A small current low signal-to-noise ratio scene electric energy meter calibration method, medium and terminal

Abstract

This invention relates to the field of electricity metering technology, specifically a method, medium, and terminal for calibrating electricity meters in low-current, low-signal-noise-ratio scenarios. The method includes: S10, determining the low-current range, defining the range as below 10% of the rated current; S20, for the current range above 10% of the rated current, implementing a segmented calibration scheme, which includes DC bias correction, voltage correction, and segmented current, power, and phase correction; S30, determining the segmented calibration current points for the low-current range; S40, establishing current and power calibration models under low current conditions; and S50, sequentially performing current, power, and phase corrections at each calibration point under low current conditions. This invention extracts useful metering information from low-signal-noise-ratio signals, achieving high-precision electricity metering under low current conditions, reducing hardware performance requirements, and saving production costs.

Description

Technical Field

[0001] This invention belongs to the field of electricity metering technology, and particularly relates to a method, medium and terminal for calibrating electricity meters in low current and low signal-to-noise ratio scenarios. Background Technology

[0002] Electricity meter calibration technology is a calibration technique that establishes a one-to-one correspondence between input signals and output displays. Its core principle is to compare the measurement results of the electricity meter under test with the measurement values ​​of a standard electricity meter, calculate the gain parameters, and compensate for the measurement results to keep the measurement error within the allowable range. The calibration results directly affect the accuracy of electricity metering.

[0003] Traditional "two-point calibration" methods divide the current into two intervals for calibration, and the widely adopted multi-segment calibration strategy divides the current into three, four, or even more intervals for calibration. While these methods can meet the accuracy requirements of power metering under most operating conditions, under low-current conditions, current transformers lose their linearity, the signal-to-noise ratio of analog-to-digital converters decreases, and the signal's resistance to radiation interference declines. Existing calibration techniques often fail to achieve ideal metering accuracy. Under low current conditions, the useful signal is almost completely drowned out by noise, which can no longer be ignored, while existing calibration techniques often assume that noise should be ignored. Patent application CN108267708A discloses a rapid calibration method for self-correction of errors in single-phase smart meters, including a standard source and an energy meter. The calibration method includes the following steps: A) The standard source provides the energy meter with rated voltage and rated current; B) An external specific signal is provided; C) The energy meter calculates the error based on the register values ​​stored in the metering chip and the data inside the meter; D) Based on the parameters of the metering chip, the error is converted into a power gain value, and the obtained power gain value is written into the metering chip; E) The meter error is corrected in segments, calculating the interval error value between the actual power in each interval and the standard power of the calibration bench; F) The calibration is completed. This patent application calibrates the energy meter through multiple intervals, neglecting the influence of noise, and thus its accuracy cannot be guaranteed, exhibiting the same drawbacks as existing technologies.

[0004] Therefore, how to provide a method for calibrating electricity meters in low-current, low-signal-noise-ratio scenarios, which can extract useful metering information from low-signal-noise-ratio signals and achieve high-precision electricity metering under low current conditions, is a problem that urgently needs to be solved by researchers in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for calibrating electricity meters in low-current, low-signal-noise-ratio scenarios, thereby solving the problem of low calibration accuracy of electricity meters in low-current, low-signal-noise-ratio scenarios due to neglecting the influence of noise. In addition, this invention also provides a calibration medium and terminal for electricity meters in low-current, low-signal-noise-ratio scenarios.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario, comprising the following steps:

[0008] S10. Determine the low current range, and set the range below 10% of the rated current as the low current range;

[0009] S20. For a current range exceeding 10% of the rated current, a segmented calibration scheme is implemented, which includes DC bias correction, voltage correction, and segmented current correction, power correction, and phase correction.

[0010] S30. Determine the segmented calibration current points for the small current range;

[0011] S40. Establish a current and power calibration model under low current conditions;

[0012] S50. Perform current correction, power correction and phase correction on each calibration point under low current conditions in sequence.

