Electric energy metering method and device of electric energy meter

Abstract

The invention is suitable for the technical field of electric energy metering, and relates to an electric energy metering method and device of an electric energy meter. Corresponding fundamental wave voltage current components, harmonic wave voltage current components, corresponding fundamental wave phase angles and harmonic wave phase angles are extracted, and 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 wave apparent power, unbalanced apparent power and the like are obtained through calculation; various electric parameters of the electric energy meter are metered so as to guide an 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.

Description

Technical Field

[0001] This invention belongs to the field of electrical energy metering technology, and particularly relates to an electrical energy metering method and device. Background Technology

[0002] With the integration of new energy sources into the power grid, they can serve as both load and power source. However, new energy sources themselves are highly unstable, and the continuous emergence of various new types of electrical equipment has led to an increasingly complex power environment. Problems such as negative sequence current, negative sequence voltage, low power factor, distortion, and harmonic pollution that arise in this complex environment pose numerous challenges to the power sector in areas such as billing, economic decision-making, and the determination of harmonic pollution sources. A calculation or evaluation scheme is needed to accurately quantify the distortion caused by nonlinear and dynamic loads and to implement a fair allocation of financial burdens, thereby ensuring the quality of power services.

[0003] Existing electricity metering schemes lack corresponding electrical parameters to guide power sector billing, engineering economic decisions, and the determination of major harmonic pollution sources. Patent application CN118688507A discloses a smart electricity meter method, device, and smart electricity meter. The method includes: acquiring the current and voltage of three-phase electricity; calculating a first apparent power, a second apparent power, and a third apparent power based on the current and voltage; the first apparent power is calculated by a metering chip, and the second and third apparent powers are calculated by a metering MCU; setting the three apparent powers into corresponding power registers and accumulating the power values ​​and power register values; and accumulating the corresponding apparent energy when any power register value reaches a preset value. This patent application merely adds three apparent power calculation schemes—vector apparent, arithmetic apparent, and effective apparent—to the existing smart electricity meter metering method and implements these schemes on the electricity meter, but it lacks additional monitoring indicators and cannot assess the severity of distortion, harmonic pollution levels, etc.

[0004] Therefore, how to measure various electrical parameters of electricity meters to guide electricity departments in billing, economic decision-making, and the determination of major harmonic pollution sources, thereby ensuring the quality of electricity services, is a problem that urgently needs to be solved by personnel in this technical field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide an energy metering method to solve the problem of low quality of electricity service caused by the single electrical parameter measured in existing energy metering schemes; in addition, this invention also provides an energy metering device.

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

[0007] In a first aspect, the present invention provides an energy metering method, comprising the following steps:

[0008] S10. Obtain the original sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling;

[0009] S20. Perform harmonic analysis on the waveform data to obtain the spectral components of the corresponding voltage and current. Determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through the subgroup algorithm.

[0010] S30. The data obtained in S20 are summed and squared to calculate the sum of squares. The calculation window is consistent with the harmonic analysis window to obtain the three-phase full-wave voltage amplitude and the three-phase full-wave current amplitude.

[0011] S40. Decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of voltage amplitude, current amplitude, and phase angle.

[0012] S50. Determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude;

[0013] S60. Determine the fundamental positive-sequence active power, reactive power, and apparent power by using the positive-sequence components, negative-sequence components, and zero-sequence components of voltage amplitude, current amplitude, and phase angle.

[0014] S70. Determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

[0015] Furthermore, in step S20, the harmonic analysis algorithm employs the discrete Fourier transform method, as shown in the following formula:

[0016]

[0017] in, For the k-th spectral component, This refers to voltage sampling point data or current sampling point data. These are the spectral components obtained by performing a discrete Fourier transform on the voltage or current sampling data. is the rotation factor.

[0018] Furthermore, the harmonics are analyzed using a subgroup algorithm, as shown in the following formula:

[0019]

[0020] in, For harmonic subgroups, For the k-th spectral component;

[0021] The corresponding fundamental and harmonic phase angles are determined based on the spectral components as follows:

[0022]

[0023] in Let be the phase angle of the i-th voltage or current, idx be the size of the harmonic analysis window, and X[idx] be the voltage or current spectral component of the corresponding order.

