An electric energy meter field calibrator

Abstract

The application discloses an electric energy meter on-site calibrator and relates to the technical field of electric energy meter detection. The application is characterized in that a plurality of algorithm units are cooperated with each other to jointly constitute the core framework of the electric energy meter on-site calibrator verification system. The average electric power P1 is calculated through a plurality of verification voltages and currents, so that the measurement error caused by a single test point can be avoided. Compared with the traditional fixed voltage verification method, the verification method can comprehensively reflect the performance of the electric energy meter under different voltage conditions, thereby improving the accuracy of the electric energy meter verification and ensuring the accuracy of the electric energy meter in actual use. The harmonic influence coefficient Hoe and the temperature change are taken into the adjusted electric power algorithm unit to calculate the adjusted electric power P2, so that the influence of the harmonic and the temperature change on the verification result can be corrected, the verification electric energy of the electric energy meter is closer to the actual consumed electric energy of the electric energy meter, and the high electric energy meter verification accuracy can be ensured under various working conditions.

Description

Technical Field

[0001] This invention relates to the field of electricity meter testing technology, specifically to an on-site calibrator for electricity meters. Background Technology

[0002] Electricity meters are an important component of the power system, used to measure electrical energy consumption and calculate electricity costs. However, over time and with increased lifespan, the accuracy of electricity meters may be affected, requiring calibration to ensure their precision and reliability.

[0003] For example, Chinese invention CN202310693384.9 discloses a meter field calibration instrument management system and method, which optimizes the process of meter testing based on the field calibration instrument and realizes automatic acquisition of meter parameters and automatic meter testing. Another example is a digital energy meter field calibration method and device disclosed in Chinese invention CN201710884469.X. This calibration device uses a specific pulse acquisition method and uses an FPGA parallel system for pulse acquisition and calibration. The total system error of energy pulse calibration is less than two high-frequency pulses, which can quickly and accurately detect the measurement error of the calibrated digital energy meter.

[0004] As mentioned in the above-mentioned references, the calibration of existing Class I electricity meters generally uses a calibration instrument that outputs a calibration voltage of 220V, which is the same as the residential voltage. However, in the actual process of residential electricity use, the voltage will fluctuate, especially during peak electricity consumption. Conventional calibration methods cannot change the output voltage of the calibration instrument to simulate the counting behavior of the electricity meter when the voltage fluctuates. This single calibration method is prone to calibration errors.

[0005] In the calibration of electricity meters, temperature changes can affect the calibration process, and harmonics can also cause distortion of the current waveform and the magnetic flux density waveform of the iron core, resulting in a nonlinear change in the hysteresis loop area, thus affecting the calibration of the electricity meter. Existing calibration meters are unable to take into account the impact of temperature changes and harmonics on the calibration.

[0006] Therefore, there is an urgent need for an on-site power meter calibrator to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to provide an on-site power meter calibrator to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an on-site power meter calibrator, comprising: a calibration system;

[0009] The verification system specifically includes:

[0010] The data collection module is used to collect energy meter verification data;

[0011] The data preprocessing module is used to decode and preprocess the data information in the database to obtain the parameters that will be used in the calculation in the calculation module.

[0012] The calculation and processing module, and the specific calculation and processing steps are as follows:

[0013] S1 is used to input the parameters obtained after decoding and preprocessing into the average power algorithm unit to calculate the average power P1.

[0014] S2, the average electric power P1 is input into the adjusted electric power algorithm unit in the calculation and processing module to calculate the adjusted electric power P2 by combining the harmonic influence term and the temperature deviation influence term, and then uploaded to the database;

[0015] S3, in the database, calculate the energy value Wmeter of the energy meter based on the adjusted power P2 and the time of the input voltage during verification;

[0016] S4, calculate the relative error Re of the electricity meter based on the electricity meter's energy value Wmeter and the standard energy value Wstd output by the calibrator. Specifically:

[0017] For Class 1 energy meters, if the relative error Re ≤ 1%, then perform subsequent energy meter pulse verification.

[0018] When the relative error Re of the electricity meter is 1% ≤ 3%, the parameter values ​​in the power algorithm unit are adjusted in the database through the feedback adjustment unit, and the calculation in the calculation processing module is re-performed.

[0019] When the relative error Re of the electricity meter is ≥3%, the electricity meter should be repaired or replaced.

[0020] Optionally, the collection of the electricity meter verification data specifically includes:

[0021] The actual voltage Van and actual current Ian are obtained through real-time monitoring using an electricity meter.

