阅读说明：本技术 一种在线识别失准电能表的方法 (Method for on-line identifying misalignment electric energy meter ) 是由 夏桃芳 林华 高琛 李建新 王雅平 陈前 詹世安 詹文 鄢盛腾 丁忠安 陈吴晓 于 2021-07-07 设计创作，主要内容包括：本发明提出一种在线识别失准电能表的方法,包括以下步骤；步骤S1：选取与待校验电能表所在表箱A最邻近的表箱B,结合用电信息采集系统电压、电流曲线与基尔霍夫电压、电流定律,递推得到与待校验电能表同相位的最邻近表箱节点电压与电流幅值；步骤S2：依据用电信息采集系统相位信息,确定同箱同相电能表数量；步骤S3：进行多元线性回归分析,得到待校验电能表运行误差；步骤S4：当待校验电能表运行误差大于允许阈值,则识别为失准电能表；本发明仅需要同表箱及邻近表箱电能表一天的电压、电流曲线数据即可准确定位待校验电能表运行误差,同时线性回归原理简单,计算高效,能够迅速及时定位失准电能表,具有较强的工程实用性。(The invention provides a method for identifying a misalignment electric energy meter on line, which comprises the following steps of; step S1: selecting a meter box B which is most adjacent to a meter box A where the electric energy meter to be verified is located, combining a voltage and current curve of an electricity utilization information acquisition system, kirchhoff voltage and current law, and recurrently obtaining a node voltage and a current amplitude value of the most adjacent meter box which is in the same phase as the electric energy meter to be verified; step S2: determining the number of the same-box and same-phase electric energy meters according to the phase information of the power utilization information acquisition system; step S3: performing multiple linear regression analysis to obtain the running error of the electric energy meter to be verified; step S4: when the running error of the electric energy meter to be verified is larger than an allowable threshold value, identifying the electric energy meter as a misalignment electric energy meter; the method can accurately position the running error of the electric energy meter to be verified only by voltage and current curve data of the electric energy meter in the same meter box and the adjacent meter box in one day, has simple linear regression principle and high calculation efficiency, can quickly and timely position the misaligned electric energy meter, and has stronger engineering practicability.)

1. A method for on-line identifying the misaligned electric energy meter is used for identifying the high-error electric energy meter in the meter box of the low-voltage distribution line, and is characterized in that: the method comprises the following steps;

step S1: selecting a meter box B which is most adjacent to a meter box A where the electric energy meter to be verified is located, combining a voltage and current curve of an electricity utilization information acquisition system, kirchhoff voltage and current law, and recurrently obtaining a node voltage and a current amplitude value of the most adjacent meter box which is in the same phase as the electric energy meter to be verified;

step S2: determining the quantity of the same-box and same-phase electric energy meters in a meter box in which the electric energy meters to be verified are located according to the phase information of the electricity utilization information acquisition system;

step S3: combining voltage and current curve data of the power utilization information acquisition system and the number of the same-box same-phase electric energy meters, and substituting the data into a corresponding formula to perform multiple linear regression analysis to obtain the running error of the electric energy meter to be verified;

step S4: and when the operation error of the electric energy meter to be verified is larger than the allowable threshold value, identifying the electric energy meter as a misaligned electric energy meter.

2. A method of on-line identifying a misaligned electrical energy meter according to claim 1, wherein: in the step S3, if the electric energy meter in the meter box a is two parallel electric energy meters with the same phase, the analysis process is the same-phase recursion, specifically as follows;

setting the resistance of a low-voltage distribution line as R; then according to kirchhoff's voltage law, the voltage and current of the node 1 and the node 2 of the electric energy meter are expressed by formula

U₁₂＝U₁+R₁I₁＝U₂+R₂I₂A first formula;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U₁₂+R₁₂I₁₂＝U₃+R₃I₃A second formula;

in the formula of U₁，U₂The voltage amplitudes of the electric energy meter 1 and the electric energy meter 2 in the meter box A are respectively; i is₁，I₂Is the corresponding current amplitude; r₁，R₂Is the corresponding line resistance value; u shape₁₂、I₁₂The voltage amplitude and the current amplitude of the common upper node of the electric energy meter 1 and the electric energy meter 2 are considered as the voltage amplitude and the current amplitude of a meter box node A; u shape₃、I₃The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r₁₂、R₃The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving formula three from formula two: u shape₃＝U₁₂+R₁₂I₁₂-R₃I₃A formula III;

respectively substituting the voltage and current of the node 1 and the node 2 of the electric energy meter expressed by the formula one into a formula three to obtain the following formula