[0024] Furthermore, in S30, the formula is as follows:

[0025]

[0026]

[0027] in, Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. The instantaneous voltage sample value at time t; Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. The instantaneous voltage sample value at time t.

[0028] Furthermore, in S40, the formula for the symmetric component is as follows:

[0029]

[0030] in, These are the positive-sequence, negative-sequence, and zero-sequence components of voltage or current, respectively. The fundamental voltage or fundamental current components calculated for channels A, B, and C. For complex number operators, ;

[0031] The formulas for the positive-sequence and negative-sequence components of the amplitude and phase angle are as follows:

[0032]

[0033]

[0034]

[0035]

[0036] in, , , The angle between the three-phase fundamental voltage and current. , , , The positive and negative sequence calculation values ​​are the angles between the three-phase voltage or current and the three-phase fundamental voltage and current.

[0037] Furthermore, in S50, the formula is as follows:

[0038]

[0039]

[0040]

[0041]

[0042] Among them, V a V b V c For three-phase full-wave phase voltage, V ab V bc V ca For the full-wave line voltage, I a I b I c For three-phase full-wave current, I n For the full-wave neutral current, V e and I e For the corresponding full-wave effective voltage and effective current, V a1 V b1 V c1 The fundamental phase voltage of the three-phase circuit is V. ab1 V bc1 V ca1 I is the fundamental line voltage. a1 I b1 I c1 For the three-phase fundamental current, I n1 For the fundamental neutral current, V e1 and I e1 These are the corresponding fundamental effective voltage and effective current;

[0043] The corresponding formulas for non-fundamental voltage and non-fundamental current are as follows:

[0044]

[0045] .

[0046] Furthermore, in S60, the formula is as follows:

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] in, , , To calculate the fundamental positive-sequence active power, reactive power, and apparent power, , , The calculated fundamental negative sequence active power, reactive power, and apparent power are given.

[0054] Furthermore, in S70, the formula is as follows:

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] in, For voltage distortion power, This refers to the power distortion due to current. For harmonic apparent power, For harmonic distortion power, For non-fundamental equivalent apparent power, This refers to the unbalanced apparent power.

[0062] Furthermore, in S10, the sampling rate of synchronous sampling is greater than 6.4Kp / s, that is, the number of sampling points per cycle is greater than 128.

[0063] Secondly, the present invention also provides an energy metering device, comprising:

[0064] The data acquisition module is used to acquire the raw sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling;

[0065] The harmonic analysis module is used to perform harmonic analysis on the waveform data, obtain the spectral components of the corresponding voltage and current, and determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through a subgroup algorithm.

[0066] The full-wave calculation module is used to calculate the sum of squares of the data analyzed in the harmonic analysis module. The calculation window is consistent with the harmonic analysis window to obtain the three-phase full-wave voltage amplitude and the three-phase full-wave current amplitude.

[0067] The unbalanced component calculation module is used to decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of voltage amplitude, current amplitude, and phase angle.

[0068] The non-fundamental amplitude calculation module is used to determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude.

[0069] The fundamental power calculation module is used to determine the fundamental positive sequence active power, reactive power, and apparent power by using the positive sequence components, negative sequence components, and zero sequence components of voltage amplitude, current amplitude, and phase angle.

[0070] The distortion power calculation module is used to determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

[0071] Compared with the prior art, the electricity metering method and device provided by the present invention have at least the following advantages:

[0072] Existing electricity metering methods measure only a single electrical parameter, lacking the corresponding parameters to guide power sector billing, engineering economic decisions, and the determination of major harmonic pollution sources, resulting in low-quality electricity services. This invention features a simple process and convenient operation. It utilizes harmonic analysis algorithms to process voltage and current sampling data, extracting the corresponding fundamental voltage and current components, harmonic voltage and current components, and the corresponding fundamental and harmonic phase angles. Based on this data, it calculates the fundamental positive-sequence active power, reactive power, non-fundamental equivalent apparent power, voltage distortion power, current distortion power, harmonic apparent power, and unbalanced apparent power, thus enabling the measurement of multiple electrical parameters from the electricity meter. This allows for guidance in power sector billing, economic decision-making, and the determination of major harmonic pollution sources, significantly improving the quality of electricity services. Attached Figure Description

