Current measuring circuit, current measuring device and current measuring method

Abstract

The invention relates to a current measuring circuit, a current measuring device and a current measuring method. The current measuring circuit comprises a magnetic induction module used for inducing a to-be-measured current to obtain an induced current, and further comprises a first filtering module, the input end of the first filtering module is connected with the output end of the magnetic induction module, and the first filtering module is used for filtering magnetic induction noise included in the induced current based on preset filtering parameters to obtain a second filtering module. The system further comprises a measurement module, the input end of the measurement module is connected with the output end of the first filtering module, the measurement module is used for obtaining processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used for determining current data corresponding to the current to be measured. According to the technical scheme provided by the embodiment of the invention, the measurement accuracy of the current data of the to-be-measured current can be improved.

Description

Technical Field

[0001] The present application relates to the field of magnetic induction technology, and in particular to a current measurement circuit, a measurement device and a measurement method. Background Art

[0002] The time difference type fluxgate sensor circuit is often used to measure the current data corresponding to the current to be measured due to its high precision, low power consumption, small size and high reliability.

[0003] A conventional time-difference-type fluxgate sensor circuit usually utilizes a magnetic field to sense the circuit under test, obtains an induced current, and measures current data of the current to be measured based on the induced current.

[0004] However, the above current measurement circuit has low measurement accuracy for the current to be measured. Summary of the invention

[0005] Based on this, in order to solve the above technical problems, a current measurement circuit, a measurement device and a measurement method are provided, which can improve the measurement accuracy of the current to be measured.

[0006] In a first aspect, the present application provides a current measurement circuit, including a magnetic induction module, the magnetic induction module is used to sense a current to be measured to obtain an induced current;

[0007] A first filtering module, wherein an input end of the first filtering module is connected to an output end of the magnetic induction module, and the first filtering module is used to filter the magnetic induction noise included in the induced current based on preset filtering parameters to obtain a noise reduction current;

[0008] A measuring module, wherein the input end of the measuring module is connected to the output end of the first filtering module, and the measuring module is used to obtain processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine current data corresponding to the current to be measured.

[0009] In one of the embodiments, the first filtering module is specifically used to filter the magnetic induction noise based on preset filtering parameters to obtain the noise current, and perform statistical processing on the induced current and the noise current to obtain the noise reduction current.

[0010] In one embodiment, the measurement module includes:

[0011] an amplifier circuit, wherein an input end of the amplifier circuit is connected to an output end of the first filter module, and the amplifier circuit is used to amplify the noise reduction current to obtain the noise reduction current after amplification;

[0012] A shaping circuit, wherein the input end of the shaping circuit is connected to the output end of the amplifying circuit, and the shaping circuit is used to obtain processing parameters according to the noise reduction current after the amplification processing.

[0013] In one embodiment, the measurement module further includes:

[0014] a second filtering circuit, wherein the input end of the second filtering circuit is connected to the output end of the amplifying circuit, the output end of the second filtering circuit is connected to the input end of the shaping circuit, and the second filtering circuit is used to filter the noise reduction current after the amplification process to obtain the noise reduction current after the filtering process;

[0015] The shaping circuit is specifically used to obtain processing parameters according to the noise reduction current after filtering.

[0016] In one embodiment, the shaping circuit comprises:

[0017] A bias circuit, wherein an input end of the bias circuit is connected to an output end of the second filter circuit, and the bias circuit is used to generate a threshold voltage;

[0018] A comparison circuit, wherein an input end of the comparison circuit is connected to an output end of the bias circuit, and an input end of the comparison circuit is connected to an output end of the second filter circuit, and the comparison circuit is used to compare a voltage corresponding to the noise reduction current after filtering with a threshold voltage, and output a level signal;

[0019] A counting chip, the input end of the counting chip is connected to the output end of the comparison circuit, and the counting chip is used to determine the duration of the level signal according to the level signal, and determine the processing parameter according to the duration.