[0013] Furthermore, in S30, the segmented calibration current points include 10% of the rated current, 5% of the rated current, 2% of the rated current, and 1% of the rated current.

[0014] Furthermore, in S40, the sampled signal includes a useful signal and a noise signal, as expressed below:

[0015] ;

[0016] in, These represent the current and power values ​​of the sampled signal from the energy meter under test, respectively. These represent the current and power values ​​of the useful signal in the sampled signal of the energy meter under test, respectively. These are the noise current and noise power in the sampling signal of the energy meter under test, respectively.

[0017] Furthermore, the relationship between the sampled signal and the actual signal is expressed as follows:

[0018] ;

[0019] in, These are the actual current value and the power value, respectively. This represents the gain of the sampling circuit on the actual signal.

[0020] Furthermore, a linear calibration model is established between the sampled signal and the actual signal:

[0021] ;

[0022] in, For current gain and power gain, For current bias and power bias;

[0023] Current gain and power gain for:

[0024] ;

[0025] Current bias and power bias for:

[0026] ;

[0027] set up:

[0028] ;

[0029] in, The relative error of the current between the sampled signal and the actual signal. The relative error of the current between the useful signal and the actual signal in the sampled signal. The relative power error between the sampled signal and the actual signal. This represents the relative power error between the useful signal and the actual signal in the sampled signal.

[0030] Furthermore, in S50, the specific steps for current correction are as follows:

[0031] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.0.

[0032] The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test.

[0033] Use the RMS current value of the standard meter as The effective value of the full-wave current of the energy meter under test is used as The effective value of the fundamental current of the energy meter under test is used as... The effective values ​​of the full-wave current, the fundamental current, and the standard meter current were read three times, and their average values ​​were calculated to obtain the results. ;

[0034] Calculate the relative error using the average value. ;

[0035] The current gain can be obtained from the formula. Current bias .

[0036] Furthermore, in S50, the specific steps for power correction are as follows:

[0037] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.0.

[0038] The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test.

[0039] Set an appropriate pulse constant according to requirements;

[0040] The power values ​​were read from the standard meter multiple times and the average value was calculated. ;

[0041] By adjusting the pulse output mode to full-wave mode, the relative power error between the sampled signal and the actual signal can be obtained using the pulse method. ;

[0042] By adjusting the pulse output mode to the fundamental frequency mode, the relative power error between the useful signal and the actual signal in the sampled signal can be obtained using the pulse method. The power gain can be obtained from the formula. Power bias .

[0043] Furthermore, in S50, the specific steps of phase correction are as follows:

[0044] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 0.5.

[0045] Perform the phase correction process of the S20 conventional meter calibration scheme.

[0046] In a second aspect, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0047] Thirdly, the present invention also provides an electronic terminal, comprising: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the terminal to perform the method described above.

[0048] The meter calibration method, medium, and terminal for low-current, low-signal-to-noise ratio scenarios provided by this invention have at least the following advantages compared with existing technologies:

[0049] Existing technologies suffer from low calibration accuracy of electricity meters in low-current, low-signal-to-noise ratio scenarios due to neglecting the impact of noise. This invention improves the metering accuracy of electricity meters in low-current operating modes. The proposed meter calibration method addresses the problems of existing technologies from an algorithmic perspective, reducing hardware performance requirements and saving production costs. By correcting current and power values ​​under low current conditions, it provides more accurate instantaneous electricity metering values, which is beneficial for analyzing electricity metering problems. Attached Figure Description

[0050] To more clearly illustrate the solution of the present invention, a brief introduction will be given to the drawings used in the description of the embodiments below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a flowchart illustrating a method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario, as provided in an embodiment of the present invention. Detailed Implementation

[0052] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0054] This invention provides a method for calibrating electricity meters in low-current, low-signal-noise-ratio scenarios, applicable to power systems. The method includes the following steps:

[0055] S10. Determine the low current range, setting the range below 10% of the rated current as the low current range; S20. For the current range above 10% of the rated current, implement a segmented calibration scheme, which includes DC bias correction, voltage correction, and segmented current correction, power correction, and phase correction; S30. Determine the segmented calibration current points for the low current range; S40. Establish a current and power calibration model under low current; S50. Perform current correction, power correction, and phase correction under low current on each calibration point in sequence.

