High-precision voltage and current synchronous metering system for AC / DC integrated standard energy meters

Abstract

This invention relates to the field of electricity metering technology, specifically to a high-precision voltage and current synchronous metering system for AC / DC integrated standard electricity meters. The system uses a hysteresis analysis module and an eddy current analysis module to analyze the current signal, obtaining the hysteresis intensity factor and eddy current loss factor of the electricity meter. Then, through a hysteresis and eddy current coupling module, time scale weights and instantaneous energy loss ratios are introduced to analyze the combined loss factor of eddy current and hysteresis effects, achieving adaptive allocation of their weights and performing primary compensation on the current signal. A temperature compensation module analyzes the temperature effect on the electricity meter and performs temperature compensation on both the voltage and current signals. This system can effectively handle complex dynamic operating conditions, ensure temperature stability of measurements, and cut off the transmission and accumulation path of errors at their source, improving metering accuracy under AC / DC mixed signals and ensuring the interpretability and reliability of the system.

Description

Technical Field

[0001] This invention relates to the field of electricity metering technology, specifically to a high-precision voltage and current synchronous metering system for AC / DC integrated standard electricity meters. Background Technology

[0002] AC energy meters serve as terminal devices for measuring electrical energy and are also an important means of economic accounting and power grid operation status assessment in the power grid system.

[0003] In the field of AC / DC integrated power metering, the measurement error introduced by fluxgate current sensors due to their non-ideal characteristics is a core challenge restricting metering accuracy. The hysteresis effect of the fluxgate current sensor core prevents its magnetization state from keeping up with changes in the external magnetic field, resulting in amplitude and phase distortion. Meanwhile, the eddy current effect creates a reverse magnetic field within the core under alternating magnetic fields, further distorting the output signal. The hysteresis and eddy current effects are coupled, and their influence dynamically changes with the amplitude, frequency, and direction of the current signal. Especially under complex operating conditions, such as rapid current transients or wide-frequency operation, fixed weighting strategies struggle to distinguish the dominance of the hysteresis and eddy current effects, leading to insufficient or excessive compensation. Furthermore, sensor gain drifts with temperature, and the thermal sensitivity of the resistive voltage divider network and the magnetic core permeability further introduces slowly varying errors. Summary of the Invention

[0004] To address the above technical problems, this invention provides a high-precision voltage and current synchronous metering system for AC / DC integrated standard energy meters.

[0005] The high-precision voltage and current synchronous metering system of the AC / DC integrated standard energy meter provided in the embodiments of this application specifically includes:

[0006] The data acquisition module is used to collect the current signal, voltage signal, and temperature data of the electricity meter;

[0007] The hysteresis analysis module is used to obtain the magnetic memory state and direction recognition factor of the energy meter based on the current signal, and to obtain the hysteresis coefficient of the energy meter by performing DC current testing on the energy meter, thereby obtaining the hysteresis intensity factor of the energy meter.

[0008] The eddy current analysis module is used to obtain the current change rate of the energy meter based on the current signal, and to obtain the eddy current effect coefficient of the energy meter by performing AC current testing on the energy meter, thereby obtaining the eddy current loss factor of the energy meter.

[0009] The hysteresis and eddy current coupling module is used to introduce time scale weight and instantaneous energy loss ratio, and combine the hysteresis intensity factor and the eddy current loss factor to analyze the comprehensive loss factor of eddy current effect and hysteresis effect, and perform a first compensation on the current signal.

[0010] The temperature compensation module is used to analyze the voltage gain variation factor and current gain variation factor of the electricity meter based on the temperature data, and to perform temperature compensation on the voltage signal and current signal to complete the electricity metering.

[0011] In some embodiments of the present invention, the hysteresis analysis module includes a magnetic memory state acquisition unit, used to obtain the magnetic memory state of the energy meter based on the current signal, wherein the magnetic memory state acquisition unit is configured to:

[0012] Obtain the historical amplitude extreme point sequence of the current signal;

[0013] In the historical amplitude extreme value sequence, the amplitude maximum and minimum values ​​closest to any sampling time are obtained, and the arithmetic mean of the amplitude maximum and minimum values ​​is calculated to obtain the magnetic memory state of the fluxgate current sensor in the energy meter at any sampling time.

[0014] In some embodiments of the present invention, the hysteresis analysis module further includes a direction identification factor acquisition unit, used to obtain the direction identification factor of the energy meter based on the current signal, wherein the direction identification factor acquisition unit is configured as follows:

[0015] Obtain the direction of change of the current signal at any sampling time, let 1 represent increase and -1 represent decrease, and denote it as the direction recognition factor of the fluxgate current sensor in the energy meter at any sampling time.

[0016] In some embodiments of the present invention, the hysteresis analysis module further includes a hysteresis coefficient acquisition unit, used to obtain the hysteresis coefficient by performing a DC current test on the energy meter, wherein the hysteresis coefficient acquisition unit is configured as follows:

[0017] A slow, incremental DC test current, starting from 0, is applied to the fluxgate current sensor in the energy meter to form a symmetrical magnetization curve containing multiple sub-loops.

[0018] Record the current value after each DC test current step stabilizes;

[0019] Analyze the difference in current amplitude between the rising and falling curves at the same current point in the magnetization curve;

[0020] The hysteresis coefficient of the fluxgate current sensor in the energy meter is obtained by fitting the relationship between the DC test current and the difference in current amplitude using linear regression.

[0021] In some embodiments of the present invention, the eddy current analysis module includes a current change rate acquisition unit, used to obtain the current change rate of the energy meter based on the current signal, wherein the current change rate acquisition unit is configured to:

[0022] Based on the current signal, the output current signal corresponding to any sampling time and the previous sampling time is obtained, and the corresponding sampling time interval is calculated to obtain the current change rate of the fluxgate current sensor in the energy meter at any sampling time.

