阅读说明：本技术 自动化检定系统计量过程能力的在线监测预警方法和系统 (On-line monitoring and early warning method and system for metering process capability of automatic verification system ) 是由 李亮波 胡翔 王再义 谢震宇 田天 耿睿 王雪 古雄 郭正 蔡文嘉 李云峰 于 2019-12-30 设计创作，主要内容包括：本发明公开了自动化检定系统计量过程能力的在线监测预警方法和系统,方法为：实时采集低压电流互感器自动化检定系统基本误差数据；将采集到的误差数据传输到数据处理中心并计算其所对应的综合过程性能指数P<Sub>pL</Sub>’；以P<Sub>pL</Sub>’为分析对象,建立过程能力均值-标准差控制图,并根据P<Sub>pL</Sub>’分布情况在线监测检定系统计量过程能力,若异常则报警；反之,继续根据下控制限的波动情况对检定系统计量过程能力进行不同情况预警。本发明克服了低压电流互感器自动化检定系统在大批量、高负荷工况下,运行状态缺乏实时监测的弊端,不仅能定量计算检定系统过程能力,还可在线监测过程能力变化趋势,及时提供风险预警,确保检定过程处于统计控制状态,降低计量风险。(The invention discloses an on-line monitoring and early warning method and a system for the metering process capability of an automatic verification system, wherein the method comprises the following steps: acquiring basic error data of an automatic verification system of the low-voltage current transformer in real time; transmitting the collected error data to a data processing center and calculating a corresponding comprehensive process performance index P pL '; with P pL ' As an analysis object, a process capability mean-standard deviation control chart is established and is based on P pL The distribution condition on-line monitoring and verification system measures the process ability, if abnormal, the alarm is given; and otherwise, continuously carrying out early warning on the capacity of the metering process of the verification system under different conditions according to the fluctuation condition of the lower control limit. The invention overcomes the defect that the operation state of the automatic verification system of the low-voltage current transformer is lack of real-time monitoring under the working condition of large batch and high load, not only can quantitatively calculate the process capability of the verification system, but also can monitor the change trend of the process capability on line, provide risk early warning in time, ensure that the verification process is in a statistical control state and reduce the metering risk.)

1. An on-line monitoring and early warning method for the metering process capability of an automatic verification system is characterized by comprising the following steps:

(1) acquiring basic error data of an automatic verification system on line in real time;

(2) transmitting the basic error data acquired in the step (1) to a data processing center in real time, and calculating the comprehensive process performance index P corresponding to the basic error data in real time_pL’；

(3) The comprehensive process performance index P obtained in the step (2)_pL' As an analysis object, a process capability mean-standard deviation control chart is established in real time and is used for analyzing the process capability mean-standard deviation control chart according to a comprehensive process performance index P_pLThe distribution condition on-line monitoring verification system measures the process capacity, if abnormal, then alarm; otherwise, the next step is carried out;

(4) and (4) carrying out early warning on the capacity of the metering process of the verification system under different conditions based on the fluctuation condition of the lower control limit of the mean control chart updated in real time in the step (3).

2. The on-line monitoring and early warning method for the metrological process capability of the automatic verification system as claimed in claim 1, wherein in the step (2), the comprehensive process performance index P_pL' Process Performance index P for a plurality of workstations_pLAverage value of (1), measurement process performance index P of each station_pLThe performance index P of the measuring process of the error data obtained under different working conditions of the station_pL(n)Calculating to obtain;

wherein, P_pL(n)N in the sequence is 1, 2 and 3 … i … n, i is the ith working condition in each station, and n is the number of the working conditions in each station; the working condition in each station comprises that the low-voltage current transformer is verified under the load condition and the light load condition under the rated current ratio of 1%, 5%, 20%, 100% and 120%.

3. The on-line monitoring and early warning method for the metrological process capability of the automatic verification system as claimed in claim 1, characterized in that in the step (3), the comprehensive process performance index P obtained in the step (2) is used_pL' the verification time of the tested low-voltage current transformer is taken as the sequence, and the performance index P of the comprehensive process for continuous N times is selected_pL' is 1 subgroup, continuously collecting M subgroup data, calculating sample data mean value and standard deviation, and on-line real-time establishing processMean of capability-standard deviation control chart.

