CN104330759A - Value traceability and monitoring method for low-voltage current transformer automation verification system - Google Patents

Abstract

The invention provides a value traceability and monitoring method of a low-voltage current transformer automatic verification system. The value traceability uses a network-based remote calibration method to trace the value of the low-voltage current transformer automatic verification system; the monitoring method uses a statistical method for monitoring The low-voltage current transformer output by the verification system checks the test data of the sample, and carries out risk warning for the low-voltage current transformer based on the test data. Compared with the prior art, the method for traceability and monitoring of the value of a low-voltage current transformer automatic verification system provided by the present invention shortens the time required for calibration, reduces the cost of calibration, and reduces the lost time of the metering center; Before the verification process is completed, the results can be re-inspected online, which improves the calibration quality; the sample test and verification data statistical processing are automatically completed through computer control, which reduces the workload of the automatic verification system status monitoring and improves the status monitoring of the automated verification system. reliability and timeliness.

Description

Quantity traceability and monitoring method of low-voltage current transformer automatic verification system

technical field

The invention relates to a value traceability and monitoring method of a verification system, in particular to a value traceability and monitoring method of a low-voltage current transformer automatic verification system.

Background technique

Low-voltage current transformers are used for energy measurement in 0.4kV distribution lines. In order to ensure the fairness and justice of energy trade settlement, low-voltage current transformers must pass the verification before they can be installed and put into operation on site. With the rapid development of the economy, the demand for electricity in various regions is increasing day by day, and the use of low-voltage current transformers for metering is also increasing rapidly. The traditional manual method of testing low-voltage current transformers has low work efficiency and high operating costs, and it is difficult to ensure a high degree of consistency between the verification standards and the verification results.

The automatic verification system integrates the management platform, automatic transmission facilities and automatic transformer verification device, and can complete automatic transmission, transformer automatic verification, data processing and whole-process monitoring according to the verification plan issued by the production scheduling platform. It is generally composed of preprocessing, Loading, conveying, identification and positioning, insulation resistance measurement, power frequency withstand voltage test, secondary winding inter-turn insulation strength test, basic error measurement, magnetic saturation margin measurement, sorting and labeling, blanking, post-processing and other units .

While the automatic verification line improves the verification efficiency, it also brings new challenges to the work of the metrological verification institution. Because once the reliability of the automatic verification line itself is not good, false detection or false detection occurs, which will cause distortion of the verification results of a large number of transformers. If this situation is not discovered in time, the use of these transformers will lead to a loss of control over a wide range of electric energy measurement results, seriously affecting the fairness and justice of electric energy trade. Therefore, it is of great significance to study the method of quantity traceability and operation status monitoring of automatic calibration system.

The current transformer automatic verification system has the functions of loading and unloading, identification, connection and disconnection, test test, data processing and result report, which integrates standard current transformer, transformer calibrator, load box, insulation resistance meter and withstand voltage Testers and other measurement standards and instruments. The traditional method of traceability of quantity value is to send the above-mentioned standards and instruments to the legal metrological verification institution for verification or calibration on a regular basis in accordance with the corresponding verification regulations and calibration specifications, so as to ensure that they meet the requirements of the regulations and specifications before carrying out the work of value transfer. . There are the following problems in calibrating the automatic verification system with this traditional value transfer method:

①: The structure of the automatic verification system is complex, the volume is large, the overall transportation is difficult, and it does not meet the conditions for overall inspection;

②: After the installation and commissioning of the automatic calibration system is completed, some standard equipment and measuring instruments cannot or are difficult to be completely disassembled, making it difficult to send them for inspection;

③: The inspection process of instruments and equipment lasts for a long time, which brings inconvenience to users and affects the completion of their production tasks;

④: The verification cycle of most instruments and equipment is one year. During this year, some of them may have been out of tolerance, and it is difficult to determine the time of their out-of-tolerance with the current measurement method;

⑤: Personnel costs and travel costs are high, and on-site calibration in multiple locations cannot be performed at the same time, and the advantages of measurement experts cannot be fully utilized.

To sum up, it is necessary to propose a value traceability and monitoring method for the automatic calibration system of low-voltage current transformers, to realize the value traceability, operation status monitoring and risk warning of the low-voltage current transformer automatic calibration system, and to ensure that the value of the calibration system is reliable. .

Contents of the invention

In order to meet the needs of the prior art, the present invention provides a method for traceability of the value of the low-voltage current transformer automatic verification system. The method uses a network-based remote calibration method to measure the value of the low-voltage current transformer automatic verification system. Traceability; calibration data is passed through the network step by step.

