Current sampling detection circuit and method and electric energy meter automation system

Abstract

The invention relates to the technical field of equipment testing, and particularly discloses a current sampling detection circuit and method and an electric energy meter automation system. The circuit comprises a switch control module, an operational amplification module and an MCU controller. The input end of the switch control module is connected with the access end of the to-be-tested electric energy meter, the output end of the switch control module is connected with the first input end of the MCU controller, the input end of the operational amplification module is connected with the discharge end of the to-be-tested electric energy meter, and the output end of the operational amplification module is connected with the second input end of the MCU controller. When the switch control module detects that the to-be-detected electric energy meter is connected, a sampling driving signal is generated and transmitted to the MCU controller; the operational amplification module collects working parameters of the to-be-tested electric energy meter and transmits the working parameters to the MCU controller; and the MCU controller judges whether the current value in the working parameters is within the preset current range or not under the condition of receiving the sampling starting signal, so that the automatic detection of the discharge current after the power failure of the electric energy meter is realized.

Description

Technical Field

[0001] This invention relates to the field of equipment testing technology, and in particular to a current sampling and detection circuit, method, and automated system for electricity meters. Background Technology

[0002] With the continuous advancement of smart grid construction, the demand for smart meters is showing a steady growth trend. The requirements for automation levels, testing efficiency, and product quality control in the meter manufacturing process are also gradually increasing. In the performance testing of smart meters, the discharge current of the battery or supercapacitor after power failure ensures the low-power stability of the meter in standby mode, which is a key indicator.

[0003] Currently, current detection in the event of a power outage relies on manual operation using a handheld multimeter to measure the voltage across the resistor at two pre-installed test points on the meter. This requires manual operation on a per-meter basis, resulting in lengthy testing times and extremely low efficiency, making it unsuitable for large-scale production. Furthermore, manual calculation and data entry are prone to errors, directly impacting the accuracy of the test data and potentially leading to substandard products entering the market or qualified products being misjudged.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a current sampling and detection circuit, method, and automated system for electricity meters, aiming to solve the technical problem of low current detection efficiency in existing electricity meters.

[0006] To achieve the above objectives, the present invention provides a current sampling and detection circuit, which is applied to an energy meter. The current sampling and detection circuit includes: a switch control module, an operational amplifier module, and an MCU controller. The input terminal of the switch control module is connected to the access terminal of the energy meter under test, the output terminal of the switch control module is connected to the first input terminal of the MCU controller, the input terminal of the operational amplifier module is connected to the discharge terminal of the energy meter under test, and the output terminal of the operational amplifier module is connected to the second input terminal of the MCU controller. The switch control module is used to generate a sampling drive signal when the power meter under test is detected to be connected, and transmit the sampling start signal to the MCU controller. The operational amplifier module is used to collect the operating parameters of the energy meter under test and transmit the operating parameters to the MCU controller; The MCU controller is used to determine whether the current value in the operating parameters is within a preset current range when the sampling start signal is received.

[0007] In one embodiment, the operational amplifier module includes: a differential amplifier unit and a single-ended amplifier unit; The first input terminal of the differential amplifier unit is connected to the positive discharge terminal of the energy meter under test, the second input terminal of the differential amplifier unit is connected to the negative discharge terminal of the energy meter under test, the output terminal of the differential amplifier unit is connected to the input terminal of the single-ended amplifier unit, and the output terminal of the single-ended discharge unit is connected to the second input terminal of the MCU controller. The differential amplifier unit is used to receive the differential voltage signal from the energy meter under test, perform a first-stage amplification process on the differential voltage signal to generate a primary amplified signal, and transmit the primary amplified signal to the single-ended amplifier unit. The single-ended amplification unit is used to perform a second-stage amplification process on the primary amplified signal to generate the operating parameters, and then transmit the operating parameters to the MCU controller.

[0008] In one embodiment, the differential amplifier unit includes: first to fifth resistors and a first operational amplifier; The first end of the first resistor is connected to the negative discharge terminal of the energy meter under test. The second end of the first resistor is connected to the first end of the second resistor and the inverting input terminal of the first operational amplifier. The second end of the second resistor is connected to the output terminal of the first operational amplifier. The first end of the third resistor is connected to the positive discharge terminal of the energy meter under test. The second end of the third resistor is connected to the first end of the fourth resistor and the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is also connected to the first end of the fifth resistor. The second end of the fourth resistor is connected to the second end of the fifth resistor and grounded.

[0009] The single-ended amplifier unit includes: a sixth to a ninth resistor and a second operational amplifier; The first end of the sixth resistor is connected to the output of the differential amplifier unit, the second end of the sixth resistor is connected to the non-inverting input of the second operational amplifier, the first end of the seventh resistor is grounded, the second end of the seventh resistor is connected to the inverting input of the second operational amplifier and the first end of the eighth resistor, the output of the second operational amplifier is connected to the second end of the eighth resistor and the first end of the ninth resistor, and the second end of the ninth resistor is connected to the second input of the MCU controller.

[0010] In one embodiment, the switch control module includes: a micro switch, a tenth resistor, an eleventh resistor, and a first capacitor; The first end of the micro switch is connected to the pull-up power input terminal, the second end of the micro switch is connected to the first end of the tenth resistor and the first end of the eleventh resistor, the second end of the tenth resistor is grounded, the second end of the eleventh resistor is connected to the first end of the first capacitor and the first input terminal of the MCU controller, and the second end of the first capacitor is grounded.