[0022] The rated voltage Vrn and rated current Irn are obtained through a programmable AC power supply.

[0023] The offset value Ih of the h-th harmonic, the highest harmonic order H to be compensated, and the harmonic order h are obtained by using an FFT spectrum analyzer.

[0024] The actual temperature Ta is obtained in real time through a temperature sensor;

[0025] And upload them to the database together.

[0026] Optionally, the adjustment of parameter values ​​in the adjusted power algorithm unit specifically includes:

[0027] The adjusted power P2 and the energy value of the electricity meter Wmeter are input into the compensation coefficient adjustment algorithm unit in the calculation and processing module to calculate the adjusted temperature compensation coefficient αnew and the adjusted harmonic compensation coefficient β. new Then, the calculation in the calculation processing module is re-performed.

[0028] Optionally, the calculation and processing module includes an average electric power algorithm unit, an adjusted electric power algorithm unit, a compensation coefficient adjustment value algorithm unit, and a feedback adjustment unit.

[0029] Optionally, the average electric power algorithm unit is as follows:

[0030]

[0031] in:

[0032] P1 represents the average electric power:

[0033] N represents the number of times the voltage is checked and output;

[0034] Van represents the actual voltage, which is the voltage value received by the energy meter when the voltage is output for the nth time;

[0035] Ian represents the actual current, which is the current value received by the energy meter during the nth voltage output.

[0036] Vrn represents the rated voltage, which is the rated voltage value output by the programmable AC power supply at the nth voltage output.

[0037] Irn represents the rated current, which is the rated current value output by the programmable AC power supply at the nth voltage output.

[0038] The rated voltage Vrn always satisfies:

[0039]

[0040] This part, calculated by dividing the actual voltage Van by the rated voltage Vrn, represents the impact of voltage deviation in the calculation of average power P1. In an electricity meter, voltage deviation from the rated value causes nonlinear changes in the driving force of the electromagnetic components and affects metering accuracy. This part amplifies the effect of voltage deviation on average power P1 using a power function of voltage deviation;

[0041] This part, calculated by dividing the actual current Ian by the rated current Irn, represents the impact of current deviation in the calculation of average power P1. In an electricity meter, current affects the accuracy of the device through thermal effects and electromagnetic interference. This part amplifies the effect of current deviation on average electric power P1 through a power function of voltage deviation;

[0042] Multiply the actual voltage Van by the actual current Ian, and then multiply by the voltage deviation term. and current deviation term The power of the energy meter at the nth verification is obtained. The power obtained from the N verifications is added together to get the total power. Then, the total power is divided by the number of verification voltage outputs N to get the average power P1.

[0043] Optionally, the adjusted electric power algorithm unit is as follows:

[0044] P2=P1×exp(α×|Ta-Ts|)×(1+β×Hoe)

[0045] in:

[0046] P2 represents the adjusted electrical power;

[0047] P1 represents the average electrical power;

[0048] Ta represents the actual temperature;

[0049] Ts represents the standard temperature, with a preset value of 25.

[0050] α represents the temperature compensation coefficient, with a default value of 0.1;

[0051] Hoe represents the harmonic influence coefficient;

[0052] β represents the harmonic compensation coefficient, with a default value of 0.1;

[0053] The |Ta-Ts| part uses the absolute difference between the actual temperature Ta and the standard temperature Ts as the exponent of the natural constant e to reflect the nonlinear effect of temperature change on the calculation of the adjusted electric power P2. As the absolute difference between the actual temperature Ta and the standard temperature Ts increases, the calculated value of the exp(α×|Ta-Ts|) part increases, thereby increasing the calculated adjusted electric power P2.

[0054] The spectrum of the test signal is analyzed by an FFT spectrum analyzer. It is set that harmonics with amplitudes exceeding 0.5% of the fundamental frequency need to be compensated. When the current is a pure sine wave, Hoe = 0, and the part 1 + β × Hoe is 1, so there is no additional compensation.

[0055] Optionally, the formula for calculating the harmonic influence coefficient Hoe is as follows:

[0056]

[0057] in:

[0058] Hoe represents the harmonic influence coefficient;

[0059] Ih represents the offset value of the h-th harmonic;

[0060] H represents the highest harmonic order that needs to be compensated;

[0061] h represents the harmonic order;

[0062] Regarding molecules When the harmonic order h = 1, it represents the fundamental wave, which is the main energy carrier of the power system. When the harmonic order h takes the value of 2 to 5, the 2nd to 5th harmonics are the low-order harmonics with the highest proportion in industrial and civil scenarios. The sum of squares operation linearly superimposes the amplitude energy of each harmonic to reflect the total pollution level of low-order harmonics.

