A method for smart meter range calibration and error compensation for nonlinear loads

Abstract

This invention relates to the field of smart meter metering technology, and particularly to a method for range calibration and error compensation of smart meters for nonlinear loads. By real-time acquisition of the secondary current signal and casing temperature of a current transformer, a temperature influence factor reflecting the effect of temperature on permeability and a distortion loss factor reflecting the additional loss of distorted current are calculated. These two factors are then fused to construct a unified coupled-state error potential (error risk factor). Using this factor as a decision variable, the amplitude compensation coefficient and phase compensation time offset are directly calculated using explicit mathematical formulas based on physical laws. Finally, these compensation parameters are applied to correct the original measurement signal in real time, thereby outputting high-precision electrical energy data after dynamic decoupling compensation.

Description

Technical Field

[0001] This invention relates to the field of smart meter metering technology, and in particular to a method for range calibration and error compensation of smart meters for nonlinear loads. Background Technology

[0002] In the fields of smart grids and industrial automation, the accuracy of electricity metering is crucial. As the core sensing component of electricity meters, the performance of current transformers directly determines the accuracy of metering. However, with the widespread application of nonlinear loads such as frequency converters, rectifiers, and switching power supplies, the grid current contains a large number of harmonic and DC components, leading to increasingly harsh operating environments for current transformers.

[0003] The errors of current transformers mainly manifest as ratio errors and phase errors. Under ideal sine wave and low current conditions, these errors are small and stable. However, under nonlinear load conditions, harmonics and DC components generate significant additional iron losses (eddy current losses and hysteresis losses) in the current transformer core. These losses are converted into heat energy, causing the core temperature to rise. The increase in core temperature leads to a decrease in its permeability and saturation flux density, making the core more likely to enter the nonlinear saturation region under the same excitation current. This makes the error characteristics of the current transformer a dynamic and highly nonlinear unknown function. The traditional fixed compensation model calibrated under steady-state, pure sine wave conditions fails, resulting in systemic deviations that are difficult to trace under conditions requiring precise metering, such as variable frequency speed regulation and impulsive loads, leading to power disputes.

[0004] Existing technologies do not model and control the core temperature rise and distortion excitation errors as a dynamic, interactive system in a holistic manner. They neglect or simplify the inherent physical mechanisms of coupling, thus failing to effectively track and compensate for time-varying and nonlinear errors during dynamic changes in nonlinear loads without significantly increasing costs. Summary of the Invention

[0005] The main objective of this invention is to provide a method for range calibration and error compensation of smart meters under nonlinear loads. This method aims to solve the problem of inaccurate energy metering caused by the bidirectional dynamic coupling between the core temperature, harmonics, and DC excitation of current transformers under nonlinear load conditions. By real-time acquisition of the secondary current signal and casing temperature of the current transformer, a temperature influence factor reflecting the effect of temperature on permeability and a distortion loss factor reflecting the additional loss of distorted current are calculated. These two factors are then fused to construct a unified coupled-state error potential (error risk factor). Using this factor as the decision variable, the amplitude compensation coefficient and phase compensation time offset are directly calculated using explicit mathematical formulas based on physical laws. Finally, these compensation parameters are applied to correct the original measurement signal in real time, thereby outputting high-precision energy data after dynamic decoupling compensation. This fundamentally solves the problem of time-varying error of current transformers under nonlinear loads, which existing technologies cannot address, and improves the long-term metering accuracy and reliability of smart meters in complex industrial environments without increasing hardware costs.

[0006] The technical solution of the present invention is as follows:

[0007] Firstly, a method for range calibration and error compensation of smart meters for nonlinear loads is proposed, which includes the following steps:

[0008] S1. Obtain the discrete current sequence at a preset sampling frequency and the temperature of the current transformer casing. Calculate the fundamental effective value and harmonic effective value of the current after performing a windowed fast Fourier transform on the discrete current sequence. Obtain the temperature influence factor using the temperature of the current transformer casing.