[0023] In some embodiments of the present invention, the eddy current analysis module further includes an eddy current effect coefficient acquisition unit, used to perform AC current testing on the energy meter to obtain the eddy current effect coefficient of the energy meter, wherein the eddy current effect coefficient acquisition unit is configured as follows:

[0024] Applying different frequencies to the fluxgate current sensor in the electricity meter The sinusoidal AC test current is used to measure the phase lag of the test current signal output by the fluxgate current sensor relative to the standard reference current transformer signal. ;

[0025] Fitting by linear regression and The relationship between these factors is used to obtain the eddy current effect coefficient of the fluxgate current sensor in the energy meter.

[0026] In some embodiments of the present invention, the hysteresis and eddy current coupling module includes a time-scale weighting unit for introducing time-scale weights, wherein the time-scale weighting unit is configured to:

[0027] The ratio between the absolute value of the current change rate and the absolute value of the magnetic memory state is calculated, and combined with the minimum value function, the time scale weight of the fluxgate current sensor in the energy meter at any sampling time is obtained.

[0028] In some embodiments of the present invention, the hysteresis and eddy current coupling module further includes an instantaneous energy loss ratio introduction unit for introducing an instantaneous energy loss ratio, wherein the instantaneous energy loss ratio introduction unit is configured to:

[0029] Based on the magnetic memory state, the hysteresis coefficient, the current change rate, and the eddy current effect coefficient, the severity of the total loss of the fluxgate current sensor in the energy meter at any sampling time is determined.

[0030] Based on the severity of the total loss, combined with the rate of change of current and the eddy current effect coefficient, a comprehensive eddy current weight based on the proportion of instantaneous energy loss is obtained.

[0031] In some embodiments of the present invention, the temperature compensation module includes:

[0032] The gain variation factor acquisition unit is used to acquire the difference between the actual collected temperature data and the reference temperature, as well as to acquire the resistance temperature coefficient of the voltage sensor and the core material temperature coefficient of the fluxgate current sensor, and to obtain the voltage gain variation factor of the voltage sensor and the current gain variation factor of the fluxgate current sensor.

[0033] A voltage compensation unit is used to perform temperature compensation on the voltage signal according to the voltage gain change factor to obtain the compensation voltage of the voltage sensor.

[0034] The current compensation unit is used to perform temperature compensation on the current signal according to the current gain change factor to obtain the secondary compensation current of the fluxgate current sensor.

[0035] In some embodiments of the present invention, the data acquisition module includes a voltage and current synchronous acquisition unit for acquiring the current signal and voltage signal of the energy meter, wherein the voltage and current synchronous acquisition unit is configured as follows:

[0036] The sampling clocks of the voltage sensor and fluxgate current sensor in the energy meter are synchronously triggered and simultaneously sent to the analog-to-digital converters of the voltage and current channels of the energy meter. The input analog voltage and current signals are sampled at the same sampling time to obtain the current and voltage signals of the energy meter.

[0037] Compared with existing technologies, the high-precision voltage and current synchronous metering system of the AC / DC integrated standard energy meter provided by this invention has the following beneficial effects:

[0038] This invention utilizes a data acquisition module to collect and preprocess current, voltage, and temperature data from an energy meter. A hysteresis analysis module analyzes the current signal to obtain the energy meter's magnetic memory state and direction recognition factor, and performs DC current testing to obtain the hysteresis coefficient, thus yielding the hysteresis intensity factor. An eddy current analysis module analyzes the current signal to obtain the energy meter's current change rate, and performs AC current testing to obtain the eddy current effect coefficient, thus yielding the eddy current loss factor. A hysteresis and eddy current coupling module introduces time scale weights and instantaneous energy loss ratios, combining the hysteresis intensity factor and eddy current loss factor to analyze the combined loss factor of eddy current and hysteresis effects, performing initial compensation on the current signal. Finally, a temperature compensation module analyzes the voltage gain variation factor and current gain variation factor affected by temperature, performing temperature compensation on the voltage and current signals to complete energy metering. This invention achieves high-precision correction of measurement errors in fluxgate current sensors by constructing a dynamic weighted comprehensive loss factor and a full-chain compensation mechanism. By introducing time-scale weights and instantaneous energy loss ratios, it achieves adaptive allocation of hysteresis and eddy current effects, ensuring that hysteresis compensation is emphasized during slow current changes and eddy current compensation is emphasized during rapid current changes, effectively addressing complex dynamic conditions. Furthermore, a temperature compensation model based on material physics properties eliminates the influence of ambient temperature changes on the voltage and current channel gains, ensuring the temperature stability of the measurement. Finally, by using pure voltage and current signals after multi-stage compensation for instantaneous power calculation and energy accumulation, the propagation and accumulation paths of errors are fundamentally cut off, improving the measurement accuracy under AC / DC mixed signals and further ensuring the interpretability and reliability of the measurement system. Attached Figure Description

[0039] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic diagram of the basic components of a high-precision voltage and current synchronous metering system for an integrated AC / DC standard energy meter provided in one embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the basic components of a high-precision voltage and current synchronous metering system for an AC / DC integrated standard energy meter, as provided in one embodiment of the present invention. Detailed Implementation

[0042] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the high-precision voltage and current synchronous metering system for AC / DC integrated standard energy meters proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0043] 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. Terms such as “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or device comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such article or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of additional identical elements in the article or device that includes the element.

[0044] The following description, in conjunction with the accompanying drawings, details the specific scheme of a high-precision voltage and current synchronous metering system for an integrated AC / DC standard energy meter provided by the present invention.

[0045] Please see Figure 1 This illustrates the basic components of a high-precision voltage and current synchronous metering system for an integrated AC / DC standard energy meter provided by an embodiment of the present invention.

[0046] like Figure 1 As shown in the figure, an embodiment of the present invention provides a high-precision voltage and current synchronous metering system for an AC / DC integrated standard energy meter. The system mainly includes a data acquisition module 1, a hysteresis analysis module 2, an eddy current analysis module 3, a hysteresis and eddy current coupling module 4, and a temperature compensation module 5.