[0063] Regarding the denominator It is the weighted sum of squares of harmonic currents according to their order. This part eliminates the influence of the absolute magnitude of the harmonic amplitude by dividing the numerator by the denominator, and calculates the harmonic influence coefficient Hoe based on the order distribution characteristics.

[0064] Optionally, the compensation coefficient adjustment value algorithm unit is as follows:

[0065]

[0066]

[0067] in:

[0068] α new This represents the adjusted temperature compensation coefficient;

[0069] β new This represents the adjusted harmonic compensation coefficient;

[0070] α represents the temperature compensation coefficient;

[0071] β represents the harmonic compensation coefficient;

[0072] Hoe represents the harmonic influence coefficient;

[0073] Pstd represents standard electrical power;

[0074] P2 represents the adjusted electrical power;

[0075] Ta represents the actual temperature;

[0076] Ts represents the standard temperature, with a preset value of 25.

[0077] Re represents the relative error of the electricity meter, and the calculation formula is as follows:

[0078]

[0079] in:

[0080] Wstd represents the standard electrical energy value;

[0081] Wmeter represents the electrical energy value measured by the electricity meter.

[0082] This part standardizes the deviation between the adjusted power P2 and the standard power Pstd by dividing the difference between the standard power Pstd and the adjusted power P2 by the standard power Pstd, and directly affects the adjusted temperature compensation coefficient α. new As the deviation between the adjusted power P2 and the standard power Pstd increases, the calculated adjusted temperature compensation coefficient α... new The larger;

[0083] In this section, the molecule |Ta-Ts| represents the absolute deviation between the actual temperature and the standard temperature. The denominator is a variation of the Sigmoid function, used to control for excessive effects at extreme temperatures. The numerator is divided by the denominator. This part represents the effect of temperature deviation on the adjusted temperature compensation coefficient α. new The effective impact value;

[0084] This part represents the relative error of electrical energy during the meter calibration, calculated by subtracting the absolute difference between the standard electrical energy value Wstd and the electrical energy value Wmeter, and then dividing by the electrical energy value Wmeter.

[0085] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0086] I. The calibration system within the calibrator of this invention, through the cooperation of multiple algorithm units, constitutes the core architecture of the on-site calibration system for electricity meters. By combining multiple calibration output voltages and calculating the average power P1 using multiple calibration voltages and currents, measurement errors caused by a single test point can be avoided. Compared with the traditional fixed voltage calibration method, this calibration method can more comprehensively reflect the performance of the electricity meter under different voltage conditions, thereby improving the accuracy of electricity meter calibration, helping to discover potential problems of the electricity meter under different working conditions, and ensuring its accuracy in actual use.

[0087] Second, by incorporating the harmonic influence coefficient Hoe into the adjusted power algorithm unit and calculating the adjusted power P2, this invention can correct the influence of harmonics on the verification results, making the verification power of the electricity meter closer to the actual power consumed by the electricity meter. By incorporating the temperature influence term into the adjusted power algorithm unit, it can correct the influence of temperature changes on the measurement results of the electricity meter. Thus, it can evaluate the performance of the electricity meter under harmonics and temperature changes during the electricity meter verification process, ensuring high accuracy of electricity meter verification under various operating conditions.

[0088] Third, this invention dynamically adjusts the values ​​of the temperature compensation coefficient α and harmonic compensation coefficient β in the power adjustment algorithm unit by real-time power deviation and energy deviation. This allows the calibration system to more accurately adjust the influence of temperature and harmonics on the adjusted power P2 according to actual environmental conditions, thereby improving the adaptability of the calibration system. Through dynamic parameter adjustment, the calibration of the energy meter of the calibrator is upgraded from "passive detection in a fixed mode" to "active calibration with environmental adaptation", providing a core algorithm guarantee for high-precision metering of smart grids. Attached Figure Description

[0089] Figure 1 A flowchart of a field test system for an electrical energy meter.

[0090] Figure 2 This is a schematic diagram of the overall structure of a field tester system for electrical energy meters. Detailed Implementation

[0091] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0092] Example 1, please refer to Figures 1 to 2 The present invention provides an on-site power meter calibrator, including a calibration system;

[0093] The verification system specifically includes:

[0094] The data collection module is used to collect electricity meter verification data, specifically including:

[0095] The actual voltage Van and actual current Ian are obtained through real-time monitoring using an electricity meter.

[0096] The rated voltage Vrn and rated current Irn are obtained through a programmable AC power supply.