[0073] To more clearly illustrate the solution of the present invention, a brief introduction will be given to the drawings used in the description of the embodiments below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0074] Figure 1 This is a flowchart of an energy metering method provided in an embodiment of the present invention. Detailed Implementation

[0075] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0077] This invention provides a method for measuring electricity using an electricity meter, applied to the multi-parameter measurement process of smart meters in a computerized electricity metering scheme. The method for measuring electricity using an electricity meter is as follows:

[0078] S10. Obtain the original sampled waveform data of the three-phase voltage and three-phase current obtained from synchronous sampling; S20. Perform harmonic analysis on the waveform data to obtain the spectral components of the corresponding voltage and current, and determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through a subgroup algorithm; S30. Calculate the sum of squares of the data obtained in S20, with the calculation window consistent with the harmonic analysis window, to obtain the three-phase full-wave voltage amplitude and three-phase full-wave current amplitude; S40. Decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components and determine the voltage amplitude. S50. Determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude; S60. Determine the fundamental positive-sequence active power, reactive power, and apparent power using the positive-sequence components, negative-sequence components, and zero-sequence components of the voltage amplitude, current amplitude, and phase angle; S70. Determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive-sequence components of the voltage phase angle and current phase angle.

[0079] This invention features a simple process and convenient operation. It utilizes harmonic analysis algorithms to process voltage and current sampling data, extracting the corresponding fundamental voltage and current components, harmonic voltage and current components, and the corresponding fundamental and harmonic phase angles. Based on the above data, it calculates the fundamental positive-sequence active power, reactive power, non-fundamental equivalent apparent power, voltage distortion power, current distortion power, harmonic apparent power, and unbalanced apparent power, thereby enabling the measurement of multiple electrical parameters of the electricity meter. This can be used to guide electricity departments in billing, economic decision-making, and the determination of major harmonic pollution sources, greatly improving the quality of electricity services.

[0080] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0081] This invention provides a method for measuring electricity using an electricity meter, applied to the multi-parameter measurement process of smart meters in a computerized electricity metering scheme, such as... Figure 1 As shown in this embodiment, the energy metering method is as follows:

[0082] S10. Obtain the original sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling.

[0083] Specifically, in this embodiment, the source of the original sampling data is not limited in any way and can be any object that needs to be metered for electricity. The sampling rate of synchronous sampling is greater than 6.4 Kp / s, that is, the number of sampling points per cycle is greater than 128.

[0084] S20. Perform harmonic analysis on the waveform data to obtain the spectral components of the corresponding voltage and current. Determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through the subgroup algorithm.

[0085] Specifically, in this embodiment, the harmonic analysis can use a 10-cycle analysis window, that is, the harmonic calculation is performed once every 10 cycles, which is applicable to the analysis of harmonics with fluctuations. The harmonic analysis algorithm adopts the discrete Fourier transform method to analyze and obtain the voltage spectrum components and current spectrum components of each order, as shown in the following formula:

[0086]

[0087] in, For the k-th spectral component, This refers to voltage sampling point data or current sampling point data. These are the spectral components obtained by performing a discrete Fourier transform on the voltage or current sampling data. is the rotation factor.

[0088] Furthermore, in this embodiment, the amplitude fluctuation may cause the energy of the harmonic components to leak into adjacent harmonic frequencies. To improve the evaluation accuracy, a subgroup algorithm is used for harmonics, as shown in the following formula:

[0089]

[0090] in, For the defined 10-cycle harmonic subgroup, For the k-th spectral component;

[0091] At the same time, the corresponding fundamental phase angle and harmonic phase angle are calculated based on these spectral components.

[0092]

[0093] in Let be the voltage phase angle or current phase angle of the i-th order, idx be the size of the harmonic analysis window, and X[idx] be the voltage or current spectral component of the corresponding order.

[0094] In other embodiments, the harmonic analysis algorithm may also be other methods capable of analyzing and obtaining the various spectral components.

[0095] S30. The sum of squares of the data obtained from the analysis in S20 is calculated. The calculation window is consistent with the harmonic analysis window to obtain the amplitude of the three-phase full-wave voltage and the amplitude of the three-phase full-wave current.