[0047] Data acquisition module 1 is used to acquire current signals, voltage signals, and temperature data from the electricity meter. Further, such as... Figure 2 As shown, the data acquisition module 1 includes a voltage and current synchronous acquisition unit 11, a temperature data acquisition unit 12, and a data preprocessing unit 13, wherein:

[0048] The voltage and current synchronous acquisition unit 11 is used to acquire the current and voltage signals of the energy meter. Specifically, the voltage and current synchronous acquisition unit 11 is configured to synchronously trigger the sampling clocks of the voltage sensor and the fluxgate current sensor in the energy meter (the sampling clocks are generated using an FPGA field-programmable gate array for high stability), and simultaneously send them to the analog-to-digital converters (ADCs) of the voltage and current channels of the energy meter through a high-speed, low-latency signal transmission line. The input analog voltage and current signals are sampled at the same sampling time to obtain the current and voltage signals of the energy meter. During the multi-signal synchronous acquisition process, the output signal of the voltage sensor is connected to the corresponding analog input channel of the ADC to acquire the voltage signal output from the voltage channel, reflecting the voltage change. The fluxgate current sensor detects the change in the magnetic field generated by the primary current, inducing a corresponding voltage signal on the secondary side. This voltage signal is processed by conditioning circuits, such as amplification and filtering, and then input to another analog input channel of the ADC for sampling, realizing the acquisition of the current signal output from the current channel, reflecting the change in the primary current. It should be noted that the resolution of the ADC converter is no less than 24 bits. The higher the resolution, the smaller the smallest change in the analog signal that the ADC converter can distinguish, that is, the smaller the quantization error.

[0049] Temperature data acquisition unit 12 is used to acquire temperature data from the electricity meter. Specifically, it uses a temperature sensor to acquire temperature data inside the AC / DC integrated standard electricity meter.

[0050] The data preprocessing unit 13 is used to preprocess the acquired current signal, voltage signal and temperature data. The preprocessing includes applying a digital FIR (Finite Impulse Response) filter to suppress high-frequency noise. The data (current signal, voltage signal and temperature data) are organized into time series data frames to maintain the correspondence between sampling points and facilitate subsequent data processing and analysis.

[0051] The hysteresis analysis module 2 is used to obtain the magnetic memory state and direction recognition factor of the energy meter based on the current signal, and to obtain the hysteresis coefficient of the energy meter by performing DC current testing on the energy meter, thereby obtaining the hysteresis intensity factor of the energy meter.

[0052] As a commonly used current measurement sensor, the output distortion of fluxgate current sensors is often influenced by a combination of physical factors. The magnetization state of the fluxgate core, made of ferromagnetic material, does not completely follow changes in the magnetic field, exhibiting a certain hysteresis. When the magnetic field strength increases, the magnetization of the core gradually rises; however, when the magnetic field strength decreases, the magnetization does not decrease along its original path but forms a hysteresis loop. This causes differences in the output signal of the fluxgate current sensor under different magnetic field change directions and rates, leading to measurement errors. For example, in alternating current measurement, the hysteresis effect distorts both the phase and amplitude of the current signal output by the fluxgate current sensor during the positive and negative half-cycles of the magnetic field change.

[0053] Based on the above analysis, in the embodiments of the present invention, the hysteresis analysis module 2 obtains the magnetic memory state and direction recognition factor of the energy meter based on the current signal, and obtains the hysteresis coefficient of the energy meter by performing a DC current test on the energy meter, thereby obtaining the hysteresis intensity factor of the energy meter. Further, as... Figure 2 As shown, the hysteresis analysis module 2 includes a magnetic memory state acquisition unit 21, a direction recognition factor acquisition unit 22, a hysteresis coefficient acquisition unit 23, and a hysteresis intensity factor calculation unit 24, wherein:

[0054] The magnetic memory state acquisition unit 21 is used to obtain the magnetic memory state of the energy meter based on the current signal. Specifically, the historical amplitude extreme point sequence of the current signal contains key inflection point information during the rise and fall of the hysteresis loop. These key inflection points reflect the changes in the magnetization state of the fluxgate current sensor core under different magnetic fields. By tracking and analyzing these extreme points, the dynamic change process of the hysteresis phenomenon can be captured. Therefore, the magnetic memory state acquisition unit 21 is configured to: first, acquire the historical amplitude extreme point sequence of the current signal; then, in the historical extreme point sequence, acquire the amplitude maximum and minimum values ​​most recent at any sampling time, and calculate the arithmetic mean of the amplitude maximum and minimum values ​​to obtain the magnetic memory state of the fluxgate current sensor in the energy meter at any sampling time. The magnetic memory state can represent the current magnetization level of the fluxgate current sensor.

[0055] The direction identification factor acquisition unit 22 is used to obtain the direction identification factor of the energy meter based on the current signal. Specifically, the direction identification factor acquisition unit 22 is configured to: acquire the direction of change of the current signal at any sampling time, let 1 represent an increase, indicating that the fluxgate current sensor is currently in the magnetization process; -1 represents a decrease, indicating that the fluxgate current sensor is currently in the demagnetization process; denoted as the direction identification factor of the fluxgate current sensor in the energy meter at any sampling time.

[0056] The hysteresis coefficient acquisition unit 23 is used to obtain the hysteresis coefficient by performing DC current testing on the energy meter. Specifically, the hysteresis coefficient acquisition unit 23 is configured as follows: First, a slow DC test current with an amplitude increasing from 0 is applied to the fluxgate current sensor in the energy meter to form a symmetrical magnetization curve containing multiple sub-loops; then, the current value after each DC test current step stabilizes is recorded; next, the difference in current amplitude at the same current point between the rising and falling curves in the magnetization curve is analyzed, and this difference in current amplitude is mainly caused by hysteresis; finally, the relationship between the DC test current and the difference in current amplitude is fitted by linear regression to obtain a fitted straight line, and the slope of the fitted straight line is obtained. The slope of the fitted straight line represents the hysteresis coefficient of the fluxgate current sensor in the energy meter. This hysteresis coefficient value characterizes the hysteresis characteristics of a specific fluxgate current sensor core, and the larger the value, the more severe the hysteresis phenomenon.

