阅读说明：本技术 一种基于Pareto分布的电能表计量准确性估计系统和方法 (Electric energy meter metering accuracy estimation system and method based on Pareto distribution ) 是由 依溥治 雷婧婷 李建波 贺云隆 李迪星 高少杰 吕荣 郭龙弟 徐军 曲井致 吴国 于 2021-07-22 设计创作，主要内容包括：本发明提出一种基于Pareto分布的电能表计量准确性估计系统和方法,属于电能表计量准确性估计领域。具体包括,数据采集模块、通讯模块和控制模块；所述数据采集模块、通讯模块和控制模块依次连接；所述数据采集模块用于采集电能表实时电能；所述通讯模块用于将所述数据采集模块采集的数据传输至所述控制模块；所述控制模块用于实时对所述数据采集模块下发数据采集的命令并对接收到的数据进行分析和处理。解决了现有技术中存在的无法对智能电能表进行实时误差监测以及无法识别具体智能电能表故障的技术问题。实现了提高智能电能表的运行稳定性和计量准确性保障电能计费的准确性,降低智能电能表的运行维护费用的技术效果。(The invention provides an electric energy meter metering accuracy estimation system and method based on Pareto distribution, and belongs to the field of electric energy meter metering accuracy estimation. The system specifically comprises a data acquisition module, a communication module and a control module; the data acquisition module, the communication module and the control module are sequentially connected; the data acquisition module is used for acquiring real-time electric energy of the electric energy meter; the communication module is used for transmitting the data acquired by the data acquisition module to the control module; the control module is used for issuing a data acquisition command to the data acquisition module in real time and analyzing and processing the received data. The technical problems that real-time error monitoring can not be carried out on the intelligent electric energy meter and faults of the intelligent electric energy meter can not be identified in the prior art are solved. The technical effects of improving the operation stability and the metering accuracy of the intelligent electric energy meter, ensuring the accuracy of electric energy charging and reducing the operation maintenance cost of the intelligent electric energy meter are achieved.)

1. A system for estimating metering accuracy of an electric energy meter based on Pareto distribution is characterized by comprising the following steps: the device comprises a data acquisition module, a communication module and a control module; the data acquisition module, the communication module and the control module are sequentially connected;

the data acquisition module is used for acquiring real-time electric energy of the electric energy meter;

the communication module is used for transmitting the data acquired by the data acquisition module to the control module;

the control module is used for issuing a data acquisition command to the data acquisition module in real time and analyzing and processing the received data.

2. The system of claim 1, wherein the data acquisition module comprises an intelligent electric energy meter, a district total meter and a concentrator; the concentrator is respectively in communication connection with the intelligent electric energy meter and the distribution room master meter; the concentrator is connected with the control module; the intelligent electric energy meter is used for collecting the real-time electric energy of residents; the concentrator is used for collecting real-time electric energy of the intelligent electric energy meter and the distribution room master meter and transmitting the real-time electric energy to the control module.

3. The system of claim 2, wherein the control module comprises an electric energy meter metering accuracy evaluation module, a master station server and a working terminal; the master station server is respectively connected with the electric energy meter measuring accuracy evaluation module and the working terminal; the master station server is connected with the data acquisition module through the communication module and is used for receiving the data transmitted by the data acquisition module; the electric energy meter measuring accuracy evaluation module is used for evaluating the measuring accuracy of the electric energy meter; and the working terminal is used for displaying the evaluation result.

4. The method is realized by depending on the Pareto distribution-based electric energy meter metering accuracy estimation system in any one of claims 1 to 3, and is characterized by comprising the following steps of:

step one, establishing a tree-shaped topological structure of an electric energy meter area;

calculating the relative error between the increment of the intelligent electric energy meter and the increment of the true value;

step three, calculating the power supply amount of a total table of the distribution room in the acquisition period;

step four, obtaining the working operation error of each electric energy meter in the transformer area according to N periods of data of the transformer area and a column equation set;

step five, determining the range of the overrun threshold;

step six, substituting the error overrun data into a maximum likelihood estimation formula of generalized Pareto distribution, and calculating scale parameters and shape parameters to obtain a working error distribution function meeting the generalized Pareto distribution;

and step seven, establishing a risk rate function to estimate the probability of the out-of-tolerance of the working error, and judging the out-of-tolerance risk according to the risk rate function value.

5. The method according to claim 4, wherein the specific method for calculating the relative error between the increment of the intelligent electric energy meter and the increment of the true value in the second step is as follows:

relative error epsilon of jth electric energy meter in transformer area_j：

Transforming formula (1) into:

wherein the content of the first and second substances,increment of reading for jth block of sub-table, P_jIs the true increment of the jth block.