[0009] S2. Based on the fundamental effective value and harmonic effective value of the current, the total harmonic distortion rate of the current, the DC component of the current and the true effective value of the current are obtained, and the distortion loss factor is further obtained.

[0010] S3. Based on the temperature influence factor, the true effective value of the current, and the distortion loss factor, construct the error risk factor, compare the magnitude of the error risk factor with the compensation threshold, adopt the dynamic compensation strategy when the error risk factor is greater than the compensation threshold, and adopt the fixed basic compensation strategy when the error risk factor is not greater than the compensation threshold, and output the compensation parameters.

[0011] S4. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters, and obtain the corrected discrete current sequence by linear interpolation of the discrete current sequence, and further obtain the calibrated cumulative energy.

[0012] A further improvement of the present invention is that step S1 includes the following specific steps:

[0013] S11. Obtain the discrete current sequence at a preset sampling frequency. And obtain the temperature of the current transformer casing. For discrete current sequences Perform a windowed Fast Fourier Transform and set the analysis window length to an integer multiple of the power frequency period to obtain the spectrum. Where n is the sampling point index and k is the frequency point index;

[0014] S12, the frequency point corresponding to the fundamental frequency. The fundamental frequency spectrum was obtained. Calculate the effective value of the fundamental current. The formula is: ;in, The amplitude of the fundamental frequency spectrum. The amplitude recovery coefficient of the Fast Fourier Transform window function;

[0015] S13. Locate the frequency point corresponding to the h-th harmonic. The harmonic spectrum is obtained. Calculate the effective value of harmonic current. The formula is: Where h is the harmonic order index, and the value of h is 2-H. Let h be the harmonic spectrum amplitude of the h-th harmonic. This represents the effective value of the harmonic current of the h-th harmonic.

[0016] A further improvement of the present invention is that step S1 further includes obtaining a temperature influence factor using the temperature of the current transformer casing, wherein the calculation formula for the temperature influence factor is: ;in, Indicates the influence factor of temperature. The temperature coefficient of magnetic permeability of the core material. This is a reference temperature.

[0017] A further improvement of the present invention is that step S2 includes the following specific steps:

[0018] S21, Based on the fundamental effective value of the current wave RMS value of harmonic current Calculate the total harmonic distortion rate of the current. The formula is: H represents the upper limit of the harmonic order;

[0019] S22, for discrete current sequences The DC component of the current is obtained by arithmetically averaging over a single power frequency cycle. The formula is: ;in, The number of sampling points within a single power frequency cycle is obtained from the ratio of the preset sampling frequency to the fundamental frequency;

[0020] S23. Obtain the total number of sampling points N in the current analysis window and calculate the true RMS value of the current. The formula is: ;

[0021] S24, Based on the total harmonic distortion of current Effective value of fundamental current and the DC component of the current The distortion loss factor was obtained. The formula is: ;in, The first fixed loss factor, This is the second fixed loss coefficient.

[0022] A further improvement of the present invention is that step S3 includes the following specific steps:

[0023] S31, Based on temperature influence factors True RMS value of current and distortion loss factor Constructing error risk factors The formula is: ;in, This is the temperature-error sensitivity coefficient. The distortion loss-risk conversion factor is used. It is a constant, and its value is... ;

[0024] S32, Set compensation threshold ,when A dynamic compensation strategy is employed, and compensation parameters are output, including amplitude compensation coefficients. and phase compensation time offset The formula for calculating the amplitude compensation coefficient is as follows: ;in, Rated current, For the current amplitude term coefficient, This is the coefficient for the temperature effect term. Here is the distortion loss term coefficient; the formula for calculating the phase compensation time offset is: The inherent time constant of the current transformer; when At that time, a fixed foundation compensation strategy is adopted and fixed foundation compensation parameters are output, wherein the fixed foundation compensation parameters include the base value of the amplitude compensation coefficient. and phase compensation time offset base value .