[0011] In one embodiment, the current sampling and detection circuit further includes: an analog-to-digital conversion unit; The input terminal of the analog-to-digital converter is connected to the output terminal of the operational amplifier module, and the output terminal of the analog-to-digital converter is connected to the second input terminal of the MCU controller. The operational amplifier module is also used to transmit the operating parameters to the analog-to-digital conversion unit; The analog-to-digital conversion unit is used to convert the operating parameters into digital signals, generate digital sampling signals, and transmit the digital sampling signals to the MCU controller. The MCU controller is also used to determine whether the current value of the digital sampling signal is within a preset current range.

[0012] In one embodiment, the analog-to-digital conversion unit includes: an AD sampling chip and a reference power supply chip; The input terminal of the AD sampling chip is connected to the output terminal of the operational amplifier module, the output terminal of the AD sampling chip is connected to the second input terminal of the MCU controller, the input terminal of the reference power supply chip is connected to the pull-up power supply input terminal, and the output terminal of the reference power supply chip is connected to the power supply terminal of the AD sampling chip.

[0013] In one embodiment, the current sampling and detection circuit further includes: a first indicator module and a second indicator module; The input terminals of both the first indicator module and the second indicator module are connected to the control terminal of the MCU controller. The MCU controller is used to generate a qualified control signal when the current value of the operating parameter is within the preset current range, and transmit the qualified control signal to the first indication module. The MCU controller is also configured to generate a fault control signal when the current value of the operating parameter exceeds the preset current range, and transmit the fault control signal to the first indication module. The first indicating module is used to indicate the working status of the energy meter under test based on the qualified control signal and the fault control signal; The MCU controller is further configured to generate a status control signal upon receiving the sampling start signal, and transmit the status control signal to the second indication module; The second indicating module is used to indicate the operating state of the current sampling and detection circuit based on the state control signal.

[0014] In one embodiment, the first indicating module includes: at least one first display unit, the first display unit including: a first LED, a first switching transistor, and twelfth to fourteenth resistors; The first end of the twelfth resistor is connected to the pull-up power input terminal, the output terminal of the twelfth resistor is connected to the anode of the first LED, the cathode of the first LED is connected to the input terminal of the first switching transistor, the control terminal of the first switching transistor is connected to the first end of the thirteenth resistor and the first end of the fourteenth resistor, the second end of the thirteenth resistor is connected to the control terminal of the MCU controller, and the second end of the fourteenth resistor and the output terminal of the first switching transistor are grounded. And / or, the first indicator module includes: a buzzer, fifteenth to seventeenth resistors, and a second switching transistor; The first end of the fifteenth resistor is connected to the pull-up power input terminal, the second end of the fifteenth resistor is connected to the input terminal of the buzzer, the output terminal of the buzzer is connected to the input terminal of the second switch, the control terminal of the second switch is connected to the first end of the sixteenth resistor and the first end of the seventeenth resistor, the second end of the sixteenth resistor is connected to the control terminal of the MCU controller, and the second end of the seventeenth resistor and the output terminal of the second switch are grounded. The second indicator module includes: a second display unit, wherein the second display unit includes: a second LED, a third switching transistor, and eighteenth to twentieth resistors; The first end of the eighteenth resistor is connected to the pull-up power input terminal. The output terminal of the eighteenth resistor is connected to the anode of the second LED. The cathode of the second LED is connected to the input terminal of the third switch. The control terminal of the third switch is connected to the first end of the eighteenth resistor and the first end of the twentieth resistor. The second end of the eighteenth resistor is connected to the control terminal of the MCU controller. The second end of the twentieth resistor and the output terminal of the third switch are grounded.

[0015] Furthermore, to achieve the above objectives, the present invention also proposes a current sampling and detection method, which is applied to the current sampling and detection circuit described above. The steps of the current sampling and detection method include: When the power meter under test is detected to be connected, a sampling drive signal is generated; The operating parameters of the energy meter under test are collected and connected. Upon receiving the sampling start signal, determine whether the current value within the operating parameters is within the preset current range.

[0016] In addition, to achieve the above objectives, the present invention also proposes an automated electricity meter system, which includes an electricity meter, a MES system, and a current sampling and detection circuit as described above.

[0017] This invention provides a current sampling and detection circuit, method, and automated system for electricity meters. The current sampling and detection circuit includes a switch control module, an operational amplifier module, and an MCU controller. The input terminal of the switch control module is connected to the access terminal of the electricity meter under test, the output terminal of the switch control module is connected to the first input terminal of the MCU controller, the input terminal of the operational amplifier module is connected to the discharge terminal of the electricity meter under test, and the output terminal of the operational amplifier module is connected to the second input terminal of the MCU controller. The switch control module generates a sampling drive signal and transmits the sampling start signal to the MCU controller when the electricity meter under test is detected to be connected. The operational amplifier module collects the operating parameters of the electricity meter under test and transmits the operating parameters to the MCU controller. The MCU controller determines whether the current value within the operating parameters is within a preset current range upon receiving the sampling start signal. By automatically starting the switch control module, automatically collecting data from the operational amplifier module, and automatically judging the data using the MCU, the automation level of the detection is improved, the detection time for a single electricity meter is significantly shortened, and the detection accuracy is ensured. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the first embodiment of the current sampling and detection circuit proposed in this invention; Figure 2 This is a circuit connection diagram of the second embodiment of the current sampling and detection circuit of this application; Figure 3 This is a circuit connection diagram of the third embodiment of the current sampling and detection circuit of this application; Figure 4 This is a circuit connection diagram of the filtering and shielding in the third embodiment of the current sampling and detection circuit of this application; Figure 5 This is a schematic diagram of the module of the fourth embodiment of the current sampling and detection circuit of this application; Figure 6 This is a circuit connection diagram of the fourth embodiment of the current sampling and detection circuit of this application; Figure 7 This is a schematic diagram of the module of the fifth embodiment of the current sampling and detection circuit of this application; Figure 8 This is a first circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application; Figure 9 This is a second circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application; Figure 10 This is a third circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application; Figure 11 This is a schematic flowchart of an embodiment of the current sampling and detection method of this application; Figure 12 This is a schematic diagram of a module of an embodiment of the electricity meter automation system of this application.

