Inductive current measuring circuit capable of automatically switching measuring range and current measuring method

Abstract

The invention provides an inductive current measuring circuit capable of automatically switching measuring ranges and a current measuring method, and the circuit comprises a current sampling module which is used for sampling a current signal inputted by a secondary side of an inductive current sensor and converting the current signal into an AC sampling voltage signal; the voltage comparison and amplification module is used for comparing the alternating current sampling voltage signal with a set gear shifting reference voltage signal, outputting a level signal to a driving switch according to a comparison result, and outputting the alternating current sampling voltage signal; and the driving switch is used for switching on and off according to the level signal so as to switch gears. The device and the method do not need to be realized through programming of a single chip microcomputer, high and low gears are automatically adjusted by directly utilizing a current signal input by the secondary side of the sensor to realize automatic switching of the measuring range, and an alternating current sampling voltage signal is output while gear switching is carried out, so that subsequent processing and analysis of a processor are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of electrical signal measurement, and more specifically, to an inductive current measurement circuit and a current measurement method capable of automatically switching a measuring range. Background Art

[0002] Current measurement is a routine task in the power distribution operation and maintenance and power consumption inspection of the power system. Operation and maintenance personnel analyze the operation status of the power grid by testing the current size of the line and monitoring the changes.

[0003] However, in the current operation of the power grid, the level of the measured current is not fixed. For example, in the main power lines of the distribution network, due to load fluctuations, the load current ranges from a few amperes to several thousand amperes; while the short-circuit grounding current and lightning current are often tens of kiloamperes. At present, current measurement usually uses conventional multimeters, open-type current clamps and online metering devices, all of which require pre-defining the range of the measured current and selecting the appropriate range according to the current range. When the range of the measured current changes, it will cause measurement errors and damage to the equipment.

[0004] For example, when using a conventional multimeter for measurement, if the range is not selected properly, the multimeter may be damaged; when using a clamp ammeter, the range needs to be adjusted repeatedly, which reduces work efficiency; some online metering equipment or online detection equipment use multiple range sensors in parallel, and the control system uses the large and small range enumeration method to determine the appropriate range of sensors for measurement. The use of multiple sensors increases costs, and for fault currents, the measurement accuracy may be affected due to untimely response. Summary of the invention

[0005] In order to solve the technical problems in the prior art that the level of measured current is not fixed, the range of the current measuring device is relatively fixed, resulting in insufficient flexibility in current measurement, or the device that can measure multiple ranges is too expensive, and the measurement accuracy is low, the present invention provides an inductive current measurement circuit and a current measurement method with automatic range switching.

[0006] According to one aspect of the present invention, the present invention provides an inductive current measurement circuit with automatic range switching, the current measurement circuit comprising:

[0007] A current sampling module, used to sample the current signal input from the secondary side of the inductive current sensor and convert the current signal into an AC sampling voltage signal;

[0008] A voltage comparison and amplification module, used to compare the AC sampling voltage signal with a set shift reference voltage signal, output a level signal to the drive switch according to the comparison result, and output the AC sampling voltage signal, wherein the level signal includes a high level signal and a low level signal;

[0009] The driving switch is used to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the primary side current signal range of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and low range of the primary side current signal of the inductive current sensor.

[0010] According to another aspect of the present invention, the present invention provides a current measurement method using any one of the current measurement circuits described in the present invention, the method comprising:

[0011] Sampling the current signal input from the secondary side of the inductive current sensor, and converting the current signal into an AC sampling voltage signal;

[0012] Compare the AC sampling voltage signal with a set shift reference voltage signal, output a level signal to a drive switch according to the comparison result, and output the AC sampling voltage signal;

[0013] The switch is driven to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the primary side current signal range of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and the low range of the primary side current signal of the inductive current sensor.

[0014] According to another aspect of the present invention, the present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program is used to execute the method described in any one of the above aspects of the present invention.

[0015] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of the above aspects of the present invention.