4. The on-line monitoring and early warning method for the metrological process capability of the automatic verification system as claimed in claim 3, characterized in that in step (3), the comprehensive process performance index P is used_pL' as an analysis object, the sample volume includes a real-time updated integrated process performance index and a historically stored integrated process performance index;

wherein N is more than or equal to 5; m ≧ 25, and M increases as the number of updated integrated process performance indices increases.

5. The on-line monitoring and early-warning method for the metrological process capability of an automatic verification system as claimed in claim 1, wherein in step (3), the process capability mean-standard deviation control chart adopts a lower single-sided mean control chart and a lower double-sided standard deviation control chart;

the double-side standard deviation control chart is used for observing the performance index fluctuation condition of the comprehensive process, is only used as a reference for verifying the reliability of the system, and does not distinguish the standard deviation control chart;

the lower unilateral mean control chart takes a comprehensive process performance index reflecting the verification process condition as an analysis object and is used for observing the distribution condition of the comprehensive process performance index, if the comprehensive process performance index is judged to be different, an alarm is given to indicate that the verification system is insufficient in metering process capacity and needs to be maintained; if the performance index of the comprehensive process is normal, the next step is carried out; wherein, the difference judgment method adopts the method that the difference is judged when the point is out of bounds;

the lower unilateral mean control chart includes a centerlineAnd lower control limitAnd the center lineLower control limitThe value of (c) varies as the number of integrated process performance index statistics increases.

6. The on-line monitoring and early warning method for the capacity of the metering process of the automatic verification system as claimed in claim 1, wherein in the step (4), the early warning of the capacity of the metering process of the verification system is performed according to the fluctuation condition of the lower control limit of the mean control chart updated in the step (3) in real time, and the specific method is as follows:

1) acquiring the numerical value of the lower control limit of the lower unilateral mean control chart in real time on line;

2) establishing an early warning graph by taking the measurement times as an abscissa and taking the value of the lower control limit of the lower unilateral mean control graph as an ordinate, wherein an upper judgment reference line and a lower judgment reference line are set in the early warning graph;

3) respectively and correspondingly comparing the lower control limit of the lower unilateral mean control chart obtained in real time in the step 1) with an upper judgment reference line and a lower judgment reference line in the early warning chart, and judging the metering process capacity of the verification system;

the judgment process is as follows: the upper judgment reference line and the lower judgment reference line divide the early warning image into 3 intervals of an area A, an area B and an area C: the following control limits are dotted on the early warning picture, the area A is a red warning area and corresponds to the lower control limit<A lower judgment reference line, namely a lower control limit is positioned in the area A, which indicates that the capacity of the calibration system in the metering process is insufficient and the calibration system needs to be overhauled; the B area is a yellow warning area corresponding to the lower judgment reference line being less than or equal to the lower control limitWhen the reference line is judged to be not more than the upper part, namely the lower control is limited in the B area, which shows that the capacity of the measuring process of the verification system is sufficient and needs to pay close attention; the C region is a blue normal region corresponding to the lower control limit>When the reference line is judged upwards, namely the lower control is limited in the area C, the capacity of the calibration system in the metering process is sufficient, and the calibration system is stable and controllable.

7. An on-line monitoring and early warning system for the metering process capability of an automatic verification system is characterized by comprising an automatic verification system database (1), a production scheduling platform center system (2) and a data processing center (3);

the automatic verification system database (1) is used for collecting basic error data generated in the verification process of the automatic verification system of the low-voltage current transformer and uploading the data to the production scheduling platform center system (2);

the production scheduling platform center system (2), namely an MDS system, is used for receiving basic error data of the low-voltage current transformer uploaded by an automatic verification system database in real time and transmitting the data to a data processing center;