[0025] A further improvement of the present invention is that step S4 includes the following specific steps:

[0026] S41. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters. The formula is: Where f is the preset sampling frequency, when a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, ;

[0027] S42, For discrete current sequences The corrected discrete current sequence is obtained through linear interpolation. The formula is: ;in, , Indicates rounding down. When a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, ;

[0028] S43, Based on the modified discrete current sequence The calibrated cumulative electrical energy is obtained. The formula is: ;in, A discrete voltage sequence synchronized with a discrete current sequence.

[0029] Secondly, a computer-readable storage medium is proposed, on which a computer program is stored. When the computer program is executed by a processor, it implements the above-mentioned method for range calibration and error compensation of smart meters for nonlinear loads.

[0030] Thirdly, an electronic device is proposed, including a memory for storing instructions and a processor for executing the instructions, causing the device to perform the above-described method for range calibration and error compensation of a smart meter for nonlinear loads.

[0031] The technical effects of this invention are as follows:

[0032] A method for range calibration and error compensation of smart meters under nonlinear loads was developed. By real-time acquisition of the secondary current signal and casing temperature of the current transformer, a temperature influence factor reflecting the effect of temperature on permeability and a distortion loss factor reflecting the additional loss of distorted current were calculated. These two factors were then fused to construct a unified coupled-state error potential (error risk factor). Using this factor as the decision variable, the amplitude compensation coefficient and phase compensation time offset were directly calculated using explicit mathematical formulas based on physical laws. Finally, these compensation parameters were applied to correct the original measurement signal in real time, resulting in high-precision electrical energy data with dynamic decoupling compensation. This method fundamentally solves the problem of time-varying error of current transformers under nonlinear loads, which is unmanageable by existing technologies. Without increasing hardware costs, it significantly improves the long-term metering accuracy and reliability of smart meters in complex industrial environments. Attached Figure Description

[0033] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 This is a flowchart illustrating a method for range calibration and error compensation of a smart meter for nonlinear loads according to Embodiment 1 of the present invention. Detailed Implementation

[0035] Example 1: This example constructs a method for range calibration and error compensation of smart meters for nonlinear loads. By real-time acquisition of the secondary current signal and casing temperature of the current transformer, a temperature influence factor reflecting the effect of temperature on permeability and a distortion loss factor reflecting the additional loss of distorted current are calculated. These two factors are then fused to construct a unified coupled-state error potential (error risk factor). Using this factor as the decision variable, the amplitude compensation coefficient and phase compensation time offset are directly calculated using explicit mathematical formulas based on physical laws. Finally, these compensation parameters are applied to correct the original measurement signal in real time, thereby outputting high-precision electrical energy data after dynamic decoupling compensation. This fundamentally solves the problem of time-varying error of current transformers under nonlinear loads, which existing technologies cannot address, and improves the long-term metering accuracy and reliability of smart meters in complex industrial environments without increasing hardware costs.

[0036] A method for range calibration and error compensation of smart meters for nonlinear loads, such as... Figure 1 As shown, the specific steps include the following:

[0037] S1. Obtain a discrete current sequence at a preset sampling frequency and obtain the temperature of the current transformer casing. Perform a windowed fast Fourier transform on the discrete current sequence to calculate the effective value of the fundamental current and the effective value of the harmonic current. Use the temperature of the current transformer casing to obtain the temperature influence factor.

[0038] In this embodiment, S1 includes the following specific steps:

[0039] S11. Obtain the discrete current sequence at a preset sampling frequency. And obtain the temperature of the current transformer casing. For discrete current sequences Perform a windowed Fast Fourier Transform and set the analysis window length to an integer multiple of the power frequency period to obtain the spectrum. Where n is the sampling point index and k is the frequency point index; in this embodiment, the Hanning window is selected to be applied.

