Method and system for confirming metering performance of charging facility group based on MAP scheme

Abstract

The invention provides a method and a system for confirming metering performance of a charging facility group based on an MAP scheme. The method comprises the following steps: S1, an online calculation link of an operation error of a charging facility; s2, an MAP process link; s3, a classification processing link; s4, a sampling check link based on an online calculation result; and S5, a metering performance confirmation link. According to the invention, a multi-mode comprehensive metering technical scheme of'metering data monitoring + metering quality assurance scheme + dynamic sampling verification + metering performance confirmation 'is adopted, and charging facility batch metering performance confirmation under specific environmental conditions of Fujian province is fully considered; economical and continuous monitoring and dynamic supervision of electric energy metering operation errors of large-scale charging facilities are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of metering performance confirmation of a charging facility group, and in particular to a method and system for metering performance confirmation of a charging facility group based on a MAP scheme. Background Art

[0002] In the field of electric vehicle charging facility operation and services, measurement accuracy and fairness are core indicators for the settlement of electric vehicle charging service trade. These indicators are directly related to the fairness and reliability of charging trade settlement, which in turn affects the healthy and sustainable development of the electric vehicle industry.

[0003] In 2018, the state promulgated JJG 1148-2018, "Verification Regulations for Electric Vehicle AC Charging Facilities," and JJG 1149-2018, "Verification Regulations for Off-Board Chargers for Electric Vehicles," clarifying the specific content and requirements for metrological verification of charging facilities. Subsequently, in 2019, the state included electric vehicle charging facilities in the catalog of mandatory verification measuring instruments in Announcement No. 48, requiring regular verification of operating charging facilities.

[0004] According to the calibration procedures JJG 1148-2018 and 1149-2018, the calibration of charging facilities must be conducted on-site, requiring the participation of two calibrators and one driver. The calibration of DC charging facilities takes 50 to 70 minutes per unit, while that of AC charging facilities takes 60 to 90 minutes per unit (excluding round-trip time); the energy consumption for each charging facility is approximately 3 to 5 kilowatt-hours. Comprehensive calibration of all charging facilities is inefficient and costly, making it extremely difficult to implement. In light of this, the state issued the "Announcement of the State Administration for Market Regulation on the Release of the Catalogue of Measuring Instruments Subject to Mandatory Management (No. 48 of 2019)" on October 26, 2020 (hereinafter referred to as the "Announcement"), less than a year after the release of the "Announcement of the State Administration for Market Regulation on the Release of the Catalogue of Measuring Instruments Subject to Mandatory Management (No. 42 of 2020)" in 2019. The "Announcement" clearly states that electric vehicle charging facilities are still work measuring instruments subject to mandatory inspection, but proposes to postpone the mandatory inspection of electric vehicle charging facilities to January 1, 2023, and encourages local governments to explore specific mandatory inspection methods.

[0005] In July 2022, Announcement No. 22 of 2022 was issued, approving the verification procedures "JJG 1149-2022 Verification Procedure for Non-onboard Chargers of Electric Vehicles (Trial)" and "JJG 1148-2022 Verification Procedure for AC Charging Facilities of Electric Vehicles (Trial)", which are scheduled to be implemented on December 28, 2022. The new regulations simplify the verification items and extend the verification cycle. However, the mandatory verification and supervision of existing operating charging facilities still faces problems such as high cost, low efficiency, heavy tasks, and staff shortages. According to the latest verification procedures, in addition to on-site verification, online monitoring methods are also introduced as a condition for extending the verification cycle to solve the problems of low verification efficiency and high cost.

[0006] By applying big data analysis technology to calibrate the metrological performance of charging facilities, the efficiency of mandatory inspection and supervision of charging facilities can be significantly enhanced, fundamentally solving the problem of insufficient inspection resources, and showing broad application potential. However, according to the latest research conclusions, either obtaining more comprehensive charging station operation data requires a certain degree of modification of charging stations, which inevitably leads to certain safety risks and difficulty in promotion; or relying on existing data (order data), due to the involvement of multiple charging stations and multiple vehicles and the complex and diverse environment, the results of single measurement calculations fluctuate greatly and have poor repeatability.