[0057] The hysteresis factor calculation unit 24 is used to calculate the hysteresis factor of the fluxgate current sensor in the energy meter at any sampling time based on the magnetic memory state, direction recognition factor, and hysteresis coefficient. Specifically, the hysteresis factor calculation unit 24 is configured with the following formula for calculating the hysteresis factor of the fluxgate current sensor in the energy meter at any sampling time:

[0058]

[0059] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The hysteresis factor at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The magnetic memory state at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. Direction identification factor at time; This represents the hysteresis coefficient of the fluxgate current sensor in the energy meter.

[0060] Hysteresis factor The larger the absolute value, the more severe the hysteresis effect, indicating that the metering system is under strong magnetization or undergoing a drastic change in magnetization direction, requiring a large compensation amount to correct the error; hysteresis intensity factor The positive or negative sign indicates the direction of compensation. A positive value means that compensation needs to be increased because hysteresis causes the actual output to be too small; a negative value means that compensation needs to be reduced because hysteresis causes the actual output to be too large.

[0061] Eddy current analysis module 3 is used to obtain the current change rate of the energy meter based on the current signal, and to obtain the eddy current effect coefficient of the energy meter by performing AC current testing on the energy meter, thereby obtaining the eddy current loss factor of the energy meter.

[0062] Eddy current losses also significantly affect the output of fluxgate current sensors. According to the law of electromagnetic induction, when an alternating magnetic field passes through a conductive magnetic core material, an induced electromotive force is generated inside the core, forming closed eddy currents. The flow of these eddy currents within the core generates Joule heat, leading to energy loss. Simultaneously, the magnetic field generated by the eddy currents interacts with the original magnetic field, altering the magnetic field distribution within the core. This changes the magnetic field signal detected by the fluxgate current sensor, ultimately causing output signal distortion. This effect is particularly pronounced during high-frequency current measurements, where the rate of change of the magnetic field increases, making the eddy current effect even more significant and its impact on the sensor output more severe.

[0063] According to the law of electromagnetic induction, when an alternating magnetic field passes through the core of a fluxgate current sensor, an induced electromotive force is generated inside the core, thus forming closed eddy currents. The calculation of the eddy current loss factor is based on this physical principle. Since the eddy current effect is proportional to the rate of change of the magnetic field, and the current signal output by the fluxgate current sensor reflects the change of the magnetic field, the eddy current loss factor can be calculated by processing the current signal.

[0064] Based on the above analysis, in the embodiments of the present invention, the eddy current analysis module 3 obtains the current change rate of the energy meter based on the current signal, and obtains the eddy current effect coefficient of the energy meter by performing AC current testing on the energy meter, thereby obtaining the eddy current loss factor of the energy meter. Further, as... Figure 2 As shown, the eddy current analysis module 3 includes a current change rate acquisition unit 31, an eddy current effect coefficient acquisition unit 32, and an eddy current loss factor calculation unit 33, wherein:

[0065] The current change rate acquisition unit 31 is used to obtain the current change rate of the energy meter based on the current signal. Specifically, the current change rate acquisition unit 31 is configured to: acquire the output current signal corresponding to any sampling time and the previous sampling time based on the current signal, calculate the corresponding sampling time interval, and then calculate the ratio of the difference between the amplitude of the output current signal corresponding to any sampling time and the previous sampling time to the sampling time interval, thereby obtaining the current change rate of the fluxgate current sensor in the energy meter at any sampling time.

[0066] The eddy current effect coefficient acquisition unit 32 is used to obtain the eddy current effect coefficient of the energy meter by performing AC current testing. Specifically, theoretically, phase lag is related to the frequency of the current; therefore, the eddy current effect coefficient acquisition unit 32 is configured to: first, apply different frequencies to the fluxgate current sensor in the energy meter. A sinusoidal AC test current (e.g., 50Hz, 100Hz, 1kHz) is applied, and the phase lag of the test current signal output by the fluxgate current sensor relative to the standard reference current transformer signal is measured. This phase lag is mainly caused by the eddy current effect; then, it is fitted by linear regression. and The relationship between the two is used to obtain a fitted straight line. The slope of the fitted straight line is obtained. The slope of the fitted straight line represents the eddy current effect coefficient of the fluxgate current sensor in the energy meter. The value of the eddy current effect coefficient characterizes the eddy current loss characteristics of the core of a specific fluxgate current sensor. The larger the value, the stronger the loss.

[0067] The eddy current loss factor calculation unit 33 is used to calculate the eddy current loss factor of the fluxgate current sensor in the energy meter at any sampling time, based on the current change rate acquisition unit 31 and the eddy current effect coefficient acquisition unit 32. Specifically, the eddy current loss factor calculation formula configured in the eddy current loss factor calculation unit 33 for the fluxgate current sensor in the energy meter at any sampling time is as follows:

[0068]

[0069] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. Eddy current loss factor at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The rate of change of current at that time; This represents the eddy current effect coefficient of the fluxgate current sensor in the energy meter.

[0070] When the eddy current loss factor A positive value indicates that the reverse magnetic field generated by the eddy current is resisting the increase in current, resulting in a smaller actual current value sensed by the fluxgate current sensor, and a more significant eddy current effect; when the eddy current loss factor... A negative value indicates that the reverse magnetic field generated by the eddy current is resisting the decrease in current, causing the fluxgate current sensor to detect a larger current value than intended; while the eddy current loss factor... The larger the absolute value of the value, the more significant the eddy effect.