[0040] S12, the frequency point corresponding to the fundamental frequency. The fundamental frequency spectrum was obtained. Calculate the effective value of the fundamental current. The formula is: ;in, The amplitude of the fundamental frequency spectrum. These are the amplitude recovery coefficients of the Fast Fourier Transform window function. For the Hanning window, their amplitude recovery coefficients are... The fundamental effective value of the current characterizes the magnitude of the sinusoidal component that does useful work in the load current.

[0041] S13. Locate the frequency point corresponding to the h-th harmonic. The harmonic spectrum is obtained. Calculate the effective value of harmonic current. The formula is: Where h is the harmonic order index, and the value of h is 2-H. Let h be the harmonic spectrum amplitude of the h-th harmonic. is the effective value of the harmonic current of the h-th harmonic, which is used to quantify the independent intensity of each harmonic.

[0042] In this embodiment, S1 further includes obtaining a temperature influence factor using the temperature of the current transformer casing. The formula for calculating the temperature influence factor is as follows: ;in, The temperature coefficient of magnetic permeability of the core material is negative and its unit is 100°C. , For reference temperature, the value is [value to be filled in]. , Indicates the influence factor of temperature. It is a dimensionless number used to quantify the attenuation ratio of the magnetization capability (excitation inductance) of the current transformer core relative to the reference state at the current temperature.

[0043] S2. Based on the fundamental effective value and harmonic effective value of the current, the total harmonic distortion rate of the current, the DC component of the current, and the true effective value of the current are obtained, and the distortion loss factor is further obtained.

[0044] In this embodiment, S2 includes the following specific steps:

[0045] S21, Based on the fundamental effective value of the current wave RMS value of harmonic current Calculate the total harmonic distortion rate of the current. The formula is: H is the upper limit of the harmonic order; the total harmonic distortion rate of the current is used to characterize the degree of total distortion of the current waveform from a sine wave, and is a dimensionless number.

[0046] S22, for discrete current sequences The DC component of the current is obtained by arithmetically averaging over a single power frequency cycle. The formula is: ;in, The number of sampling points within a single power frequency cycle is obtained by the ratio of the preset sampling frequency to the fundamental frequency; the DC component of the current is used to characterize the DC bias that causes unidirectional magnetic saturation of the current transformer.

[0047] S23. Obtain the total number of sampling points N in the current analysis window and calculate the true RMS value of the current. The formula is: The true effective value of current is a measure of the overall thermal effect of current.

[0048] S24, Based on the total harmonic distortion of current Effective value of fundamental current and the DC component of the current The distortion loss factor was obtained. The formula is: ;in, The first fixed loss factor, This is the second fixed loss factor. Distortion loss factor. The unit is watts (W). It calculates the power generated and converted into heat by current waveform distortion (harmonics and DC) in the current transformer core, using the first fixed loss factor. The second fixed loss factor represents the additional loss coefficient caused by harmonic distortion under a unit square fundamental current, expressed in ohms. It represents the additional loss coefficient generated by the DC component alone, and the unit is ohms.

[0049] In this embodiment, the first fixed loss coefficient The method of obtaining it is: at the reference temperature Under these conditions, a pure sinusoidal current is applied to the rated value. At this point, both the total harmonic distortion (THD) and the DC component of the current are zero. The power loss of the current transformer is measured. Then, a distorted current with a known harmonic distortion rate but no DC component is applied, and the total loss is measured. The additional loss is then the difference between the total loss and the power loss of the current transformer. This additional loss is present in the measurement. From this, the first fixed loss coefficient can be derived. .

[0050] In this embodiment, the second fixed loss coefficient The method of obtaining it is: at the reference temperature Below, after applying a pure DC current, the power loss of the current transformer is measured. Since the harmonic distortion rate is zero at this time, the power loss of the current transformer is... From this, the second fixed loss coefficient can be derived. .