[0097] The offset value Ih of the h-th harmonic, the highest harmonic order H to be compensated, and the harmonic order h are obtained by using an FFT spectrum analyzer.

[0098] The actual temperature Ta is obtained in real time through a temperature sensor;

[0099] And upload them together to the database;

[0100] The data preprocessing module is used to decode and preprocess the data information in the database to obtain the parameters that will be used in the calculation in the calculation module.

[0101] The calculation and processing module, and the specific calculation and processing steps are as follows:

[0102] S1 is used to input the parameters obtained after decoding and preprocessing into the average power algorithm unit to calculate the average power P1.

[0103] S2, the average electric power P1 is input into the adjusted electric power algorithm unit in the calculation and processing module to calculate the adjusted electric power P2 by combining the harmonic influence term and the temperature deviation influence term, and then uploaded to the database;

[0104] S3, in the database, calculate the energy value Wmeter of the energy meter based on the adjusted power P2 and the time of the input voltage during verification;

[0105] S4, calculate the relative error Re of the electricity meter based on the electricity meter's energy value Wmeter and the standard energy value Wstd output by the calibrator. Specifically:

[0106] For Class 1 energy meters, if the relative error Re ≤ 1%, then perform subsequent energy meter pulse verification.

[0107] When the relative error Re of the electricity meter is 1% ≤ 3%, the parameter values ​​in the power algorithm unit are adjusted in the database through the feedback adjustment unit, and the calculation in the calculation processing module is re-performed.

[0108] When the relative error Re of the electricity meter is ≥3%, the electricity meter should be repaired or replaced.

[0109] In this embodiment:

[0110] The calibration system within the calibrator of this invention, through the cooperation of multiple algorithm units, constitutes the core architecture of the on-site calibration system for electricity meters. By combining multiple calibration output voltages and calculating the average power P1 using multiple calibration voltages and currents, it avoids measurement errors caused by a single test point. This calibration method can more comprehensively reflect the performance of the electricity meter under different voltage conditions, thereby improving the accuracy of electricity meter calibration. Traditional calibration methods may only focus on the performance of the electricity meter under specific voltage or current conditions, while the new calibration method, through multiple measurements and average calculations, can more comprehensively evaluate the performance of the electricity meter. This helps to discover potential problems of the electricity meter under different operating conditions and ensure its accuracy in actual use.

[0111] Furthermore, in actual operation, the presence of harmonics in electricity meters can cause distortion of the current waveform, thus affecting the measurement accuracy of the electricity meter. By incorporating the harmonic influence coefficient Hoe into the calculation of the adjusted power algorithm unit and calculating the adjusted power P2, the influence of harmonics on the verification results can be corrected, making the verification value of the electricity meter closer to the actual energy consumed by the electricity meter. By incorporating the temperature influence term into the calculation of the adjusted power algorithm unit and calculating the adjusted power P2, the influence of temperature changes on the measurement results of the electricity meter can be corrected. Thus, the performance of the electricity meter under harmonics and temperature changes can be evaluated during the electricity meter verification process, ensuring high verification accuracy of the electricity meter under various operating conditions.

[0112] Please see Figures 1 to 2 The average power algorithm unit is as follows:

[0113]

[0114] in:

[0115] P1 represents the average electric power:

[0116] N represents the number of times the voltage is checked and output;

[0117] Van represents the actual voltage, which is the voltage value received by the energy meter during the nth voltage output, obtained through real-time monitoring by the energy meter.

[0118] Ian represents the actual current, which is the current value received by the energy meter during the nth voltage output, obtained through real-time monitoring by the energy meter.

[0119] Vrn represents the rated voltage, which is the rated voltage value output by the programmable AC power supply at the nth voltage output.

[0120] Irn represents the rated current, which is the rated current value output by the programmable AC power supply at the nth voltage output.

[0121] The rated voltage Vrn always satisfies:

[0122]

[0123] in:

[0124] This part, calculated by dividing the actual voltage Van by the rated voltage Vrn, represents the impact of voltage deviation in the calculation of average power P1. In an electricity meter, voltage deviation from the rated value causes nonlinear changes in the driving force of the electromagnetic components and affects metering accuracy. This part amplifies the effect of voltage deviation on average power P1 using a power function of voltage deviation;

[0125] This part, calculated by dividing the actual current Ian by the rated current Irn, represents the impact of current deviation in the calculation of average power P1. In an electricity meter, current affects the accuracy of the device through thermal effects and electromagnetic interference. This part amplifies the effect of current deviation on average electric power P1 through a power function of voltage deviation;

[0126] Multiply the actual voltage Van by the actual current Ian, and then multiply by the voltage deviation term. and current deviation term The power of the energy meter at the nth verification is obtained. The power obtained from the N verifications is added together to get the total power. Then, the total power is divided by the number of verification voltage outputs N to get the average power P1.