[0020] In one embodiment, the shaping circuit further comprises:

[0021] A voltage conversion circuit, wherein the input end of the voltage conversion circuit is connected to the output end of the second filter circuit, the output end of the voltage conversion circuit is connected to the input end of the comparison circuit and the input end of the bias circuit, and the voltage conversion circuit is used to perform voltage conversion on the noise reduction current after filtering to obtain a voltage corresponding to the noise reduction current after filtering.

[0022] In one embodiment, the threshold voltage includes a first threshold voltage or a second threshold voltage, and the first threshold voltage is greater than the second threshold voltage;

[0023] The comparison circuit is specifically used to output a high level signal when the voltage corresponding to the noise reduction current after filtering is greater than the first threshold voltage;

[0024] The comparison circuit is also specifically configured to output a low level signal when the voltage corresponding to the noise reduction current after filtering is less than the second threshold voltage.

[0025] In one of the embodiments, the measurement module is further used to send the processing parameters to the host computer, so that the host computer determines the current data corresponding to the current to be measured according to the processing parameters.

[0026] In a second aspect, the present application provides a current measuring device, which includes a host computer and a current measuring circuit as described in any one of the first aspects, wherein the host computer is connected to the current measuring circuit.

[0027] In a third aspect, the present application provides a current measurement method, which is used in the host computer of the second aspect, and the method includes:

[0028] Acquire a processing parameter sent by a current measurement circuit, where the processing parameter is obtained by filtering the magnetic induction noise included in the current to be measured by the current measurement circuit to obtain a noise reduction current, and is obtained based on the noise reduction current;

[0029] Substitute the processing parameters into the preset current measurement equation group to obtain the current data corresponding to the current to be measured.

[0030] The above-mentioned current measurement circuit, measuring device and measuring method, the current measurement circuit includes a magnetic induction module, the magnetic induction module is used to sense the current to be measured, and obtain the induced current, and also includes a first filtering module, the input end of the first filtering module is connected to the output end of the magnetic induction module, the first filtering module is used to filter the magnetic induction noise included in the induced current based on the preset filtering parameters to obtain the noise reduction current, and also includes a measuring module, the input end of the measuring module is connected to the output end of the first filtering module, the measuring module is used to obtain the processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine the current data corresponding to the current to be measured. In this way, the induced current obtained by the magnetic induction module sensing the current to be measured will not be directly measured, but the magnetic induction noise included in the induced current is first filtered by the first filtering module, so as to offset the magnetic induction noise in the induced current, and the current data of the current to be measured is determined based on the processing parameters obtained by the noise reduction current obtained after filtering, and the current data is more accurate, avoiding the problem of low measurement accuracy in the traditional technology of ignoring the magnetic induction noise that may exist in the induced current and directly determining the current data of the current to be measured based on the induced current, thereby improving the measurement accuracy of the current data of the current to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic diagram of a current measurement circuit in an embodiment of the present application;

[0033] Figure 2 is a schematic diagram of an exemplary magnetic induction module in an embodiment of the present application;

[0034] Figure 3 is a schematic diagram of an exemplary first filtering module in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of a measurement module in an embodiment of the present application;

[0036] Figure 5 is a schematic diagram of an exemplary amplifier circuit in an embodiment of the present application;

[0037] Figure 6 is a schematic diagram of another measurement module in an embodiment of the present application;

[0038] Figure 7 is a schematic diagram of an exemplary second filtering circuit in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of a shaping circuit in an embodiment of the present application;

[0040] Fig. 9 A schematic diagram of another shaping circuit in an embodiment of the present application;

[0041] Fig.10 is a schematic diagram of an exemplary shaping circuit in an embodiment of the present application;

[0042] Fig.11 is a schematic diagram of an exemplary current measurement circuit in an embodiment of the present application;

[0043] Fig.12 A schematic diagram of a current measuring device in an embodiment of the present application;

[0044] Fig.13 Schematic diagram of a current measurement method in an embodiment of the present application.