[0051] S3. Based on the temperature influence factor, the true effective value of the current, and the distortion loss factor, construct an error risk factor, compare the relationship between the error risk factor and the compensation threshold, adopt a dynamic compensation strategy when the error risk factor is greater than the compensation threshold, and adopt a fixed basic compensation strategy when the error risk factor is not greater than the compensation threshold, and output the compensation parameters.

[0052] In this embodiment, S3 includes the following specific steps:

[0053] S31, Based on temperature influence factors True RMS value of current and distortion loss factor Constructing error risk factors The formula is: ;in, This is the temperature-error sensitivity coefficient. The distortion loss-risk conversion factor is used. It is a constant, and its value is... .

[0054] In this embodiment, Temperature-error sensitivity coefficient represents the contribution of the temperature term to risk. This is a dimensionless number, obtained through a temperature rise experiment. Specifically, it is obtained by applying a pure sinusoidal current and fixing the effective value to the rated value. At this point, both the total harmonic distortion (THD) and the DC component of the current are zero. The ambient temperature is set to zero, and the ambient temperature is set from the reference temperature. Heat up to , making From 1 to At each stable temperature point, the actual value of the comprehensive error of the current transformer (the combined modulus of the ratio error and angle error) is measured using a standard meter. The actual value of the comprehensive error is then fitted with the value using the least squares method. The linear relationship yields the slope, which is the temperature-error sensitivity coefficient. .

[0055] In this embodiment, The distortion loss-risk conversion factor represents the contribution of the distortion term to the risk. The unit is The results were obtained using a pure harmonic experiment. Specifically, the ambient temperature was controlled at a reference temperature. ,at this time With the fundamental current at zero and its effective value maintained at the rated value, a specific harmonic content is injected. Under each distortion condition, the actual value of the comprehensive error of the current transformer (the combined modulus of the ratio error and the phase angle error) is measured, and the corresponding equivalent distortion loss resistance is calculated simultaneously. The equivalent distortion loss resistance is determined by... The ratio of the ratio to the square of the rated current is used to obtain the linear relationship between the actual value of the overall error and the equivalent distortion loss resistance. The resulting slope is the distortion loss-risk conversion coefficient. .

[0056] S32, Set compensation threshold ,when A dynamic compensation strategy is employed, and compensation parameters are output, including amplitude compensation coefficients. and phase compensation time offset The formula for calculating the amplitude compensation coefficient is as follows: ;in, Rated current, For the current amplitude term coefficient, This is the coefficient for the temperature effect term. Here is the distortion loss term coefficient; the formula for calculating the phase compensation time offset is: ; The inherent time constant of the current transformer; when At that time, a fixed foundation compensation strategy is adopted and fixed foundation compensation parameters are output, wherein the fixed foundation compensation parameters include the base value of the amplitude compensation coefficient. and phase compensation time offset base value Amplitude compensation coefficient This is a dimensionless number. Compensation threshold. Designed based on engineering experience.

[0057] In this embodiment, in the formula for calculating the amplitude compensation coefficient, This is the current amplitude term, used to compensate for changes in the linearity of the current transformer caused by the operating current deviating from the rated value. The ratio-current characteristic was obtained through experiments, measuring different current points under reference temperature and distortion-free conditions. The ratio difference of the current transformer, the fitting ratio difference and The linear relationship yields the slope. .

[0058] In this embodiment, in the formula for calculating the amplitude compensation coefficient, This is a temperature-dependent term used to compensate for the transformer ratio drift caused by the decrease in permeability due to temperature. The result was obtained through a constant current temperature variation experiment, maintaining the current at [value missing]. By changing the ambient temperature, the ratio error of the current transformer is measured, and the fitting ratio error is compared with... The linear relationship yields the slope. .

[0059] In this embodiment, This is a distortion loss term, used to compensate for the effect of thermal saturation caused by the additional loss of the distortion current on the turns ratio. The distortion loss factor was obtained through a constant-temperature distortion experiment. Under reference temperature and rated fundamental current, different harmonic or DC content was varied to obtain different distortion loss factors. The ratio error of the current transformer was measured, and the fitting ratio error increased with... The slope of the change is obtained .