[0016] The inductive current measurement circuit and current measurement method with automatic range switching described in the present invention, wherein the current measurement circuit includes a current sampling module, which is used to sample the current signal input from the secondary side of the inductive current sensor and convert the current signal into an AC sampling voltage signal; a voltage comparison and amplification module, which is used to compare the AC sampling voltage signal with the set shift reference voltage signal, output a level signal to the drive switch according to the comparison result, and output the AC sampling voltage signal; the drive switch is used to open and close according to the level signal to switch the gear position, so as to realize the automatic switching of the current signal range on the primary side of the inductive current sensor. The beneficial effects of the device and method include:

[0017] 1. It has strong versatility and does not require single-chip computer programming. It can directly use the current signal input from the secondary side of the sensor to automatically adjust the high and low gears to achieve automatic switching of the range. It also outputs AC sampling voltage signals while switching gears, which is convenient for subsequent processor processing and analysis.

[0018] 2. Automatic shifting can be achieved by controlling the input and output of the current sampling module by driving the switch without increasing the number of sensors;

[0019] 3. The switching range is wide, which can be applied to the automatic shifting from ampere level to kiloampere level required for current measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0021] Figure 1 A functional structure diagram of an inductive current measurement circuit for automatically switching ranges according to a preferred embodiment of the present invention;

[0022] Figure 2 A circuit diagram of an inductive current measurement circuit with automatic range switching according to a preferred embodiment of the present invention;

[0023] Figure 3 is a flow chart of a current measuring method according to a preferred embodiment of the present invention;

[0024] Figure 4 Schematic diagram of the structure of an electronic device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0025] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0026] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0027] Exemplary Devices

[0028] Figure 1FIG. 1 is a functional structure diagram of an inductive current measurement circuit for automatically switching the measuring range according to a preferred embodiment of the present invention. Figure 1 As shown, the current measurement circuit described in this preferred embodiment includes:

[0029] The current sampling module 101 is used to sample the current signal input from the secondary side of the inductive current sensor and convert the current signal into an AC sampling voltage signal;

[0030] The voltage comparison and amplification module 102 is used to compare the AC sampling voltage signal with the set shift reference voltage signal, output a level signal to the drive switch according to the comparison result, and output the AC sampling voltage signal, wherein the level signal includes a high level signal and a low level signal;

[0031] The driving switch 103 is used to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the primary side current signal range of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and low range of the primary side current signal of the inductive current sensor.

[0032] Preferably, the current measurement circuit also includes a protection module, one end of which is connected to the secondary side of the inductive current sensor, and the other end is connected to the current sampling module. The protection module includes a diode for protecting the current sampling module, and a filter capacitor for filtering high-frequency interference signals in the current signal output by the secondary side of the inductive current sensor.

[0033] Preferably, the current sampling module includes a small current sampling submodule, a large current sampling submodule and a reference voltage circuit, wherein:

[0034] The small current sampling submodule and the large current sampling submodule are used to convert the current signal input from the secondary side of the inductive current sensor into an AC sampling voltage signal, wherein the small current sampling submodule includes a first sampling resistor, and the large current sampling submodule includes a second sampling resistor, and the resistance value of the first sampling resistor is greater than the resistance value of the second sampling resistor;

[0035] The reference voltage circuit is used to provide a direct reference voltage for the small current sampling submodule and the large current sampling submodule.

[0036] Preferably, the voltage comparison and amplification module includes:

[0037] A signal amplification submodule, comprising a voltage follower composed of an operational amplifier and a third resistor, for outputting the AC sampling voltage signal to a processor to calculate a current signal outputted by the primary side of the inductive current sensor;

[0038] A peak-to-peak value detection submodule, comprising a diode and a capacitor connected in series, for detecting a peak value of the AC sampling voltage signal, wherein the peak value is not greater than a DC reference voltage;

[0039] The voltage comparison submodule includes a voltage comparator composed of an operational amplifier, a first comparison resistor and a second comparison resistor, and is used to compare the peak value with a first shift reference signal when the current measurement circuit is operating in a low gear, and when the peak value is greater than the first shift reference signal, output a high level signal to the drive switch; and when the current measurement circuit is operating in a high gear, compare the peak value with a second shift reference signal, and when the peak value is less than the shift reference signal, output a low level signal to the drive switch.

[0040] Preferably, the driving switch is opened and closed according to the level signal to switch the gear position, so as to realize automatic switching of the primary side current signal range of the inductive current sensor, including:

[0041] When the voltage comparison and amplification module outputs a high-level signal, the drive switch is closed, the first sampling resistor and the second sampling resistor are connected in parallel, the first comparison resistor and the second comparison resistor are connected in parallel, the current signal flows through the first sampling resistor and the second sampling resistor, and the first comparison resistor and the second comparison resistor at the same time, and the current measurement circuit is switched from a low gear to a high gear to measure a high-range current signal on the primary side of the inductive current sensor;

[0042] When the voltage comparison and amplification module outputs a low-level signal, the driving switch is turned on, the current signal only flows through the first sampling resistor and the first comparison resistor, and the current measurement circuit switches from a high gear to a low gear to measure the low-range current signal on the primary side of the inductive current sensor.