the data processing center (3) comprises a metering process performance index calculation unit (31), a metering process performance index analysis unit (32), a metering process capacity online monitoring unit (33) and a central database (34);

the central database (34) is in data connection with the production scheduling platform central system (2) and stores basic error data of the low-voltage current transformer uploaded by the production scheduling platform central system (2) in real time;

the metering process performance index calculating unit (31) is in data connection with the central database (34) and is used for reading and calling basic error data of the low-voltage current transformer stored in the central database (34) and calculating the metering process performance index P of each working condition in each station in the basic error_pL(n)(ii) a The measuring process performance index analyzing unit (32) is in data connection with the measuring process performance index calculating unit (31) and is used for calculating the measuring process performance index P according to each working condition in each station_pL(n)Calculating to obtain the performance index P of the metering process of each working condition_pLPerformance index P of metering process for multiple stations_pLComprehensive measurement for calculating and reflecting measurement process capability of verification systemPerformance index P_pL', and by the overall process performance index P_pL' establishing a process capability mean-standard deviation control chart in real time on line as an analysis object; the measurement process capacity on-line monitoring unit (33) is in data connection with the measurement process performance index analysis unit (32) and is used for analyzing the current comprehensive process performance index P according to a real-time process capacity mean-standard deviation control chart_pLIf the distribution condition of the' is abnormal, alarming, otherwise, continuously carrying out different condition early warning on the capacity of the metering process of the verification system according to the fluctuation condition of the lower control limit of the current mean value control chart;

the central database (34) is also in data connection with the metering process performance index analysis unit (32) and is used for storing a new comprehensive metering performance index P_pL' and process capability mean-standard deviation control chart, and provides the measurement process performance index analysis unit (32) to call the historical stored comprehensive measurement performance index P_pL’；

The central database (34) is also in data connection with the metering process capacity on-line monitoring unit (33) and is used for storing the monitoring result of the metering process capacity of the verification system in real time.

8. The on-line monitoring and early-warning system for the metering process capability of the automatic verification system according to claim 7, wherein the data processing center (3) further comprises a monitoring display unit (35) and an early-warning unit (36), the monitoring display unit (35) is in data connection with the on-line monitoring unit for the metering process capability (33) and the central database (34) and is respectively used for dynamically displaying the monitoring result of the metering process capability of the verification system obtained by the on-line monitoring unit for the metering process capability (33) in real time and calling the historical monitoring result stored in the central database (34);

the early warning unit (36) is in data connection with the online measuring process capacity monitoring unit (33) and is used for early warning different fluctuation conditions of the comprehensive process performance index judgment alarm and the lower control limit of the mean value control chart in the online measuring process capacity monitoring unit (33).

9. An on-line monitoring and early warning system for the capacity of the metering process of an automatic verification system as claimed in claim 7, wherein the basic error data comprises different rated current percentage values, ratio differences under different loads and phase difference values in different stations.

Technical Field

The invention belongs to the field of electrical measurement, relates to an online monitoring and early warning method and system for the metering process capability of an automatic verification system, and particularly relates to monitoring of the metering process capability of the automatic verification system of a low-voltage current transformer.

Background

The low-voltage current transformer is widely applied to electric energy metering in a distribution line, belongs to a forced inspection metering verification instrument for trade calculation listed in a national forced verification catalogue, and the metering performance of the low-voltage current transformer directly influences the accuracy of electric energy metering. With the development of the smart grid, low-voltage current transformer automatic verification systems (hereinafter, verification systems) are established in succession in various provinces of the whole country, large-scale automatic verification of low-voltage current transformers is achieved, verification efficiency is greatly improved, however, how to guarantee the reliability of the large-scale automatic verification systems and the accuracy of verification results under a long-time heavy-load working state is provided, and new tests are provided for the work of a metering verification mechanism.