[0019] Explanation of reference numerals in the attached figures: 10. Switch control module; 20. Operational amplifier module; 30. MCU controller; 40. Analog-to-digital converter unit; 50. First indicator module; 60. Second indicator module; 201. Differential amplifier unit; 202. Single-ended amplifier unit; R1~R20, first to twentieth resistors; U1, first operational amplifier; U2, second operational amplifier; U3, power management chip; U4, AD sampling chip; U5, reference power chip; S1, micro switch; C1~C5, first to fifth capacitors; L1, first inductor; L2, common-mode inductor; D1, first LED; D2, second LED; S2, buzzer; Q1~Q3, first to third switching transistors.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0025] Reference Figure 1 , Figure 1 This is a schematic diagram of the first embodiment of the current sampling and detection circuit proposed in this invention. Based on Figure 1 The first embodiment of the current sampling and detection circuit of the present invention is presented.

[0026] In this embodiment, the current sampling and detection circuit includes: a switch control module 10, an operational amplifier module 20, and an MCU controller 30; the input terminal of the switch control module 10 is connected to the access terminal of the energy meter under test, the output terminal of the switch control module 10 is connected to the first input terminal of the MCU controller 30, the input terminal of the operational amplifier module 20 is connected to the discharge terminal of the energy meter under test, and the output terminal of the operational amplifier module 20 is connected to the second input terminal of the MCU controller 30.

[0027] It should be noted that the switch control module 10 can be used to generate a sampling drive signal when the energy meter under test is detected to be connected, and transmit the sampling start signal to the MCU controller 30; the operational amplifier module 20 can be used to collect the operating parameters of the energy meter under test and transmit the operating parameters to the MCU controller 30; the MCU controller 30 can be used to determine whether the current value in the operating parameters is within a preset current range when the sampling start signal is received.

[0028] Understandably, the current sampling and detection circuit can be a detection circuit designed for the discharge current of the battery or supercapacitor after the electricity meter loses power, realizing the automated acquisition and judgment of the discharge current, replacing the traditional manual multimeter detection method. The electricity meter can be an electronic device used for power data acquisition, metering and transmission in the smart grid. After power loss, it needs to rely on the battery or supercapacitor to maintain a standby state. The industry requires that the discharge current in this standby state be controlled within 10uA (corresponding to the preset current range).

[0029] It should be understood that the switch control module 10 can be a functional module for detecting whether the energy meter under test is connected to the testing fixture. After the energy meter is correctly connected to the testing circuit, it automatically generates a sampling start signal and notifies the MCU controller 30 to start the test. The sampling start signal can be a trigger signal generated by the switch control module 10 after detecting that the energy meter is connected. The operational amplifier module 20 can be a functional module for acquiring and amplifying the weak electrical signal at the discharge terminal of the energy meter. Since the voltage across the sampling resistor (10Ω) corresponding to the discharge current of the energy meter is only within 100uV, this module needs to amplify the signal to a stable and identifiable range (such as 0.1V, i.e., 1000 times) to provide an accurate raw signal for subsequent current calculation. The MCU controller 30 can be an electronic device with data acquisition, processing, and transmission control functions. It can receive the sampling start signal from the switch control module 10 and, based on the operating parameters transmitted by the operational amplifier module 20, convert the operating parameters into the discharge current value of the energy meter through calculation, and then determine whether the current value is within the preset current range to determine whether the energy meter under test is qualified.

[0030] In this embodiment, the current sampling and detection circuit includes a switch control module, an operational amplifier module, and an MCU controller. The input terminal of the switch control module is connected to the access terminal of the energy meter under test, the output terminal of the switch control module is connected to the first input terminal of the MCU controller, the input terminal of the operational amplifier module is connected to the discharge terminal of the energy meter under test, and the output terminal of the operational amplifier module is connected to the second input terminal of the MCU controller. The switch control module generates a sampling drive signal and transmits the sampling start signal to the MCU controller when the energy meter under test is detected to be connected. The operational amplifier module collects the operating parameters of the energy meter under test and transmits the operating parameters to the MCU controller. The MCU controller determines whether the current value within the operating parameters is within a preset current range upon receiving the sampling start signal. By automatically starting the switch control module, automatically collecting data from the operational amplifier module, and automatically judging the data using the MCU, the automation level of the detection is improved, the detection time for a single energy meter is significantly shortened, and the detection accuracy is ensured.

[0031] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 , Figure 2 This is a circuit connection diagram of the second embodiment of the current sampling and detection circuit of this application.