Preferably, the network includes a communication network sequentially connected to the operation management system of the national grid measurement system, the production scheduling platform of the provincial measurement center and the automatic verification system;

After the automatic verification system verifies the transfer standard, it sends the verification result to the production scheduling platform;

Preferably, the calibration data of the low-voltage current transformer is sent to the State Grid Metering Center, the Provincial Metering Center and the automatic verification system step by step in the order from high level to low level;

Preferably, the quantity limit of the transfer standard is the same as that of the automatic verification system; the accuracy of the transfer standard is greater than 0.02S level.

In order to meet the needs of the prior art, the present invention provides a monitoring method for the automatic verification system of low-voltage current transformers based on the communication network used in the method of quantity traceability. The method uses statistical methods to monitor the low-voltage output of the verification system. The current transformer checks the test data of the sample, and carries out risk warning for the low-voltage current transformer according to the test data; the test data includes the ratio difference and the phase difference of the low-voltage current transformer.

Preferably, the verification system regularly performs verification tests on the low-voltage current transformer inspection samples, and sends the test data to the production dispatching platform of the provincial metering center; the data processing module of the production dispatching platform statistically calculates the test data mean and standard deviation, and construct the mean control chart and standard deviation control chart of the test data according to the calculation results;

Preferably, the timing interval is a fixed time period or a fixed number of low-voltage current transformer verifications;

Preferably, according to the JJF1033-2008 standard, calculate the center line, upper control limit and lower control limit of the mean control chart and standard deviation control chart respectively, and divide the control range of the upper control limit and the lower control limit into 6 equally from top to bottom Zone, the first zone and the sixth zone from top to bottom are risk warning zones;

When the test data is in the risk early warning area of the mean control chart, it indicates that the automated verification system is affected by uncontrolled system effects; when the test data is in the risk early warning area of the standard deviation control chart, it indicates that the automated verification system is The checking system is not affected by controlled random effects.

The method monitors the monitoring device of the automatic verification system of the low-voltage current transformer, which includes an upper computer arranged on the production dispatching platform of the provincial metering center and a lower computer arranged on the automatic verification system;

The upper computer is used to manage the verification task of the low-voltage current transformer, and statistically analyze the test data of the low-voltage current transformer verification sample sent by the lower computer;

The lower computer executes the verification task.

Preferably, the host computer includes a verification task management module, a data receiving module and a data processing module;

The verification task management module is used to formulate the verification task of the low-voltage current transformer, and issue the verification task to the lower computer; the method for formulating the verification task includes:

Mode 1: The lower computer controls the automatic verification system to perform a verification on the low-voltage current transformer after the same time period each time;

Method 2: Divide the low-voltage current transformers into N groups, each group includes M low-voltage current transformers, and the lower-position computer controls the automatic verification system to verify the next group of low-voltage current transformers after completing the verification of a group of low-voltage current transformers , both M and N are at least 1;

The data receiving module is used to receive the test data of the low-voltage current transformer verification sample;

The data processing module calculates the mean value and standard deviation of the test data, and constructs the mean control chart and standard deviation control chart of the test data according to the calculation results; If the test data is normal, it will be stored in the database. If the test data is abnormal, an early warning signal will be sent to the production scheduling platform of the provincial measurement center.

Compared with the closest prior art, the excellent effect of the present invention is:

The value traceability and monitoring method of the low-voltage current transformer automatic verification system proposed by the present invention greatly shortens the time required for calibration, reduces the cost of calibration, and reduces the delay time of the metering center; the operation instructions and calibration data are transmitted through the network, Before the verification process is completed, the results can be re-inspected online, which greatly improves the calibration quality; the verification results are stored in the database, which is convenient for later management, calibration and verification. The statistical processing of sample testing and verification data is completed, reducing the workload of statistical control and improving the reliability and timeliness of statistical control.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Figure 1: Schematic diagram of the value traceability and monitoring method of the low-voltage current transformer automatic verification system in the embodiment of the present invention;

Fig. 2: the average value and the standard deviation control diagram of the measurement results of the low-voltage current transformer automatic verification system in the embodiment of the present invention;

Fig. 3: Structural diagram of the detection device of the low-voltage current transformer automatic verification system in the embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

1. The functions of the low-voltage current transformer automatic verification system, the national grid metering system operation management system, the provincial metering center production scheduling platform and the intelligent storage system involved in the embodiment of the present invention are:

1. Low-voltage current transformer automatic verification system;

The automatic verification system of low-voltage current transformers is seamlessly connected with the intelligent storage system to realize automatic transmission, automatic wiring, automatic verification, automatic sorting, automatic labeling, automatic packing, automatic warehousing and other operations of transformers. Carry out visual inspection, insulation resistance measurement, power frequency withstand voltage test, secondary turn-to-turn dielectric strength test, error verification test and magnetic saturation margin test, etc. The production scheduling platform of the provincial metrology center manages various information such as the storage capacity and verification results of the transformer automatic verification system.