At present, most researches on the reliability and accuracy of the verification system are carried out by periodically sending main measurement standard appliances of the verification system, such as a standard current transformer, a calibrator, a load box and the like, with verification intervals of 1 to 2 years, carrying out capacity verification such as period verification, spot check and the like, and carrying out measurement supervision and other measures to ensure the measurement performance of the verification system according to verification rules and calibration standards. The traditional verification method cannot find abnormal products in time and even take measures in time, has larger hysteresis, lacks effective monitoring on the running state of the verification system, and can form a large-scale electric energy metering result out of control once the verification system has problems, thereby seriously influencing the fairness and justice of electric energy trade.

The process capability refers to the capability of the processing level of the process to meet the technical standard, and depends on various factors such as human, machine, material, method, ring and the like, and the process capability level directly influences the quality performance of the product. Analysis of process capability, originally applied to industrial production for improving the quality control level, has been widely used for various processes such as design process, management process, flow process. The invention carries out continuous statistical inspection on the metering process by analyzing key quantity values, namely basic error data, of the automatic verification system of the low-voltage current transformer, carries out quantitative calculation on the process capability by taking a process performance index as an index, establishes a control chart, leads the measurement result of each time and the established initial process parameter to be closed-loop, and establishes an online monitoring system for the metering process capability of the verification system. The system not only can quantitatively reflect the process capability of the verification system, but also can monitor the process capability change trend on line, provide risk early warning in time, ensure the stability and reliability of the verification process and reduce the risk of the metering process.

Disclosure of Invention

In order to solve the problems in the background art, the invention aims to provide an online monitoring and early warning method and system for the metering process capability of an automatic verification system of a low-voltage current transformer.

In order to achieve the purpose, the invention adopts the technical scheme that:

an on-line monitoring and early warning method for the metering process capability of an automatic verification system comprises the following steps:

(1) acquiring basic error data of an automatic verification system on line in real time;

(2) transmitting the basic error data acquired in the step (1) to a data processing center in real time, and calculating the comprehensive process performance index P corresponding to the error data in real time_pL’；

(3) The comprehensive process performance index P obtained in the step (2)_pL' As an analysis object, a process capability mean-standard deviation control chart is established in real time and is used for analyzing the process capability mean-standard deviation control chart according to a comprehensive process performance index P_pLThe distribution condition on-line monitoring verification system measures the process capacity, if abnormal, then alarm; otherwise, the next step is carried out;

(4) and (4) carrying out early warning on the capacity of the metering process of the verification system under different conditions based on the fluctuation condition of the lower control limit of the mean control chart updated in real time in the step (3).

In the above technical scheme, in the step (2), the performance index P of the comprehensive process_pL' Process Performance index P for a plurality of workstations_pLAverage value of (1), measurement process performance index P of each station_pLThe performance index P of the measuring process of the error data obtained under different working conditions of the station_pL(n)Calculating to obtain;

wherein, P_pL(n)N is 1, 2, 3 … i … n, i is the ith working condition in each station, and n is the number of the working conditions in each station; the working conditions in each station comprise that the low-voltage current transformer is verified under the load condition and the light load condition at the rated current ratios of 1 percent, 5 percent, 20 percent, 100 percent and 120 percent.

In the above technical scheme, in the step (3), the step (c) is carried outThe comprehensive process performance index P obtained in the step (2)_pL' the verification time of the tested low-voltage current transformer is taken as the sequence, and the performance index P of the comprehensive process for continuous N times is selected_pLThe method comprises the steps of continuously collecting M subgroups of data, calculating the mean value and standard deviation of sample data, and establishing a process capability mean value-standard deviation control chart in real time on line, wherein the' 1 subgroup is obtained.

In the above technical scheme, in the step (3), the comprehensive process performance index P is used_pL' as an analysis object, the sample volume includes a real-time updated integrated process performance index and a historically stored integrated process performance index;

wherein N is more than or equal to 5; m ≧ 25, and M increases as the number of updated integrated process performance indices increases.

