mentioned in this embodiment can also be understood as a winding. The number of turns in the winding is not limited and its implementation can be determined according to the specific implementation scenario. Similarly, the resistance value, model, and type of the first input resistor, second input resistor, first fully differential resistor, and second fully differential resistor mentioned in this embodiment are not limited. However, generally, as long as a resistor with a suitable resistance value is selected, the filtering function of the fully differential amplifier circuit can be achieved. The specific resistance value setting can be determined according to the implementation scenario. At the same time, the model and type of the differential amplifier mentioned in this embodiment are not limited, as long as the differential amplifier can achieve the filtering function of the fully differential amplifier circuit based on the first input resistor, second input resistor, first fully differential resistor, and second fully differential resistor. At this point, by driving the excitation and coil through multiple H-bridges, it is possible to detect both DC and AC currents. In addition, the sampling resistor, DSP, and comparator further realize specific functions. By obtaining the DC and AC characteristic values, the type of B current corresponding to the excitation voltage signal to be detected is detected and determined. At this point, it is possible to fully detect the types of B currents.

[0148] Figure 2 This is a flowchart illustrating a current detection method provided in an embodiment of this application. Figure 2 As shown, the current detection method includes:

[0149] S20: Controls multiple H-bridge drives to output excitation voltage signals.

[0150] The excitation voltage signal includes a positive voltage signal and a negative voltage signal. The positive voltage signal is used to make the coil work in the positive magnetic saturation region, and the negative voltage signal is used to make the coil work in the negative magnetic saturation region.

[0151] The H-bridge drives the excitation output of voltage signals in the form of positive and negative square waves, causing the coil to flip back and forth and enabling the coil to operate in the positive and negative magnetic saturation regions.

[0152] S21: Acquire and transmit the excitation voltage signal to be detected to the DSP through the sampling resistor.

[0153] S22: Obtain the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected.

[0154] S23: Detect and determine the type of B-current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and AC characteristic value.

[0155] The process of obtaining the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected includes the following steps:

[0156] Multiple positive voltage values ​​corresponding to the excitation voltage signal are extracted in the positive magnetic linear region, and multiple negative voltage values ​​corresponding to the excitation voltage signal are extracted in the negative magnetic linear region.

[0157] The region where the magnetic permeability changes rapidly can be called the linear region, and the linear region is generally located near the magnetic field strength H=0 of the hysteresis loop.

[0158] Multiple positive voltage values ​​are used as the first sequence x1 = [x 11 ,x 12 ,…,x 1N1 [and determine the first average value of the first sequence] Multiple negative voltage values ​​are used as the second sequence x2 = [x 21 ,x 22 ,…,x 2N2 [and determine the second average value of the second sequence] The number of first and second average values ​​is equal to the number of H-bridge drive excitations; N1 represents that the first sequence contains N1 elements (i.e., positive voltage values), and N2 represents that the second sequence contains N2 elements (i.e., negative voltage values).

[0159] Differential processing is performed on the first and second averages to obtain all difference values ​​Y, where, Then, all the difference values ​​are combined to form a difference sequence, which is y1.

[0160] By inverting the difference sequence in odd positions, we obtain odd-numbered and even-numbered sequences. The basic sequence obtained after inverting the difference sequence in odd positions can be represented in the following form:

[0161]

[0162] Where -Y[i] is an odd sequence, Y[i] is an even sequence, and i is the difference of the mean value corresponding to the i-th H-bridge driving excitation.

[0163] Using a preset sampling length L as a condition, the basic sequence is sampled to obtain the sampled sequence y;

[0164] The third average value determined based on the sampling sequence is used as the DC characteristic value;

[0165] Based on the DFT, AC characteristic values ​​are determined according to the sampling sequence. These AC characteristic values ​​correspond to the AC characteristic values ​​of a 50Hz sinusoidal AC circuit. The formula for determining the AC characteristic values ​​based on the DFT is as follows:

[0166]

[0167] Where n is any one of the differences of the mean values ​​of the i H-bridge drive excitations, and j is the imaginary part of the complex number (the AC characteristic value is the value expressed in complex form).