6. The method according to claim 5, wherein the specific method for calculating the total table power supply amount of the distribution room in the acquisition period in the step three is as follows:

calculating the power supply amount y (i) of a total table of the station area in the ith acquisition period:

the formula (2) can be substituted for the formula (3):

wherein the content of the first and second substances,reading increment of the jth block of the sub-meter in the ith acquisition period of the electric energy data set acquisition layer, epsilon_jError of block j in the acquisition period, epsilon_yFor the line loss rate of the station zone of the acquisition cycle, epsilon₀The loss is fixed for the station area.

7. The method according to claim 6, wherein the specific method for obtaining the operating error of each electric energy meter in the transformer area according to the data of the transformer area in N periods and the column equation system in the step four is as follows:

8. the method of claim 7, wherein the specific method for determining the overrun threshold range in step five is: selecting a proper overrun threshold value in the determined range;

from x_iA series of threshold values mu are randomly selected, an average excess function graph is drawn by a point set (mu, e (mu)), and if a function curve fluctuates around a straight line, the finally selected threshold value is suitable.

9. The method according to claim 8, wherein the specific method for obtaining the working error distribution function satisfying the generalized Pareto distribution in the sixth step is:

let f (x) be the distribution function of the overrun data x with threshold value μ, then f (x) asymptotically conforms to the generalized Pareto distribution, and the distribution function f (x) and the probability density function f (x) are respectively:

wherein beta is a scale parameter, and xi is a shape parameter.

10. The method according to claim 9, wherein the step seven of establishing the risk function estimates the probability of the out-of-tolerance of the working error, and the specific method for judging the out-of-tolerance risk according to the risk function value is as follows:

wherein, F (x) is a working error distribution function satisfying the generalized Pareto distribution, and f (x) is a probability density function of F (x).

Technical Field

The invention relates to an electric energy meter accuracy estimation system, in particular to an electric energy meter metering accuracy estimation system and method based on Pareto distribution, and belongs to the field of electric energy meter metering accuracy estimation.

Background

Electric energy metering is the legal basis for the electric power industry for electric energy trade and settlement of electricity charges. With the advancement of the power system reform, the separation of a power plant and a power network, the reformation of power transmission and distribution prices and the separation of power transmission and distribution, an electricity selling company will become an important role in electric energy trade, the settlement gateway point of electric quantity transaction of a power grid and the electric energy metering point of a user are increased, and the required electric energy metering device is further increased in multiples. Therefore, the operation and maintenance of the electric energy metering device are important in the electric energy metering work of the power grid company.

According to the statistics of the state network camps, in the fault event of the intelligent electric energy meter, the case caused by equipment fault accounts for 80.5%, and in 11 typical faults, the error out-of-tolerance bit is listed as the first bit. At present, each electric power company has different requirements on online monitoring of the intelligent electric energy meter, but most of the electric power companies have some problems: if the intelligent electric energy meter cannot be monitored for errors in real time, data uploaded by individual intelligent electric energy meters cannot be received, and an error out-of-tolerance early warning mechanism of the intelligent electric energy meter is lacked.

With the steady advance of the development work of a new generation of intelligent electric energy meter, the calculation capability of the management core is greatly improved, how to fully utilize the internal resources of the intelligent electric energy meter, how to strengthen the online monitoring of the intelligent electric energy meter and improve the fault early warning capability is the future development direction. Therefore, real-time online monitoring of the intelligent electric energy meter is achieved, and early warning of potential faults is necessary and urgent.

The intelligent electric meter is an important component of the intelligent power grid, the operation error of the intelligent electric meter is the basis of power grid operation control and trade settlement of both power supply and power utilization parties, and the metering result is directly related to the safety of the power grid and whether the trade settlement of both parties is fair and reasonable, so that the operation error state of the intelligent electric meter is particularly important to judge.

In 2016, the state releases DL/T448-2016 technical management regulations of electric energy meters, further standardizes and improves the requirements on classification, configuration, operation and other aspects of the electric energy meters, and definitely maintains the operation reliability of the electric energy meters mainly by means of field inspection, periodic rotation sampling inspection and the like. In the national grid system, state information of errors and the like of the electric energy meter is mainly obtained by a regular on-site calibration mode of an on-site calibration instrument so as to evaluate and dispose the state of the electric energy meter. However, the field test is greatly influenced by the operating environment factors, but the load fluctuating at any time brings large deviation to the measurement of the comprehensive error of the electric energy meter, and the accurate operating state of the electric energy meter cannot be obtained in real time.