[0096] Specifically, in this embodiment, the single-cycle sampling point data is calculated according to the corresponding voltage and current amplitude calculation formulas. The sum of squares formula can be used to obtain the single-cycle voltage and current amplitudes. The calculation window is consistent with the harmonic analysis window. The 10-cycle voltage and current amplitudes are obtained by averaging 10 consecutive single-cycle voltage and current amplitudes, as shown in the following formula:

[0097]

[0098]

[0099] in, Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. for The instantaneous voltage sample value at time 10:00; Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. for The instantaneous voltage sample value at a given moment.

[0100] S40. Decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of voltage amplitude, current amplitude, and phase angle.

[0101] Specifically, in this embodiment, the formula for the symmetric component is as follows:

[0102]

[0103] in, These are the positive-sequence, negative-sequence, and zero-sequence components of voltage or current, respectively. The fundamental voltage or fundamental current components calculated for channels A, B, and C. For complex number operators, .

[0104] Furthermore, in this embodiment, the corresponding positive-order components and negative-order components can be further decomposed into:

[0105]

[0106]

[0107] Therefore, the formulas for calculating the positive-sequence and negative-sequence components of the amplitude and phase angle are as follows:

[0108]

[0109]

[0110]

[0111]

[0112] In the above formula, , , The angle between the three-phase fundamental voltage and the three-phase fundamental voltage-current. , , , The positive and negative sequence calculation values ​​are the angles between the three-phase voltage or three-phase current and the three-phase fundamental voltage and three-phase fundamental current.

[0113] S50. Determine the non-fundamental voltage amplitude and non-fundamental current amplitude by using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude.

[0114] Specifically, in this embodiment, the corresponding full-wave equivalent voltage, full-wave equivalent current, fundamental equivalent voltage, and fundamental equivalent current are calculated using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude. The formulas are illustrated using a three-phase four-wire system as an example, and are as follows:

[0115]

[0116]

[0117]

[0118]

[0119] Among them, V a V b V c For three-phase full-wave phase voltage, V ab V bc V ca For the full-wave line voltage, I a I b I c For three-phase full-wave current, I n For the full-wave neutral current, V e and I e For the corresponding full-wave effective voltage and effective current, V a1 V b1 V c1 The fundamental phase voltage of the three-phase circuit is V. ab1 V bc1 V ca1 I is the fundamental line voltage. a1 I b1 I c1 For the three-phase fundamental current, I n1 For the fundamental neutral current, V e1 and I e1 These are the corresponding fundamental effective voltage and effective current;

[0120] The corresponding formulas for non-fundamental voltage and non-fundamental current are as follows:

[0121]

[0122] .

[0123] S60. Determine the fundamental positive-sequence active power, reactive power, and apparent power by using the positive-sequence components, negative-sequence components, and zero-sequence components of voltage amplitude, current amplitude, and phase angle.

[0124] Specifically, in this embodiment, the corresponding fundamental positive-sequence active power, reactive power, and apparent power, and the negative-sequence active power, reactive power, and apparent power are calculated based on the positive-sequence and negative-sequence components of the fundamental voltage, current, and phase angle. The active and reactive power are calculated by multiplying the voltage by the current by the cosine or sine of the phase angle. The apparent power can be calculated by multiplying the voltage and current or by using a vector triangle formula, taking the square root of the sum of the squares of the active and reactive power. The specific calculation formula is as follows:

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131] in, , , To calculate the fundamental positive-sequence active power, reactive power, and apparent power, , , The calculated fundamental negative sequence active power, reactive power, and apparent power are given.

[0132] S70. Determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

[0133] Specifically, in this embodiment, the voltage distortion power can be calculated using the non-fundamental voltage and the fundamental effective current. Current distortion power The harmonic apparent power is the product of the fundamental effective voltage and the non-fundamental current. Harmonic distortion power is the product of non-fundamental voltage and non-fundamental current. The result is obtained by subtracting the square of the harmonic active power (obtained by subtracting the fundamental active power from the total active power) from the square of the harmonic apparent power, and then taking the square root. The non-fundamental equivalent apparent power is calculated from the effective apparent power and the fundamental effective apparent power, and can also be calculated from the voltage and current distortion power and harmonic apparent power. The unbalanced apparent power... It is obtained from the fundamental effective apparent power and the fundamental positive-sequence apparent power. The formula is as follows:

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140] in, For voltage distortion power, This refers to the power distortion due to current. For harmonic apparent power, For harmonic distortion power, For non-fundamental equivalent apparent power, This refers to the unbalanced apparent power.