[0127] In this embodiment:

[0128] The average power algorithm unit, by combining the effects of current and voltage deviations during energy meter calibration with multiple calibration output voltages and calculating the average power P1 using multiple sets of calibration voltages and currents, avoids measurement errors caused by a single test point. This calibration method more comprehensively reflects the performance of the energy meter under different voltage conditions, thereby improving the accuracy of energy meter calibration. The average power algorithm unit also comprehensively considers the effects of current and voltage deviations, meaning that when calculating the average power, it considers not only the actual values ​​of voltage and current but also their deviations from the rated values. This comprehensive consideration allows for a more accurate evaluation of the energy meter's performance in actual use. Traditional calibration methods may only focus on the energy meter's performance under specific voltage or current conditions, while the new calibration method, through multiple measurements and averaging calculations, can more comprehensively evaluate the energy meter's performance. This helps to identify potential problems with the energy meter under different operating conditions, ensuring its accuracy in actual use.

[0129] In summary, by performing multiple measurements and averaging calculations, the new verification method can reduce the impact of single measurement errors or abnormal performance under specific working conditions on the final results. This helps to improve the reliability of the verification results and reduce the risk of errors.

[0130] Please see Figures 1 to 2 The adjusted power algorithm unit is as follows:

[0131] P2=P1×exp(α×|Ta-Ts|)×(1+β×Hoe)

[0132] in:

[0133] P2 represents the adjusted electrical power;

[0134] P1 represents the average electrical power;

[0135] Ta represents the actual temperature;

[0136] Ts represents the standard temperature, with a preset value of 25.

[0137] α represents the temperature compensation coefficient, with a default value of 0.1, which can be self-adjusted in the calibration system;

[0138] Hoe represents the harmonic influence coefficient;

[0139] β represents the harmonic compensation coefficient, with a default value of 0.1, which can be self-adjusted in the calibration system;

[0140] In the formula calculation:

[0141] Both excessively high and low ambient temperatures can affect the performance of internal components of an electricity meter, especially resistive elements. The resistivity of metals increases with temperature, causing a shift in the resistance value of the current sampling resistor and affecting the accuracy of current measurement. The part |Ta-Ts| uses the absolute difference between the actual temperature Ta and the standard temperature Ts as the exponent of the natural constant e to reflect the nonlinear effect of temperature changes on the calculation of the adjusted power P2. As the absolute difference between the actual temperature Ta and the standard temperature Ts increases, the calculated value of exp(α×|Ta-Ts|) increases, thereby increasing the calculated adjusted power P2.

[0142] In the calibration of electricity meters, harmonics can cause distortion of the current waveform and the magnetic flux density waveform of the iron core, resulting in a nonlinear change in the hysteresis loop area. When the current is a pure sine wave, Hoe = 0, and the part 1 + β × Hoe is 1, with no additional compensation. By analyzing the spectrum of the test signal using an FFT spectrum analyzer, it is set that harmonics with amplitudes exceeding 0.5% of the fundamental wave need to be compensated. The FFT analyzer automatically identifies the harmonic order h that needs to be compensated and determines the highest harmonic order H that needs to be compensated. This is a relatively mature existing technology in the field of harmonic analysis, which will not be described in detail here.

[0143] The formula for calculating the harmonic influence factor Hoe is as follows:

[0144]

[0145] in:

[0146] Hoe represents the harmonic influence coefficient;

[0147] Ih represents the offset value of the h-th harmonic, which is obtained by an FFT spectrum analyzer;

[0148] H represents the highest harmonic order that needs to be compensated, which is obtained through an FFT spectrum analyzer.

[0149] h represents the harmonic order, which is obtained using an FFT spectrum analyzer;

[0150] In the formula calculation:

[0151] Regarding molecules When the harmonic order h = 1, it represents the fundamental wave, which is the main energy carrier of the power system. When the harmonic order h takes the value of 2 to 5, the 2nd to 5th harmonics are the low-order harmonics with the highest proportion in industrial and civil scenarios. The sum of squares operation linearly superimposes the amplitude energy of each harmonic to reflect the total pollution level of low-order harmonics.