[0168] It should also be noted that when the H-bridge drive does not output a positive or negative square wave voltage signal, the AC current is determined by the induced current in the coil. Specifically, according to step S23: the type of type B current corresponding to the voltage signal to be detected is determined by detecting the DC characteristic value and the AC 50Hz characteristic value, including:

[0169] The excitation voltage signal acquired across the sampling resistor is filtered using a signal conditioning sampling circuit. The sampling rate of the ADC in the signal conditioning sampling circuit is set to a high-frequency sampling rate of 1 Msps. Simultaneously, the excitation voltage signal acquired across the sampling resistor is downsampled to reduce the number of computation points. It should be noted that at this time, the H-bridge drive does not output positive or negative voltage values; the excitation voltage signal is the induced current obtained by the coil through electromagnetic induction. The signal conditioning sampling circuit then performs low-pass filtering to remove high-frequency interference from the induced current.

[0170] A windowing function is set for the filtered excitation voltage signal; this windowing function is set to 20ms to reduce spectral leakage; the excitation voltage signal here is still the induced current obtained by the coil through electromagnetic induction;

[0171] With a spectral resolution of 50Hz, the FFT amplitude of the excitation voltage signal is determined based on FFT. The resulting FFT amplitude is the FFT amplitude of the AC signal from 50Hz to 1kHz. Multiple channels are set up for the 50Hz to 1kHz AC signal according to preset frequency combinations. For example, 50Hz, 100Hz, and 150Hz can be set as the first, second, and third channels, respectively. The formula for determining the FFT amplitude of the excitation voltage signal is as follows:

[0172]

[0173] Where N is the number of sampling points for the FFT amplitude, and k is any frequency in N;

[0174] The type of B current is determined based on the FFT amplitude.

[0175] The types of type B current corresponding to the excitation voltage signal to be detected and determined based on DC and AC characteristic values ​​include:

[0176] Determine whether the value of each element in the sampled sequence is greater than the first threshold;

[0177] If so, then summarize the elements that are greater than the first threshold and obtain the first subsequence y. p =[y 1_p ,y 2_p ,…,x P_p ]; where P represents that there are P elements in the first subsequence;

[0178] If not, then summarize the elements that are not greater than the first threshold and obtain the second subsequence y. q =[y 1_q ,y 2_q ,…,x Q_q ]; where Q represents the presence of Q elements in the first subsequence;

[0179] The type of B-type current is determined based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the criteria for pulsating DC. The criteria for pulsating DC is that the number of sampling points with signal values ​​of 0 and / or signal values ​​not exceeding 6mA within one cycle is greater than 40% of the total number of sampling points.

[0180] In addition, before determining whether the value of each element in the sampled sequence is greater than the first threshold, the following steps are also included:

[0181] Determine whether the DC characteristic value exceeds the second threshold;

[0182] If so, then the excitation voltage signal contains DC current; among which, DC current generally includes smoothed DC, AC superimposed smoothed DC, pulsating DC superimposed smoothed DC, and pulsating DC.

[0183] If not, then the excitation voltage signal contains AC current; AC current generally includes sinusoidal AC, AC residual current below 1kHz, and composite residual current.

[0184] The determination of the type of B-type current based on the number of elements in the first and second subsequences and whether the first and second subsequences meet the criteria for pulsating DC current includes:

[0185] When the number of elements P in the first subsequence is greater than the number of elements Q in the second subsequence and the first subsequence meets the standard that the type of B current is pulsating DC, determine whether the first subsequence contains negative numbers.

[0186] If the first subsequence contains negative numbers, then the type of B current is determined to be negative pulsating DC superimposed with positive polarity DC;

[0187] If the first subsequence does not contain negative numbers, then the type of B current is determined to be positive pulsating DC superimposed with positive polarity DC;

[0188] When the number of elements in the second subsequence is greater than the number of elements in the first subsequence and the second subsequence meets the standard that the type of B current is pulsating DC, determine whether the second subsequence contains positive numbers.