U₃＝U₁+R₁I₁+R₁₂I₁₂-R₃I₃A formula IV;

U₃＝U₂+R₂I₂+R₁₂I₁₂-R₃I₃a formula V;

according to kirchhoff's current law, the current of the meter box A satisfies the following relation:

I₁₂＝I₁+I₂a formula six;

substituting the formula six into the formula four and the formula five to obtain the following formula

U₃＝U₁+(R₁+R₁₂)I₁+R₁₂I₂-R₃I₃A formula seven;

U₃＝U₂+R₁₂I₁+(R₂+R₁₂)I₂-R₃I₃a formula eight;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the formula seven and the formula eight can be converted into the following formulas

U₃＝U₁+(R₁+R₁₂)kI₁’+R₁₂I₂-R₃I₃A formula of nine;

U₃＝U₂+kR₁₂I₁’+(R₂+R₁₂)I₂-R₃I₃a formula ten;

constructing a multiple linear regression equation by linearly regressing the formula nine and the formula decimal line through the voltage and current curves, and expressing the multiple linear regression equation as the formula

U_3，i＝β₁U_1，i+β₂I’_1，i+β₃I_2，i-β₄I_3，iA formula eleven;

U_3，i＝β₅U_2，i+β₆I’_1，i+β₇I_2，i-β₈I_3，ia formula twelve;

in the formula, i is the time sequence number 1,2,3, … … 96, and curve data samples are selected. In a multiple linear fit regression equation, U_3，iAs dependent variable samples of the regression equation, U_1，i、U_2，i、I′_1，i、I_2，i、I_3，iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining formula nine, formula ten, formula eleven, formula twelve, and current I'_1，iAnd I_2，iRegression coefficient beta₆And beta₃Is expressed as

In the formula, k is the correction error of the electric energy meter 1; the calculated operating error of the electric energy meter 1 is shown as follows:

calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

3. A method of on-line identifying a misaligned electrical energy meter according to claim 1, wherein: in the step S3, if the electric energy meters in the meter box a are parallel and in-phase electric energy meters, and the total number of the electric energy meters is greater than two, the analysis process is in-phase recursion, specifically as follows;

according to kirchhoff's voltage law, the voltage and current of nodes 1,2 and 3 of the electric energy meter are expressed by the following formula

U_{General assembly}＝U₁+R₁I₁＝U₂+R₂I₂＝U₃+R₃I₃A formula fifteen;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U_{General assembly}+R_{General assembly}I_{General assembly}＝U₄₁+R₄₁I₄₁Sixthly, a formula is formed;

in the formula of U₁，U₂，U₃Respectively obtaining voltage amplitudes of electric energy meters 1,2 and 3 in the meter box A; i is₁，I₂，I₃Is the corresponding current amplitude; r₁，R₂，R₃Is the corresponding line resistance value; u shape_{General assembly}Consider the voltage amplitude at node a of the meter box; u shape₄₁、I₄₁The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r_{General assembly}、R₄₁The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving U from a formula₄₁＝U_{General assembly}+R_{General assembly}I_{General assembly}-R₄₁I₄₁Seventeen, a formula;

will U_{General assembly}＝U₂+R₂I₂Substituting into formula seventeen to obtain

U₄₁＝U₂+R₂I₂+R_{General assembly}I_{General assembly}-R₄₁I₄₁Eighteen formulas;

the current of the meter box A can satisfy the following relation according to kirchhoff current law:

I_{general assembly}＝I₁+I₂+…I_nNineteen in formula;

substituting the nineteen formula into the eighteen formula to obtain

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}I₁+R_{General assembly}(I₃+I₄+…I_n)-R₄₁I₄₁

A formula twenty;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the equation twenty can be converted into

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}kI′₁+R_{General assembly}(I₃+I₄+...I_n)-R₄₁I₄₁

A formula of twenty-one;

linear regression is carried out on the equation twenty-one through voltage and current curves, and a multiple linear regression equation is constructed