[0043] Figure 2 FIG. 1 is a circuit diagram of an inductive current measurement circuit for automatically switching a measuring range according to a preferred embodiment of the present invention. Figure 2As shown, the secondary side output of the inductive current sensor is connected to the protection module, and the protection module includes a TVS diode D1 and a filter capacitor C1. The small current sampling submodule in the current sampling module is the first sampling resistor R4, the large current sampling submodule is the second sampling resistor R5, and the reference voltage circuit includes an operational amplifier U1B, resistors R8, R9 and R10. In this preferred embodiment, the DC reference voltage is half of the microcontroller operating voltage of 3.3V, that is, 1.65V. The signal amplification submodule in the voltage comparison and amplification module includes an operational amplifier U1A and a third resistor R1, and the output signal is I_CNV; the peak-to-peak detection submodule includes a diode VD1 and a capacitor C2. Taking the maximum current of primary side current I1 as 800A (AC) and high range coil ratio of 1:4000 as an example, the secondary side current I2 = I1 / 4000, the AC sampling voltage Vs = I2*Rs after passing through the sampling resistor Rs (resistor R4, or resistors R4 and R5 in parallel), and the AC sampling voltage Vs superimposed on the DC reference voltage to enter the sampling calculation, it can be seen that the peak value of Vs is Vs*1.414 = Vsp∈[0,1.65V). In practical applications, when the effective value of the AC sampling voltage is less than 0.01V, the sampling value error is large. Therefore, when considering the grading, it should be ensured that at the low gear, the minimum primary side current is as small as possible while ensuring that the effective value of the sampling voltage Vs is greater than 0.01V; when switching to the high gear, the minimum sampling voltage is greater than 0.01V. At the same time, regardless of the high or low gear, the peak value of the highest sampling voltage is less than 1.65V. When the primary current is 0-8A, Vs>0.01V and Vsp<1.65V are required, and Rs≤583.45Ω is obtained. The common resistance value is 510Ω, and the primary current is 0.078A when Vs=0.01V. Similarly, when the primary current I1 ranges from 8-800A at high gear, Rs<5.83Ω is obtained. Rs=5Ω is taken. When the primary current is 8A, Vs=0.01414, which meets the measurement requirements. Therefore, the primary range of the device is 0.01A-800A(AC), the low range is 0.01A-8A(AC), and the high range is 8A-800A(AC). Further, from Figure 2It can be seen that the voltage comparator sub-module includes an operational amplifier U2, a first comparison resistor R3, a second comparison resistor R7, and resistors R2 and R6. The drive switch includes Q2 and Q3 connected to the current sampling module, and Q1 connected to the voltage comparator sub-module. The peak value of the AC sampling voltage Vs is taken by the peak-to-peak detection sub-module. When the primary side current is 8A, the peak value of the AC sampling voltage Vsp = 1.44V. Therefore, by setting the resistors R7 and R2, the first shift reference signal Vc1 = 3.3V * R2 / (R7 + R2) = 1.44V can be calculated and determined. When the current measurement circuit operates in the low gear and the primary side current is greater than 8A such that Vsp > Vc1, U2 outputs a high level as the shift signal. This shift signal is given to the drive switch Q1 and at the same time controls the analog switch. When this analog switch is closed, the first comparison resistor R3, which is in parallel with the second comparison resistor R7 at the inverting input terminal of U2, is used to reduce the output voltage value of U2 to the second shift reference signal Vc2. U2 continuously outputs a high level, so that the current measurement circuit automatically switches from the low gear to the high gear and remains there. When the current measurement circuit operates in the high gear and the primary side current decreases such that Vsp < Vc2, U2 outputs a low level as the shift signal, and at the same time the parallel resistor R3 is removed, increasing the voltage at the inverting terminal of U2. U2 continuously outputs a low level, so that the current measurement circuit automatically switches back from the high gear to the low gear and remains there.