[0032] In this embodiment, the operational amplifier module 20 includes a differential amplifier unit 201 and a single-ended amplifier unit 202; the first input terminal of the differential amplifier unit 201 is connected to the positive discharge terminal of the energy meter under test, the second input terminal of the differential amplifier unit 201 is connected to the negative discharge terminal of the energy meter under test, the output terminal of the differential amplifier unit 201 is connected to the input terminal of the single-ended amplifier unit 202, and the output terminal of the single-ended amplifier unit is connected to the second input terminal of the MCU controller 30.

[0033] It should be noted that the differential amplifier unit 201 can be used to receive the differential voltage signal from the energy meter under test, perform a first-stage amplification process on the differential voltage signal to generate a primary amplified signal, and transmit the primary amplified signal to the single-ended amplifier unit 202. The single-ended amplifier unit 202 can be used to perform a second-stage amplification process on the primary amplified signal to generate the operating parameters, and transmit the operating parameters to the MCU controller 30.

[0034] Understandably, using differential amplifier unit 201 in contact with the measured resistance R0 of the energy meter requires only two signal lines, eliminating the need for a common ground. These two signal lines are in a high-impedance input state, which will not affect the energy meter. Since the input signal is relatively weak, typically below 100uV, the input bias voltage of this differential operational amplifier is chosen to be around 10uV. To improve sampling stability, the amplified voltage signal is approximately 0.1V, and a gain of 1000 is selected. However, excessively high gain in a single operational amplifier can lead to distortion. Therefore, a single-ended amplifier unit 202 is connected in series at the output of differential amplifier unit 201. With a gain of 50 for differential amplifier unit 201 and 20 for single-ended amplifier unit 202, a gain of 1000 is achieved.

[0035] In one possible implementation, the differential amplifier unit includes: first to fifth resistors and a first operational amplifier U1. The first terminal of the first resistor R1 is connected to the negative discharge terminal of the energy meter under test; the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the inverting input terminal of the first operational amplifier U1; the second terminal of the second resistor R2 is connected to the output terminal of the first operational amplifier U1; the first terminal of the third resistor R3 is connected to the positive discharge terminal of the energy meter under test; the second terminal of the third resistor R3 is connected to the first terminal of the fourth resistor R4 and the non-inverting input terminal of the first operational amplifier U1; the output terminal of the first operational amplifier U1 is also connected to the first terminal of the fifth resistor R5; and the second terminal of the fourth resistor R4 is connected to the second terminal of the fifth resistor R5 and grounded. The non-inverting and inverting input terminals of the first operational amplifier U1 can also be grounded via Zener diodes to achieve surge and electrostatic discharge protection.

[0036] Furthermore, the single-ended amplification unit includes: a sixth to a ninth resistor and a second operational amplifier U2. The first end of the sixth resistor R6 is connected to the output terminal of the differential amplification unit 201, the second end of the sixth resistor R6 is connected to the non-inverting input terminal of the second operational amplifier U2, the first end of the seventh resistor R7 is grounded, the second end of the seventh resistor R7 is connected to the inverting input terminal of the second operational amplifier U2 and the first end of the eighth resistor R8, the output terminal of the second operational amplifier U2 is connected to the second end of the eighth resistor R8 and the first end of the ninth resistor R9, and the second end of the ninth resistor R9 is connected to the second input terminal of the MCU controller 30.

[0037] In this embodiment, the operational amplification module includes a differential amplification unit and a single-ended amplification unit. The first input terminal of the differential amplification unit is connected to the positive discharge terminal of the energy meter under test, the second input terminal of the differential amplification unit is connected to the negative discharge terminal of the energy meter under test, the output terminal of the differential amplification unit is connected to the input terminal of the single-ended amplification unit, and the output terminal of the single-ended amplification unit is connected to the second input terminal of the MCU controller. The differential amplification unit receives the differential voltage signal from the energy meter under test, performs a first-stage amplification on the differential voltage signal to generate a primary amplified signal, and transmits the primary amplified signal to the single-ended amplification unit. The single-ended amplification unit performs a second-stage amplification on the primary amplified signal to generate the operating parameters, and transmits the operating parameters to the MCU controller. This two-stage amplification ensures that the signal from the energy meter under test is accurately amplified to a sampleable and detectable voltage signal. Differential input suppresses common-mode interference, improving signal acquisition and amplification accuracy and ensuring the accuracy of discharge current detection.

[0038] Based on the above embodiments of this application, in the third embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 , Figure 3 This is a circuit connection diagram of the third embodiment of the current sampling and detection circuit of this application.

[0039] The switch control module 10 includes: a micro switch S1, a tenth resistor R10, an eleventh resistor R11, and a first capacitor C1; the first end of the micro switch S1 is connected to the pull-up power input terminal VCC, the second end of the micro switch S1 is connected to the first end of the tenth resistor R10 and the first end of the eleventh resistor R11, the second end of the tenth resistor R10 is grounded, the second end of the eleventh resistor R11 is connected to the first end of the first capacitor C1 and the first input terminal of the MCU controller 30, and the second end of the first capacitor C1 is grounded.