U_41，i＝β₁₁U_2，i+β₂I_2，i+β₁I_1，i+β₃I_3，i+β₄I_4，i+...β_nI_n，i-β₄₁I_41，i

A formula twenty-two;

in the formula, i is a time sequence number 1,2,3, … … 96, and curve data samples are selected; in a multiple linear fit regression equation, U_41，iAs dependent variable samples of the regression equation, U_2，i、I′_1，i、I_2，i、I_3，i、I_4，i、…I_n，i、I_41，iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining the formula twenty-one and the formula twenty-two, the current I'_1，iAnd I_3，iRegression coefficient beta₃And beta₄In relation to (2)

Expressed as a formula

The running error of the electric energy meter is

Calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

4. A method of on-line identifying a misaligned electrical energy meter according to claim 2, wherein: when the formula nine and the formula decimal line linear regression analysis are carried out, the selected curve data samples are the voltage curve data and the current curve data at 96 points in one day.

5. A method of on-line identifying a misaligned electrical energy meter according to claim 3, wherein: when the linear regression analysis is performed on the formula twenty-one, the curve data sample is selected as the voltage and current curve data at 96 points in a day.

6. A method of on-line identification of misaligned electrical energy meters according to claim 1,2,3, 4 or 5, wherein: the meter box B is a multi-meter position meter box or a discrete single-meter position meter box.

7. A method of on-line identifying a misaligned electrical energy meter according to claim 1, wherein: in step S1, the marketing system profile information is combined to select the meter box B closest to the meter box a where the electric energy meter to be checked is located.

Technical Field

The invention relates to the technical field of power grid operation and maintenance, in particular to a method for identifying a misalignment electric energy meter on line.

Background

The collection, metering, storage and transmission of electric energy mainly depend on the electric energy meter, and the accuracy of the electric energy meter is related to the vital interests of power grid enterprises and each user. In order to ensure the measurement fairness, at present, a power grid enterprise mainly manages and controls a measurement misalignment device in ways of pull-back verification, periodic alternation, periodic sampling inspection, field test and the like, and consumes large manpower, material resources and financial resources, but sometimes a misalignment meter cannot be found and replaced in time. Therefore, the on-line monitoring of the operation errors of the electric energy meter based on the electric power data is an important means for realizing the management of the whole life cycle of the metering device including the site. At present, the following methods are mainly used for online identification of misaligned electric energy meters:

(1) statistical-based methods: the method considers the total-diversity of the electric energy metering levels, combines a statistical analysis method to perform data fitting, and combines a fitting coefficient and the correlation of the electric energy meter operation error to position the misaligned electric energy meter. However, in the conventional method, the electric quantity data is adopted for fitting, the duration of the required sample size needs several months, and the misalignment meter cannot be found in time.

(2) The clustering-based method comprises the following steps: the method considers that normal similar users have similarity on indexes such as load curve forms, and in order to highlight common abnormalities such as decline of power consumption trend, daily load curve abnormality, low reporting capacity utilization rate and the like of the inaccurate users, indexes such as monthly/daily power consumption, voltage/current three-phase unbalance, load change rate, fluctuation rate and the like are mostly adopted for clustering in the clustering-based method, but a large number of users have obvious discreteness in power consumption behaviors in engineering practice, and the false alarm rate of clustering and identifying the abnormal users is often higher than that of the classification-based method.

(3) Method based on state estimation: the method identifies abnormal electric quantity data reported by users by utilizing the characteristic that state quantities such as voltage, injection power and line electrical parameters of each node of the line have strong coupling, and detects abnormality through the strong coupling of the user electrical quantity on the same line. However, the method has high requirement on data accuracy, and factors such as accuracy of electric parameters of the distribution lines can influence detection results.

Although the method can be used for positioning the partially aligned electric energy meter by a data method, the method has the limitations in engineering application, such as low accuracy, high data dependence degree or long required sample time span.

Disclosure of Invention

The invention provides a method for identifying the misalignment electric energy meter on line, which can accurately position the operation error of the electric energy meter to be checked only by voltage and current curve data of the electric energy meter in the same meter box and the adjacent meter box in one day.

The invention adopts the following technical scheme.