[0045] Description of reference numerals:

[0046] Magnetic induction module: 100; first filtering module: 200; measuring module: 300; amplifying circuit: 310; shaping circuit: 320; second filtering circuit: 330; bias circuit: 321; comparison circuit: 322; counting chip: 323; voltage conversion circuit: 324. DETAILED DESCRIPTION

[0047] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0049] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0050] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0051] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0052] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0053] Compared with the Hall element to measure current, the fluxgate sensor is often used to measure the current to be measured due to its high precision, low power consumption, small size and high reliability. For example, the time difference fluxgate current sensor circuit using the fluxgate sensor mainly includes two parts: a sensitive unit and a detection circuit. The sensitive unit includes a magnetic field for sensing the current to be measured, and the detection circuit is used to detect the circuit.

[0054] A conventional time-difference-based fluxgate sensor circuit usually utilizes a magnetic field to sense the circuit under test to obtain an induced current. Then, a detection circuit measures current data of the current to be measured based on the induced current.

[0055] However, due to the irreversible and discontinuous displacement of the magnetic field, the induced current may contain magnetic induction noise, such as Barkhausen noise. If the magnetic induction noise included in the induced current is not processed, directly determining the current data of the measured current based on the induced current will lead to low measurement accuracy.

[0056] In the related technology, when processing magnetic induction noise, methods such as wavelet threshold method and zero-phase filtering method are usually used. These methods apply a large amount of mathematical model analysis, have a large amount of calculation, and have low calculation accuracy. For example, the wavelet threshold method includes the selection of wavelet basis functions, and the selection of threshold functions and threshold estimation will have a great impact on the measurement results. If the selected threshold function and threshold estimation are not accurate enough, the measurement accuracy of the current to be measured will be low.

[0057] In view of this, the present application provides a current measurement circuit, a measuring device and a measuring method, wherein the current measurement circuit includes a magnetic induction module, the magnetic induction module is used to sense the current to be measured, obtain the induced current, and also includes a first filtering module, the input end of the first filtering module is connected to the output end of the magnetic induction module, the first filtering module is used to filter the magnetic induction noise included in the induced current based on the preset filtering parameters to obtain the noise reduction current, and also includes a measuring module, the input end of the measuring module is connected to the output end of the first filtering module, the measuring module is used to obtain the processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine the current data corresponding to the current to be measured. In this way, the induced current obtained by the magnetic induction module sensing the current to be measured will not be directly measured, but the magnetic induction noise included in the induced current is first filtered by the first filtering module, so as to offset the magnetic induction noise in the induced current, and the current data of the current to be measured is determined based on the processing parameters obtained by the noise reduction current obtained after filtering, and the current data is more accurate, which avoids the problem of low measurement accuracy in the traditional technology of ignoring the magnetic induction noise that may exist in the induced current and directly determining the current data of the current to be measured based on the induced current, thereby improving the measurement accuracy of the current data of the current to be measured.

[0058] like Figure 1 As shown, a schematic diagram of a current measurement circuit provided by an embodiment of the present application is shown. Figure 1 As shown, the current measurement circuit includes a magnetic induction module 100 , a first filtering module 200 and a measurement module 300 .

[0059] In the embodiment of the present application, the magnetic induction module 100 is used to sense the current to be measured to obtain the induced current.

[0060] Optionally, the magnetic induction module may be a component made of a magnetic material; optionally, the magnetic induction module may be an electromagnetic circuit capable of generating a magnetic field, referring to Figure 2, is an exemplary magnetic induction module 100, which includes a magnetic core made of magnetic material, an induction coil wound on the magnetic core, and an excitation coil. The excitation coil is connected to an external excitation source and can generate a magnetic field. The induction coil can sense the current to be measured (im) to obtain an induced current (ig).

[0061] The output end of the magnetic induction module 100 is connected to the input end of the first filter module 200 , so that the first filter module 200 can obtain the induced current output by the magnetic induction module 100 .

[0062] In the embodiment of the present application, the input end of the first filter module 200 is connected to the output end of the magnetic induction module 100, and the first filter module 200 is used to filter the magnetic induction noise included in the induced current based on preset filtering parameters to obtain a noise-reduced current.

[0063] It is understandable that the induced current generated by the magnetic induction module 100 may include magnetic induction noise. Optionally, the magnetic induction noise may be Barkhausen noise. In order to improve the accuracy of measuring the current to be measured, in the embodiment of the present application, the magnetic induction noise in the induced current is filtered by the first filtering module 200 to obtain a filtered noise-reduced current.