[0189] If the second subsequence contains positive numbers, then the type of B current is determined to be positive pulsating DC superimposed with negative polarity DC;

[0190] If the second subsequence does not contain positive numbers, then the type of B current is determined to be negative pulsating DC superimposed with negative polarity DC.

[0191] It should also be noted that after determining the type of B-type current based on the number of elements in the first and second subsequences and whether the first and second subsequences meet the criteria for pulsating DC, the following is also included:

[0192] The sampling sequence DC value y, which characterizes whether pulsating DC is present, is determined based on the type of B current. DC ;

[0193] Determine whether the DC value of the sampled sequence exceeds the standard for pulsating DC;

[0194] If yes, then pulsating DC is confirmed to exist; if no, then pulsating DC is confirmed to not exist.

[0195] Based on the above embodiments, after determining the sampling sequence DC value representing whether there is pulsating DC current according to the type of B current, the method further includes:

[0196] When it is determined that the excitation voltage signal contains DC current and that there is pulsating DC current, determine the absolute value of the difference between the maximum and minimum values ​​among the multiple elements contained in the sampling sequence.

[0197] Determine if the difference exceeds 6mA;

[0198] If the difference does not exceed 6mA, then the type of current B is determined to be smoothed DC, and the DC characteristic value is determined to be the amplitude of smoothed DC.

[0199] If the difference exceeds 6mA, then determine whether the difference exceeds the third threshold;

[0200] If the difference exceeds the third threshold, the type of B current is determined to be pulsating DC superimposed with smooth DC, and the amplitude of pulsating DC superimposed with smooth DC is determined according to the DC characteristic value and AC characteristic value.

[0201] If the difference does not exceed the third threshold, the type of B current is determined to be pulsating DC, and the AC characteristic value is determined to be the amplitude of pulsating DC.

[0202] When it is determined that the excitation voltage signal contains DC current and that there is no pulsating DC current, the type of B current is determined to be AC ​​residual current superimposed with smoothed DC, and the amplitude of AC residual current superimposed with smoothed DC is determined according to the DC characteristic value and AC characteristic value.

[0203] When it is determined that the excitation voltage signal contains AC current and that there is pulsating DC current, it is determined whether the difference exceeds the third threshold.

[0204] If the difference exceeds the third threshold, the type of B current is determined to be pulsating DC superimposed with smooth DC.

[0205] If the difference does not exceed the third threshold, then the type of B current is determined to be pulsating DC.

[0206] Based on the above embodiments, the specific method for determining AC current is as follows: determining the type of Type B current based on the FFT amplitude includes:

[0207] When it is determined that the excitation voltage signal contains AC current and there is no pulsating DC current, the type of B current is determined according to the relationship between the AC characteristic value and the fourth threshold and the relationship between the FFT amplitude and the preset number; where the preset number is the number of FFT amplitudes that exceed the fifth threshold representing the preset value of FFT, and this value is generally set to 1.

[0208] When the AC characteristic value exceeds the fourth threshold and the FFT amplitude equals the preset number, the type of B current is determined to be sinusoidal AC.

[0209] When the AC characteristic value exceeds the fourth threshold and the FFT amplitude is greater than the preset number, the type of B current is determined to be composite residual current.

[0210] When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is equal to the preset number, the type of B current is determined to be a sinusoidal AC signal below 1kHz.

[0211] When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is greater than the preset number, the type of B current is determined to be composite residual current.

[0212] In the above embodiments, the current detection method has been described in detail. This application also provides embodiments corresponding to the current detection device. It should be noted that this application describes the embodiments of the device part from two perspectives: one is based on the functional module, and the other is based on the hardware.

[0213] Figure 3This is a structural diagram of a current detection device provided in an embodiment of this application. Figure 3 As shown, this application also provides a current detection device, including:

[0214] The control module 30 is used to control multiple H-bridge drive excitations to output excitation voltage signals. The excitation voltage signals include positive voltage signals and negative voltage signals. The positive voltage signal is used to make the coil work in the positive magnetic saturation region, and the negative voltage signal is used to make the coil work in the negative magnetic saturation region.