A method of identifying misaligned electrical energy meters on-line for identifying high error electrical energy meters in a meter box of a low voltage distribution line, the method comprising the steps of;

step S1: selecting a meter box B which is most adjacent to a meter box A where the electric energy meter to be verified is located, combining a voltage and current curve of an electricity utilization information acquisition system, kirchhoff voltage and current law, and recurrently obtaining a node voltage and a current amplitude value of the most adjacent meter box which is in the same phase as the electric energy meter to be verified;

step S2: determining the quantity of the same-box and same-phase electric energy meters in a meter box in which the electric energy meters to be verified are located according to the phase information of the electricity utilization information acquisition system;

step S3: combining voltage and current curve data of the power utilization information acquisition system and the number of the same-box same-phase electric energy meters, and substituting the data into a corresponding formula to perform multiple linear regression analysis to obtain the running error of the electric energy meter to be verified;

step S4: and when the operation error of the electric energy meter to be verified is larger than the allowable threshold value, identifying the electric energy meter as a misaligned electric energy meter.

In the step S3, if the electric energy meter in the meter box a is two parallel electric energy meters with the same phase, the analysis process is the same-phase recursion, specifically as follows;

setting the resistance of a low-voltage distribution line as R; then according to kirchhoff's voltage law, the voltage and current of the node 1 and the node 2 of the electric energy meter are expressed by formula

U₁₂＝U₁+R₁I₁＝U₂+R₂I₂A first formula;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U₁₂+R₁₂I₁₂＝U₃+R₃I₃A second formula;

in the formula of U₁,U₂The voltage amplitudes of the electric energy meter 1 and the electric energy meter 2 in the meter box A are respectively; i is₁,I₂Is the corresponding current amplitude; r₁,R₂Is the corresponding line resistance value; u shape₁₂、I₁₂The voltage amplitude and the current amplitude of the common upper node of the electric energy meter 1 and the electric energy meter 2 are considered as the voltage amplitude and the current amplitude of a meter box node A; u shape₃、I₃The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r₁₂、R₃The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving formula three from formula two: u shape₃＝U₁₂+R₁₂I₁₂-R₃I₃A formula III;

respectively substituting the voltage and current of the node 1 and the node 2 of the electric energy meter expressed by the formula one into a formula three to obtain the following formula

U₃＝U₁+R₁I₁+R₁₂I₁₂-R₃I₃A formula IV;

U₃＝U₂+R₂I₂+R₁₂I₁₂-R₃I₃a formula V;

according to kirchhoff's current law, the current of the meter box A satisfies the following relation:

I₁₂＝I₁+I₂a formula six;

substituting the formula six into the formula four and the formula five to obtain the following formula

U₃＝U₁+(R₁+R₁₂)I₁+R₁₂I₂-R₃I₃A formula seven;

U₃＝U₂+R₁₂I₁+(R₂+R₁₂)I₂-R₃I₃a formula eight;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the formula seven and the formula eight can be converted into the following formulas

U₃＝U₁+(R₁+R₁₂)kI’₁+R₁₂I₂-R₃I₃A formula of nine;

U₃＝U₂+kR₁₂I’₁+(R₂+R₁₂)I₂-R₃I₃a formula ten;

constructing a multiple linear regression equation by linearly regressing the formula nine and the formula decimal line through the voltage and current curves, and expressing the multiple linear regression equation as the formula

U_3，i＝β₁U_1，i+β₂I’_1，i+β₃I_2，i-β₄I_3，iA formula eleven;

U_3，i＝β₅U_2，i+β₆I’_1，i+β₇I_2，i-β₈I_3，ia formula twelve;

in the formula, i is the time sequence number 1,2,3, … … 96, and curve data samples are selected. In a multiple linear fit regression equation, U_3,iAs dependent variable samples of the regression equation, U_1,i、U_2,i、I′_1,i、I_2,i、I_3,iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining formula nine, formula ten, formula eleven, formula twelve, and current I'_1,iAnd I_2,iRegression coefficient beta₆And beta₃Is expressed as

In the formula, k is the correction error of the electric energy meter 1; the calculated operating error of the electric energy meter 1 is shown as follows:

calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

In the step S3, if the electric energy meters in the meter box a are parallel and in-phase electric energy meters, and the total number of the electric energy meters is greater than two, the analysis process is in-phase recursion, specifically as follows;

according to kirchhoff's voltage law, the voltage and current of nodes 1,2 and 3 of the electric energy meter are expressed by the following formula