[0040] It should be noted that the micro switch S1 can be a short-distance travel trigger switch. When the energy meter under test is connected to the test circuit, there may be cases where the connection is not complete, resulting in inaccurate sampling. By setting a short-distance travel trigger switch, after the energy meter under test is properly connected, the pressure trigger switch closes, and the switch control module 10 outputs a high-level sampling start signal. If the energy meter under test is not properly connected, the pressure trigger switch opens, and the switch control module 10 outputs a low-level sampling start signal. The MCU controller starts the current value judgment within the operating parameters when it receives a high-level sampling start signal, and stops the current value judgment within the operating parameters when it receives a low-level sampling start signal.

[0041] Furthermore, when detecting power failures in the electricity meter, a filtering and shielding circuit for the connected pull-up power supply can be configured. (See reference...) Figure 4 , Figure 4 This is a circuit connection diagram for filtering and shielding in the third embodiment of the current sampling and detection circuit of this application. The filtering and shielding circuit may include: a power management chip U3, second to fifth capacitors, a first inductor L1, and a common-mode inductor L2. The non-inverting input terminal of the power management chip U3 is connected to the pull-up power input terminal and the first terminal of the second capacitor C2. The inverting input terminal of the power management chip U3 is connected to the second terminal of the second capacitor C2 and grounded. The non-inverting output terminal of the power management chip U3 is connected to the first terminal of the third capacitor C3 and the first terminal of the first inductor L1. The second terminal of the first inductor L1 is connected to the first terminal of the fourth capacitor C4 and the first input terminal of the common-mode inductor L2. The inverting output terminal of the power management chip U3 is connected to the second terminal of the third capacitor C3, the second terminal of the fourth capacitor C4, and the second input terminal of the common-mode inductor L2. The first output terminal of the common-mode inductor L2 is connected to the first terminal of the fifth capacitor C5. The second output terminal of the common-mode inductor L2 is connected to the second terminal of the fifth capacitor C5 and grounded. The pull-up power supply, after being processed by power filtering and shielding circuits, can be transmitted to each power-consuming module in the current sampling and detection circuit through the terminal block.

[0042] In this embodiment, the switch control module includes a micro switch, a tenth resistor, an eleventh resistor, and a first capacitor. Through the mechanical triggering logic of the micro switch, the connection is determined to be in place only when the energy meter is physically connected and the micro switch is pressed firmly, replacing manual visual judgment and avoiding invalid detections caused by misjudgments of the connection status. A capacitor is used to filter contact bounce and power supply noise, outputting a stable and continuous sampling start signal, ensuring that the MCU receives only one valid trigger command, avoiding detection errors caused by signal interference, and improving the accuracy of energy meter performance testing.

[0043] Based on the above embodiments of this application, in the fourth embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 5 , Figure 5 This is a schematic diagram of the module of the fourth embodiment of the current sampling and detection circuit of this application.

[0044] In this embodiment, the current sampling and detection circuit further includes an analog-to-digital converter 40; the input terminal of the analog-to-digital converter 40 is connected to the output terminal of the operational amplifier module 20, and the output terminal of the analog-to-digital converter 40 is connected to the second input terminal of the MCU controller 30.

[0045] It should be noted that the operational amplifier module 20 can also be used to transmit the operating parameters to the analog-to-digital conversion unit 40; the analog-to-digital conversion unit 40 can be used to perform analog-to-digital conversion on the operating parameters to generate a digital sampling signal, and transmit the digital sampling signal to the MCU controller 30; the MCU controller 30 can also be used to determine whether the current value of the digital sampling signal is within a preset current range.

[0046] Understandably, an analog-to-digital converter (ADC) is a functional module that converts analog signals to digital signals. It can convert the approximately 0.1V analog voltage signal (operating parameter) output by the operational amplifier module into a digital signal that the MCU can directly process, thus solving the problem of analog signals being susceptible to interference. The digital sampling signal can be the digital form output by the ADC, that is, a digital representation (such as a binary or decimal value) of the 0.1V analog voltage signal, which has a linear relationship with the discharge current of the electricity meter.

[0047] Reference Figure 6 , Figure 6 This is a circuit connection diagram of the fourth embodiment of the current sampling and detection circuit of this application. The analog-to-digital conversion unit 40 includes an AD sampling chip U4 and a reference power supply chip U5. The input terminal of the AD sampling chip U4 is connected to the output terminal of the operational amplifier module 20, and the output terminal of the AD sampling chip U4 is connected to the second input terminal of the MCU controller 30. The input terminal of the reference power supply chip U5 is connected to the pull-up power supply input terminal, and the output terminal of the reference power supply chip U5 is connected to the power supply terminal of the AD sampling chip U4.

[0048] It should be noted that a 24-bit high-precision AD sampling chip (such as the SGM58600 chip) can be selected. 24 bits represents its sampling resolution; the higher the resolution, the more accurate the identification of subtle signal changes. The AD sampling chip and the MCU controller use SPI communication to achieve high-speed and stable data transmission, avoiding loss or distortion of digital signals during transmission. The reference power supply chip can be a device that provides a stable reference voltage to the AD sampling chip. For example, a 2.048V, 0.1% accuracy reference power supply (such as the SGM4027-2.048 chip) can be selected to provide a fixed, fluctuation-free reference voltage to the AD sampling chip, ensuring that the conversion accuracy of the AD sampling chip is not affected by power supply fluctuations.