[0007] Currently, Fujian Province has yet to establish technical specifications for the metrological performance calibration of public electric vehicle charging facilities based on big data analysis methods. Given the unique geographical environment of Fujian Province, including differences in the natural environments of island and non-island areas, the calibration standards for the metrological performance of charging facilities are significantly impacted. Therefore, there is an urgent need to develop a set of batch metrological performance confirmation technologies for charging facilities adapted to the specific conditions of Fujian Province and formulate corresponding technical specifications accordingly. This will provide a unified technical solution and management template for the mandatory verification of charging facilities across the province, ensuring the standardization of mandatory verification work, the effective implementation of supervisory and management responsibilities, and the stability of the metering system for electricity trade. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method and system for confirming the metering performance of a group of charging facilities based on the MAP scheme. It adopts a multi-mode comprehensive metering technology scheme of "metering data monitoring + metering quality assurance scheme + dynamic sampling verification + metering performance confirmation", and fully considers the batch metering performance confirmation of charging facilities under the specific environmental conditions of Fujian Province, thereby realizing economical, continuous monitoring and dynamic supervision of the operating errors of electricity metering of large-scale charging facilities.

[0009] In a first aspect, the present invention provides a method for confirming the metering performance of a charging facility group based on the MAP solution, comprising:

[0010] S1. Online calculation of charging facility operation errors, including:

[0011] S11. Obtain relevant data of the charging station in real time through the online platform, establish an online calculation model for operation error, and calculate the operation error of each charging facility in the charging station;

[0012] S12. Evaluate the uncertainty of the operating error obtained by the online calculation model;

[0013] S2, MAP process, includes the following steps:

[0014] S21. Determine the grouping method of the virtual verification standard value, calculate the running errors M times to form a group, and perform t-test and F-test on each P group;

[0015] S22, calculate the k-th running error of the j-th pile group i as its virtual verification standard value

[0016] S23, calculate the mean value of the i-th group of the j-th pile according to the following formula Within-group standard deviation

[0017]

[0018] S24. Perform a gross error test on the i-th group of data for the j-th pile according to the following formula:

[0019]

[0020] Where G 1-α (M) is the critical value of the Grubbs criterion. If the above formula is satisfied, the k-th operation error calculation result passes the gross error test and can form a set of data. Otherwise, it should be eliminated and returned to the online calculation link of the charging facility operation error.

[0021] S25, calculate the inter-group mean A of the first P groups of virtual verification standard values ​​of the j-th pile according to the following formula jC , standard deviation between groups S jB , combined standard deviation S jP :

[0022]

[0023] S26: When the jth pile P+1 group adds the lth running error calculation result, calculate the current virtual verification standard value according to S22 When M calculations are accumulated, a set of virtual verification standard values ​​is formed, and the mean value of the P+1 group is calculated according to S23. Within-group standard deviation And perform gross error inspection according to S24;

[0024] S27. Calculate the t-test value and F-test value of the virtual verification standard value of the P+1th group, and perform the t-test and F-test. The charging facility group MAP verification is considered qualified if and only if the following two equations are satisfied; otherwise, the charging facility group MAP verification is considered unqualified:

[0025]

[0026] Where, t p (P-1) represents the critical value of the t distribution with a confidence probability of p and a degree of freedom of P-1;

[0027] F a (M-1, (M-1)P) represents the critical value of the F distribution at the significance level α with degrees of freedom of M-1 and (M-1)P respectively, which can be obtained by looking up the table;

[0028] S28: If the MAP verification is qualified, the next set of data will be entered into the cumulative sum calculation. If the MAP verification is unqualified, the data of this set will be eliminated and the next set of data will be entered into the cumulative sum calculation.