[0064] The first filter module 200 may be a high-pass filter. The specific structure of the filter module 200 may be referred to Figure 3 , the high-pass filter can filter the magnetic induction noise included in the induced current based on the preset filtering parameters, and the transfer function can refer to the following formula:

[0065] (1)

[0066] Among them, s is the Laplace variable, w c is the cut-off frequency.

[0067] Optionally, the preset filter parameter may be a cutoff frequency, and the preset filter parameter may be set according to the magnetic induction noise. For example, the magnetic induction noise is Barkhausen noise, and the frequency band of Barkhausen noise is 10kHz-100kHz, then the cutoff frequency corresponding to the preset filter parameter may be set to 10kHz.

[0068] Regarding the specific steps performed by the first filtering module 200, optionally, the first filtering module 100 is specifically used to filter the magnetic induction noise based on preset filtering parameters to obtain the noise current, and perform statistical processing on the induced current and the noise current to obtain the noise reduction current.

[0069] Exemplarily, the first filtering module 200 filters the induced current ig to obtain the noise power ig', and then performs statistical processing on ig and ig', which can be a subtraction, so that the magnetic induction noise is offset in the induced current ig, and the noise reduction current i with the magnetic induction noise filtered out is obtained.

[0070] The output end of the first filtering module 200 is connected to the input end of the measuring module 300 , so that the measuring module 300 can obtain the noise reduction current output by the first filtering module 200 .

[0071] In the embodiment of the present application, the input end of the measuring module 300 is connected to the output end of the first filtering module 200, and the measuring module 300 can be used to obtain processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine the current data corresponding to the current to be measured.

[0072] It can be understood that the processing parameters can be data converted from the influence of the noise reduction current on the magnetic field. Optionally, the measurement circuit 300 can digitize the influence of the noise reduction current on the magnetic field to obtain the processing parameters; optionally, the measurement circuit 300 can convert the influence of the noise reduction current on the magnetic field into electrical signals, such as high and low level signals, and the measurement circuit 300 can use the time difference between the duration of the high and low level signals as the processing parameter.

[0073] Based on the processing parameters, the current data corresponding to the current to be measured can be determined, and the current data can be the numerical value of the current to be measured. As for the process of determining the current data corresponding to the current to be measured, optionally, the output end of the measurement circuit 300 can be connected to a processor with processing capabilities, and the current data corresponding to the current to be measured can be obtained by sending the processing parameters to the processor; optionally, the measurement module 300 is also used to send the processing parameters to the host computer, so that the host computer determines the current data corresponding to the current to be measured according to the processing parameters. In this embodiment, the measurement module 300 can be electrically connected to the host computer to achieve wired communication, and the measurement module 300 can also achieve wireless communication with the host computer through a preset communication protocol.

[0074] In general, the current measurement circuit of the above embodiment includes a magnetic induction module, which is used to sense the current to be measured and obtain the induced current, and also includes a first filtering module, the input end of the first filtering module is connected to the output end of the magnetic induction module, and the first filtering module is used to filter the magnetic induction noise included in the induced current based on the preset filtering parameters to obtain the noise reduction current, and also includes a measuring module, the input end of the measuring module is connected to the output end of the first filtering module, and the measuring module is used to obtain the processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine the current data corresponding to the current to be measured. In this way, the induced current obtained by the magnetic induction module sensing the current to be measured will not be measured directly, but the magnetic induction noise included in the induced current is first filtered by the first filtering module, so as to offset the magnetic induction noise in the induced current, and the current data of the current to be measured is determined based on the processing parameters obtained by the noise reduction current obtained after filtering, and the current data is more accurate, which avoids the problem of low measurement accuracy in the traditional technology that ignores the magnetic induction noise that may exist in the induced current and directly determines the current data of the current to be measured based on the induced current, thereby improving the measurement accuracy of the current data of the current to be measured.