[0141] The calculated distortion power, unbalanced power, fundamental positive-sequence active power, reactive power, voltage distortion power, current distortion power, harmonic apparent power, and unbalanced apparent power can all be used to assess line loss. Further combined calculations can reflect line utilization. Non-fundamental equivalent apparent power can be used to assess the severity of distortion, indicating the harmonic pollution of the load's operating environment. It can also quantify the compensation capacity required for dynamic compensators or active filters to compensate for non-fundamental loads only. The degree of load imbalance can be assessed through unbalanced apparent power, which integrates load current imbalance and supply voltage asymmetry.

[0142] This invention also provides an energy metering device, comprising:

[0143] The data acquisition module is used to acquire the raw sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling;

[0144] The harmonic analysis module is used to perform harmonic analysis on waveform data, obtain the spectral components of the corresponding voltage and current, and determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through subgroup algorithms.

[0145] The full-wave calculation module is used to calculate the sum of squares of the data obtained from the harmonic analysis module. The calculation window is the same as the harmonic analysis window, and the three-phase full-wave voltage amplitude and three-phase full-wave current amplitude are obtained.

[0146] The unbalanced component calculation module is used to decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of voltage amplitude, current amplitude, and phase angle.

[0147] The non-fundamental amplitude calculation module is used to determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude.

[0148] The fundamental power calculation module is used to determine the fundamental positive sequence active power, reactive power, and apparent power by using the positive sequence components, negative sequence components, and zero sequence components of voltage amplitude, current amplitude, and phase angle.

[0149] The distortion power calculation module is used to determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

[0150] The electricity metering method and device described in the above embodiments, compared with the prior art, address the issue that existing electricity metering schemes measure only a single electrical parameter, lacking the corresponding parameters to guide power sector billing, engineering economic decisions, and the determination of major harmonic pollution sources, resulting in lower quality electricity services. This invention features a simple process and convenient operation. It utilizes harmonic analysis algorithms to process voltage and current sampling data, extracting the corresponding fundamental voltage and current components, harmonic voltage and current components, and the corresponding fundamental and harmonic phase angles. Based on this data, it calculates the fundamental positive-sequence active power, reactive power, non-fundamental equivalent apparent power, voltage distortion power, current distortion power, harmonic apparent power, and unbalanced apparent power, thus enabling the measurement of multiple electrical parameters of the electricity meter. This allows for guidance of power sector billing, economic decisions, and the determination of major harmonic pollution sources, significantly improving the quality of electricity services.

[0151] Obviously, the embodiments described above are merely preferred embodiments of the present invention, and not all embodiments. The accompanying drawings illustrate preferred embodiments of the present invention, but do not limit the scope of the patent. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this invention.

Claims

1. A method for measuring electrical energy using an electricity meter, characterized in that, Includes the following steps: S10. Obtain the original sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling; S20. Perform harmonic analysis on the waveform data to obtain the spectral components of the corresponding voltage and current. Determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through the subgroup algorithm. S30. The data obtained in S20 are summed and squared to calculate the sum of squares. The calculation window is consistent with the harmonic analysis window to obtain the three-phase full-wave voltage amplitude and the three-phase full-wave current amplitude. S40. Decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of the voltage amplitude, current amplitude, and phase angle. S50. Determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude; S60. Determine the fundamental positive-sequence active power, reactive power, and apparent power by using the positive-sequence components, negative-sequence components, and zero-sequence components of voltage amplitude, current amplitude, and phase angle. S70. Determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

2. The method for measuring electricity energy using an electricity meter according to claim 1, characterized in that, In S20, the harmonic analysis algorithm uses the discrete Fourier transform method, and the formula is as follows: ； in, For the k-th spectral component, This refers to voltage sampling point data or current sampling point data. These are the spectral components obtained by performing a discrete Fourier transform on the voltage or current sampling data. is the rotation factor.

3. The method for measuring electricity energy using an electricity meter according to claim 2, characterized in that, The harmonics algorithm uses a subgroup approach, and the formula is as follows: ； in, For harmonic subgroups, For the k-th spectral component; The corresponding fundamental and harmonic phase angles are determined based on the spectral components as follows: ； in Let be the phase angle of the i-th voltage or current, idx be the size of the harmonic analysis window, and X[idx] be the voltage or current spectral component of the corresponding order.