[0060] In this embodiment, For the current transformer at the reference temperature The inherent time constant is obtained by connecting a known load resistor to the secondary side of the current transformer, measuring the equivalent inductance of the secondary side of the current transformer, and then calculating the ratio of the equivalent inductance to the load resistance. .

[0061] In this embodiment, the fixed foundation compensation parameters are the inherent parameters of the equipment, and the amplitude compensation coefficient is the base value. and phase compensation time offset base value The method for obtaining the data is as follows: Under rated operating conditions, the electricity meter is compared with a standard electricity meter for testing, and fine adjustments are made. and To make the energy reading consistent with the standard energy meter, the result obtained is... and These are the base values ​​for amplitude compensation coefficient and phase compensation time offset.

[0062] S4. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters, and obtain the corrected discrete current sequence by linear interpolation of the discrete current sequence, and further obtain the calibrated cumulative energy.

[0063] In this embodiment, S4 includes the following specific steps:

[0064] S41. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters. The formula is: Where f is the preset sampling frequency, when a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, .

[0065] S42, For discrete current sequences The corrected discrete current sequence is obtained through linear interpolation. The formula is: ;in, , Indicates rounding down. When a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, .

[0066] S43, Based on the modified discrete current sequence The calibrated cumulative electrical energy is obtained. The formula is: ;in, A discrete voltage sequence synchronized with a discrete current sequence.

[0067] Example 2: This example provides an electronic device, including a processor and a memory, wherein the memory stores a computer program that can be called by the processor; the processor executes the above-described method for range calibration and error compensation of a smart meter for nonlinear loads by calling the computer program stored in the memory.

[0068] The electronic device can vary considerably depending on its configuration or performance. It may include one or more Central Processing Units (CPUs) and one or more memories, wherein the memory stores at least one computer program, which is loaded and executed by the processor to implement the method for range calibration and error compensation of smart meters for nonlinear loads provided in the above-described embodiment. The electronic device may also include other components for implementing its functions; for example, it may have wired or wireless network interfaces and input / output interfaces for data input and output. Further details are omitted here.

[0069] Those skilled in the art will recognize that this invention can be implemented as a system, method, or computer program product. Therefore, this disclosure can be embodied in the following forms: it can be entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, the invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.

[0070] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0071] This invention is described with reference to flowchart illustrations and block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and block diagrams, as well as combinations of blocks in the flowchart illustrations and block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart. Figure 1 One or more processes and boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and boxes Figure 1 The steps of the function specified in one or more boxes.