[0075] In one embodiment, based on the above embodiment, see Figure 4 In the embodiment of the present application, the measurement module 300 includes:

[0076] The amplifier circuit 310, wherein the input end of the amplifier circuit 310 is connected to the output end of the first filter module 200, and the amplifier circuit 310 can be used to amplify the noise reduction current to obtain the noise reduction current after amplification.

[0077] It can be understood that the noise reduction current is the current from which the magnetic induction noise is filtered out, and the current signal is a small signal. In order to facilitate subsequent measurements, the noise reduction current can be amplified by the amplifier circuit 310 to obtain the noise reduction current after amplification.

[0078] In the embodiment of the present application, the amplifier circuit 310 may include a low-frequency integrated circuit differential amplifier, which can differentially amplify the noise reduction current to obtain a differential current. The amplifier circuit 310 may also include a first-stage subtraction circuit, based on which the differential current can be converted into a single-ended current output. Figure 5 , which is an exemplary amplifier circuit 310.

[0079] Wherein, R5=R7=R, R8=R9=R10=R11, R is the set loop resistance, then the amplification factor of the amplifier circuit 310 is:

[0080] (2)

[0081] A is the gain, and the gain of the amplifier circuit 310 can be adjusted by the conditions R and the size of R6.

[0082] In an embodiment of the present application, the output end of the amplifier circuit 310 can be connected to the input end of the shaping circuit 320, that is, the input end of the shaping circuit 320 is connected to the output end of the amplifier circuit 310, and the shaping circuit 320 is used to obtain processing parameters according to the noise reduction current after amplification.

[0083] It can be understood that after the amplifier circuit 310 amplifies the noise reduction current based on the preset amplification factor, the interference noise in the noise reduction current will also be amplified. In order to improve the accuracy of subsequent measurements, in the embodiment of the present application, reference is made to Figure 6 , the measurement module 300 further includes:

[0084] The second filter circuit 330, wherein the input end of the second filter circuit 330 is connected to the output end of the amplifier circuit 310, and the output end of the second filter circuit 330 is connected to the input end of the shaping circuit 320, and the second filter circuit 330 is used to filter the noise reduction current after amplification to obtain the noise reduction current after filtering.

[0085] In the embodiment of the present application, the second filtering circuit 330 may include a Bessel low-pass filter with small fluctuations, and its structure may refer to Figure 7 The second filtering circuit 330 can filter the noise reduction current after the amplification processing based on preset filtering parameters. Optionally, the filtering parameters can be a 5th order filter with a cutoff frequency of 1 kHz.

[0086] The second filtering circuit 330 filters the noise reduction current after the amplification process to obtain the noise reduction current after the filtering process, and the shaping circuit 320 can be used to obtain processing parameters according to the noise reduction current after the filtering process.

[0087] In one embodiment, based on the above embodiment, see Figure 8 In the embodiment of the present application, the shaping circuit 320 includes: a bias circuit 321, a comparison circuit 322 and a counting chip 323.

[0088] The bias circuit 321 has an input end connected to the output end of the second filter circuit 330 , and the bias circuit 321 is used to generate a threshold voltage.

[0089] The comparison circuit 322 has an input end connected to the output end of the bias circuit 321, and an input end of the comparison circuit 322 is connected to the output end of the second filter circuit 320. The comparison circuit 322 is used to compare the voltage corresponding to the noise reduction current after filtering with the threshold voltage and output a level signal.

[0090] The counting chip 323 has an input terminal connected to the output terminal of the comparison circuit, and is used to determine the duration of the level signal according to the level signal, and to determine the processing parameter according to the duration.

[0091] Since the second filter circuit 330 outputs the noise reduction current after filtering, in order to facilitate subsequent processing, in one embodiment, refer to Fig. 9 , the shaping circuit 320 further includes:

[0092] The voltage conversion circuit 324 has an input end connected to the output end of the second filter circuit 330, and an output end of the voltage conversion circuit 324 is connected to the input end of the comparison circuit 322 and the input end of the bias circuit 321. The voltage conversion circuit 324 is used to perform voltage conversion on the noise reduction current after filtering to obtain a voltage corresponding to the noise reduction current after filtering, and the voltage may be related to the magnetic field.