At present, although most of electric energy meters have large error values within the range of the operation error limit value specified by an electric power system, the field operation climate environment is variable, and the unpredictable performance of the electric energy meter can be more prominent due to the drastic changes of external conditions such as high temperature, low temperature, humidity and the like, so that the electric energy meter with large error is out of tolerance, and even the normal settlement of users is influenced due to the inaccurate measurement. Therefore, risk assessment needs to be carried out on the error larger value so as to ensure the metering accuracy of the electric energy meter.

Compared with the traditional metering system, the most remarkable characteristic of the existing intelligent power grid information acquisition system is that abundant communication and computing resources are integrated, so that the acquisition cost of metering data is extremely low. If the intelligent electric meter error remote judgment can be realized by utilizing the acquired data, the information contained in the measured data is fully mined, the accuracy and the real-time performance of the error remote estimation of the intelligent electric meter are improved, quantitative analysis is carried out on the error larger value of the intelligent electric meter, suspected abnormal metering points can be found in time from the technical means, the bottleneck that the workload of manual inspection is large and pertinence is lacked at present is overcome, the maintenance cost of the electric meter error can be greatly reduced, and support is provided for efficient power utilization inspection.

Disclosure of Invention

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to determine the key or critical elements of the present invention, nor is it intended to limit the scope of the present invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

The invention provides an electric energy meter metering accuracy estimation system based on Pareto distribution, which comprises a data acquisition module, a communication module and a control module, wherein the data acquisition module is used for acquiring data; the data acquisition module, the communication module and the control module are sequentially connected;

the data acquisition module is used for acquiring real-time electric energy of the electric energy meter;

the communication module is used for transmitting the data acquired by the data acquisition module to the control module;

the control module is used for issuing a data acquisition command to the data acquisition module in real time and analyzing and processing the received data.

Preferably, the data acquisition module comprises an intelligent electric energy meter, a distribution area total meter and a concentrator; the concentrator is respectively in communication connection with the intelligent electric energy meter and the distribution room master meter; the concentrator is connected with the control module; the intelligent electric energy meter is used for collecting the real-time electric energy of residents; the concentrator is used for collecting real-time electric energy of the intelligent electric energy meter and the distribution room master meter and transmitting the real-time electric energy to the control module.

Preferably, the control module comprises an electric energy meter metering accuracy evaluation module, a master station server and a working terminal; the master station server is respectively connected with the electric energy meter measuring accuracy evaluation module and the working terminal; the master station server is connected with the data acquisition module through the communication module and is used for receiving the data transmitted by the data acquisition module; the electric energy meter measuring accuracy evaluation module is used for evaluating the measuring accuracy of the electric energy meter; and the working terminal is used for displaying the evaluation result.

A method for estimating metering accuracy of an electric energy meter based on Pareto distribution comprises the following steps:

step one, establishing a tree-shaped topological structure of an electric energy meter area;

calculating the relative error between the increment of the intelligent electric energy meter and the increment of the true value;

step three, calculating the power supply amount of a total table of the distribution room in the acquisition period;

step four, obtaining the working operation error of each electric energy meter in the transformer area according to N periods of data of the transformer area and a column equation set;

step five, determining the range of the overrun threshold;

step six, substituting the error overrun data into a maximum likelihood estimation formula of generalized Pareto distribution, and calculating scale parameters and shape parameters to obtain a working error distribution function meeting the generalized Pareto distribution;

and step seven, establishing a risk rate function to estimate the probability of the out-of-tolerance of the working error, and judging the out-of-tolerance risk according to the risk rate function value.

Preferably, the specific method for calculating the relative error between the increment of the intelligent electric energy meter and the true value increment in the second step is as follows:

relative error epsilon of jth electric energy meter in transformer area_j：

Transforming formula (1) into:

wherein the content of the first and second substances,increment of reading for jth block of sub-table, P_jIs the true increment of the jth block.

Preferably, the specific method for calculating the power supply amount of the total table of the distribution room in the acquisition period in the step three is as follows:

calculating the power supply amount y (i) of a total table of the station area in the ith acquisition period:

the formula (2) can be substituted for the formula (3):

wherein the content of the first and second substances,increasing the reading number of the jth block of sub-meter in the ith acquisition period of the electric energy data set acquisition layerAmount of epsilon_jError of block j in the acquisition period, epsilon_yFor the line loss rate of the station zone of the acquisition cycle, epsilon₀The loss is fixed for the station area.