[0071] The hysteresis and eddy current coupling module 4 is used to introduce time scale weights and instantaneous energy loss ratios, and combine the hysteresis intensity factor and eddy current loss factor to analyze the comprehensive loss factor of eddy current effect and hysteresis effect, and perform a first compensation on the current signal to obtain a first compensation current.

[0072] Under dynamic operating conditions, when the amplitude, frequency, and direction of change of the current signal change rapidly, a fixed weighting allocation cannot accurately reflect the dynamic changes in the actual contributions of the two physical effects, hysteresis and eddy current. For example, in low-frequency, high-current applications, the hysteresis effect dominates, while in high-frequency, low-current applications, the eddy current effect is more significant. Existing technologies cannot adaptively identify the switching of this dominant effect, resulting in a significant decrease in compensation accuracy under dynamic operating conditions.

[0073] Based on the above analysis, in the embodiments of the present invention, the hysteresis and eddy current coupling module 4, by introducing time scale weights and instantaneous energy loss ratios, and combining the hysteresis intensity factor and eddy current loss factor, analyzes the combined loss factor of eddy current effect and hysteresis effect, and performs a first compensation on the current signal to obtain a first compensation current. Further, as... Figure 2 As shown, the hysteresis and eddy current coupling module 4 includes a time-scale weighting unit 41, an instantaneous energy loss ratio input unit 42, a comprehensive weight calculation unit 43, a comprehensive loss factor calculation unit 44, and a primary current compensation unit 45, wherein:

[0074] The time-scale weighting unit 41 is used to introduce time-scale weights. Specifically, the time-scale weighting unit 41 is configured to: calculate the ratio between the absolute value of the current change rate and the absolute value of the magnetic memory state, and combine this ratio with a minimum value function to obtain the time-scale weights. More specifically, the absolute value of the magnetic memory state is first extracted... This reflects the current remanence level of the magnetic core; the absolute value of the current change rate is extracted. The rate of change directly reflects the intensity of the magnetic field change. The greater the rate of change, the stronger the eddy current induced electromotive force and the more significant the eddy current effect. When the current signal changes slowly, the difference in current amplitude between the rising and falling curves at the same current point is small. In this case, the eddy current effect is weak, but the hysteresis effect may still be significant. In this situation, the weight should be tilted towards hysteresis. Conversely, when the current signal changes drastically, the difference in current amplitude between the rising and falling curves at the same current point is large. In this case, the weight should be tilted towards eddy current. Therefore, obtaining the absolute value of the rate of change of current is crucial. The absolute value of magnetic memory state The ratio between them is denoted as ,Right now:

[0075]

[0076] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The absolute value of the rate of change of current at time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The absolute value of the magnetic memory state at that time; Indicates taking the absolute value; This represents the minimum value greater than 0. This is to prevent the denominator from being 0, so that it is set ; The absolute value of the rate of change of current The absolute value of magnetic memory state The ratio between them reflects the difference in current between the fluxgate current sensor and the sampling time in the electricity meter. The ratio of instantaneous change to historical state is used to determine the relative proportion of the change to the historical state. If the ratio is greater than 1, it indicates that the rate of change is dominant and the eddy current effect is more prominent. If the ratio is less than 1, it indicates that the magnetization state is dominant and the hysteresis effect is more prominent.

[0077] Then, based on the minimum value function, the upper limit of the ratio is ensured to be 1, thus the time scale weight is obtained as follows:

[0078]

[0079] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. Time scale weighting; This represents a minimum value function. It should be understood that a minimum value function is defined on... and When making comparisons, try to... The value of and Compare them.

[0080] When time scale weight When the value approaches 1, the metering system is in the eddy current effect dominance region, which usually occurs when the current signal changes at high frequency or jumps sharply, and eddy current loss becomes the main source of error; conversely, when the value approaches 0, the metering system is in the hysteresis effect dominance region, which usually occurs in the scenario where the current signal changes slowly but the magnetic core has strong residual magnetism.

[0081] The instantaneous energy loss ratio introduction unit 42 is used to introduce the instantaneous energy loss ratio. Specifically, at any sampling moment, the total loss of the metering system is composed of hysteresis loss and eddy current loss, and their respective weights should reflect their contribution to the total loss at that sampling moment. Therefore, the instantaneous energy loss ratio introduction unit 42 is configured to: firstly, determine the severity of the total loss of the fluxgate current sensor in the energy meter at any sampling moment based on the magnetic memory state, hysteresis coefficient, current change rate, and eddy current effect coefficient; more specifically, the instantaneous energy loss ratio introduction unit 42 is configured with the following formula for calculating the severity of the total loss of the fluxgate current sensor in the energy meter at any sampling moment:

[0082]

[0083] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The severity of the total loss over time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The absolute value of the magnetic memory state at that time; This represents the hysteresis coefficient of the fluxgate current sensor in the energy meter; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The absolute value of the rate of change of current at time; This represents the eddy current effect coefficient of the fluxgate current sensor in the energy meter; Indicates taking the absolute value; This represents a linear normalization function used to normalize numerical values ​​to the range [0,1].

[0084] Total severity of loss The larger the value, the more significant the overall loss effect the metering system is experiencing at the current sampling time; the severity of the total loss. The smaller the value, the weaker the loss effect of the metering system at the current sampling time, which is close to the ideal measurement conditions.

[0085] Then, based on the severity of the total loss, combined with the rate of change of current and the eddy current effect coefficient, a comprehensive eddy current weight based on the proportion of instantaneous energy loss is obtained. More specifically, the severity of the total loss is set... Let the absolute value of the rate of change of current be used as the denominator. With eddy current effect coefficient The product of these factors is used as the numerator, thus obtaining the eddy current comprehensive weight of the fluxgate current sensor in the energy meter based on the instantaneous energy loss ratio at any sampling time:

[0086]

[0087] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The eddy current comprehensive weight is based on the proportion of instantaneous energy loss. This indicates the sampling time of the fluxgate current sensor in the electricity meter. The severity of the total loss over time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The absolute value of the rate of change of current at time; This represents the eddy current effect coefficient of the fluxgate current sensor in the energy meter; Indicates taking the absolute value; This represents the minimum value greater than 0. This is to prevent the denominator from being 0, so that it is set .