[0215] The acquisition and transmission module 31 is used to acquire and transmit the excitation voltage signal to be detected to the DSP through the sampling resistor;

[0216] The acquisition module 32 is used to acquire the DC characteristic value and AC characteristic value generated by the DSP based on the excitation voltage signal to be detected;

[0217] The detection and determination module 33 is used to detect and determine the type of type B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value.

[0218] In addition, the device also includes the following modules:

[0219] Preferably, obtaining the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected includes:

[0220] The extraction module is used to extract multiple positive voltage values ​​corresponding to the excitation voltage signal in the positive magnetic linear region and multiple negative voltage values ​​corresponding to the excitation voltage signal in the negative magnetic linear region.

[0221] The first determining module is used to take multiple positive voltage values ​​as a first sequence and determine the first average value of the first sequence, take multiple negative voltage values ​​as a second sequence and determine the second average value of the second sequence, wherein the number of the first average value and the number of the second average value are both equal to the number of H-bridge drive excitations;

[0222] The difference processing module is used to process the first average and the second average to obtain all difference values, and then merge all difference values ​​into a difference sequence.

[0223] The odd-number inversion module is used to invert the difference sequence by odd numbers, resulting in odd and even sequences.

[0224] The sampling module is used to sample the basic sequence based on a preset sampling length to obtain a sampled sequence, wherein the basic sequence consists of an odd sequence and an even sequence.

[0225] The second determining module is used to take the third average value determined according to the sampling sequence as the DC characteristic value;

[0226] The third determination module is used to determine the AC characteristic value based on the DFT and the sampled sequence.

[0227] Preferably, detecting and determining the type of type B current corresponding to the excitation voltage signal to be detected based on DC and AC characteristic values ​​includes:

[0228] The first judgment module is used to determine whether the value of each element in the sampled sequence is greater than the first threshold.

[0229] If so, the first induction module is triggered to inductively summarize elements greater than the first threshold and obtain the first subsequence.

[0230] If not, the second induction module is triggered to inductively summarize elements that are not greater than the first threshold and obtain the second subsequence.

[0231] The fourth determining module is used to determine the type of type B current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard of pulsating DC for type B current. The standard of pulsating DC is that the number of sampling points of signal values ​​that are 0 and / or signal values ​​that do not exceed 6mA in one cycle is greater than 40% of the total number of sampling points.

[0232] Preferably, before determining whether the value of each element in the sampling sequence is greater than the first threshold, the method further includes:

[0233] The second judgment module is used to determine whether the DC characteristic value exceeds the second threshold.

[0234] If so, the fifth determination module is triggered to determine whether the excitation voltage signal contains DC current.

[0235] If not, the sixth determination module is triggered to determine whether the excitation voltage signal contains AC current.

[0236] Preferably, determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the criteria for pulsating DC current, includes:

[0237] The third judgment module is used to determine whether the first subsequence contains negative numbers when the number of elements in the first subsequence is greater than the number of elements in the second subsequence and the first subsequence meets the standard that the type of B current is pulsating DC.

[0238] The seventh determination module is used to determine the type of B-type current as negative pulsating DC superimposed with positive polarity DC if the first subsequence contains negative numbers.

[0239] The eighth determining module is used to determine the type of B-type current as positive pulsating DC superimposed with positive polarity DC if the first subsequence does not contain negative numbers.

[0240] The fourth judgment module is used to determine whether the second subsequence contains positive numbers when the number of elements in the second subsequence is greater than the number of elements in the first subsequence and the second subsequence meets the standard that the type of B current is pulsating DC.

[0241] The ninth determining module is used to determine the type of B-type current as positive pulsating DC superimposed with negative polarity DC if the second subsequence contains positive numbers.

[0242] The tenth determination module is used to determine the type of B-type current as negative pulsating DC superimposed with negative polarity DC if the second subsequence does not contain positive numbers.

[0243] Preferably, after determining the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of B-type current is pulsating DC, the method further includes:

[0244] The eleventh determination module is used to determine the DC value of the sampling sequence that indicates whether there is pulsating DC, based on the type of B current.