Preferably, the specific method for obtaining the working operation error of each electric energy meter in the transformer area according to the data of the transformer area in N periods and the equation system in the column in the step four is as follows:

preferably, the specific method for determining the out-of-limit threshold range in step five is as follows: selecting a proper overrun threshold value in the determined range;

from x_iA series of threshold values mu are randomly selected, an average excess function graph is drawn by a point set (mu, e (mu)), and if a function curve fluctuates around a straight line, the finally selected threshold value is suitable.

Preferably, the specific method for obtaining the working error distribution function satisfying the generalized Pareto distribution in the step six is as follows:

let f (x) be the distribution function of the overrun data x with threshold value μ, then f (x) asymptotically conforms to the generalized Pareto distribution, and the distribution function f (x) and the probability density function f (x) are respectively:

wherein beta is a scale parameter, and xi is a shape parameter.

Preferably, the step seven of establishing the risk function to estimate the probability of the out-of-tolerance of the working error, and the specific method of judging the out-of-tolerance risk according to the risk function value is as follows:

wherein, F (x) is a working error distribution function satisfying the generalized Pareto distribution, and f (x) is a probability density function of F (x).

The invention has the following beneficial effects: the method mainly considers data with larger errors in the risk evaluation of the metering accuracy of the electric energy meter, adopts a super-threshold (POT) model of an extreme value theory, takes the error data of the super-threshold as a sample sequence, utilizes generalized Pareto distribution fitting sub-sample sequences to obtain a distribution function of the sample sequence, selects an optimal over-threshold by an over-threshold mean function method and a kurtosis value method, finally takes the upper limit of the error extreme as an early warning index to quantify whether the metering is accurate or not, gives the risk probability of the over-threshold error through a risk rate function, and further completes the evaluation of the metering accuracy risk of the quantitative electric energy meter. The invention can improve the working efficiency in the fields of electric energy metering and electric energy meter monitoring. The operation stability and the metering accuracy of the intelligent electric energy meter are improved, the electric energy charging accuracy is guaranteed, and the operation maintenance cost of the intelligent electric energy meter is reduced. The method improves the accuracy and the real-time performance of the remote error estimation of the intelligent ammeter, solves the bottleneck that the prior manual investigation has large workload and lacks of targeted detection, and greatly reduces the maintenance cost of the ammeter error.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic diagram of a system according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart of a method according to an embodiment of the present invention;

fig. 3 is a schematic topology diagram of a method step according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions and advantages of the embodiments of the present application more apparent, the following further detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings makes it clear that the described embodiments are only a part of the embodiments of the present application, and are not exhaustive of all embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

First embodiment, the first embodiment is described with reference to fig. 1, and a system for estimating the metering accuracy of an electric energy meter based on Pareto distribution includes a data acquisition module, a communication module and a control module; the data acquisition module, the communication module and the control module are sequentially connected;

the data acquisition module is used for acquiring real-time electric energy of the electric energy meter;

the communication module is used for transmitting the data acquired by the data acquisition module to the control module;

the control module is used for issuing a data acquisition command to the data acquisition module in real time and analyzing and processing the received data.

Specifically, the data acquisition module comprises an intelligent electric energy meter, a distribution area total meter and a concentrator; the concentrator is respectively in communication connection with the intelligent electric energy meter and the distribution room master meter; the concentrator is connected with the control module; the intelligent electric energy meter is used for collecting the real-time electric energy of residents; the concentrator is used for collecting real-time electric energy of the intelligent electric energy meter and the distribution room master meter and transmitting the real-time electric energy to the control module.

Specifically, the control module comprises an electric energy meter metering accuracy evaluation module, a master station server and a working terminal; the master station server is respectively connected with the electric energy meter measuring accuracy evaluation module and the working terminal; the master station server is connected with the data acquisition module through the communication module and is used for receiving the data transmitted by the data acquisition module; the electric energy meter measuring accuracy evaluation module is used for evaluating the measuring accuracy of the electric energy meter; and the working terminal is used for displaying the evaluation result.

Specifically, the communication module provides an available communication channel, and establishes communication connection, conversion, data acquisition, data transmission, protocol conversion and command exchange between the control module and the data acquisition module. The high-speed collection and transmission of the freezing data of the intelligent electric energy meter acquired by the control module and the data acquisition module are realized, a link foundation is provided for information interaction of the control module and the intelligent electric energy meter, and the master station server is ensured to be capable of quickly and accurately acquiring all monitoring and monitoring information.

Specifically, the intelligent electric energy meter and the distribution room master meter are single/three-phase electric energy meters with a data freezing function.