[0056] This invention extracts useful metering information from signals with low signal-to-noise ratios, achieving high-precision power metering under low current conditions, reducing hardware performance requirements, and saving production costs.

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0058] This invention provides a method for calibrating energy meters in low-current, low-signal-to-noise-ratio scenarios, applicable to power systems, such as... Figure 1 As shown in this embodiment, the meter calibration method for low current and low signal-to-noise ratio scenarios includes the following steps:

[0059] S10. Determine the low current range. Generally, the low current range is set to less than 10% of the rated current.

[0060] S20. For current ranges exceeding 10% of the rated current, implement a segmented calibration scheme. The segmented calibration scheme includes DC bias correction, voltage correction, and segmented current correction, power correction, and phase correction.

[0061] S30. Determine segmented calibration current points for the small current range, which are 10%, 5%, 2% and 1% of the rated current, respectively. Alternatively, you can define the calibration current points yourself according to your needs.

[0062] S40. Establish a current and power calibration model under low current conditions.

[0063] Specifically, in this embodiment, under low current conditions, the noise signal with low signal-to-noise ratio cannot be ignored. The sampled signal includes the useful signal and the noise signal, as expressed below:

[0064] ;

[0065] in, These represent the current and power values ​​of the sampled signal from the energy meter under test, respectively. These represent the current and power values ​​of the useful signal in the sampled signal of the energy meter under test, respectively. These are the noise current and noise power in the sampling signal of the energy meter under test, respectively.

[0066] Furthermore, in this embodiment, the relationship between the sampled signal and the actual signal is expressed as follows:

[0067] ;

[0068] in, These are the actual current value and the power value, respectively. This represents the gain of the sampling circuit on the actual signal.

[0069] Furthermore, in this embodiment, a linear calibration mathematical model is established between the sampled signal and the actual signal:

[0070] ;

[0071] in, For current gain and power gain, For current bias and power bias.

[0072] Furthermore, in this embodiment, the current gain and power gain for:

[0073] ;

[0074] Current bias and power bias for:

[0075] ;

[0076] set up:

[0077] ;

[0078] in, The relative error of the current between the sampled signal and the actual signal. The relative error of the current between the useful signal and the actual signal in the sampled signal. The relative power error between the sampled signal and the actual signal. This represents the relative power error between the useful signal and the actual signal in the sampled signal.

[0079] Then current gain and power gain for:

[0080] ;

[0081] Current bias and power bias for:

[0082] .

[0083] S50. Perform current correction, power correction and phase correction on each calibration point under low current conditions in sequence.

[0084] Specifically, in this embodiment, step S50 further includes the following sub-steps:

[0085] S501, Select the first small current calibration point;

[0086] S502, Perform current correction:

[0087] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.0.

[0088] The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test.

[0089] Use the RMS current value of the standard meter as The effective value of the full-wave current of the energy meter under test is used as The effective value of the fundamental current of the energy meter under test is used as... The effective values ​​of the full-wave current, the fundamental current, and the standard meter current were read three times, and their average values ​​were calculated to obtain the results. ;

[0090] Calculate the relative error using the average value. ;

[0091] The current gain can be obtained from the formula. Current bias .

[0092] S503, Perform power calibration:

[0093] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.0.

[0094] The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test.