U_{General assembly}＝U₁+R₁I₁＝U₂+R₂I₂＝U₃+R₃I₃A formula fifteen;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U_{General assembly}+R_{General assembly}I_{General assembly}＝U₄₁+R₄₁I₄₁Sixthly, a formula is formed;

in the formula of U₁,U₂,U₃Respectively obtaining voltage amplitudes of electric energy meters 1,2 and 3 in the meter box A; i is₁,I₂,I₃Is the corresponding current amplitude; r₁,R₂,R₃Is the corresponding line resistance value; u shape_{General assembly}Consider the voltage amplitude at node a of the meter box; u shape₄₁、I₄₁The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r_{General assembly}、R₄₁The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving U from a formula₄₁＝U_{General assembly}+R_{General assembly}I_{General assembly}-R₄₁I₄₁Seventeen, a formula;

will U_{General assembly}＝U₂+R₂I₂Substituting into formula seventeen to obtain

U₄₁＝U₂+R₂I₂+R_{General assembly}I_{General assembly}-R₄₁I₄₁Eighteen formulas;

the current of the meter box A can satisfy the following relation according to kirchhoff current law:

I_{general assembly}＝I₁+I₂+...I_nNineteen in formula;

substituting the nineteen formula into the eighteen formula to obtain

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}I₁+R_{General assembly}(I₃+I₄+...I_n)-R₄₁I₄₁A formula twenty;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the formula can be twenty-foldInto

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}kI′₁+R_{General assembly}(I₃+I₄+...I_n)-R₄₁I₄₁A formula of twenty-one;

linear regression is carried out on the equation twenty-one through voltage and current curves, and a multiple linear regression equation is constructed

U_41，i＝β₁₁U_2，i+β₂I_2，i+β₁I′_1，i+β₃I_3，i+β₄I_4，i+...β_nI_n，i-β₄₁I_41，iA formula twenty-two;

in the formula, i is a time sequence number 1,2,3, … … 96, and curve data samples are selected; in a multiple linear fit regression equation, U_41,iAs dependent variable samples of the regression equation, U_2,i、I′_1,i、I_2,i、I_3,i、I_4,i、…I_n,i、I_41,iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining the formula twenty-one and the formula twenty-two, the current I'_1,iAnd I_3,iRegression coefficient beta₃And beta₄Is expressed by formula

The running error of the electric energy meter is

Calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

When the formula nine and the formula decimal line linear regression analysis are carried out, the selected curve data samples are the voltage curve data and the current curve data at 96 points in one day.

When the linear regression analysis is performed on the formula twenty-one, the curve data sample is selected as the voltage and current curve data at 96 points in a day.

The meter box B is a multi-meter position meter box or a discrete single-meter position meter box.

In step S1, the marketing system profile information is combined to select the meter box B closest to the meter box a where the electric energy meter to be checked is located.

According to the method, kirchhoff voltage and current laws and multivariate linear regression analysis are combined, the corresponding relation between the voltage and the current of a plurality of electric energy meters containing fitting coefficients is obtained by recursion from bottom to top, and the correlation between the running error of the electric energy meter to be verified and the fitting coefficients is determined by formula deduction, so that an accurate expression of the running error of the electric energy meter is obtained, and the misaligned electric energy meter is accurately identified.

The method of the invention has the advantages that:

1. the method can analyze and calculate the misalignment electric energy meter only by combining voltage and current curve data of one day, has small time span of required samples, quickly positions the misalignment electric energy meter in time, and realizes the field-containing full-life cycle management of the metering device.

2. The multivariate linear fitting algorithm is simple, the calculation speed is high, and the method has good engineering practicability.

3. A brand new verification method is provided for the inaccurate replacement of the electric energy meter.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic diagram of an electrical topology structure of a same-meter-box same-phase electric energy meter with the total number of two;

FIG. 2 is a schematic diagram of an electrical topology when the total number of in-phase electric energy meters in the same meter box is more than two;

FIG. 3 is a schematic flow diagram of the process of the present invention.