[0093] For the specific structure of the shaping circuit 320, please refer to Fig.10 , wherein the bias circuit 321 may include an external power supply chip ADR440, capacitors C2-C5, and voltage-dividing resistors R16 and R17, and a threshold voltage may be generated through the bias circuit 321.

[0094] It is understood that the comparison circuit 322 may include a chip capable of processing data. Fig.10 , the chip model may be AD8561, and the processing chip also requires an external power supply. For example, the voltage of the power supply is V + It can be 5V. Since the output of the bias circuit 321 is connected to the input of the comparison circuit 322, the reference voltage V REF That is, the voltage output by the bias circuit 321.

[0095] Then, the comparison circuit can obtain different threshold voltages through the voltage-dividing resistor. In a possible embodiment, the threshold voltage includes a first threshold voltage or a second threshold voltage, wherein the first threshold voltage is greater than the second threshold voltage. Fig.10 In the circuit shown, the first threshold voltage V H The expression can refer to the following formula:

[0096] (3)

[0097] The expression of the second threshold voltage VL can refer to the following formula:

[0098] (4)

[0099] After obtaining different threshold voltages, the comparison circuit 320 can be specifically used to output a high-level signal when the voltage corresponding to the noise reduction current after filtering is greater than the first threshold voltage; the comparison circuit 320 is also specifically used to output a low-level signal when the voltage corresponding to the noise reduction current after filtering is less than the second threshold voltage.

[0100] In this way, the influence of the measured current on the magnetic field can be converted into different level signals, and the level signals are transmitted to the counting chip 323 so that the counting chip 323 obtains the duration of the level signal. Optionally, the duration of the high level signal can be recorded as T+, and the duration of the low level signal can be recorded as T-.

[0101] Optionally, the counting chip 323 can directly use the duration as a processing parameter. Optionally, the counting chip 323 can also use the statistical value between the durations corresponding to the high and low level signals as a processing parameter. The statistical value can be a difference value or a value obtained by substituting into a preset statistical function. The preset statistical function can refer to the following formula:

[0102] (5)

[0103] Based on different forms of processing parameters, the subsequent process of determining the current data of the current to be measured according to the processing parameters is different.

[0104] In the embodiment of the present application, the duration of the high level is as follows:

[0105] (6)

[0106] The duration of the low level is as follows:

[0107] (7)

[0108] Where L is the inductance of the excitation coil, x max and x min are parameters related to the current to be measured, among which, x min =i min / i R , x max =i max / i R ,i R =U / R,i min 、i max are the coil currents in reverse saturation and forward saturation, respectively, and R is the loop resistance; i min +i m =-i s ,i max +i m =i s,i s is the current required to reach saturation when no current to be measured is applied. , where Hs is the magnetic field, l is the circumference of the core, n is the number of turns of the excitation coil, i m is the current to be measured.

[0109] Through the above introduction, the following formula can be derived:

[0110] (8)

[0111] Therefore, when determining the current to be measured based on the processing parameters, the processing parameters can be substituted into a preset current calculation formula (ie, formula (8)) to obtain current data corresponding to the current to be measured.

[0112] Reference Fig.11 , an exemplary current measurement circuit is given.

[0113] In one embodiment, see Fig.12 , provides a current measuring device, which includes a host computer and the current measuring circuit described in any of the above embodiments, and the host computer is connected to the current measuring circuit.

[0114] In one embodiment, see Fig.13 , a current measurement method is provided, the current measurement method is used for the host computer as described in the above current measurement device, the method comprises the following steps:

[0115] Step 1301: Obtain processing parameters sent by the current measurement circuit.

[0116] The processing parameter is obtained by filtering the magnetic induction noise included in the current to be measured by the current measurement circuit to obtain a noise reduction current, and is obtained based on the noise reduction current.

[0117] Step 1302: Substitute the processing parameters into the preset current measurement equation group to obtain current data corresponding to the current to be measured.

[0118] The specific limitations and beneficial effects of the current measurement method can be found in the above-mentioned embodiments of the current measurement circuit, which will not be described in detail here.