[0152] Regarding the denominator It is the weighted sum of squares of harmonic currents according to their order. This part eliminates the influence of the absolute magnitude of the harmonic amplitude by dividing the numerator by the denominator, and calculates the harmonic influence coefficient Hoe through the order distribution characteristics;

[0153] In this embodiment:

[0154] In actual operation, the presence of harmonics in electricity meters can cause distortion of the current waveform, thus affecting the measurement accuracy. By incorporating the harmonic influence coefficient Hoe into the calculation of the adjusted power algorithm unit and obtaining the adjusted power P2, the influence of harmonics on the verification results can be corrected, making the verification value of the electricity meter closer to the actual energy consumed by the meter. This also provides more accurate data support for subsequent power system monitoring, management, and billing. The performance of electricity meters is affected by temperature. The deviation of the actual temperature Ta from the standard temperature Ts can cause errors in electricity meter verification. By incorporating the temperature influence term into the calculation of the adjusted power algorithm unit and obtaining the adjusted power P2, the influence of temperature changes on the electricity meter measurement results can be corrected, further improving the verification accuracy.

[0155] By calculating the adjusted power P2 using the adjusted power algorithm unit, the performance of the electricity meter under harmonic and temperature changes can be evaluated during the electricity meter calibration process, so as to ensure high calibration accuracy of the electricity meter under various operating conditions.

[0156] Multiplying the calculated adjusted power P2 by the input voltage time during verification yields the energy value Wmeter of the energy meter. Based on this energy value, subsequent energy meter pulse verification is performed, specifically including:

[0157] Connect the pulse output terminal of the meter to the input terminal of the calibrator using a dedicated pulse cable;

[0158] Input parameters such as the energy meter's pulse constant (e.g., 1600 imp / kWh), voltage, and current ratio into the calibrator;

[0159] Set a preset number of pulses (1000), and the calibrator will simultaneously record the actual number of pulses from the energy meter and the standard number of pulses, and calculate the error.

[0160] The calibrator automatically compares the measured pulse count with the theoretical pulse count, calculates the result according to the error formula, and rounds it to the specified decimal place.

[0161] Pulse verification of electricity meters is a relatively mature existing technology, so it will not be discussed in detail here.

[0162] Please see Figures 1 to 2 The algorithm unit for adjusting the compensation coefficient is as follows:

[0163]

[0164] in:

[0165] α new This represents the adjusted temperature compensation coefficient;

[0166] β new This represents the adjusted harmonic compensation coefficient;

[0167] α represents the temperature compensation coefficient;

[0168] β represents the harmonic compensation coefficient;

[0169] Hoe represents the harmonic influence coefficient;

[0170] Pstd represents the standard power, which is calculated from the rated voltage and rated current of the calibrator outputting 220V. Specifically: Standard power = Rated voltage × Rated current × Phase angle between current and voltage;

[0171] P2 represents the adjusted electrical power;

[0172] Ta represents the actual temperature;

[0173] Ts represents the standard temperature, with a preset value of 25.

[0174] Re represents the relative error of the electricity meter, and the calculation formula is as follows:

[0175]

[0176] in:

[0177] Wstd represents the standard energy value, which is obtained through the internal data of the calibrator and is the standard value for calibrating energy values.

[0178] Wmeter represents the electrical energy value measured by the electricity meter.

[0179] In the formula calculation:

[0180] This part standardizes the deviation between the adjusted power P2 and the standard power Pstd by dividing the difference between the standard power Pstd and the adjusted power P2 by the standard power Pstd, and directly affects the adjusted temperature compensation coefficient α. new As the deviation between the adjusted power P2 and the standard power Pstd increases, the calculated adjusted temperature compensation coefficient α... new The larger;

[0181] In this section, the molecule |Ta-Ts| represents the absolute deviation between the actual temperature and the standard temperature. The denominator is a variation of the Sigmoid function, used to control for excessive effects at extreme temperatures. The numerator is divided by the denominator. This part represents the effect of temperature deviation on the adjusted temperature compensation coefficient α. new The effective impact value;

[0182] This part is calculated by subtracting the absolute difference between the standard energy value Wstd and the energy value Wmeter of the energy meter, and then dividing by the energy value Wmeter of the energy meter. This represents the relative error of the energy during the energy meter calibration.