[0245] The fifth judgment module is used to determine whether the DC value of the sampling sequence exceeds the standard of pulsating DC.

[0246] If so, the twelfth determination module is triggered to determine the presence of pulsating DC.

[0247] If not, the thirteenth determination module is triggered to determine that there is no pulsating DC.

[0248] Preferably, detecting and determining the type of type B current corresponding to the voltage signal to be detected based on the DC characteristic value and the AC 50Hz characteristic value includes:

[0249] The filtering module is used to filter the excitation voltage signal collected across the sampling resistor using the signal conditioning sampling circuit;

[0250] The configuration module is used to set the windowing function for the filtered excitation voltage signal;

[0251] The fourteenth determination module is used to determine the FFT amplitude of the excitation voltage signal based on FFT, with a spectral resolution of 50Hz as the condition.

[0252] The fifteenth determination module is used to determine the type of B-type current based on the FFT amplitude.

[0253] Preferably, after determining the sampling sequence DC value representing whether pulsating DC current is present based on the type of type B current, the method further includes:

[0254] The sixteenth determination module is used to determine the absolute value of the difference between the maximum and minimum values ​​among multiple elements in the sampling sequence when it is determined that the excitation voltage signal contains DC current and that there is pulsating DC current.

[0255] The sixth judgment module is used to determine whether the difference exceeds 6mA;

[0256] The seventeenth determination module is used to determine the type of B current as smoothed DC if the difference does not exceed 6mA, and to determine the DC characteristic value as the amplitude of smoothed DC.

[0257] The seventh judgment module is used to determine whether the difference exceeds the third threshold if the difference exceeds 6mA.

[0258] The eighteenth determination module is used to determine the type of B current as pulsating DC superimposed with smooth DC if the difference exceeds the third threshold, and to determine the amplitude of pulsating DC superimposed with smooth DC based on the DC characteristic value and AC characteristic value.

[0259] The nineteenth determination module is used to determine the type of B current as pulsating DC if the difference does not exceed the third threshold, and to determine the AC characteristic value as the amplitude of pulsating DC.

[0260] The twentieth determination module is used to determine the type of type B current as AC residual current superimposed smoothed DC when it is determined that the excitation voltage signal contains DC current and that there is no pulsating DC current, and to determine the amplitude of AC residual current superimposed smoothed DC based on the DC characteristic value and AC characteristic value.

[0261] The eighth judgment module is used to determine whether the difference exceeds the third threshold when it is determined that the excitation voltage signal contains AC current and that there is pulsating DC current.

[0262] The twenty-first determination module is used to determine the type of B current as pulsating DC superimposed with smooth DC if the difference exceeds the third threshold.

[0263] The twenty-second determination module is used to determine the type of B current as pulsating DC if the difference does not exceed the third threshold.

[0264] Preferably, determining the type of B-type current based on the FFT amplitude includes:

[0265] The twenty-third determination module is used to determine the type of type B current based on the relationship between the AC characteristic value and the fourth threshold and the relationship between the FFT amplitude and the preset number when it is determined that the excitation voltage signal contains AC current and there is no pulsating DC current.

[0266] The twenty-fourth determination module is used to determine the type of B-type current as sinusoidal AC when the AC characteristic value exceeds the fourth threshold and the FFT amplitude is equal to a preset number; wherein, the preset number is the number of FFT amplitudes that exceed the fifth threshold representing the preset value of FFT.

[0267] The twenty-fifth determination module is used to determine the type of B-type current as composite residual current when the AC characteristic value exceeds the fourth threshold and the FFT amplitude is greater than the preset number.

[0268] The twenty-sixth determination module is used to determine that the type of B current is a sinusoidal AC signal below 1kHz when the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is equal to the preset number.

[0269] The twenty-seventh determination module is used to determine the type of B-type current as composite residual current when the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is greater than the preset number.

[0270] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0271] Figure 4 This is a structural diagram of a current detection system provided in an embodiment of this application, as shown below. Figure 4 As shown, the current detection system includes:

[0272] Memory 40 is used to store computer programs;

[0273] The processor 41 is used to execute a computer program to implement the steps of the current detection method mentioned in the above embodiments.