In the above technical solution, in the step (3), the process capability mean-standard deviation control chart adopts a lower single-side mean control chart and a double-side standard deviation control chart;

the double-side standard deviation control chart is used for observing the performance index fluctuation condition of the comprehensive process, is only used as a reference for verifying the reliability of the system, and does not distinguish the standard deviation control chart;

the lower single-side control chart takes a comprehensive process performance index reflecting the verification process condition as an analysis object and is used for observing the distribution condition of the comprehensive process performance index, and if the comprehensive process performance index is judged to be different, an alarm is given to indicate that the verification system is insufficient in metering process capacity and needs to be maintained; if the performance index of the comprehensive process is normal, the next step is carried out; wherein, the difference judgment method adopts the method that the difference is judged when the point is out of bounds;

the lower unilateral mean control chart includes a centerlineAnd lower control limitAnd the center lineLower control limitThe value of (c) varies as the number of integrated process performance index statistics increases.

In the above technical solution, in the step (4), different condition early warning is performed on the capacity of the measurement process of the verification system based on the fluctuation range of the lower control limit of the mean control chart updated in real time in the step (3), and the specific method is as follows:

1) acquiring the lower control limit of the lower unilateral mean control chart in real time on line;

2) establishing an early warning graph by taking the measurement times as an abscissa and taking the value of the lower control limit of the lower unilateral mean control graph as an ordinate, wherein an upper judgment reference line and a lower judgment reference line are set in the early warning graph;

3) respectively and correspondingly comparing the lower control limit of the lower unilateral mean control chart obtained in real time in the step 1) with an upper judgment reference line and a lower judgment reference line in the early warning chart, and judging the metering process capacity of the verification system;

the judgment process is as follows: the upper judgment reference line and the lower judgment reference line divide the unilateral mean value control chart into 3 intervals of an area A, an area B and an area C: the following control limits are dotted on the early warning picture, and the area A is a red warning area corresponding to the red warning area Namely, the lower control limit is in the area A, which indicates that the measuring process capacity of the verification system is insufficient and needs to be maintained; the B area is a yellow warning area and is correspondingly judged In time, the lower control limit is positioned in the B area, which shows that the measuring process capacity of the verification system is good and needs to pay close attention; zone C is a blue normal zone corresponding toWhen the temperature of the water is higher than the set temperature,namely, the lower control limit is positioned in the C area, which shows that the measuring process capacity of the verification system is sufficient, and the verification system is stable and controllable.

An on-line monitoring and early warning system for the metering process capability of an automatic verification system comprises an automatic verification system database, a production scheduling platform center system and a data processing center;

the automatic verification system database is used for collecting basic error data generated in the verification process of the low-voltage current transformer automatic verification system (hereinafter referred to as verification system) and uploading the data to the production scheduling platform center system;

the production scheduling platform central system, namely an MDS system, is used for receiving basic error data of the low-voltage current transformer uploaded by an automatic verification system database in real time and transmitting the data to a data processing center;

the data processing center comprises a metering process performance index calculation unit, a metering process performance index analysis unit, a metering process capacity online monitoring unit and a central database;

the central database is in data connection with a production scheduling platform central system and stores basic error data of the low-voltage current transformer uploaded by the production scheduling platform central system in real time;

the performance index calculation unit of the metering process is in data connection with the central database and is used for reading and calling the basic error data of the low-voltage current transformer stored in the central database and calculating the performance index P of the metering process of each working condition in each station in the basic error_pL(n)(ii) a The measurement process performance index analysis unit is in data connection with the measurement process performance index calculation unit and is used for calculating the measurement process performance index P according to each working condition in each station_pL(n)Calculating to obtain the performance index P of the metering process of each working condition_pLPerformance index P of metering process for multiple stations_pLCalculating a comprehensive measurement performance index P reflecting the measurement process capability of the verification system_pL', and by the overall process performance index P_pL' establishing a process capability mean-standard deviation control chart in real time on line as an analysis object; on-line monitoring unit for measuring process capacity and measurementA process performance index analysis unit in data connection for analyzing a current integrated process performance index P based on a real-time process capability mean-standard deviation control chart_pLIf the distribution condition of the' is abnormal, alarming is carried out, otherwise, different condition early warning is carried out on the capacity of the metering process of the verification system according to the fluctuation condition of the lower control limit of the current mean value control chart.