Detailed Description

As shown in the figure, a method for on-line identification of misaligned electric energy meters for identifying high-error electric energy meters in a meter box of a low-voltage distribution line, comprises the following steps;

step S1: selecting a meter box B which is most adjacent to a meter box A where the electric energy meter to be verified is located, combining a voltage and current curve of an electricity utilization information acquisition system, kirchhoff voltage and current law, and recurrently obtaining a node voltage and a current amplitude value of the most adjacent meter box which is in the same phase as the electric energy meter to be verified;

step S2: determining the quantity of the same-box and same-phase electric energy meters in a meter box in which the electric energy meters to be verified are located according to the phase information of the electricity utilization information acquisition system;

step S3: combining voltage and current curve data of the power utilization information acquisition system and the number of the same-box same-phase electric energy meters, and substituting the data into a corresponding formula to perform multiple linear regression analysis to obtain the running error of the electric energy meter to be verified;

step S4: and when the operation error of the electric energy meter to be verified is larger than the allowable threshold value, identifying the electric energy meter as a misaligned electric energy meter.

In the step S3, if the electric energy meter in the meter box a is two parallel electric energy meters with the same phase, the analysis process is the same-phase recursion, specifically as follows;

setting the resistance of a low-voltage distribution line as R; then according to kirchhoff's voltage law, the voltage and current of the node 1 and the node 2 of the electric energy meter are expressed by formula

U₁₂＝U₁+R₁I₁＝U₂+R₂I₂A first formula;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U₁₂+R₁₂I₁₂＝U₃+R₃I₃A second formula;

in the formula of U₁,U₂The voltage amplitudes of the electric energy meter 1 and the electric energy meter 2 in the meter box A are respectively; i is₁,I₂Is the corresponding current amplitude; r₁,R₂Is the corresponding line resistance value; u shape₁₂、I₁₂The voltage amplitude value of the common upper node of the electric energy meter 1 and the electric energy meter 2The current amplitude, which is considered herein to be the voltage amplitude and the current amplitude at the meter box node A; u shape₃、I₃The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r₁₂、R₃The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving formula three from formula two: u shape₃＝U₁₂+R₁₂I₁₂-R₃I₃A formula III;

respectively substituting the voltage and current of the node 1 and the node 2 of the electric energy meter expressed by the formula one into a formula three to obtain the following formula

U₃＝U₁+R₁I₁+R₁₂I₁₂-R₃I₃A formula IV;

U₃＝U₂+R₂I₂+R₁₂I₁₂-R₃I₃a formula V;

according to kirchhoff's current law, the current of the meter box A satisfies the following relation:

I₁₂＝I₁+I₂a formula six;

substituting the formula six into the formula four and the formula five to obtain the following formula

U₃＝U₁+(R₁+R₁₂)I₁+R₁₂I₂-R₃I₃A formula seven;

U₃＝U₂+R₁₂I₁+(R₂+R₁₂)I₂-R₃I₃a formula eight;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the formula seven and the formula eight can be converted into the following formulas

U₃＝U₁+(R₁+R₁₂)kI’₁+R₁₂I₂-R₃I₃A formula of nine;

U₃＝U₂+kR₁₂I’₁+(R₂+R₁₂)I₂-R₃I₃a formula ten;

constructing a multiple linear regression equation by linearly regressing the formula nine and the formula decimal line through the voltage and current curves, and expressing the multiple linear regression equation as the formula

U_3，i＝β₁U_1，i+β₂I’_1，i+β₃I_2，i-β₄I_3，iA formula eleven;

U_3，i＝β₅U_2，i+β₆I’_1，i+β₇I_2，i-β₈I_3，ia formula twelve;

in the formula, i is the time sequence number 1,2,3, … … 96, and curve data samples are selected. In a multiple linear fit regression equation, U_3,iAs dependent variable samples of the regression equation, U_1,i、U_2,i、I′_1,i、I_2,i、I_3,iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining formula nine, formula ten, formula eleven, formula twelve, and current I'_1,iAnd I_2,iRegression coefficient beta₆And beta₃Is expressed as

