CN-121995105-A - Electric energy metering method and device for electric energy meter

CN121995105ACN 121995105 ACN121995105 ACN 121995105ACN-121995105-A

Abstract

The invention is suitable for the technical field of electric energy metering, relates to an electric energy metering method and a device of an electric energy meter, has simple flow, convenient operation, utilizes a harmonic analysis algorithm to process voltage sampling data and current sampling data, extracts corresponding fundamental voltage and current components, harmonic voltage and current components and corresponding fundamental phase angle and harmonic phase angle, based on the data, fundamental wave positive sequence active power, reactive power, non-fundamental wave equivalent apparent power, voltage distortion power, current distortion power, harmonic apparent power, unbalanced apparent power and the like are calculated, so that various electric parameters of the electric energy meter are measured, and the electric energy meter is used for guiding the electric power department to charge, make economic decisions, measure main harmonic pollution sources and the like, and the quality of electric power service is greatly improved.

Inventors

PAN XIAOYAN
ZHAO YANTAO
WANG LONGFENG
LIU JIAN
WANG MING
LIU XUJIE
LI ZHANGCHENG

Assignees

威胜集团有限公司

Dates

Publication Date: 20260508
Application Date: 20251217

Claims (10)

1. The electric energy metering method of the electric energy meter is characterized by comprising the following steps of: S10, acquiring original sampling waveform data of three-phase voltage and three-phase current obtained by synchronous sampling; s20, respectively carrying out harmonic analysis on the waveform data to obtain frequency spectrum components of corresponding voltage and current, and determining fundamental wave voltage amplitude, fundamental wave current amplitude, harmonic wave voltage amplitude, harmonic wave current amplitude, and corresponding fundamental wave phase angle and harmonic wave phase angle through a subgroup algorithm; s30, performing accumulated square sum calculation on the data obtained by analysis in the S20, wherein a calculation window is consistent with a harmonic analysis window, and a three-phase full-wave voltage amplitude and a three-phase full-wave current amplitude are obtained; s40, decomposing fundamental wave voltage and fundamental wave current obtained by harmonic analysis into symmetrical components, and determining positive sequence components, negative sequence components and zero sequence components of voltage amplitude, current amplitude and phase angle; s50, determining a non-fundamental wave voltage amplitude and a non-fundamental wave current amplitude through a full-wave voltage amplitude, a full-wave current amplitude, a fundamental wave voltage amplitude and a fundamental wave current amplitude; S60, determining fundamental wave positive sequence active power, reactive power and apparent power through positive sequence components, negative sequence components and zero sequence components of voltage amplitude, current amplitude and phase angle; and S70, determining voltage distortion power, current distortion power, unbalanced apparent power and harmonic apparent power through the non-fundamental voltage amplitude, the non-fundamental current amplitude, the fundamental voltage amplitude, the fundamental current amplitude, the positive sequence components of the voltage phase angle and the current phase angle.
2. The method for measuring electric energy of an electric energy meter according to claim 1, wherein in S20, a harmonic analysis algorithm adopts a discrete fourier transform method, and the formula is as follows: ; Wherein, the For the kth spectral component, For voltage sampling point data or current sampling point data, For each sub-spectral component obtained by performing a discrete fourier transform on the voltage sample point data or the current sample point data, Is a twiddle factor.
3. The method for measuring electric energy of an electric energy meter according to claim 2, wherein the harmonic wave adopts a subgroup algorithm, and the formula is as follows: ; Wherein, the As a subset of the harmonics, Is the kth spectral component; The corresponding fundamental and harmonic phase angles are determined from the spectral components as follows: ; Wherein the method comprises the steps of For the ith voltage or current phase angle, idx is the harmonic analysis window size and X [ idx ] is the corresponding voltage or current spectral component.
4. The method for measuring electric energy of an electric energy meter according to claim 3, wherein in S30, the formula is as follows: ; ; Wherein, the Is the single-cycle voltage amplitude, N is the number of single-cycle sampling points, The instantaneous voltage sampling value at the time t; is the single-cycle voltage amplitude, N is the number of single-cycle sampling points, Is the instantaneous voltage sample at time t.