[0095] Set an appropriate pulse constant according to requirements;

[0096] The power values ​​were read from the standard meter multiple times and the average value was calculated. ;

[0097] By adjusting the pulse output mode to full-wave mode, the relative power error between the sampled signal and the actual signal can be obtained using the pulse method. ;

[0098] By adjusting the pulse output mode to the fundamental frequency mode, the relative power error between the useful signal and the actual signal in the sampled signal can be obtained using the pulse method. The power gain can be obtained from the formula. Power bias .

[0099] S504. Perform phase correction:

[0100] Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 0.5.

[0101] Perform the phase correction procedure of the S20 traditional calibration scheme.

[0102] S505. Switch to the next small current calibration point. Execute steps S502 to S505 in sequence. If the current calibration point is the last one, end the calibration.

[0103] This invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the methods in this embodiment.

[0104] This invention also provides an electronic terminal, including: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the terminal performs any of the methods in this embodiment.

[0105] As will be understood by those skilled in the art, the computer-readable storage medium described in this embodiment allows for the implementation of all or part of the steps in the above method embodiments by computer program-related hardware. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0106] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver, and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication between them. The memory is used to store computer programs, the communication interface is used to perform communication, and the processor and the transceiver are used to run the computer programs, so that the electronic terminal performs the steps of the above method.

[0107] Example 1

[0108] This embodiment uses a single-phase energy meter of a certain model as an example, with a rated current of 1A, a maximum current of 10A, and a rated voltage of 220V. The meter calibration equipment adopts a three-phase energy meter calibration device (platform), and the standard energy meter accuracy class is 0.05. The energy meter to be calibrated has a built-in analog-to-digital converter and digital signal processor, supports full-wave and fundamental pulse output modes, and can read the RMS value of the full-wave current, the RMS value of the fundamental current, and the power value.

[0109] Before calibration, connect the energy meter under test and the standard meter to the test platform simultaneously, ensuring that the voltage loop is connected in parallel and the current loop is connected in series. Set the platform's output voltage to 220V and the output frequency to 50Hz. Determine the minimum current range to be less than 10% of the rated current, i.e., less than 0.1A.

[0110] Traditional segmented calibration (>10% of rated current):

[0111] Step 1: DC bias correction. With the output voltage of the test bench at 220V and the current loop open, read the voltage and current sampling values ​​of the energy meter under test, calculate the DC bias and compensate it so that the metering value is zero when there is zero input.

[0112] Step 2: Voltage calibration. Set the platform voltage to 220V, current to 1A (rated current), and power factor to 1.0. Using the effective value of the standard meter voltage as a reference, adjust the voltage gain of the meter under test to ensure that the voltage error is less than ±0.1%.

[0113] Step 3: Segmented Current, Power, and Phase Correction. Select four typical current points (e.g., 10A, 5A, 1A, 0.5A) within the current range of 10A to 0.1A, and perform current correction, power correction, and phase correction sequentially using conventional methods (with power factors set to 1.0 and 0.5, respectively). This part is existing technology and will not be elaborated further.

[0114] After completing the above steps, the metering error of the energy meter under test under operating conditions above 0.1A meets the requirements.

[0115] Small current segmented calibration (≤10% of rated current):

[0116] Step 1: Determine the calibration points for low current. Use 10% (0.1A), 5% (0.05A), 2% (0.02A), and 1% (0.01A) of the rated current as calibration points within the low current range. In practical applications, calibration points can be added or removed as needed, for example, adding a 0.5% rated current point (0.005A).

[0117] Step 2: Establish a mathematical model for low-current calibration. Based on the formulas given earlier, in low-current, low-signal-to-noise ratio scenarios, the sampled signal contains both useful and noise components. The useful signal can be obtained through fundamental frequency extraction. A linear calibration model between the sampled signal and the actual signal is then established, defining current gain, current bias, power gain, and power bias, and providing their calculation formulas (see the invention description for specific formulas). This embodiment directly applies this model for calculation.

[0118] Step 3: Perform current calibration at the first small current calibration point (0.1A).