In the formula, k is the correction error of the electric energy meter 1; the calculated operating error of the electric energy meter 1 is shown as follows:

calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

In the step S3, if the electric energy meters in the meter box a are parallel and in-phase electric energy meters, and the total number of the electric energy meters is greater than two, the analysis process is in-phase recursion, specifically as follows;

according to kirchhoff's voltage law, the voltage and current of nodes 1,2 and 3 of the electric energy meter are expressed by the following formula

U_{General assembly}＝U₁+R₁I₁＝U₂+R₂I₂＝U₃+R₃I₃A formula fifteen;

the voltage and the current of the meter box A and the meter box B are expressed by formula

U₀＝U_{General assembly}+R_{General assembly}I_{General assembly}＝U₄₁+R₄₁I₄₁Sixthly, a formula is formed;

in the formula of U₁,U₂,U₃Respectively obtaining voltage amplitudes of electric energy meters 1,2 and 3 in the meter box A; i is₁,I₂,I₃Is the corresponding current amplitude; r₁,R₂,R₃Is the corresponding line resistance value; u shape_{General assembly}Consider the voltage amplitude at node a of the meter box; u shape₄₁、I₄₁The node voltage amplitude and the current amplitude of the meter box A closest to the meter box B can be obtained by recursion of an in-phase electric energy meter in the adjacent meter box by combining kirchhoff voltage and current law; r_{General assembly}、R₄₁The resistance values of upper-layer nodes corresponding to the meter box A and the meter box B are obtained; u shape₀Is the upper node voltage amplitude;

deriving U from a formula₄₁＝U_{General assembly}+R_{General assembly}I_{General assembly}-R₄₁I₄₁Seventeen, a formula;

will U_{General assembly}＝U₂+R₂I₂Substituting into formula seventeen to obtain

U₄₁＝U₂+R₂I₂+R_{General assembly}I_{General assembly}-R₄₁I₄₁Eighteen formulas;

the current of the meter box A can satisfy the following relation according to kirchhoff current law:

I_{general assembly}＝I₁+I₂+...I_nNineteen in formula;

substituting the nineteen formula into the eighteen formula to obtain

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}I₁+R_{General assembly}(I₃+I₄+...I_n)-R₄₁I₄₁A formula twenty;

assuming that the electric energy meter 1 is a misalignment electric energy meter, the electric energy meter is I'₁The actual value of the current is kI'₁And k is the correction error, the equation twenty can be converted into

U₄₁＝U₂+(R₂+R_{General assembly})I₂+R_{General assembly}kI′₁+R_{General assembly}(I₃+I₄+...I_n)-R₄₁I₄₁A formula of twenty-one;

linear regression is carried out on the equation twenty-one through voltage and current curves, and a multiple linear regression equation is constructed

U_41，i＝β₁₁U_2，i+β₂I_2，i+β₁I′_1，i+β₃I_3，i+β₄I_4，i+...β_nI_n，i-β₄₁I_41，iA formula twenty-two;

in the formula, i is a time sequence number 1,2,3, … … 96, and curve data samples are selected; in a multiple linear fit regression equation, U_41,iAs dependent variable samples of the regression equation, U_2,i、I′_1,i、I_2,i、I_3,i、I_4,i、…I_n,i、I_41,iIs a regression equation independent variable sample, beta is a corresponding fitting coefficient;

combining the formula twenty-one and the formula twenty-two, the current I'_1,iAnd I_3,iRegression coefficient beta₃And beta₄Is expressed by formula

The running error of the electric energy meter is

Calculating the errors of other electric energy meters in the meter box A according to the method; when the calculation result epsilon in the formula is a positive number, the electric energy meter has a positive error, namely the electric energy meter measures more electric quantity; when the calculation result epsilon is a negative number, the electric energy meter has a negative error, namely the electric energy meter is less in metering electric quantity; and if the calculated running error epsilon exceeds a specified running error threshold value, determining as a misalignment electric energy meter.

When the formula nine and the formula decimal line linear regression analysis are carried out, the selected curve data samples are the voltage curve data and the current curve data at 96 points in one day.

When the linear regression analysis is performed on the formula twenty-one, the curve data sample is selected as the voltage and current curve data at 96 points in a day.

The meter box B is a multi-meter position meter box or a discrete single-meter position meter box.

In step S1, the marketing system profile information is combined to select the meter box B nearest to the meter box a where the electric energy meter to be verified is located.