[0049] In this embodiment, the current sampling and detection circuit further includes: an analog-to-digital conversion unit; the input terminal of the analog-to-digital conversion unit is connected to the output terminal of the operational amplifier module, and the output terminal of the analog-to-digital conversion unit is connected to the second input terminal of the MCU controller; the operational amplifier module is further used to transmit the operating parameters to the analog-to-digital conversion unit; the analog-to-digital conversion unit is used to perform analog-to-digital conversion on the operating parameters to generate a digital sampling signal, and transmit the digital sampling signal to the MCU controller; the MCU controller is further used to determine whether the current value of the digital sampling signal is within a preset current range. This ensures that the analog-to-digital conversion error is controlled within a very small range, significantly improves the discharge current detection accuracy, strengthens the signal anti-interference capability, and ensures detection stability in complex production environments.

[0050] Based on the above embodiments of this application, in the fifth embodiment of this application, the same or similar content as the above embodiments can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 7 , Figure 7 This is a schematic diagram of the module of the fifth embodiment of the current sampling and detection circuit of this application.

[0051] In this embodiment, the current sampling and detection circuit further includes a first indicator module 50 and a second indicator module 60; the input terminals of the first indicator module 50 and the second indicator module 60 are both connected to the control terminal of the MCU controller 30.

[0052] It should be noted that the MCU controller 30 can generate a qualified control signal when the current value of the operating parameter is within the preset current range, and transmit the qualified control signal to the first indication module 50. The MCU controller 30 can also generate a fault control signal when the current value of the operating parameter exceeds the preset current range, and transmit the fault control signal to the first indication module 50. The first indication module 50 can indicate the operating status of the energy meter under test based on the qualified control signal and the fault control signal.

[0053] Furthermore, the MCU controller 30 can also generate a status control signal upon receiving the sampling start signal, and transmit the status control signal to the second indication module 60. The second indication module 60 can indicate the operating status of the current sampling detection circuit based on the status control signal.

[0054] Reference Figure 8 , Figure 8 This is a first circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application. The first indicating module 50 includes at least one first display unit, which includes a first LED D1, a first switching transistor Q1, and twelfth to fourteenth resistors. The first end of the twelfth resistor R12 is connected to the pull-up power input terminal, the output terminal of the twelfth resistor R12 is connected to the anode of the first LED D1, the cathode of the first LED D1 is connected to the input terminal of the first switching transistor Q1, the control terminal of the first switching transistor Q1 is connected to the first end of the thirteenth resistor R13 and the first end of the fourteenth resistor R14, the second end of the thirteenth resistor R13 is connected to the control terminal of the MCU controller 30, and the second end of the fourteenth resistor R14 and the output terminal of the first switching transistor Q1 are grounded.

[0055] It should be understood that a primary display unit can be set up, using different colors of an LED to represent different operating states of the energy meter under test. For example, a green light can illuminate when a qualified control signal is received, and a red light can illuminate when a fault control signal is received. Alternatively, multiple primary display units can be set up, with each unit independently controlling one LED to represent different operating states of the energy meter under test.

[0056] Furthermore, refer to Figure 9 , Figure 9This is a second circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application. The first indicating module 50 may further include: a buzzer S2, a fifteenth to a seventeenth resistor, and a second switching transistor Q2. The first end of the fifteenth resistor R15 is connected to the pull-up power supply input terminal, the second end of the fifteenth resistor R15 is connected to the input terminal of the buzzer S2, the output terminal of the buzzer S2 is connected to the input terminal of the second switching transistor Q2, the control terminal of the second switching transistor Q2 is connected to the first end of the sixteenth resistor R16 and the first end of the seventeenth resistor R17, the second end of the sixteenth resistor R16 is connected to the control terminal of the MCU controller 30, and the second end of the seventeenth resistor R17 and the output terminal of the second switching transistor Q2 are grounded.

[0057] Understandably, in addition to using LED lights to visually display the working status of the energy meter under test, a buzzer can also be used to provide audible alerts. For example, the buzzer sounds once when a qualified control signal is received, and sounds continuously when a fault control signal is received.

[0058] Furthermore, refer to Figure 10 , Figure 10 This is a third circuit connection diagram of the fifth embodiment of the current sampling and detection circuit of this application. The second indicating module 60 includes: a second display unit, the second display unit including: a second LED D2, a third switch Q3, and eighteenth to twentieth resistors. The first end of the eighteenth resistor R18 is connected to the pull-up power input terminal, the output terminal of the eighteenth resistor R18 is connected to the anode of the second LED D2, the cathode of the second LED D2 is connected to the input terminal of the third switch Q3, the control terminal of the third switch Q3 is connected to the first end of the eighteenth resistor R18 and the first end of the twentieth resistor R20, the second end of the eighteenth resistor R18 is connected to the control terminal of the MCU controller 30, and the second end of the twentieth resistor R20 and the output terminal of the third switch Q3 are grounded.

[0059] It is understandable that the second indicator module 60 uses an LED to represent the working state of the current sampling detection circuit. This can be controlled by the MCU controller based on the received sampling start signal. For example, when the MCU controller 30 receives the sampling start signal, it controls the second LED D2 to flash, or when the MCU controller 30 receives the sampling start signal, it controls the second LED D2 to stay on.