[0119] (1) Set the signal parameters of the platform: voltage 220V, current 0.1A, power factor 1.0;

[0120] (2) Simultaneously transmit the platform signal to the standard meter and the energy meter under test, and start reading the signal after the signal stabilizes;

[0121] (3) Read the effective value of the current of the standard meter, the effective value of the full wave current of the meter under test, and the effective value of the fundamental wave current of the meter under test three times in succession, and calculate the average value of each;

[0122] (4) Calculate the relative error of the current according to the formula in the invention;

[0123] (5) Calculate the current gain and current bias according to the formula, and write the calculation results into the calibration register of the energy meter under test. Reread the current value to verify that the error should be less than ±0.02%.

[0124] Step 4: Perform power correction at the same calibration point (0.1A).

[0125] (1) Keep the platform parameters unchanged (220V, 0.1A, power factor 1.0).

[0126] (2) Set an appropriate pulse constant (e.g., 20000imp / kWh);

[0127] (3) Read the power value of the standard meter, and take the average of three consecutive readings;

[0128] (4) Set the pulse output mode of the meter under test to full-wave mode and use the pulse method to obtain the relative error of the full-wave power;

[0129] (5) Switch the pulse output mode to the fundamental mode and use the pulse method to obtain the relative error of the fundamental power;

[0130] (6) Calculate the power gain and power bias according to the formula in the invention, write them into the corresponding registers, and re-verify the power error. The error should be less than ±0.02%.

[0131] Step 5: Perform phase correction on the same calibration point (0.1A).

[0132] (1) Maintain a voltage of 220V and a current of 0.1A, and set the power factor to 0.5;

[0133] (2) Perform the phase correction process in the traditional meter calibration scheme. This part belongs to the existing technology and will not be described in detail.

[0134] Step 6: Switch to the next small current calibration point.

[0135] Repeat steps 3 through 5 for points of 0.05A, 0.02A, and 0.01A. Note that at extremely low current values ​​(e.g., 0.01A), the RMS value of the full-wave current may deviate significantly from the actual value, but the RMS value of the fundamental current can still reflect the useful signal, and the calibration model remains applicable. In this embodiment, the measured current gains are approximately 1.0658 at 0.05A, approximately 1.0865 at 0.02A, and approximately 1.1044 at 0.01A; the current biases are approximately 0.00309A, 0.00157A, and 0.00094A, respectively. The power gain and power bias are calculated using the same method.

[0136] Step 7: Determine if the current calibration point is the last one. Once the 0.01A point calibration is complete, end the small current calibration process.

[0137] Verification of calibration results: After completing the calibration of all calibration points, current points that were not calibrated (e.g., 0.08A, 0.03A, 0.015A) were selected for verification. The corresponding output current of the test bench was set, with power factors of 1.0 and 0.5 respectively. The energy measurement values ​​of the standard meter and the meter under test were recorded, and the relative error was calculated. In this embodiment, the current error at each verification point was less than ±0.2%, and the power error was less than ±0.03%, meeting the high-precision metering requirements under low-current conditions.

[0138] Summary of Results: This embodiment significantly improves the metering accuracy of electricity meters under low signal-to-noise ratio (SNR) conditions by employing a linear calibration model based on signal-to-noise separation within a low current range, performing piecewise corrections on current, power, and phase. Compared to solutions that simply improve the hardware SNR, this method solves the low-current metering problem at the algorithmic level, reducing the performance requirements for ADCs and current transformers, thereby saving production costs. Furthermore, since both fundamental and full-wave data are recorded simultaneously during calibration, it can be used to analyze power quality and noise interference, facilitating subsequent fault diagnosis.