5. The method for measuring electric energy of an electric energy meter according to claim 4, wherein in S40, the symmetrical component formula is as follows: ; Wherein, the Positive sequence component, negative sequence component and zero sequence component of voltage or current respectively, The calculated fundamental voltage or fundamental current components for the A, B, C three channels, For the complex number operator, ; The positive and negative sequence components of the amplitude and phase angle are formulated as follows: ; ; ; ; Wherein, the 、、 Is the included angle between the three-phase fundamental wave voltage and current, 、、、 The value is calculated for the positive sequence and the negative sequence of the included angle between the three-phase voltage or current and the three-phase fundamental voltage and current.
6. The method for measuring electric energy of an electric energy meter according to claim 5, wherein in S50, the formula is as follows: ; ; ; ; Wherein V a 、V b 、V c is a three-phase full-wave phase voltage, V ab 、V bc 、V ca is a full-wave line voltage, I a 、I b 、I c is a three-phase full-wave current, I n is a full-wave zero line current, V e and I e are corresponding full-wave effective voltages and effective currents, V a1 、V b1 、V c1 is a three-phase fundamental wave phase voltage, V ab1 、V bc1 、V ca1 is a fundamental wave line voltage, I a1 、I b1 、I c1 is a three-phase fundamental wave current, I n1 is a fundamental wave zero line current, and V e1 and I e1 are corresponding fundamental wave effective voltages and effective currents; The corresponding non-fundamental voltage and non-fundamental current formulas are as follows: ; 。
7. The method for measuring electric energy of an electric energy meter according to claim 6, wherein in S60, the formula is as follows: ; ; ; ; ; ; Wherein, the 、、 For calculating the obtained fundamental wave positive sequence active power, reactive power and apparent power, 、、 The calculated fundamental wave negative sequence active power, reactive power and apparent power are obtained.
8. The method for measuring electric energy of an electric energy meter according to claim 7, wherein in S70, the formula is as follows: ; ; ; ; ; ; Wherein, the For the voltage distortion power to be high, For the current distortion power, For the harmonic apparent power of the wave, For the harmonic distortion power, For non-fundamental equivalent apparent power, Is unbalanced apparent power.
9. The method according to claim 1, wherein in S10, the sampling rate of synchronous sampling is greater than 6.4Kp/S, i.e. the number of sampling points per week wave is greater than 128 points.
10. An electric energy meter electric energy metering device, characterized by comprising: The data acquisition module is used for acquiring original sampling waveform data of the three-phase voltage and the three-phase current obtained by synchronous sampling; the harmonic analysis module is used for respectively carrying out harmonic analysis on the waveform data, analyzing to obtain frequency spectrum components of corresponding voltage and current, and determining fundamental wave voltage amplitude, fundamental wave current amplitude, harmonic wave voltage amplitude, harmonic wave current amplitude, and corresponding fundamental wave phase angle and harmonic wave phase angle through a subgroup algorithm; The full-wave calculation module is used for carrying out accumulated square sum calculation on the data obtained by analysis in the harmonic analysis module, and the calculation window is consistent with the harmonic analysis window to obtain a three-phase full-wave voltage amplitude and a three-phase full-wave current amplitude; The unbalanced component calculation module is used for decomposing fundamental wave voltage and fundamental wave current obtained by harmonic analysis into symmetrical components and determining positive sequence components, negative sequence components and zero sequence components of voltage amplitude, current amplitude and phase angle; The non-fundamental wave amplitude calculation module is used for determining a non-fundamental wave voltage amplitude and a non-fundamental wave current amplitude through a full-wave voltage amplitude, a full-wave current amplitude, a fundamental wave voltage amplitude and a fundamental wave current amplitude; The fundamental wave power calculation module is used for determining fundamental wave positive sequence active power, reactive power and apparent power through positive sequence components, negative sequence components and zero sequence components of voltage amplitude, current amplitude and phase angle; the distortion power calculation module is used for determining voltage distortion power, current distortion power, unbalanced apparent power and harmonic apparent power through non-fundamental wave voltage amplitude, non-fundamental wave current amplitude, fundamental wave voltage amplitude, fundamental wave current amplitude, positive sequence components of voltage phase angle and current phase angle.