[0183] In this embodiment:

[0184] During the on-site calibration of electricity meters by the calibrator, the voltage and current characteristic curves of the electricity meters exhibit nonlinearity when deviating from the rated values ​​(such as core magnetic saturation, thermal effects, etc.). Traditional fixed-parameter compensation models cannot cover the entire range. The compensation coefficient adjustment algorithm unit dynamically adjusts the values ​​of the temperature compensation coefficient α and harmonic compensation coefficient β in the adjusted power algorithm unit based on real-time power deviation and energy deviation. This allows the calibration system to more accurately adjust the influence of temperature and harmonics on the adjusted power P2 according to actual environmental conditions (such as sudden temperature drops during outdoor calibration, or harmonic abrupt changes caused by inverter start-up and shutdown in new energy power plants). This improves the adaptability of the calibration system. Through dynamic parameter adjustment, the electricity meter calibration of the calibrator is upgraded from "passive detection in fixed mode" to "environmentally adaptive active calibration," providing core algorithmic support for high-precision metering in smart grids.

[0185] The effect of temperature on electricity meters is a complex process; the measurement error of electricity meters may vary at different temperatures. By dynamically adjusting the temperature compensation coefficient, the algorithm module can more accurately correct the impact of temperature on the electricity meter measurement results based on actual temperature changes, thereby improving the accuracy of the measurement results. Harmonics can cause distortion of the current waveform, affecting the measurement accuracy of electricity meters. Dynamically adjusting the harmonic compensation coefficient can more effectively suppress harmonic interference based on the actual harmonic content, making the measured value of the electricity meter closer to the actual energy consumption. Furthermore, different models and brands of electricity meters may have different sensitivities to temperature and harmonics. Dynamically adjusting the compensation coefficient allows the algorithm module to better adapt to the characteristics of different electricity meters, ensuring accurate calibration for various types of electricity meters.

[0186] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An on-site power meter calibrator, characterized in that, include: Verification system; The verification system specifically includes: The data collection module is used to collect energy meter verification data; The data preprocessing module is used to decode and preprocess the data information in the database to obtain the parameters that will be used in the calculation in the calculation module. The calculation and processing module, and the specific calculation and processing steps are as follows: S1 is used to input the parameters obtained after decoding and preprocessing into the average power algorithm unit to calculate the average power P1. S2, the average electric power P1 is input into the adjusted electric power algorithm unit in the calculation and processing module to calculate the adjusted electric power P2 by combining the harmonic influence term and the temperature deviation influence term, and then uploaded to the database; S3, in the database, calculate the energy value Wmeter of the energy meter based on the adjusted power P2 and the time of the input voltage during verification; S4, calculate the relative error Re of the electricity meter based on the electricity meter's energy value Wmeter and the standard energy value Wstd output by the calibrator. Specifically: For Class 1 energy meters, if the relative error Re ≤ 1%, then perform subsequent energy meter pulse verification. When the relative error Re of the electricity meter is 1% ≤ 3%, the parameter values ​​in the power algorithm unit are adjusted in the database through the feedback adjustment unit, and the calculation in the calculation processing module is re-performed. When the relative error Re of the electricity meter is ≥3%, the electricity meter should be repaired or replaced. The calculation and processing module includes an average electric power algorithm unit, an adjusted electric power algorithm unit, a compensation coefficient adjustment value algorithm unit, and a feedback adjustment unit. The average electric power algorithm unit is as follows: ； Where P1 represents the average power, N represents the number of voltage output verifications, Van represents the actual voltage, which is the voltage value received by the energy meter during the nth voltage output, Ian represents the actual current, which is the current value received by the energy meter during the nth voltage output, Vrn represents the rated voltage, which is the rated voltage value output by the programmable AC power supply during the nth voltage output, and Irn represents the rated current, which is the rated current value output by the programmable AC power supply during the nth voltage output. The adjusted electric power algorithm unit is as follows: ； Where P2 represents the adjusted power, P1 represents the average power, Ta represents the actual temperature, Ts represents the standard temperature (preset value is 25), α represents the temperature compensation coefficient (default value is 0.1), Hoe represents the harmonic influence coefficient, and β represents the harmonic compensation coefficient (default value is 0.1).

2. The on-site verification instrument for electrical energy meters according to claim 1, characterized in that: The collection of the electricity meter verification data specifically includes: The actual voltage Van and actual current Ian are obtained through real-time monitoring using an electricity meter. The rated voltage Vrn and rated current Irn are obtained through a programmable AC power supply. The offset value Ih of the h-th harmonic, the highest harmonic order H to be compensated, and the harmonic order h are obtained by using an FFT spectrum analyzer. The actual temperature Ta is obtained in real time through a temperature sensor; And upload them to the database together.