[0088] Eddy current composite weight The closer the value is to 1, the more the loss at the current sampling moment is mainly dominated by the eddy current effect; conversely, the closer the value is to the eddy current comprehensive weight. The closer the value is to 0, the more it indicates that the loss is mainly dominated by the hysteresis effect.

[0089] The comprehensive weight calculation unit 43 is used to calculate the eddy current comprehensive weight based on the time scale weight and the eddy current comprehensive weight based on the instantaneous energy loss ratio. Specifically, the formula for calculating the eddy current comprehensive weight of the fluxgate current sensor in the energy meter at any sampling time in the comprehensive weight calculation unit 43 is as follows:

[0090]

[0091] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The overall weight of eddy currents at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. Time scale weighting; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The eddy current comprehensive weight is based on the instantaneous energy loss ratio.

[0092] Eddy current composite weight The value ranges from [0,1], representing the eddy current comprehensive weight. The larger the value, the more dominant the eddy current effect, and the compensation should be mainly based on eddy current; conversely, when the eddy current comprehensive weight is smaller... The smaller the value, the more hysteresis is used for compensation. Therefore, the comprehensive hysteresis weight based on the proportion of instantaneous energy loss is: .

[0093] The comprehensive loss factor calculation unit 44 is used to calculate the fluxgate current sensor in the energy meter at the sampling time based on the eddy current loss factor, hysteresis intensity factor, eddy current comprehensive weight, and hysteresis comprehensive weight. The comprehensive loss factor at any sampling time. Specifically, the formula for calculating the comprehensive loss factor of the fluxgate current sensor in the energy meter configured in the comprehensive loss factor calculation unit 44 at any sampling time is as follows:

[0094]

[0095] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The overall loss factor at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. Eddy current loss factor at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The hysteresis factor at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The eddy current composite weight at that time.

[0096] Comprehensive loss factor The larger the value, the greater the dynamic stress the fluxgate current sensor is under, the more severe the non-ideal effects are, and the higher the distortion of the output signal.

[0097] The primary current compensation unit 45 is used to compensate the measured current signal according to the comprehensive loss factor to obtain the primary compensation current of the energy meter. Specifically, the comprehensive loss factor... The degree and direction of distortion of the original current signal have been quantified, providing a direct basis for correcting hysteresis and eddy current effects; when When positive, it indicates that hysteresis and eddy current effects cause the original current signal to be less than the true value, requiring the addition of a positive compensation amount; when When the value is negative, it indicates that the measured original current signal is greater than the true value, and a reverse compensation amount needs to be added to compensate the original current signal, resulting in a current value after one compensation:

[0098]

[0099] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. The compensation current at that time; Represents the original current signal; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The overall loss factor at that time.

[0100] Temperature compensation module 5 is used to analyze the voltage gain change factor and current gain change factor of the electricity meter based on temperature data, and to perform temperature compensation on the voltage signal and current signal to complete the electricity metering.

[0101] The characteristics of the core components of voltage sensors and fluxgate current sensors change with temperature, which can cause measurement gain drift. Specifically, in a resistive voltage divider network, the resistance increases with temperature, causing a change in the voltage division ratio, which ultimately causes the voltage measurement value to deviate from the true value. In a fluxgate current sensor, the magnetic permeability of the magnetic core decreases with temperature, which leads to a decrease in the sensitivity of the fluxgate current sensor, causing the current measurement value to deviate from the true value.

[0102] Based on the above analysis, in the embodiments of the present invention, the temperature compensation module 5, based on temperature data, analyzes the voltage gain change factor and current gain change factor of the energy meter, performs temperature compensation on the voltage signal and current signal, and completes energy metering. Further, as... Figure 2 As shown, the temperature compensation module 5 includes a gain change factor acquisition unit 51, a voltage compensation unit 52, and a current compensation unit 53, wherein:

[0103] The gain variation factor acquisition unit 51 is used to acquire the difference between the actual acquired temperature data and the reference temperature, as well as the resistance temperature coefficient of the voltage sensor and the core material temperature coefficient of the fluxgate current sensor, to obtain the voltage gain variation factor of the voltage sensor and the current gain variation factor of the fluxgate current sensor. Specifically, firstly, a reference temperature is set based on standard laboratory conditions (such as IEC standards), which is typically 25°C, thereby acquiring the difference between the actual acquired temperature data and the reference temperature; and then, the resistance temperature coefficient of the voltage sensor is acquired from the resistance material characteristic data, and the core material temperature coefficient of the fluxgate current sensor is acquired from the core material characteristic data. Both the resistance temperature coefficient and the core material temperature coefficient are inherent physical properties of the materials.

[0104] The relationship between the resistance of a voltage sensor's resistive material and temperature can be described with high accuracy using a linear model within a certain temperature range, namely:

[0105]

[0106] In the formula, This indicates the voltage sensor in the electricity meter at the sampling time. The resistance value at that time; This indicates the standard resistance value of the voltage sensor in the electricity meter at the reference temperature; This indicates the temperature coefficient of resistance of the voltage sensor; This indicates the internal sampling time of the electricity meter. Temperature data acquired in real time; This indicates a reference temperature set based on standard laboratory conditions.

[0107] It should be noted that in a resistive voltage divider network, for example, composed of R1 and R2 connected in series, its gain, i.e., the voltage division ratio, is R2 / (R1+R2). When the temperature changes, it is assumed that R1 and R2 are made of the same material, i.e., the temperature coefficient of resistance... If they are the same, they will change synchronously; at this time, although the absolute value of a single resistor changes, their ratio remains theoretically unchanged; therefore, considering the entire voltage sampling channel as a whole, its overall gain changes with temperature, and a linear model is also used for fitting, thus constructing the voltage gain variation factor as:

[0108]

[0109] In the formula, This indicates the voltage sensor in the electricity meter at the sampling time. Voltage gain variation factor at that time; This indicates the temperature coefficient of resistance of the voltage sensor; This indicates the internal sampling time of the electricity meter. Temperature data acquired in real time; This indicates a reference temperature set based on standard laboratory conditions.