[0119] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0120] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A current measurement circuit, characterized in that: include: A magnetic induction module, wherein the magnetic induction module is used to sense the current to be measured and obtain the induced current; A first filtering module, wherein an input end of the first filtering module is connected to an output end of the magnetic induction module, and the first filtering module is used to filter the magnetic induction noise included in the induced current based on preset filtering parameters to obtain a noise reduction current; A measuring module, wherein the input end of the measuring module is connected to the output end of the first filtering module, and the measuring module is used to obtain processing parameters corresponding to the noise reduction current according to the noise reduction current, and the processing parameters are used to determine current data corresponding to the current to be measured.

2. The circuit according to claim 1, characterized in that The first filtering module is specifically used to filter the magnetic induction noise based on the preset filtering parameters to obtain the noise current, and perform statistical processing on the induced current and the noise current to obtain the noise reduction current.

3. The circuit according to claim 1, characterized in that The measuring module comprises: an amplifier circuit, wherein an input end of the amplifier circuit is connected to an output end of the first filtering module, and the amplifier circuit is used to amplify the noise reduction current to obtain the noise reduction current after amplification; A shaping circuit, wherein the input end of the shaping circuit is connected to the output end of the amplifying circuit, and the shaping circuit is used to obtain the processing parameter according to the noise reduction current after the amplification processing.

4. The circuit according to claim 3, characterized in that The measurement module also includes: a second filtering circuit, wherein an input end of the second filtering circuit is connected to an output end of the amplifying circuit, an output end of the second filtering circuit is connected to an input end of the shaping circuit, and the second filtering circuit is used to filter the noise reduction current after the amplification process to obtain the noise reduction current after the filtering process; The shaping circuit is specifically used to obtain the processing parameter according to the noise reduction current after the filtering process.

5. The circuit according to claim 4, characterized in that The shaping circuit comprises: a bias circuit, wherein an input end of the bias circuit is connected to an output end of the second filter circuit, and the bias circuit is used to generate a threshold voltage; A comparison circuit, wherein an input end of the comparison circuit is connected to an output end of the bias circuit, and an input end of the comparison circuit is connected to an output end of the second filter circuit, and the comparison circuit is used to compare a voltage corresponding to the noise reduction current after filtering with the threshold voltage and output a level signal; A counting chip, wherein the input end of the counting chip is connected to the output end of the comparison circuit, and the counting chip is used to determine the duration of the level signal according to the level signal, and determine the processing parameter according to the duration.

6. The circuit according to claim 5, characterized in that The shaping circuit further comprises: A voltage conversion circuit, wherein the input end of the voltage conversion circuit is connected to the output end of the second filtering circuit, the output end of the voltage conversion circuit is connected to the input end of the comparison circuit and the input end of the bias circuit, and the voltage conversion circuit is used to perform voltage conversion on the noise reduction current after filtering to obtain a voltage corresponding to the noise reduction current after filtering.

7. The circuit according to claim 5, characterized in that The threshold voltage includes a first threshold voltage or a second threshold voltage, and the first threshold voltage is greater than the second threshold voltage; The comparison circuit is specifically configured to output a high level signal when the voltage corresponding to the noise reduction current after filtering is greater than the first threshold voltage; The comparison circuit is further specifically configured to output a low level signal when the voltage corresponding to the noise reduction current after filtering is less than the second threshold voltage.

8. The circuit according to claim 1, characterized in that The measuring module is further used to send the processing parameters to a host computer, so that the host computer determines the current data corresponding to the current to be measured according to the processing parameters.

9. A current measuring device, characterized in that: The device comprises a host computer and a current measuring circuit as claimed in any one of claims 1 to 8, wherein the host computer is connected to the current measuring circuit.

10. A current measurement method, characterized in that: For the host computer according to claim 9, the method comprises: Acquire a processing parameter sent by a current measurement circuit, wherein the processing parameter is obtained by filtering the magnetic induction noise included in the current to be measured by the current measurement circuit to obtain a noise reduction current, and is obtained based on the noise reduction current; Substituting the processing parameters into a preset current measurement equation group, current data corresponding to the current to be measured is obtained.

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