The working process of the automatic verification system mainly includes:

①: Receive the verification task issued by the production scheduling platform, including the model, quantity and other information of the transformer to be verified.

②: After receiving the verification task, apply to the warehouse for the outbound task request of the transformer model, quantity and other information to be verified, and check the outbound information of the warehouse.

③: Equipment verification, upload the verification results to the production scheduling platform.

2. The operation and management system of the national grid measurement system;

It is composed of verification, warehousing, and distribution modules, on-site operation management module, measurement system management module, and measurement instrument sending and receiving management module. Through the centralization of various measurement production and operation data of the State Grid Corporation, the key indicators of measurement production, measurement system construction, and work Comprehensive control and centralized supervision of quality, service quality, business execution, collection and application of electricity consumption information, and construction.

3. Provincial metering center production scheduling platform;

It is composed of production management, production monitoring, production analysis, production maintenance and other related business function modules. It accepts the work order dispatched by the business system, converts the work order into specific operation instructions, controls the automatic verification system and intelligent storage system to complete the verification and storage, etc. work tasks.

4. Intelligent storage system;

An intelligent warehousing facility based on automatic warehousing technology and a modern logistics system, which is used to realize the intelligentization of the warehousing process of low-voltage current transformers and other measuring instruments such as automatic box loading (unpacking), automatic handling, automatic inventory, automatic warehouse entry and exit, and automatic positioning. manage.

2. The value traceability method of a low-voltage current transformer automatic verification system proposed by the present invention uses a network-based remote calibration method to trace the value of the low-voltage current transformer.

1. Quantity traceability;

Refers to the characteristics that enable the measurement result or the value of a measurement standard to be related to a specified reference standard (usually a national or international measurement standard) through an uninterrupted chain of comparisons with a specified uncertainty. Value traceability.

Quantitative value traceability hierarchy diagram, which shows the relationship between the metrological characteristics of the measuring instrument and the metrological basis of a given quantity, a block diagram representing the hierarchical order. The most important technical means to realize the traceability of the quantity value is calibration and verification.

2. Delivery standard;

Refers to a measure used as a medium in comparing measures against one another.

3. As shown in Figure 1, the above-mentioned network includes the communication network connected between the operation management system of the national grid measurement system and the production scheduling platform of the provincial measurement center, as well as the communication network between the production scheduling platform and the automatic verification system.

After the automatic verification system verifies the accuracy level of low-voltage current transformers, it sends the verification results to the production dispatching platform; the provincial metrology center sends the verification results to the State Grid Metrology System Operation Management System.

In this embodiment, the calibration data is transmitted step by step through the network, specifically, the calibration data corresponding to the accuracy level of the low-voltage current transformer is sent to the State Grid metering system, provincial Metrology center and automatic verification system. Among them, the volume limit of the transmission standard for calibration is the same as the common volume limit of the automatic verification system, its accuracy is better than 0.02S level, and the external dimensions meet the transmission, connection and disconnection and testing requirements of the automatic verification system.

Three, the present invention proposes a kind of monitoring method of the low-voltage current transformer automatic verification system, this method monitors the test data of the low-voltage current transformer output of the automatic verification system with a statistical method, and carries out risk warning to the low-voltage current transformer according to the test data ; Among them, the test data includes the ratio difference and phase difference of the low-voltage current transformer.

The automatic verification system regularly performs verification tests on the verification samples of low-voltage current transformers, and sends the test data to the production dispatching platform of the provincial metrology center; the data processing module of the production dispatching platform calculates the average value and standard deviation of the test data, and based on The calculation structure constructs the mean control chart and standard deviation control chart of the test data, and finally checks the test data through the mean control chart and standard deviation control chart to judge whether the automatic identification system is working normally. Wherein, the regular time interval is a fixed time period or a fixed number of low-voltage current transformer verifications.

In this example, the quantity limit of the low-voltage current transformer check sample used is the same as the common quantity limit of the automatic verification system, its accuracy is better than 0.2S level, and the external dimensions meet the requirements of the technical specification Q-GDW572 for low-voltage current transformers for measurement , with good stability.