The central database is also in data connection with the performance index analysis unit in the metering process and is used for storing a new comprehensive metering performance index P_pL' and process capability mean-standard deviation control chart, and provides the measurement process performance index analysis unit to call the historically stored comprehensive measurement performance index P_pL’；

The central database is also in data connection with the on-line measuring process capacity monitoring unit and is used for storing the monitoring result of the measuring process capacity of the verification system in real time.

In the technical scheme, the data processing center further comprises a monitoring display unit and an early warning unit, wherein the monitoring display unit is in data connection with the online measuring process capacity monitoring unit and the central database and is respectively used for dynamically displaying the monitoring result of the measuring process capacity of the verification system obtained by the online measuring process capacity monitoring unit in real time and calling the historical monitoring result stored in the central database.

The early warning unit is in data connection with the online measuring process capacity monitoring unit and is used for performing comprehensive process performance index judgment alarm and early warning on different fluctuation conditions of the lower control limit of the mean control graph in the online measuring process capacity monitoring unit.

In the above technical solution, the basic error data includes a ratio difference and a phase difference value under different rated current percentage values and different loads in different stations.

Compared with the prior art, the invention has the beneficial effects that:

1. the method provided by the invention takes the basic error data of the tested low-voltage current transformer reflecting the metering accuracy of the verification system as an analysis object, introduces the process performance index reflecting the current process capability of the verification system, and quantitatively obtains the comprehensive process performance index of the verification system by analyzing the data of the verification system under different stations and different working conditions;

2. the invention monitors and warns the capacity of the measuring process of the verification system from the two aspects of analyzing the distribution condition of the comprehensive process performance index through the mean-standard deviation control chart and the fluctuation range of the lower control limit of the mean control chart, so that the monitoring result is more comprehensive and accurate.

3. The on-line monitoring system provided by the invention takes the obtained comprehensive process performance index as a control index, establishes a comprehensive process performance index control chart, and monitors and verifies the metering process capacity of the system on line through statistical process control. Wherein, the sample capacity comprises historical data and updated data, and the comprehensive process performance index control chart is updated in real time through statistical calculation. The system realizes alarming on abnormal conditions through the early warning module, and ensures that the verification system is always in a statistical control state.

The invention provides a method and a system for monitoring the metering process capacity of an automatic verification system of a low-voltage current transformer on line, which overcome the defect that the real-time monitoring of the metering accuracy and the stable running state is lacked under the working condition of large-batch high load of the verification system at present.

Drawings

FIG. 1 is a block diagram of the flow of the on-line monitoring and early warning method for the metering process capability of the automatic verification system according to the present invention;

FIG. 2 is a schematic structural diagram of an on-line monitoring and early warning system for the metering process capability of the automatic verification system according to the present invention;

FIG. 3 is a schematic diagram of a data processing center according to the present invention;

FIG. 4 is a block diagram of a basic error measurement process for an automated verification system of the prior art;

FIG. 5 shows the integrated process performance index P when M is 26 in the specific embodiment_pL' distribution ofA current monitoring profile of the condition; in the figure, the abscissa is the number of groups and the ordinate is the comprehensive process performance index P_pL’；

FIG. 6 is a diagram of the lower control limit fluctuation range early warning of the lower unilateral mean control diagram in a specific embodiment; in the figure, the abscissa is the number of statistics, and the ordinate is the numerical value of the lower control limit;

FIG. 7 is a graph of the integrated process performance index P in the example embodiment_pL' historical monitoring map of distribution; in the figure, the abscissa is the number of groups and the ordinate is the comprehensive process performance index P_pL’；

Description of reference numerals:

1. an automated verification system database; 2. a production scheduling platform central system; 3. a data processing center; 31. a metering process performance index calculation unit; 32. a measurement process performance index analysis unit; 33. a measurement process capacity online monitoring unit; 34. a central database; 35. a monitoring display unit; 36. and an early warning unit.

Detailed Description

In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the following description further explains how the invention is implemented by combining the attached drawings and the detailed implementation modes.