[0044] From the implementation manner of the exemplary device, it can be known that the current measurement circuit can determine the first gear reference signal and the second gear reference signal by setting reasonable values of R2, R3, and R7. Then, by comparing the peak value of the AC sampling voltage signal with the first gear reference signal, the switch from the low gear to the high gear can be achieved, and by comparing the peak value of the AC sampling voltage signal with the second gear reference signal, the switch from the high gear to the low gear can be achieved. Thus, the automatic switching of the current signal range of the inductive sensor is finally realized. At the same time, the signal "I_SIG" is input to the single-chip microcomputer, which can be used as the basis for the single-chip microcomputer to judge the current circuit gear. The current measurement circuit collected in this preferred implementation manner has strong versatility, does not require an increase in the number of sensors, and has a wide applicable current range, greatly reducing the product cost and improving the measurement accuracy.

[0045] Exemplary Methods

[0046] Figure 3 is a flowchart of the current measurement method according to the preferred implementation manner of the present invention. As Figure 3 shown, the current measurement method described in this preferred implementation manner starts from step 301.

[0047] In step 301, the current signal input to the secondary side of the inductive current sensor is sampled, and the current signal is converted into an AC sampling voltage signal;

[0048] In step 302, the AC sampling voltage signal is compared with a set shift reference voltage signal, and a level signal is output to a drive switch according to the comparison result, and the AC sampling voltage signal is output;

[0049] In step 303, the switch is driven to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the range of the primary side current signal of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and the low range of the primary side current signal of the inductive current sensor.

[0050] Preferably, comparing the AC sampling voltage signal with a set shift reference voltage signal and outputting a level signal to the drive switch according to the comparison result comprises:

[0051] Preferably, a peak value of the AC sampling voltage signal is detected, wherein the peak value is not greater than a DC reference voltage;

[0052] When the current measurement circuit operates in a low gear, the peak value is compared with a first gear shift reference signal, and when the peak value is greater than the first gear shift reference signal, a high level signal is output to the drive switch; and when the current measurement circuit operates in a high gear, the peak value is compared with a second gear shift reference signal, and when the peak value is less than the gear shift reference signal, a low level signal is output to the drive switch.

[0053] Preferably, the step of driving the switch to open and close to switch the gear according to the level signal to realize automatic switching of the primary side current signal range of the inductive current sensor includes:

[0054] When the level signal is a high level signal, the drive switch is closed, and the current measurement circuit is switched from a low gear to a high gear to measure a high-range current signal on the primary side of the inductive current sensor;

[0055] When the level signal is a low level signal, the drive switch is turned on, and the current measurement circuit is switched from a high gear to a low gear to measure a low range current signal on the primary side of the inductive current sensor.

[0056] The working process of the method described in this preferred embodiment is as follows:

[0057] The secondary current of the coil enters the sampling resistor R4 through the protection module, and is converted into an AC sampling voltage, which is then passed through the voltage follower formed by the operational amplifier U1A. At the same time, the AC sampling voltage signal is detected by the peak-to-peak detection submodule composed of VD1 and C2 to detect the peak value of the AC sampling voltage signal, and is compared with the voltage at the inverting terminal of U2. When the peak value of the AC sampling voltage signal is greater than the voltage at the inverting input terminal of U2, the comparator U3 outputs a high level. On the contrary, if the peak value of the AC sampling voltage signal is less than the voltage at the inverting input terminal of U2, the comparator U3 outputs a low level.

[0058] The signal "I_SIG" at the output end of U2 controls the on and off of Q1, Q2, and Q3. If Q1 is on, the small resistor R3 is connected in parallel with R7, so that the voltage at the inverting end of U2 is reduced. On the contrary, if Q1 is cut off, the small resistor R3 is not connected in parallel with R7, and the voltage at the inverting end of U2 is larger. When the gate signals of Q2 and Q3 are low, Q2 and Q3 are cut off, and the secondary current flows through the sampling resistor R4. Due to the large resistance of R4, the AC sampling voltage signal is amplified, which is used to measure the small current on the primary side, which is the "low gear" of current measurement. When the gate signals of Q2 and Q3 are high, Q2 and Q3 are turned on, and the sampling resistor R5 is connected in parallel with the sampling resistor R4. Since R4 is greater than R5, the amplification factor is reduced, which is used to measure the large current on the primary side, which is the "high gear" of current measurement.