[0060] In this embodiment, the current sampling and detection circuit further includes a first indicating module and a second indicating module. The input terminals of both the first and second indicating modules are connected to the control terminal of the MCU controller. The MCU controller is configured to generate a qualified control signal when the current value of the operating parameter is within the preset current range, and transmit the qualified control signal to the first indicating module. The MCU controller is also configured to generate a fault control signal when the current value of the operating parameter exceeds the preset current range, and transmit the fault control signal to the first indicating module. The first indicating module is configured to indicate the operating status of the energy meter under test based on the qualified control signal and the fault control signal. The MCU controller is also configured to generate a status control signal upon receiving the sampling start signal, and transmit the status control signal to the second indicating module. The second indicating module is configured to indicate the operating status of the current sampling and detection circuit based on the status control signal. After detection, the indicator of the energy meter's operating status is output immediately, eliminating the need for manual data verification and marking, quickly identifying faulty energy meters, simplifying fault diagnosis, and reducing labor costs and time for production and maintenance.

[0061] Furthermore, to achieve the above objectives, the present invention also proposes a current sampling and detection method, referring to... Figure 11 , Figure 11 This is a flowchart illustrating an embodiment of the current sampling and detection method of this application. The steps of the current sampling and detection method include: Step S10: When the power meter under test is detected to be connected, a sampling drive signal is generated.

[0062] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a current sampling and detection circuit capable of performing the above functions. The following description uses a current sampling and detection circuit as an example to illustrate this embodiment and the subsequent embodiments.

[0063] Understandably, an electricity meter can be an electronic device used in a smart grid for power data acquisition, metering, and transmission. After a power outage, it needs to rely on a battery or supercapacitor to maintain a standby state. Industry requirements stipulate that the discharge current in this standby state must be controlled within 10uA (corresponding to a preset current range). After the electricity meter is correctly connected to the detection circuit, a sampling start signal is generated. This sampling start signal can be a trigger signal generated after the electricity meter is detected to be connected.

[0064] Step S20: Collect the operating parameters of the connected energy meter under test.

[0065] It should be noted that the operating parameters of the energy meter under test can be acquired by collecting and amplifying the weak electrical signal at the discharge terminal of the energy meter. Since the voltage across the sampling resistor (10Ω) corresponding to the discharge current of the energy meter is only within 100uV, the signal needs to be amplified to a stable and identifiable range (such as 0.1V, i.e., 1000 times) through this module to provide an accurate raw signal for subsequent current calculation.

[0066] Step S30: Upon receiving the sampling start signal, determine whether the current value within the operating parameters is within the preset current range.

[0067] It should be noted that the operating parameters are converted into the discharge current value of the energy meter through calculation, and then the current value is judged to determine whether the energy meter under test is qualified based on whether it is within the preset current range. Upon receiving the sampling start signal, it is determined whether the current value within the operating parameters is within the preset current range. Automatic start and automatic data acquisition achieve automatic judgment, improving the level of automation in testing, significantly shortening the testing time for a single energy meter, while ensuring testing accuracy.

[0068] Since the electricity meter automation system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0069] Furthermore, to achieve the above objectives, the present invention also proposes an automated electricity meter system, referring to... Figure 12 , Figure 12 This is a schematic diagram of a module of an embodiment of the electricity meter automation system of this application. The electricity meter automation system includes an electricity meter, a MES system, and a current sampling and detection circuit as described above.

[0070] Since the electricity meter automation system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0071] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system 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 system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0072] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A current sampling and detection circuit, characterized in that, The current sampling and detection circuit is used in an energy meter, and the current sampling and detection circuit includes: a switch control module, an operational amplifier module, and an MCU controller; The input terminal of the switch control module is connected to the access terminal of the energy meter under test, the output terminal of the switch control module is connected to the first input terminal of the MCU controller, the input terminal of the operational amplifier module is connected to the discharge terminal of the energy meter under test, and the output terminal of the operational amplifier module is connected to the second input terminal of the MCU controller. The switch control module is used to generate a sampling drive signal when the power meter under test is detected to be connected, and transmit the sampling start signal to the MCU controller. The operational amplifier module is used to collect the operating parameters of the energy meter under test and transmit the operating parameters to the MCU controller; The MCU controller is used to determine whether the current value in the operating parameters is within a preset current range when the sampling start signal is received.

2. The current sampling and detection circuit as described in claim 1, characterized in that, The operational amplifier module includes: a differential amplifier unit and a single-ended amplifier unit; The first input terminal of the differential amplifier unit is connected to the positive discharge terminal of the energy meter under test, the second input terminal of the differential amplifier unit is connected to the negative discharge terminal of the energy meter under test, the output terminal of the differential amplifier unit is connected to the input terminal of the single-ended amplifier unit, and the output terminal of the single-ended discharge unit is connected to the second input terminal of the MCU controller. The differential amplifier unit is used to receive the differential voltage signal from the energy meter under test, perform a first-stage amplification process on the differential voltage signal to generate a primary amplified signal, and transmit the primary amplified signal to the single-ended amplifier unit. The single-ended amplification unit is used to perform a second-stage amplification on the primary amplified signal to generate the operating parameters, and then transmit the operating parameters to the MCU controller.

3. The current sampling and detection circuit as described in claim 2, characterized in that, The differential amplifier unit includes: first to fifth resistors and a first operational amplifier; The first end of the first resistor is connected to the negative discharge terminal of the energy meter under test. The second end of the first resistor is connected to the first end of the second resistor and the inverting input terminal of the first operational amplifier. The second end of the second resistor is connected to the output terminal of the first operational amplifier. The first end of the third resistor is connected to the positive discharge terminal of the energy meter under test. The second end of the third resistor is connected to the first end of the fourth resistor and the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is also connected to the first end of the fifth resistor. The second end of the fourth resistor is connected to the second end of the fifth resistor and grounded. The single-ended amplifier unit includes: a sixth to a ninth resistor and a second operational amplifier; The first end of the sixth resistor is connected to the output of the differential amplifier unit, the second end of the sixth resistor is connected to the non-inverting input of the second operational amplifier, the first end of the seventh resistor is grounded, the second end of the seventh resistor is connected to the inverting input of the second operational amplifier and the first end of the eighth resistor, the output of the second operational amplifier is connected to the second end of the eighth resistor and the first end of the ninth resistor, and the second end of the ninth resistor is connected to the second input of the MCU controller.