[0274] The current detection system provided in this embodiment may include, but is not limited to, smartphones, tablets, laptops, or desktop computers.

[0275] The processor 41 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 41 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 41 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 41 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 41 may also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.

[0276] The memory 40 may include one or more computer-readable storage media, which may be non-transitory. The memory 40 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 40 is used to store at least the following computer program, which, after being loaded and executed by the processor 41, is capable of implementing the relevant steps of the current detection method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 40 may also include an operating system and data, and the storage method may be temporary or permanent. The operating system may include Windows, Unix, Linux, etc. The data may include, but is not limited to, the current detection method.

[0277] In some embodiments, the current detection system may further include a display screen, an input / output interface, a communication interface, a power supply, and a communication bus.

[0278] Those skilled in the art will understand that Figure 4 The structure shown does not constitute a limitation on the current sensing system and may include more or fewer components than illustrated.

[0279] The current detection system provided in this application includes a memory 40 and a processor 41. When the processor 41 executes the program stored in the memory 40, it can implement the current detection method.

[0280] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above method embodiments.

[0281] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0282] The foregoing provides a detailed description of a current detection device, method, apparatus, system, and medium provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0283] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A current detection device, characterized in that, include: Multiple H-bridge drive excitations (10), coils, sampling resistors, DSP (11), comparator (12); Multiple H-bridge drive excitations (10) are connected to the coil to transmit the excitation voltage signals output by the multiple H-bridge drive excitations (10) to the coil. The excitation voltage signals include positive voltage signals and negative voltage signals. The positive voltage signals are used to make the coil work in the positive magnetic saturation region, and the negative voltage signals are used to make the coil work in the negative magnetic saturation region. The first end of the sampling resistor is connected to the first winding end of the coil, and the second end of the sampling resistor is connected to the second winding end of the coil, for acquiring the excitation voltage signal to be detected; The input terminal of the DSP (11) is connected to both the first and second terminals of the sampling resistor, and is used to generate DC characteristic values ​​and AC characteristic values. The comparator (12) is connected to the output terminal of the DSP (11) and is used to detect and determine the type of B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value. The current detection device is used to perform the following current detection method: Multiple H-bridge drives are controlled to output excitation voltage signals, including positive and negative voltage signals. The positive voltage signal is used to make the coil operate in the positive magnetic saturation region, and the negative voltage signal is used to make the coil operate in the negative magnetic saturation region. The excitation voltage signal to be detected is acquired and transmitted to the DSP through a sampling resistor. The DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected are obtained. The type of B-type current corresponding to the excitation voltage signal to be detected is detected and determined based on the DC and AC characteristic values. The step of obtaining the DC and AC characteristic values ​​generated by the DSP based on the excitation voltage signal to be detected includes: extracting multiple positive voltage values ​​corresponding to the excitation voltage signal in the positive magnetic linear region and extracting multiple negative voltage values ​​corresponding to the excitation voltage signal in the negative magnetic linear region; taking the multiple positive voltage values ​​as a first sequence and determining a first average value of the first sequence, taking the multiple negative voltage values ​​as a second sequence and determining a second average value of the second sequence, wherein the number of the first average value and the second average value are both equal to the number of excitations driven by the H-bridge; differentially processing the first average value and the second average value to obtain all differential values, and merging all the differential values ​​as a differential sequence; performing odd-number inversion processing on the differential sequence to obtain an odd sequence and an even sequence; sampling the basic sequence under a preset sampling length to obtain a sampling sequence, wherein the basic sequence is composed of the odd sequence and the even sequence; taking the third average value determined according to the sampling sequence as the DC characteristic value; and determining the AC characteristic value based on the sampling sequence using DFT.

2. The current detection device according to claim 1, characterized in that, Also includes: Signal conditioning and sampling circuit (13); The first input terminal of the signal conditioning sampling circuit (13) is connected to the first terminal of the sampling resistor, the second input terminal of the signal conditioning sampling circuit (13) is connected to the second terminal of the sampling resistor, and the output terminal of the signal conditioning sampling circuit (13) is connected to the input terminal of the DSP (11) for generating an accurate excitation voltage signal to be detected and transmitting the excitation voltage signal to be detected to the DSP (11).