[0110] Wherein, constant 1 represents at the reference temperature At that time, the voltage gain change factor is 1, meaning there is no change; This represents the amount of gain drift, quantifying the magnitude of gain change caused by temperature deviation from the reference value.

[0111] Since the core of a fluxgate current sensor is a magnetic core, and the permeability of the core material is a function of temperature, the permeability of most ferromagnetic materials decreases as temperature increases. Assuming that within the operating temperature range of the metering system, the change in fluxgate gain in the fluxgate current sensor is approximately linearly related to the temperature change, based on the same calculation method described above, the current gain variation factor is obtained as follows:

[0112]

[0113] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. Current gain variation factor at time; This indicates the temperature coefficient of the core material in a fluxgate current sensor. This indicates the internal sampling time of the electricity meter. Temperature data acquired in real time; This indicates a reference temperature set based on standard laboratory conditions.

[0114] in, This indicates that the sensitivity of the fluxgate current sensor has decreased. The further the temperature deviates from the reference value, the more severe the sensitivity decreases, and the greater the compensation required. The compensation action is to attenuate the original current signal. This indicates that the sensor's sensitivity has improved. The lower the temperature, the greater the increase in sensitivity, and the greater the (reverse) compensation required. The compensation action is to amplify the original current signal.

[0115] The voltage compensation unit 52 is used to perform temperature compensation on the voltage signal based on the voltage gain variation factor to obtain the compensation voltage of the voltage sensor. Specifically, it constructs the voltage sensor in the energy meter at the sampling time... The formula for calculating the compensation voltage after temperature compensation is:

[0116]

[0117] In the formula, This indicates the voltage sensor in the electricity meter at the sampling time. Compensation voltage at that time; This indicates the voltage sensor in the electricity meter at the sampling time. The original voltage signal acquired at that time; This indicates the voltage sensor in the electricity meter at the sampling time. Voltage gain variation factor at that time.

[0118] Among them, if This indicates that the increase in temperature leads to an increase in the gain of the metering system, resulting in a higher measured value. It will be larger than the actual value, so it needs to be divided by a number greater than 1 to reduce it to the correct value; conversely, if This indicates that the decrease in temperature leads to a decrease in gain, and the measured value... It's too small; it needs to be divided by a number less than 1 to amplify it to the correct value.

[0119] The current compensation unit 53 is used to perform temperature compensation on the current signal based on the current gain change factor to obtain the secondary compensation current of the fluxgate current sensor. Specifically, it constructs the fluxgate current sensor in the energy meter at the sampling time... The formula for calculating the secondary compensation current after temperature compensation is:

[0120]

[0121] In the formula, This indicates the sampling time of the fluxgate current sensor in the electricity meter. Secondary compensation current at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The compensation current at that time; This indicates the sampling time of the fluxgate current sensor in the electricity meter. The current gain variation factor at that time.

[0122] Among them, if This indicates that the sensitivity of the fluxgate current sensor has decreased. The further the temperature deviates from the reference value, the more severe the sensitivity decreases, and the greater the compensation required. The compensation action is to attenuate the original current signal, so it needs to be divided by a number greater than 1 to reduce it to the correct value. This indicates that the sensor's sensitivity has improved. The lower the temperature, the greater the increase in sensitivity, and the greater the (reverse) compensation required. The compensation action amplifies the original current signal, which needs to be divided by a number less than 1 to amplify it to the correct value.

[0123] Because dynamic losses in the sensor, such as hysteresis, eddy currents, and temperature drift, are not compensated for in real time, directly using the raw sampled values ​​to calculate power introduces significant inherent errors. These errors are generated during instantaneous power calculation and are systematically amplified and accumulated during subsequent time integration of the instantaneous power to obtain the cumulative energy. The root cause is that measurement distortions in the current and voltage signals directly enter the power multiplication operation, leading to a distorted power reference. Therefore, even with a high-precision ADC and synchronous sampling, the final cumulative energy result still has a non-negligible deviation, failing to meet the accuracy requirements of standard energy meters.

[0124] According to the principles of electromagnetism, instantaneous power equals the product of instantaneous voltage and instantaneous current. Therefore, based on the actual compensated current value obtained above... and the actual compensated voltage value Obtain actual instantaneous power By obtaining the sum of the products of instantaneous power and time interval at all sampling moments, the cumulative energy of the current energy meter can be obtained, thus achieving high-precision energy metering.