[0073] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for range calibration and error compensation of smart meters for nonlinear loads, characterized in that: The specific steps include the following: S1. Obtain the discrete current sequence at a preset sampling frequency and the temperature of the current transformer casing. Calculate the fundamental effective value and harmonic effective value of the current after performing a windowed fast Fourier transform on the discrete current sequence. Obtain the temperature influence factor using the temperature of the current transformer casing. S2. Based on the fundamental effective value and harmonic effective value of the current, the total harmonic distortion rate of the current, the DC component of the current and the true effective value of the current are obtained, and the distortion loss factor is further obtained. S3. Based on the temperature influence factor, the true effective value of the current, and the distortion loss factor, construct the error risk factor, compare the magnitude of the error risk factor with the compensation threshold, adopt the dynamic compensation strategy when the error risk factor is greater than the compensation threshold, and adopt the fixed basic compensation strategy when the error risk factor is not greater than the compensation threshold, and output the compensation parameters. S4. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters, and obtain the corrected discrete current sequence by linear interpolation of the discrete current sequence, and further obtain the calibrated cumulative energy. S3 includes the following specific steps: S31, Based on temperature influence factors True RMS value of current and distortion loss factor Constructing error risk factors The formula is: ;in, This is the temperature-error sensitivity coefficient. The distortion loss-risk conversion factor is used. It is a constant, and its value is... ; S32, Set compensation threshold ,when A dynamic compensation strategy is employed, and compensation parameters are output, including amplitude compensation coefficients. and phase compensation time offset The formula for calculating the amplitude compensation coefficient is as follows: ;in, Rated current, For the current amplitude term coefficient, This is the coefficient for the temperature effect term. Here is the distortion loss term coefficient; the formula for calculating the phase compensation time offset is: The inherent time constant of the current transformer; when At that time, a fixed foundation compensation strategy is adopted and fixed foundation compensation parameters are output, wherein the fixed foundation compensation parameters include the base value of the amplitude compensation coefficient. and phase compensation time offset base value ; S4 includes the following specific steps: S41. Calculate the sampling point offset based on the preset sampling frequency and compensation parameters. The formula is: Where f is the preset sampling frequency, when a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, ; S42, For discrete current sequences The corrected discrete current sequence is obtained through linear interpolation. The formula is: ;in, Indicates rounding down. When a dynamic compensation strategy is adopted, When a fixed foundation compensation strategy is adopted, ; S43, Based on the modified discrete current sequence The calibrated cumulative electrical energy is obtained. The formula is: ;in, A discrete voltage sequence synchronized with a discrete current sequence.

2. The method for range calibration and error compensation of a smart meter for nonlinear loads according to claim 1, characterized in that: S1 includes the following specific steps: S11. Obtain the discrete current sequence at a preset sampling frequency. And obtain the temperature of the current transformer casing. For discrete current sequences Perform a windowed Fast Fourier Transform and set the analysis window length to an integer multiple of the power frequency period to obtain the spectrum. Where n is the sampling point index and k is the frequency point index; S12, the frequency point corresponding to the fundamental frequency. The fundamental frequency spectrum was obtained. Calculate the effective value of the fundamental current. The formula is: ;in, The amplitude of the fundamental frequency spectrum. The amplitude recovery coefficient of the Fast Fourier Transform window function; S13. Locate the frequency point corresponding to the h-th harmonic. The harmonic spectrum is obtained. Calculate the effective value of harmonic current. The formula is: Where h is the harmonic order index, and the value of h is 2-H. Let h be the harmonic spectrum amplitude of the h-th harmonic. This represents the effective value of the harmonic current of the h-th harmonic.

3. The method for range calibration and error compensation of a smart meter for nonlinear loads according to claim 2, characterized in that: S1 further includes obtaining a temperature influence factor using the temperature of the current transformer casing, and the calculation formula for the temperature influence factor is as follows: ;in, Indicates the influence factor of temperature. The temperature coefficient of magnetic permeability of the core material. This is a reference temperature.

4. The method for range calibration and error compensation of a smart meter for nonlinear loads according to claim 3, characterized in that: S2 includes the following specific steps: S21, Based on the fundamental effective value of the current wave RMS value of harmonic current Calculate the total harmonic distortion rate of the current. The formula is: H represents the upper limit of the harmonic order; S22, for discrete current sequences The DC component of the current is obtained by arithmetically averaging over a single power frequency cycle. The formula is: ;in, The number of sampling points within a single power frequency cycle is obtained from the ratio of the preset sampling frequency to the fundamental frequency; S23. Obtain the total number of sampling points N in the current analysis window and calculate the true RMS value of the current. The formula is: ; S24, Based on the total harmonic distortion of current Effective value of fundamental current and the DC component of the current The distortion loss factor was obtained. The formula is: ;in, The first fixed loss factor, This is the second fixed loss coefficient.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for range calibration and error compensation of a smart meter for nonlinear loads as described in any one of claims 1-4.

6. An electronic device, characterized in that, It includes a memory for storing instructions; and a processor for executing the instructions, causing the device to perform a method for range calibration and error compensation of a smart meter for nonlinear loads as described in any one of claims 1 to 4.

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