Specifically, the intelligent electric energy meter and the distribution room master meter are connected with the concentrator through a low-voltage power line carrier network by a 485 communication module or a carrier communication module of the electric energy meter, so that the centralized collection of remote electric energy data is realized. The concentrator can collect data such as real-time electric energy, frozen electric energy and the like of each intelligent electric energy meter in real time or at regular time according to the requirements of the master station server.

Specifically, the master station server collects and controls information of the intelligent electric energy meter through a remote communication channel (GPRS and GSM), and the electric energy meter metering accuracy evaluation module and the working terminal are connected with the master station server through a local area network.

Specifically, the system has the functions of electric energy meter error data acquisition, data management, line loss analysis, error analysis, operation maintenance management and data query.

In a second embodiment, the present embodiment is described with reference to fig. 2 to 3, and the method for estimating the metering accuracy of the electric energy meter based on Pareto distribution in the second embodiment includes the following steps:

step one, establishing a tree-shaped topological structure of an electric energy meter area;

step two, the specific method for calculating the relative error between the increment of the intelligent electric energy meter and the increment of the true value is as follows:

relative error epsilon of jth electric energy meter in transformer area_j：

Transforming formula (1) into:

wherein the content of the first and second substances,increment of reading for jth block of sub-table, P_jIs the true increment of the jth block.

Step three, the specific method for calculating the power supply quantity of the total table of the distribution room in the acquisition period is as follows: according to the law of conservation of energy, the electric energy increment of the total table of the station area in the same acquisition period is equal to the sum of the real value increment of the electric energy of each user sub-table in the station area and the loss of the station area, so that the power supply amount y (i) of the total table of the station area in the ith acquisition period is calculated:

the formula (2) can be substituted for the formula (3):

wherein the content of the first and second substances,reading increment of the jth block of the sub-meter in the ith acquisition period of the electric energy data set acquisition layer, epsilon_jError of block j in the acquisition period, epsilon_yFor the line loss rate of the station zone of the acquisition cycle, epsilon₀The loss is fixed for the station area.

Step four, obtaining the working operation error of each electric energy meter in the transformer area according to the N periods of data of the transformer area and a column equation set by the specific method:

the unknown quantity epsilon can be solved through an equation system_j、ε_yAnd ε₀Thereby to makeAnd obtaining the working operation error of each electric energy meter in the transformer area.

The concrete method for determining the out-of-limit threshold range comprises the following steps: selecting a proper overrun threshold value in the determined range;

from x_iA series of threshold values mu are randomly selected, an average excess function graph is drawn by a point set (mu, e (mu)), and if a function curve fluctuates around a straight line, the finally selected threshold value is suitable.

Since the average excess function of the sample needs to be artificially judged, the average excess function needs to be verified, and the formula for verification is as follows:

the overrun threshold μ, where x is obtained according to the kurtosis coefficient rule_iIn order to over-limit the sample data,is the mean value of the overrun sample data.

Step six, substituting the error overrun data into a maximum likelihood estimation formula of generalized Pareto distribution, and calculating scale parameters and shape parameters to obtain a working error distribution function meeting the generalized Pareto distribution, wherein the specific method comprises the following steps:

let f (x) be the distribution function of the overrun data x with threshold value μ, then f (x) asymptotically conforms to the generalized Pareto distribution, and the distribution function f (x) and the probability density function f (x) are respectively:

wherein beta is a scale parameter, and xi is a shape parameter.

Step seven, establishing a risk rate function to estimate the probability of the out-of-tolerance of the working error, and judging the out-of-tolerance risk according to the risk rate function value by the specific method comprising the following steps:

wherein, F (x) is a working error distribution function satisfying the generalized Pareto distribution, and f (x) is a probability density function of F (x).

The physical meaning of λ (x) is: and in the ith acquisition cycle, when the error data of the electric energy meter is greater than the threshold value, the probability that the working error of the electric energy meter develops towards the direction exceeding the threshold value. The larger the hazard value is, the larger the out-of-tolerance probability of the electric energy meter is, the higher the inaccurate risk is, and the worse the metering accuracy is.

In the working process of the electric energy meter, the risk of errors of the electric energy meter can be determined to a certain extent that the larger the random error is, the larger the influence on the metering accuracy is, the smaller the error is, the smaller the influence is, and even the influence can be ignored, so that the metering accuracy depends on the larger value of the error. Therefore, the method has the key point that the operation error calculation model of the electric energy meter is combined with the generalized Pareto distribution, the risk probability of the over-threshold error is given, and the metering accuracy of the electric energy meter is estimated in real time.

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this description, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as described herein. Furthermore, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. The present invention has been disclosed in an illustrative rather than a restrictive sense, and the scope of the present invention is defined by the appended claims.