3. The current detection device according to claim 2, characterized in that, The signal conditioning and sampling circuit (13) includes: ADC (14) and fully differential amplifier circuit (15); The first input terminal of the fully differential amplifier circuit (15) serves as the first input terminal of the signal conditioning and sampling circuit (13), the second input terminal of the fully differential amplifier circuit (15) serves as the second input terminal of the signal conditioning and sampling circuit (13), the output terminal of the fully differential amplifier circuit (15) is connected to the input terminal of the ADC (14), and the output terminal of the ADC (14) serves as the output terminal of the signal conditioning and sampling circuit (13).

4. The current detection device according to claim 3, characterized in that, The fully differential amplifier circuit (15) includes: a first input resistor, a second input resistor, a differential amplifier, a first fully differential resistor, and a second fully differential resistor; The first end of the first input resistor serves as the first input terminal of the fully differential amplifier circuit (15), the first end of the second input resistor serves as the second input terminal of the fully differential amplifier circuit (15), the second end of the first input resistor is connected to a common terminal formed by the first end of the first fully differential resistor and the non-inverting input terminal of the differential amplifier, the second end of the second input resistor is connected to a common terminal formed by the first end of the second fully differential resistor and the inverting input terminal of the differential amplifier, and the common terminal formed by the output terminal of the differential amplifier, the second end of the first fully differential resistor, and the second end of the second fully differential resistor serves as the output terminal of the fully differential amplifier circuit (15).

5. A current detection method, applicable to the current detection device according to any one of claims 1 to 4, characterized in that, The step of detecting and determining the type of type B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value includes: Determine whether the value of each element in the sampled sequence is greater than a first threshold; If so, then summarize all the elements that are greater than the first threshold and obtain the first subsequence; If not, then summarize the elements that are not greater than the first threshold and obtain the second subsequence; The type of B-type current is determined based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of B-type current is pulsating DC. The standard for pulsating DC is that the number of sampling points with signal values ​​of 0 and / or signal values ​​not exceeding 6mA in one cycle is greater than 40% of the total number of sampling points.

6. The current detection method according to claim 5, characterized in that, Before determining whether the value of each element in the sampled sequence is greater than the first threshold, the method further includes: Determine whether the DC characteristic value exceeds the second threshold; If so, then it is determined that the excitation voltage signal contains a DC current. If not, then it is determined that the excitation voltage signal contains alternating current.

7. The current detection method according to claim 6, characterized in that, The determination of the type of B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of B-type current is pulsating DC, includes: When the number of elements in the first subsequence is greater than the number of elements in the second subsequence and the first subsequence meets the standard that the type of B current is pulsating DC, determine whether the first subsequence contains negative numbers. If the first subsequence contains the negative number, then the type of the B-type current is determined to be negative pulsating DC superimposed with positive polarity DC; If the first subsequence does not contain the negative number, then the type of the B-type current is determined to be positive pulsating DC superimposed with positive polarity DC; When the number of elements in the second subsequence is greater than the number of elements in the first subsequence and the second subsequence meets the standard that the type of B current is pulsating DC, it is determined whether the second subsequence contains a positive number. If the second subsequence contains the positive number, then the type of the B-type current is determined to be positive pulsating DC superimposed with negative polarity DC; If the second subsequence does not contain the positive number, then the type of the B-type current is determined to be negative pulsating DC superimposed with negative polarity DC.

8. The current detection method according to claim 7, characterized in that, After determining the type of the B-type current based on the number of elements contained in the first subsequence and the second subsequence, and whether the first subsequence and the second subsequence meet the standard that the type of the B-type current is pulsating DC, the method further includes: The sampling sequence DC value, which characterizes whether pulsating DC is present, is determined based on the type of B current. Determine whether the DC value of the sampled sequence exceeds the standard of the pulsating DC; If so, then pulsating DC current is confirmed to exist; If not, then it is determined that there is no pulsating DC.