[0139] The meter calibration method, medium, and terminal for low-current signal-to-noise ratio scenarios described in the above embodiments have the advantage of addressing the problem of low meter calibration accuracy in low-current, low-signal-to-noise ratio scenarios caused by neglecting noise influence. This invention improves the metering accuracy of electricity meters in low-current operating modes. The proposed meter calibration method addresses the problems of existing technologies from an algorithmic perspective, reduces hardware performance requirements, saves production costs, and provides more accurate instantaneous electricity metering values ​​by correcting current and power values ​​under low current conditions, which is beneficial for analyzing electricity metering problems.

[0140] Obviously, the embodiments described above are merely preferred embodiments of the present invention, and not all embodiments. The accompanying drawings illustrate preferred embodiments of the present invention, but do not limit the scope of the patent. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this invention.

Claims

1. A method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario, characterized in that, Includes the following steps: S10. Determine the low current range, and set the range below 10% of the rated current as the low current range; S20. For a current range exceeding 10% of the rated current, a segmented calibration scheme is implemented, which includes DC bias correction, voltage correction, and segmented current correction, power correction, and phase correction. S30. Determine the segmented calibration current points for the small current range; S40. Establish a current and power calibration model under low current conditions; S50. Perform current correction, power correction and phase correction on each calibration point under low current conditions in sequence.

2. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 1, characterized in that, In S30, the segmented calibration current points include 10% of the rated current, 5% of the rated current, 2% of the rated current, and 1% of the rated current.

3. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 1, characterized in that, In step S40, the sampled signal includes a useful signal and a noise signal, as expressed below: ； in, These represent the current and power values ​​of the sampled signal from the energy meter under test, respectively. These represent the current and power values ​​of the useful signal in the sampled signal of the energy meter under test, respectively. These are the noise current and noise power in the sampling signal of the energy meter under test, respectively.

4. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 3, characterized in that, The relationship between the sampled signal and the actual signal is expressed as follows: ； in, These are the actual current value and the power value, respectively. This represents the gain of the sampling circuit on the actual signal.

5. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 4, characterized in that, Establish a linear calibration model between the sampled signal and the actual signal: ； in, For current gain and power gain, For current bias and power bias; Current gain and power gain for: ； Current bias and power bias for: ； set up: ； in, The relative error of the current between the sampled signal and the actual signal. The relative error of the current between the useful signal and the actual signal in the sampled signal. The relative power error between the sampled signal and the actual signal. This represents the relative power error between the useful signal and the actual signal in the sampled signal.

6. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 5, characterized in that, In S50, the specific steps for current correction are as follows: Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.

0. The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test. Use the RMS current value of the standard meter as The effective value of the full-wave current of the energy meter under test is used as The effective value of the fundamental current of the energy meter under test is used as... The effective values ​​of the full-wave current, the fundamental current, and the standard meter current were read three times, and their average values ​​were calculated to obtain the results. ; Calculate the relative error using the average value. ; The current gain can be obtained from the formula. Current bias .

7. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 5, characterized in that, In S50, the specific steps for power correction are as follows: Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 1.

0. The platform signal is simultaneously transmitted to both the standard meter and the energy meter under test. Set an appropriate pulse constant according to requirements; The power values ​​were read from the standard meter multiple times and the average value was calculated. ; By adjusting the pulse output mode to full-wave mode, the relative power error between the sampled signal and the actual signal can be obtained using the pulse method. ; By adjusting the pulse output mode to the fundamental frequency mode, the relative power error between the useful signal and the actual signal in the sampled signal can be obtained using the pulse method. The power gain can be obtained from the formula. Power bias .

8. The method for calibrating an energy meter in a low-current, low-signal-to-noise ratio scenario according to claim 5, characterized in that, In S50, the specific steps of phase correction are as follows: Set the platform signal parameters: voltage to nominal voltage, current to the current calibration point current, and power factor to 0.

5. Perform the phase correction process of the S20 conventional meter calibration scheme.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 8.

10. An electronic terminal, characterized in that, include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the terminal to perform the method as described in any one of claims 1 to 8.

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