[0059] When the primary current is at a low gear, the converted AC sampling voltage signal is small, the peak value is less than the voltage at the inverting input terminal of U2, and the signal "I_SIG" is at a low level. Once the primary current exceeds the low gear range, the peak value of the AC sampling voltage signal is greater than the voltage at the inverting input terminal of U2, and the signal "I_SIG" is at a high level. From the above analysis, it can be seen that if the signal "I_SIG" is at a high level, Q1 is turned on, so that the voltage at the inverting terminal of U2 decreases, and at the same time Q2 and Q3 are turned on, reducing the amplification factor, so that the AC sampling voltage signal does not exceed the range, that is, automatically switching from a low gear to a high gear. When in a high gear, the peak value of the AC sampling voltage signal must be less than the reduced voltage at the inverting terminal of U2 after Q1 is turned on, and U2 will output a low level, that is, automatically switching from a high gear to a low gear.

[0060] The current measurement method described in this preferred embodiment uses the current measurement circuit described in the present invention to perform current measurement, and the technical effects achieved are the same, which will not be described in detail here.

[0061] Exemplary Electronic Devices

[0062] Figure 4The electronic device according to the preferred embodiment of the present invention is a schematic diagram of the structure of the electronic device. The electronic device can be any one or both of the first device and the second device, or a stand-alone device independent of them, and the stand-alone device can communicate with the first device and the second device to receive the collected input signal from them. Figure 4 FIG. 1 is a block diagram of an electronic device according to an embodiment of the present disclosure. Figure 4 As shown, the electronic device includes one or more processors 401 and a memory 402 .

[0063] The processor 401 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0064] The memory 402 may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 401 may run the program instructions to implement the energy consumption anomaly diagnosis method based on the enterprise energy consumption space of each disclosed embodiment described above and / or other desired functions. In one example, the electronic device may also include: an input device 403 and an output device 404, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0065] In addition, the input device 403 may also include, for example, a keyboard, a mouse, and the like.

[0066] The output device 404 can output various information to the outside, and can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0067] Of course, to simplify, Figure 4 Only some of the components related to the present disclosure in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application situations, the electronic device may further include any other appropriate components.

[0068] Exemplary computer program products and computer-readable storage media

[0069] In addition to the above-mentioned methods and devices, an embodiment of the present disclosure may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the current measurement method according to various embodiments of the present disclosure described in the above-mentioned "Exemplary Method" section of this specification.

[0070] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the disclosed embodiments, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0071] In addition, an embodiment of the present disclosure may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enables the processor to execute the steps of the current measurement method according to various embodiments of the present disclosure described in the above “Exemplary Method” section of this specification.

[0072] The computer readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0073] The basic principles of the present disclosure are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present disclosure. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, and are not limiting. The above details do not limit the present disclosure to the necessity of adopting the above specific details to be implemented.

[0074] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0075] The block diagrams of the devices, apparatuses, equipment, and systems involved in this disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including," "comprising," "having," and the like are open words, referring to "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or," and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0076] The method and apparatus of the present disclosure may be implemented in many ways. For example, the method and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above order of steps for the method is for illustration only, and the steps of the method of the present disclosure are not limited to the order specifically described above, unless otherwise specifically stated. In addition, in some embodiments, the present disclosure may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present disclosure. Therefore, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

[0077] It should also be noted that in the apparatus, equipment and method of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present disclosure. The above description of the disclosed aspects is provided to enable any technician in the field to make or use the present disclosure. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown here, but to the widest scope consistent with the principles and novel features disclosed herein.

[0078] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An inductive current measurement circuit with automatic range switching, characterized in that: The current measurement circuit comprises: A current sampling module, used to sample the current signal input from the secondary side of the inductive current sensor and convert the current signal into an AC sampling voltage signal; A voltage comparison and amplification module, used to compare the AC sampling voltage signal with a set shift reference voltage signal, output a level signal to the drive switch according to the comparison result, and output the AC sampling voltage signal, wherein the level signal includes a high level signal and a low level signal; The driving switch is used to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the primary side current signal range of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and low range of the primary side current signal of the inductive current sensor.

2. The current measurement circuit according to claim 1, characterized in that: The current measurement circuit also includes a protection module, one end of which is connected to the secondary side of the inductive current sensor and the other end is connected to the current sampling module. The protection module is used to protect the current sampling module and a filter capacitor for filtering high-frequency interference signals in the current signal output by the secondary side of the inductive current sensor.