[0029] S3. Classification and processing: Based on the operating errors and uncertainties of each charging facility in the charging station obtained through online calculations, as well as the inspection results of the MAP process, the charging facilities are classified into categories A, B, C, and D, where:

[0030] If both the t-test and the F-test are qualified, the charging facilities in the charging station are evaluated as Class A;

[0031] If the t-test or F-test fails, the unqualified charging facility is classified as Class B, and other charging facilities in the same charging station are classified as Class A;

[0032] If the t test fails and the F test fails, the charging facility of the unqualified pile is classified as Class C, and other charging facilities in the same charging station are classified as Class B;

[0033] If the t-test and F-test are both unaccountable or the charging facilities are not connected to the platform, all charging facilities in the station will be classified as Class D;

[0034] S4. Sampling verification based on online calculation results, including:

[0035] S41. Determine charging facility groups: Determine charging facility groups based on the classification results and group definitions of the charging facilities. Each charging facility group contains only charging facilities of a single category, i.e., charging facility groups of categories A, B, C, and D, respectively.

[0036] S42. Develop a sampling plan and determine the sample size for random inspection and standby inspection;

[0037] Formulate a sampling plan: For Class A charging facility groups, a relaxed sampling plan will be implemented. For Class B charging facility groups, different sampling plans will be selected based on the geographical characteristics of Fujian or the integrity of the companies. For Class C and D charging facility groups, a full sampling plan will be implemented, and on-site verification will be carried out for each charging facility. Among them, the different sampling plans selected based on the geographical characteristics of Fujian or the integrity of the companies are as follows:

[0038] a) For non-island areas, a single sampling is adopted and the sampling plan is a normal sampling plan. For island areas, a single sampling is adopted and the sampling plan is a tightened sampling plan.

[0039] b) For honest measurement enterprises, regardless of island and non-island areas, the sampling plan is a relaxed sampling plan;

[0040] The sampling of samples shall follow the principle of random sampling, and the normal sampling plan, the tightened sampling plan and the relaxed sampling plan shall all be based on the corresponding strictness of sampling at the inspection level S-4 and AQL 2.5;

[0041] When determining the sample size for random inspection and backup inspection, 20% of the sample size for random inspection and backup inspection shall be selected as the sample size for Class A and Class B charging facilities;

[0042] S43. Select sites and samples for sampling:

[0043] S44. Verify the sampled items and enter the verification results; verify the samples on site one by one in accordance with JJG 1148 and JJG 1149, make conformity assessments, and confirm the metrological performance based on the verification results;

[0044] S45. Determine the verification result of the charging facility group;

[0045] S5. The measurement performance confirmation step includes: confirming the measurement performance of the charging facilities based on online calculations and sampling verification results, and forming an online evaluation report on the measurement performance of the charging facilities.

[0046] Furthermore, in S21, if there is a reference pile in the charging station, assuming the reference pile is the jth pile, the virtual verification standard value is calculated according to the following formula:

[0047]

[0048] Where, The operating error calculated by the online calculation link of the charging facility operating error for the kth time in the i-th group of reference piles; The reference value at this time is the error obtained by manual verification or standard module; if the charging station has a reference pile, the reference pile is set to the jth pile, then the steps S22 to S28 of the MAP process link are correspondingly adjusted to only be performed on the reference pile.

[0049] Furthermore, in S43, the sample is selected according to the principle of random selection, and the sample is selected according to the simple random sampling method in GB / T 10111, and the sample number of the random sampling is generated by a random number table method, a random number dice method, or a playing card method;

[0050] In S44, after selecting the charging facility sampling samples, the samples are individually inspected on-site in accordance with JJG 1148 and JJG 1149, and the qualification is determined based on the on-site inspection results of the single sampling samples;

[0051] In S45, assuming that the number of samples that do not meet the maximum allowable error limit requirement for on-site sampling verification of charging facilities is d, then:

[0052] When d≤Ac, the group is judged as qualified, but the samples that failed the on-site verification are judged as unqualified;

[0053] When d≥rejection number Re, the group is judged as unqualified, the samples that pass the on-site inspection are judged as qualified, and the samples that fail the on-site inspection are judged as unqualified.