[0125] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0126] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A high-precision voltage and current synchronous metering system for AC-DC integrated standard electric energy meters, characterized in that, The system comprises: a data acquisition module for acquiring current signals, voltage signals and temperature data of the electric energy meter; a magnetic hysteresis analysis module for obtaining a magnetic memory state and a direction identification factor of the electric energy meter based on the current signals, and obtaining a magnetic hysteresis coefficient of the electric energy meter by performing a direct current test on the electric energy meter, and further obtaining a magnetic hysteresis intensity factor of the electric energy meter; an eddy current analysis module for obtaining a current change rate of the electric energy meter based on the current signals, and obtaining an eddy current effect coefficient of the electric energy meter by performing an alternating current test on the electric energy meter, and further obtaining an eddy current loss factor of the electric energy meter; a magnetic hysteresis and eddy current coupling module for introducing a time scale weight and a transient energy loss ratio, combining the magnetic hysteresis intensity factor and the eddy current loss factor, analyzing a comprehensive loss factor of the eddy current effect and the magnetic hysteresis effect, and performing a first compensation on the current signals; a temperature compensation module for analyzing a voltage gain change factor and a current gain change factor of the electric energy meter based on the temperature data, and performing temperature compensation on the voltage signals and the current signals to complete electric energy metering; The magnetic hysteresis analysis module comprises a magnetic memory state acquisition unit configured to: obtain a historical amplitude extreme point sequence of the current signals; in the historical amplitude extreme point sequence, obtain an amplitude maximum value and an amplitude minimum value closest to any sampling time, and calculate an arithmetic mean value of the amplitude maximum value and the amplitude minimum value to obtain a magnetic memory state of a magnetic flux gate current sensor in the electric energy meter at any sampling time; The magnetic hysteresis analysis module further comprises a direction identification factor acquisition unit configured to: obtain a change direction of the current signals at any sampling time, with 1 representing an increase and -1 representing a decrease, and record it as a direction identification factor of the magnetic flux gate current sensor in the electric energy meter at any sampling time; The magnetic hysteresis and eddy current coupling module comprises a time scale weight introduction unit configured to: calculate a ratio between an absolute value of the current change rate and an absolute value of the magnetic memory state, and combine a minimum value function to obtain a time scale weight of the magnetic flux gate current sensor in the electric energy meter at any sampling time; The magnetic hysteresis and eddy current coupling module further comprises a transient energy loss ratio introduction unit configured to: determine a total loss intensity of the magnetic flux gate current sensor in the electric energy meter at any sampling time according to the magnetic memory state, the magnetic hysteresis coefficient, the current change rate and the eddy current effect coefficient; obtain an eddy current comprehensive weight based on a transient energy loss ratio according to the total loss intensity, the current change rate and the eddy current effect coefficient; The magnetic hysteresis and eddy current coupling module further comprises a comprehensive weight calculation unit configured to calculate an eddy current comprehensive weight according to the time scale weight and the eddy current comprehensive weight based on the transient energy loss ratio, and take 1-eddy current comprehensive weight as a magnetic hysteresis comprehensive weight. The hysteresis and eddy current coupling module further comprises a comprehensive loss factor calculation unit configured to calculate a comprehensive loss factor of the fluxgate current sensor in the electric energy meter according to the eddy current loss factor, the hysteresis strength factor, an eddy current comprehensive weight and a hysteresis comprehensive weight. The hysteresis and eddy current coupling module further comprises a current primary compensation unit configured to compensate the measured current signal according to the comprehensive loss factor to obtain a primary compensation current of the electric energy meter. The temperature compensation module comprises: A gain variation factor acquisition unit configured to obtain a difference between the actually collected temperature data and a reference temperature, and obtain a resistance temperature coefficient of the voltage sensor and a magnetic core material temperature coefficient of the fluxgate current sensor to obtain a voltage gain variation factor of the voltage sensor and a current gain variation factor of the fluxgate current sensor.

2. The high-precision voltage and current synchronous metering system of the AC / DC integrated standard electric energy meter according to claim 1, characterized in that, The hysteresis analysis module further comprises a hysteresis coefficient acquisition unit configured to obtain a hysteresis coefficient by performing a direct current test on the electric energy meter, wherein the hysteresis coefficient acquisition unit is configured to: apply a slow direct current test current with an increasing amplitude starting from 0 to the fluxgate current sensor in the electric energy meter to form a symmetrical magnetization curve containing multiple sub-loops; record the current value after each direct current test current step stabilizes; analyze the current amplitude difference of the rising curve and the falling curve of the magnetization curve at the same current point; obtain the hysteresis coefficient of the fluxgate current sensor in the electric energy meter by linearly regressing the relationship between the direct current test current and the current amplitude difference.

3. The high-precision voltage and current synchronous metering system of AC / DC integrated standard electric energy meter according to claim 1, characterized in that, The eddy current analysis module comprises a current change rate acquisition unit configured to obtain a current change rate of the electric energy meter based on the current signal, wherein the current change rate acquisition unit is configured to: based on the current signal, obtain the output current signal corresponding to any sampling time and the previous sampling time, and calculate the corresponding sampling time interval to obtain the current change rate of the fluxgate current sensor in the electric energy meter at any sampling time.

4. The high-precision voltage and current synchronous metering system of AC / DC integrated standard electric energy meter according to claim 3, characterized in that, The eddy current analysis module further comprises an eddy current effect coefficient acquisition unit configured to obtain an eddy current effect coefficient of the electric energy meter by performing an alternating current test on the electric energy meter, wherein the eddy current effect coefficient acquisition unit is configured to: Applying different frequencies of sinusoidal ac test currents to a fluxgate current sensor in an electric energy meter and measuring the phase lag of the test current signal output by the fluxgate current sensor relative to a standard reference current transformer signal as ; The relationship between the current and the voltage is fitted by linear regression The relationship between the current and the voltage is fitted by linear regression The relationship between the current and the voltage is fitted by linear regression 5. The high-precision voltage and current synchronous metering system of AC / DC integrated standard electric energy meter according to claim 1, characterized in that, The temperature compensation module further comprises: a voltage compensation unit configured to compensate the voltage signal according to the voltage gain variation factor to obtain a compensation voltage of the voltage sensor; a current compensation unit configured to compensate the current signal according to the current gain variation factor to obtain a secondary compensation current of the fluxgate current sensor.

6. The high-precision voltage and current synchronous metering system of AC / DC integrated standard electric energy meter according to claim 1, characterized in that, The data acquisition module comprises a voltage and current synchronous acquisition unit configured to acquire the current signal and the voltage signal of the electric energy meter, wherein the voltage and current synchronous acquisition unit is configured to: synchronously trigger the sampling clock of the voltage sensor and the fluxgate current sensor in the electric energy meter, and simultaneously send to the analog-to-digital converter of the voltage channel and the current channel of the electric energy meter to sample the input analog voltage and current signals at the same sampling time to obtain the current signal and the voltage signal of the electric energy meter.

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