3. The current measurement circuit according to claim 1, characterized in that: The current sampling module includes a small current sampling submodule, a large current sampling submodule and a reference voltage circuit, wherein: The small current sampling submodule and the large current sampling submodule are used to convert the current signal input from the secondary side of the inductive current sensor into an AC sampling voltage signal, wherein the small current sampling submodule includes a first sampling resistor, and the large current sampling submodule includes a second sampling resistor, and the resistance value of the first sampling resistor is greater than the resistance value of the second sampling resistor; The reference voltage circuit is used to provide a direct reference voltage for the small current sampling submodule and the large current sampling submodule.

4. The current measurement circuit according to claim 3, characterized in that: The voltage comparison and amplification module includes: A signal amplification submodule, comprising a voltage follower composed of an operational amplifier and a third resistor, for outputting the AC sampling voltage signal to a processor to calculate a current signal outputted by the primary side of the inductive current sensor; A peak-to-peak value detection submodule, comprising a diode and a capacitor connected in series, for detecting a peak value of the AC sampling voltage signal, wherein the peak value is not greater than a DC reference voltage; The voltage comparison submodule includes a voltage comparator composed of an operational amplifier, a first comparison resistor and a second comparison resistor, and is used to compare the peak value with a first shift reference signal when the current measurement circuit is operating in a low gear, and when the peak value is greater than the first shift reference signal, output a high level signal to the drive switch; and when the current measurement circuit is operating in a high gear, compare the peak value with a second shift reference signal, and when the peak value is less than the shift reference signal, output a low level signal to the drive switch.

5. The current measurement circuit according to claim 4, characterized in that: The driving switch is opened and closed according to the level signal to switch the gear position, so as to realize the automatic switching of the primary side current signal range of the inductive current sensor, including: When the voltage comparison and amplification module outputs a high-level signal, the drive switch is closed, the first sampling resistor and the second sampling resistor are connected in parallel, the first comparison resistor and the second comparison resistor are connected in parallel, the current signal flows through the first sampling resistor and the second sampling resistor, and the first comparison resistor and the second comparison resistor at the same time, and the current measurement circuit is switched from a low gear to a high gear to measure a high-range current signal on the primary side of the inductive current sensor; When the voltage comparison and amplification module outputs a low-level signal, the driving switch is turned on, the current signal only flows through the first sampling resistor and the first comparison resistor, and the current measurement circuit switches from a high gear to a low gear to measure the low-range current signal on the primary side of the inductive current sensor.

6. A current measurement method using any one of the current measurement circuits of claims 1 to 5, characterized in that: The method comprises: Sampling the current signal input from the secondary side of the inductive current sensor, and converting the current signal into an AC sampling voltage signal; Compare the AC sampling voltage signal with a set shift reference voltage signal, output a level signal to a drive switch according to the comparison result, and output the AC sampling voltage signal; The switch is driven to open and close according to the level signal to switch the gear position, thereby realizing automatic switching of the primary side current signal range of the inductive current sensor, wherein the gear position includes a high gear position and a low gear position, which respectively correspond to the high range and the low range of the primary side current signal of the inductive current sensor.

7. The method according to claim 6, characterized in that The step of comparing the AC sampling voltage signal with a set shift reference voltage signal and outputting a level signal to a drive switch according to the comparison result comprises: Detecting a peak value of the AC sampling voltage signal, wherein the peak value is not greater than a DC reference voltage; When the current measurement circuit operates in a low gear, the peak value is compared with a first gear shift reference signal, and when the peak value is greater than the first gear shift reference signal, a high level signal is output to the drive switch; and when the current measurement circuit operates in a high gear, the peak value is compared with a second gear shift reference signal, and when the peak value is less than the gear shift reference signal, a low level signal is output to the drive switch.

8. The method according to claim 6, characterized in that The method of driving the switch to open and close according to the level signal to switch the gear position to realize the automatic switching of the primary side current signal range of the inductive current sensor includes: When the level signal is a high level signal, the drive switch is closed, and the current measurement circuit is switched from a low gear to a high gear to measure a high-range current signal on the primary side of the inductive current sensor; When the level signal is a low level signal, the drive switch is turned on, and the current measurement circuit is switched from a high gear to a low gear to measure a low range current signal on the primary side of the inductive current sensor.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 6 to 8.

10. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is used to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 6 to 8.

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