4. The current sampling and detection circuit as described in claim 1, characterized in that, The switch control module includes: a micro switch, a tenth resistor, an eleventh resistor, and a first capacitor; The first end of the micro switch is connected to the pull-up power input terminal, the second end of the micro switch is connected to the first end of the tenth resistor and the first end of the eleventh resistor, the second end of the tenth resistor is grounded, the second end of the eleventh resistor is connected to the first end of the first capacitor and the first input terminal of the MCU controller, and the second end of the first capacitor is grounded.

5. The current sampling and detection circuit as described in claim 1, characterized in that, The current sampling and detection circuit further includes: an analog-to-digital conversion unit; The input terminal of the analog-to-digital converter is connected to the output terminal of the operational amplifier module, and the output terminal of the analog-to-digital converter is connected to the second input terminal of the MCU controller. The operational amplifier module is also used to transmit the operating parameters to the analog-to-digital conversion unit; The analog-to-digital conversion unit is used to convert the operating parameters into digital signals, generate digital sampling signals, and transmit the digital sampling signals to the MCU controller. The MCU controller is also used to determine whether the current value of the digital sampling signal is within a preset current range.

6. The current sampling and detection circuit as described in claim 5, characterized in that, The analog-to-digital conversion unit includes: an AD sampling chip and a reference power supply chip; The input terminal of the AD sampling chip is connected to the output terminal of the operational amplifier module, the output terminal of the AD sampling chip is connected to the second input terminal of the MCU controller, the input terminal of the reference power supply chip is connected to the pull-up power supply input terminal, and the output terminal of the reference power supply chip is connected to the power supply terminal of the AD sampling chip.

7. The current sampling and detection circuit as described in claim 1, characterized in that, The current sampling and detection circuit further includes: a first indicator module and a second indicator module; The input terminals of both the first indicator module and the second indicator module are connected to the control terminal of the MCU controller. The MCU controller is used to generate a qualified control signal when the current value of the operating parameter is within the preset current range, and transmit the qualified control signal to the first indication module. The MCU controller is also configured to generate a fault control signal when the current value of the operating parameter exceeds the preset current range, and transmit the fault control signal to the first indication module. The first indicating module is used to indicate the working status of the energy meter under test based on the qualified control signal and the fault control signal; The MCU controller is further configured to generate a status control signal upon receiving the sampling start signal, and transmit the status control signal to the second indication module; The second indicating module is used to indicate the operating state of the current sampling and detection circuit based on the state control signal.

8. The current sampling and detection circuit as described in claim 7, characterized in that, The first indicator module includes: at least one first display unit, the first display unit including: a first LED, a first switching transistor, and twelfth to fourteenth resistors; The first end of the twelfth resistor is connected to the pull-up power input terminal, the output terminal of the twelfth resistor is connected to the anode of the first LED, the cathode of the first LED is connected to the input terminal of the first switching transistor, the control terminal of the first switching transistor is connected to the first end of the thirteenth resistor and the first end of the fourteenth resistor, the second end of the thirteenth resistor is connected to the control terminal of the MCU controller, and the second end of the fourteenth resistor and the output terminal of the first switching transistor are grounded. And / or, the first indicator module includes: a buzzer, fifteenth to seventeenth resistors, and a second switching transistor; The first end of the fifteenth resistor is connected to the pull-up power input terminal, the second end of the fifteenth resistor is connected to the input terminal of the buzzer, the output terminal of the buzzer is connected to the input terminal of the second switch, the control terminal of the second switch is connected to the first end of the sixteenth resistor and the first end of the seventeenth resistor, the second end of the sixteenth resistor is connected to the control terminal of the MCU controller, and the second end of the seventeenth resistor and the output terminal of the second switch are grounded. The second indicator module includes: a second display unit, wherein the second display unit includes: a second LED, a third switching transistor, and eighteenth to twentieth resistors; The first end of the eighteenth resistor is connected to the pull-up power input terminal. The output terminal of the eighteenth resistor is connected to the anode of the second LED. The cathode of the second LED is connected to the input terminal of the third switch. The control terminal of the third switch is connected to the first end of the eighteenth resistor and the first end of the twentieth resistor. The second end of the eighteenth resistor is connected to the control terminal of the MCU controller. The second end of the twentieth resistor and the output terminal of the third switch are grounded.

9. A current sampling and detection method, characterized in that, The current sampling and detection method is applied to the current sampling and detection circuit as described in any one of claims 1-8, and the steps of the current sampling and detection method include: When the power meter under test is detected to be connected, a sampling drive signal is generated; The operating parameters of the energy meter under test are collected and connected. Upon receiving the sampling start signal, determine whether the current value within the operating parameters is within the preset current range.

10. An automated electricity meter system, characterized in that, The electricity meter automation system includes: an electricity meter, a MES system, and a current sampling and detection circuit as described in any one of claims 1-8.

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