9. The current detection method according to claim 8, characterized in that, The process of detecting and determining the type of Type B current corresponding to the voltage signal to be detected based on the DC characteristic value and the AC 50Hz characteristic value includes: The excitation voltage signal acquired across the sampling resistor is filtered using a signal conditioning sampling circuit. A windowing function is applied to the filtered excitation voltage signal; The FFT amplitude of the excitation voltage signal is determined based on FFT, with a spectral resolution of 50Hz. The type of B current is determined based on the FFT amplitude.

10. The current detection method according to claim 9, characterized in that, After determining the sampling sequence DC value characterizing whether a pulsating DC current is present based on the type of the B-type current, the method further includes: When it is determined that the excitation voltage signal contains the DC current and the pulsating DC current exists, the absolute value of the difference between the maximum and minimum values ​​among the multiple elements contained in the sampling sequence is determined. Determine whether the difference exceeds 6mA; If the difference does not exceed 6mA, then the type of the B-current is determined to be smooth DC, and the DC characteristic value is determined to be the amplitude of the smooth DC. If the difference exceeds 6mA, then determine whether the difference exceeds the third threshold. If the difference exceeds the third threshold, the type of the B-current is determined to be pulsating DC superimposed with smooth DC, and the amplitude of the pulsating DC superimposed with smooth DC is determined according to the DC characteristic value and the AC characteristic value. If the difference does not exceed the third threshold, the type of the B-current is determined to be pulsating DC, and the AC characteristic value is determined to be the amplitude of the pulsating DC. When it is determined that the excitation voltage signal contains the DC current and that the pulsating DC current does not exist, the type of the B current is determined to be AC ​​residual current superimposed smoothed DC, and the amplitude of the AC residual current superimposed smoothed DC is determined according to the DC characteristic value and the AC characteristic value. When it is determined that the excitation voltage signal contains the AC current and the pulsating DC current exists, it is determined whether the difference exceeds the third threshold. If the difference exceeds the third threshold, then the type of the B-type current is determined to be the pulsating DC superimposed with smooth DC. If the difference does not exceed the third threshold, then the type of the B-type current is determined to be the pulsating DC.

11. The current detection method according to claim 10, characterized in that, The determination of the type of B current based on the FFT amplitude includes: When it is determined that the excitation voltage signal contains the AC current and that the pulsating DC current does not exist, the type of the B-type current is determined according to the relationship between the AC characteristic value and the fourth threshold and the relationship between the FFT amplitude and the preset number. When the AC characteristic value exceeds the fourth threshold and the FFT amplitude is equal to the preset number, the type of the B-type current is determined to be sinusoidal AC; wherein, the preset number is the number of times the FFT amplitude exceeds the fifth threshold characterizing the preset FFT value; When the AC characteristic value exceeds the fourth threshold and the FFT amplitude is greater than the preset number, the type of the B-type current is determined to be a composite residual current. When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is equal to the preset number, the type of the B-type current is determined to be a sinusoidal AC signal below 1kHz. When the AC characteristic value does not exceed the fourth threshold and the FFT amplitude is greater than the preset number, the type of the B-type current is determined to be the composite residual current.

12. A current detection device, comprising the current detection apparatus according to any one of claims 1 to 4, characterized in that, include: The control module is used to control multiple H-bridge drive excitations to output excitation voltage signals. The excitation voltage signals include positive voltage signals and negative voltage signals. The positive voltage signals are used to make the coil work in the positive magnetic saturation region, and the negative voltage signals are used to make the coil work in the negative magnetic saturation region. The acquisition and transmission module is used to acquire and transmit the excitation voltage signal to be detected to the DSP through the sampling resistor; The acquisition module is used to acquire the DC characteristic value and AC characteristic value generated by the DSP based on the excitation voltage signal to be detected; The detection and determination module is used to detect and determine the type of type B current corresponding to the excitation voltage signal to be detected based on the DC characteristic value and the AC characteristic value.

13. A current detection system, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the current detection method as described in any one of claims 5 to 11 when executing the computer program.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the current detection method as described in any one of claims 5 to 11.

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