Description

Electric energy metering method and device for electric energy meter Technical Field The invention belongs to the technical field of electric energy metering, and particularly relates to an electric energy metering method and device of an electric energy meter. Background With the new energy being connected to the power grid, the new energy can be used as a load end and a power end, and the new energy has larger instability, and various new electric equipment which is continuously emerging is added, so that the electricity utilization environment is more and more complex, and the problems of negative sequence current, negative sequence voltage, low power factor, distortion, harmonic pollution and the like in the complex electricity utilization environment bring a plurality of challenges to the power department in charging, economic decision, harmonic pollution source measurement and the like, and a calculation or evaluation scheme is required to accurately quantify distortion caused by nonlinear and dynamic load and implement fair distribution of financial burden, so that the quality of electric power service is ensured. The existing electric energy metering scheme has no corresponding electric parameters to realize the requirements of guiding the electric power department to charge, making engineering economic decisions, measuring main harmonic pollution sources and the like. The patent application with the publication number of CN118688507A provides an intelligent electric energy meter electric energy metering method, an intelligent electric energy meter electric energy metering device and an intelligent electric energy meter, wherein the method comprises the steps of obtaining current and voltage of three-phase electricity, calculating according to the current and the voltage to obtain first apparent power, second apparent power and third apparent power, calculating the first apparent power by a metering chip, and calculating the second apparent power and the third apparent power by a metering MCU; setting three kinds of apparent power into corresponding power registers respectively, and accumulating power values and power register values; when any power register value reaches a preset value, corresponding apparent electric energy is accumulated. The patent application only adds three apparent power and electric energy calculation schemes of vector apparent, arithmetic apparent and effective apparent based on the metering method of the existing intelligent electric energy meter, and realizes the scheme on the electric energy meter, but does not have more monitoring quantity indexes, and cannot evaluate distortion severity, harmonic pollution level and the like. Therefore, how to realize metering of various electric parameters of the electric energy meter, so as to be used for guiding the electric power department to charge, make economic decisions, measure main harmonic pollution sources and the like, and ensure the quality of electric power service is a problem to be solved urgently by the person skilled in the art. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide an electric energy metering method of an electric energy meter, so as to solve the problem of low quality of electric power service caused by single electric parameter measured by an electric energy meter metering scheme in the prior art. In order to solve the technical problems, the invention adopts the following technical scheme: In a first aspect, the invention provides a method for measuring electric energy of an electric energy meter, comprising the following steps: S10, acquiring original sampling waveform data of three-phase voltage and three-phase current obtained by synchronous sampling; s20, respectively carrying out harmonic analysis on the waveform data to obtain frequency spectrum components of corresponding voltage and current, and determining fundamental wave voltage amplitude, fundamental wave current amplitude, harmonic wave voltage amplitude, harmonic wave current amplitude, and corresponding fundamental wave phase angle and harmonic wave phase angle through a subgroup algorithm; s30, performing accumulated square sum calculation on the data obtained by analysis in the S20, wherein a calculation window is consistent with a harmonic analysis window, and a three-phase full-wave voltage amplitude and a three-phase full-wave current amplitude are obtained; s40, decomposing fundamental wave voltage and fundamental wave current obtained by harmonic analysis into symmetrical components, and determining positive sequence components, negative sequence components and zero sequence components of voltage amplitude, current amplitude and phase angle; s50, determining a non-fundamental wave voltage amplitude and a non-fundamental wave current amplitude through a full-wave voltage amplitude, a full-wave current amplitude, a fundamental wave voltage amplitude and a fundamental wave current amplitu