3. The on-site verification instrument for electrical energy meters according to claim 1, characterized in that: The adjustment of parameter values ​​in the adjusted power algorithm unit specifically includes: The adjusted power P2 and the energy value of the electricity meter Wmeter are input into the compensation coefficient adjustment algorithm unit in the calculation and processing module to calculate the adjusted temperature compensation coefficient α. new and the adjusted harmonic compensation coefficient β new Then, the calculation in the calculation processing module is re-performed.

4. The on-site verification instrument for electrical energy meters according to claim 3, characterized in that: The rated voltage Vrn in the average electric power algorithm unit always satisfies: ； This part, calculated by dividing the actual voltage Van by the rated voltage Vrn, represents the impact of voltage deviation in the calculation of average power P1. In an electricity meter, voltage deviation from the rated value causes nonlinear changes in the driving force of the electromagnetic components and affects metering accuracy. This part amplifies the effect of voltage deviation on average power P1 using a power function of voltage deviation; This part, calculated by dividing the actual current Ian by the rated current Irn, represents the impact of current deviation in the calculation of average power P1. In an electricity meter, current affects the accuracy of the device through thermal effects and electromagnetic interference. This part amplifies the effect of current deviation on average electric power P1 through a power function of voltage deviation; Multiply the actual voltage Van by the actual current Ian, and then multiply by the voltage deviation term. and current deviation term The power of the energy meter during the nth verification is obtained. The power obtained from the N verifications is added together to get the total power. Then, the total power is divided by the number of verification voltage outputs N to get the average power P1.

5. The on-site verification instrument for electrical energy meters according to claim 4, characterized in that: The adjusted power algorithm unit This part uses the absolute difference between the actual temperature Ta and the standard temperature Ts as the exponent of the natural constant e to reflect the nonlinear effect of temperature change on the calculation of the adjusted electric power P2. This part is achieved by increasing the absolute difference between the actual temperature Ta and the standard temperature Ts. The calculated value of this part is increased, thereby increasing the calculated adjusted electric power P2; The spectrum of the test signal was analyzed using an FFT spectrum analyzer. Harmonics with amplitudes exceeding 0.5% of the fundamental frequency were to be compensated. When the current was a pure sine wave, Hoe = 0. This part is 1, with no additional compensation.

6. The on-site verification instrument for electrical energy meters according to claim 5, characterized in that: The formula for calculating the harmonic influence coefficient Hoe is as follows: ； Where Hoe represents the harmonic influence coefficient, Ih represents the offset value of the h-th harmonic, H represents the highest harmonic order that needs to be compensated, and h represents the harmonic order. Regarding molecules When the harmonic order h=1, it represents the fundamental wave, which is the main energy carrier of the power system. When the harmonic order h takes the value of 2 to 5, the 2nd to 5th harmonics are the low-order harmonics with the highest proportion in industrial and civil scenarios. The sum of squares operation linearly superimposes the amplitude energy of each harmonic to reflect the total pollution level of low-order harmonics. Regarding the denominator It is the weighted sum of squares of harmonic currents according to their order. This part eliminates the influence of the absolute magnitude of the harmonic amplitude by dividing the numerator by the denominator, and calculates the harmonic influence coefficient Hoe based on the order distribution characteristics.

7. The on-site verification instrument for electrical energy meters according to claim 6, characterized in that, The algorithm unit for adjusting the compensation coefficient is as follows: ； ； Where α new β represents the adjusted temperature compensation coefficient. new Here, α represents the adjusted harmonic compensation coefficient, β represents the temperature compensation coefficient, Hoe represents the harmonic influence coefficient, Pstd represents the standard power, P2 represents the adjusted power, Ta represents the actual temperature, Ts represents the standard temperature (preset value is 25), and Re represents the relative error of the energy meter, calculated using the following formula: ； Where Wstd represents the standard energy value and Wmeter represents the energy value measured by the energy meter. This part standardizes the deviation between the adjusted power P2 and the standard power Pstd by dividing the difference between the standard power Pstd and the adjusted power P2 by the standard power Pstd, and directly affects the adjusted temperature compensation coefficient α. new As the deviation between the adjusted power P2 and the standard power Pstd increases, the calculated adjusted temperature compensation coefficient α... new The larger; The molecules in this part This represents the absolute deviation between the actual temperature and the standard temperature. The denominator is a variation of the Sigmoid function, used to control for excessive effects at extreme temperatures. The numerator is divided by the denominator. The overall representation of the temperature deviation with respect to the adjusted temperature compensation coefficient α new The effective impact value; This part represents the relative error of electrical energy during the meter calibration, calculated by subtracting the absolute difference between the standard electrical energy value Wstd and the electrical energy value Wmeter, and then dividing by the electrical energy value Wmeter.

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