4. The method for measuring electricity energy using an electricity meter according to claim 3, characterized in that, In S30, the formula is as follows: ； ； in, Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. The instantaneous voltage sample value at time t; Here, N represents the single-cycle voltage amplitude, and N is the number of sampling points per single cycle. The instantaneous voltage sample value at time t.

5. The method for measuring electricity energy using an electricity meter according to claim 4, characterized in that, In S40, the formula for the symmetric component is as follows: ； in, These are the positive-sequence, negative-sequence, and zero-sequence components of voltage or current, respectively. The fundamental voltage or fundamental current components calculated for channels A, B, and C. For complex number operators, ; The formulas for the positive-sequence and negative-sequence components of the amplitude and phase angle are as follows: ； ； ； ； in, , , The angle between the three-phase fundamental voltage and current. , , , The positive and negative sequence calculation values ​​are the angles between the three-phase voltage or current and the three-phase fundamental voltage and current.

6. The method for measuring electricity energy using an electricity meter according to claim 5, characterized in that, In S50, the formula is as follows: ； ； ； ； Among them, V a V b V c For three-phase full-wave phase voltage, V ab V bc V ca For the full-wave line voltage, I a I b I c For three-phase full-wave current, I n For the full-wave neutral current, V e and I e For the corresponding full-wave effective voltage and effective current, V a1 V b1 V c1 The fundamental phase voltage of the three-phase circuit is V. ab1 V bc1 V ca1 I is the fundamental line voltage. a1 I b1 I c1 For the three-phase fundamental current, I n1 For the fundamental neutral current, V e1 and I e1 These are the corresponding fundamental effective voltage and effective current; The corresponding formulas for non-fundamental voltage and non-fundamental current are as follows: ； 。 7. The method for measuring electricity energy using an electricity meter according to claim 6, characterized in that, In S60, the formula is as follows: ； ； ； ； ； ； in, , , To calculate the fundamental positive-sequence active power, reactive power, and apparent power, , , The calculated fundamental negative sequence active power, reactive power, and apparent power are given.

8. The method for measuring electricity energy using an electricity meter according to claim 7, characterized in that, In S70, the formula is as follows: ； ； ； ； ； ； in, For voltage distortion power, This refers to the power distortion due to current. For harmonic apparent power, For harmonic distortion power, For non-fundamental equivalent apparent power, This refers to the unbalanced apparent power.

9. The method for measuring electricity energy using an electricity meter according to claim 1, characterized in that, In S10, the sampling rate of synchronous sampling is greater than 6.4Kp / s, that is, the number of sampling points per cycle is greater than 128.

10. An electricity meter / electricity metering device, characterized in that, include: The data acquisition module is used to acquire the raw sampled waveform data of the three-phase voltage and three-phase current obtained by synchronous sampling; The harmonic analysis module is used to perform harmonic analysis on the waveform data, obtain the spectral components of the corresponding voltage and current, and determine the fundamental voltage amplitude, fundamental current amplitude, harmonic voltage amplitude, harmonic current amplitude, and the corresponding fundamental phase angle and harmonic phase angle through a subgroup algorithm. The full-wave calculation module is used to calculate the sum of squares of the data analyzed in the harmonic analysis module. The calculation window is consistent with the harmonic analysis window to obtain the three-phase full-wave voltage amplitude and the three-phase full-wave current amplitude. The unbalanced component calculation module is used to decompose the fundamental voltage and fundamental current obtained from harmonic analysis into symmetrical components, and determine the positive sequence component, negative sequence component, and zero sequence component of voltage amplitude, current amplitude, and phase angle. The non-fundamental amplitude calculation module is used to determine the non-fundamental voltage amplitude and non-fundamental current amplitude using the full-wave voltage amplitude, full-wave current amplitude, fundamental voltage amplitude, and fundamental current amplitude. The fundamental power calculation module is used to determine the fundamental positive sequence active power, reactive power, and apparent power by using the 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 to determine the voltage distortion power, current distortion power, unbalanced apparent power, and harmonic apparent power by using the non-fundamental voltage amplitude, non-fundamental current amplitude, fundamental voltage amplitude, fundamental current amplitude, and the positive sequence components of voltage phase angle and current phase angle.

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