As shown in Figure 3, the above method monitors the monitoring device of the automatic verification system of the low-voltage current transformer, including the upper computer set on the production dispatching platform of the provincial metering center and the lower computer set on the automatic verification system;

The upper computer is used to manage the verification task of the low-voltage current transformer, and statistically analyzes the test data of the low-voltage current transformer verification sample sent by the lower computer; the lower computer executes the verification task.

The upper computer includes a verification task management module, a data receiving module and a data processing module;

①: The verification task management module is used to formulate the verification tasks of low-voltage current transformers and send the verification tasks to the lower computer; the methods for formulating verification tasks include:

Method 1: The lower computer controls the automatic verification system to perform a verification of the low-voltage current transformer after the same time period each time;

Method 2: Divide the low-voltage current transformers into N groups, each group includes M low-voltage current transformers, and the lower-position computer controls the automatic verification system to verify the next group of low-voltage current transformers after the verification of a group of low-voltage current transformers, M and N are both at least 1;

The above method is that the automatic verification system regularly performs verification tests on the verification samples of the low-voltage current transformers.

②: The data receiving module is used to receive the test data of the low-voltage current transformer verification sample.

③: Data processing module, calculate the average value and standard deviation of the test data, and construct the average control chart and standard deviation control chart of the test data according to the calculation results; judge whether the test data is normal according to the average control chart and standard deviation control chart:

If the test data is normal, store it in the database;

If the test data is abnormal, an early warning signal will be sent to the production scheduling platform of the provincial metering center.

Four, a preferred embodiment of the traceability method proposed by the present invention is:

The State Grid Metrology Center sends the calibration data of the accuracy level of the low-voltage current transformer to the provincial metrology center, and the State Grid metrology system operation management system sends the calibration data to the production scheduling platform of the provincial metrology center. After receiving the calibration data, the provincial metrology center formulates a calibration work plan through the production scheduling platform, and issues calibration instructions to each automated verification system and intelligent storage system. After the automated verification system receives the calibration instruction, it will pass the calibration task verification standards contained in the calibration instruction. After the verification is completed, the verification result will be uploaded to the production dispatching platform, and the production dispatching platform will further upload the verification result to the operation management system of the State Grid Metrology System. After receiving the test results, the State Grid Metrology Center judges whether the measurement results are accurate. If there is any problem, it will notify the provincial metrology center for re-inspection and repeat the above process.

The traceability process does not require staff to participate, that is, there is no human factor interfering with the verification results, thus ensuring the quality of remote calibration.

Five, a preferred embodiment of the monitoring method that the present invention proposes is:

Use the statistical method to periodically test the selected verification samples and count the test results, and construct the average control chart and standard deviation control chart of the test data according to the calculation structure, so as to carry out continuous and long-term statistical control of the automatic identification system.

The operation and maintenance personnel formulate an appropriate verification plan according to the actual production and operation conditions, including verification time, verification frequency and verification samples. The production scheduling platform of the provincial metrology center will issue monitoring tasks, statistical test data and determine whether the verification results are qualified according to the verification plan.

The methods for constructing mean control chart and standard deviation control chart are:

1. The automatic verification system performs n independent repeated measurements on the verification sample, and each measurement includes the process of transportation, wiring, and disconnection of the verification sample; the measurement results of the n times of measurement are regarded as a subgroup.

2. Repeat step 1 for each period of time. In this embodiment, a total of k subgroups are measured; the time interval is a fixed time period or the next measurement is performed after detecting a fixed number of low-voltage current transformers.

3. Calculate the mean of each subgroup and standard deviation s, and the mean of the k subgroups and standard deviation

4. Calculate the center line CL _s and control upper limit of the average control chart and the lower control limit The calculation formulas are:

${\mathrm{<span\; class="notranslate">\; CL</span>}}_{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; UCL</span>}}_{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; LCL</span>}}_{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

Calculate the center line CL _s , upper control limit UCL _s and lower control limit LCL _s of the standard deviation control chart, and the calculation formulas are:

${\mathrm{<span\; class="notranslate">\; CL</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; UCL</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; LCL</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Among them, the values of A ₃ , B ₃ and B ₄ are related to the size of the verification sample, and the specific values can be found in Appendix C-1 of JJF1033-2008 "Measurement Standard Assessment Specification".

5. Draw the control chart as shown in Figure 2 according to the calculation result of step 4, and draw the mean value control chart and standard deviation control chart according to the specific calculation result and the sample of the control chart.

As shown in Figure 2, when judging the verification results of the control chart, the control range is divided into 6 areas from top to bottom, marked as A, B, C, C, B, A, and the width of each area is equal. Equivalent to the standard deviation of the statistical control used. Under normal circumstances, the probability of measuring points appearing in area A is about 4.28%, so it is allowed to occasionally have measuring points appearing in area A, but at this time, attention should be paid to the future development trend of the control chart, so area A is the automatic verification system. Risk warning area. Anomalies in the mean chart indicate that the measurement process is affected by uncontrolled systematic effects, and abnormalities in the standard deviation chart indicate that the measurement process is affected by uncontrolled random effects. When an abnormal situation occurs, the operation and maintenance personnel need to judge whether the verification system is faulty, and take appropriate maintenance measures to eliminate the abnormality.

Finally, it should be noted that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Claims (10)

1. a method for traceability of value of low-voltage current transformer automatic calibration system, it is characterized in that, described method carries out quantitative traceability to described low-voltage current transformer automatic calibration system with remote calibration method based on network; Calibration data passes through The above network is transmitted step by step. 2. The method according to claim 1, wherein the network comprises a communication network connected in turn between the operation management system of the national grid measurement system, the production dispatching platform of the provincial measurement center and the automatic verification system; After the automatic verification system verifies the transfer standard, it sends the verification result to the production scheduling platform. 3. The method according to claim 1, characterized in that, the calibration data of the low-voltage current transformer is sent to the State Grid Metering Center and the Provincial Metering Center step by step in the order from high level to low level and automated verification systems. 4. The method according to claim 2, wherein the quantity limit of the transfer standard is the same as that of the automatic verification system; the accuracy of the transfer standard is greater than 0.02S level. 5. A monitoring method of a low-voltage current transformer automatic verification system, characterized in that, the method monitors the test data of the low-voltage current transformer checking sample output by the verification system with a statistical method, and the low-voltage current transformer is checked according to the test data. The current transformer performs risk warning; the test data includes the ratio difference and phase difference of the low-voltage current transformer. 6. the method for claim 5 is characterized in that, described verification system regularly carries out verification test to low-voltage current transformer inspection sample, and test data is sent to the production scheduling platform of provincial metering center; Said production scheduling The data processing module of the platform statistically calculates the mean value and standard deviation of the test data, and constructs the mean control chart and standard deviation control chart of the test data according to the calculation results. 7. The method according to claim 6, wherein the timing interval is a fixed time period or a fixed number of low-voltage current transformer verifications. 8. the method for claim 5 is characterized in that, according to JJF1033-2008 standard calculates respectively the center line, upper control limit and lower control limit of described mean value control chart and standard deviation control chart, and upper control limit and lower control limit The control area is divided into 6 areas from top to bottom, and the first and sixth areas from top to bottom are risk warning areas; When the test data is in the risk early warning area of the mean control chart, it indicates that the automated verification system is affected by uncontrolled system effects; when the test data is in the risk early warning area of the standard deviation control chart, it indicates that the automated verification system is The checking system is not affected by controlled random effects. 9. The method according to claim 5, characterized in that, the monitoring device for monitoring the automatic verification system of the low-voltage current transformer in the method includes an upper computer arranged on the production dispatching platform of the provincial metering center and an automatic verification system arranged on the the lower computer; The upper computer is used to manage the verification task of the low-voltage current transformer, and statistically analyze the test data of the low-voltage current transformer verification sample sent by the lower computer; The lower computer executes the verification task. 10. The method according to claim 9, wherein the upper computer comprises a verification task management module, a data receiving module and a data processing module; The verification task management module is used to formulate the verification task of the low-voltage current transformer, and issue the verification task to the lower computer; the method for formulating the verification task includes: Mode 1: The lower computer controls the automatic verification system to perform a verification on the low-voltage current transformer after the same time period each time; Method 2: Divide the low-voltage current transformers into N groups, each group includes M low-voltage current transformers, and the lower-position computer controls the automatic verification system to verify the next group of low-voltage current transformers after completing the verification of a group of low-voltage current transformers , both M and N are at least 1; The data receiving module is used to receive the test data of the low-voltage current transformer verification sample; The data processing module calculates the mean value and standard deviation of the test data, and constructs the mean control chart and standard deviation control chart of the test data according to the calculation results; If the test data is normal, it will be stored in the database. If the test data is abnormal, an early warning signal will be sent to the production scheduling platform of the provincial measurement center.