[0054] Furthermore, the S5 is specifically:

[0055] For Class A charging facility groups, metering performance confirmation is performed as follows:

[0056] The samples that have passed the on-site verification in the group are confirmed as qualified by measurement and a verification certificate is issued; other Class A charging facilities are evaluated as qualified online;

[0057] For samples in the group that fail on-site verification, they will be confirmed as unqualified by metrology and a verification result notice will be issued; other Class A samples at the charging station where the samples that failed on-site verification are located will be downgraded to Class B, and other Class A charging facilities other than the charging station where the samples that failed on-site verification are located will be qualified by online evaluation;

[0058] For Class B charging facilities, the metering performance confirmation is carried out as follows:

[0059] For groups that pass on-site verification, the samples in the group that pass on-site verification are metrologically confirmed as qualified, and a verification certificate is issued, and they are qualified in the online evaluation; the samples in the group that fail on-site verification are metrologically confirmed as unqualified, and a verification result notice is issued; the other samples outside the charging station where the unqualified samples are located in the group are metrologically confirmed as qualified and are qualified in the online evaluation report; the other Class B samples in the charging station where the samples that fail on-site verification are located are downgraded to Class C, and 100% random inspection is implemented;

[0060] For the group that fails the on-site verification, the samples that pass the on-site verification in the group will be confirmed as qualified by metrology, and a verification certificate will be issued, and they will be qualified in the online evaluation report; the samples that fail the on-site verification in the group will be confirmed as unqualified by metrology, and a verification result notice will be issued, and they will be unqualified in the online evaluation report; other Class B samples in the group will be downgraded to Class C, and 100% random inspection will be implemented;

[0061] For Class C charging facility groups, metering performance confirmation is performed as follows:

[0062] After on-site verification in accordance with JJG 1148 and JJG 1149, metrological confirmation is carried out based on the verification results. If the on-site verification is qualified, the metrological confirmation is qualified, a verification certificate is issued, and it is qualified in the online evaluation report; if the on-site verification is unqualified, the metrological confirmation is unqualified, a verification result notice is issued, and it is unqualified in the online evaluation report;

[0063] For Class D charging facility groups, metering performance confirmation is performed as follows:

[0064] On-site calibration is carried out in accordance with JJG 1148 and JJG 1149. A calibration certificate will be issued for qualified products, and a calibration result notice will be issued for unqualified products.

[0065] Furthermore, the online calculation period for charging facility operation errors is one month, the sampling verification period is one year, and the measurement confirmation and online evaluation period is one year. For charging facilities classified as Class D, the verification period shall be handled in accordance with JJG 1148 and JJG 1149.

[0066] In a second aspect, the present invention provides a system for confirming the metering performance of a charging facility group based on the MAP solution, which is used to implement the method described in the first aspect.

[0067] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0068] 1. The MAP scheme is introduced in the statistical analysis of the calculation results. Instead of using a single error calculation result as the basis for classification, the t-test and F-test are used to compare with the historical data trend. This follows the rule that the error calculation results are dynamically changing data, and provides a more reliable classification basis from a mathematical perspective.

[0069] 2. Taking into account the differences in environmental impacts between islands and non-islands in Fujian Province, a special distinction was made in the sampling plan. For island areas, due to the influence of specific environmental temperature and humidity, charging facilities may be affected to varying degrees. Therefore, a stricter sampling plan was adopted for the parent population of the same category.

[0070] 3. Introduce the use of enterprise integrity evaluation results. For honest measurement enterprises, regardless of island areas and non-island areas, the sampling plan is a relaxed sampling plan. This not only improves the verification efficiency, but also reduces unnecessary inspection costs, which is of great significance to promoting the healthy development of the charging facilities industry.

[0071] 4. In the sampling plans for Class A and Class B charging facility groups, 20% (≥1) of the sampling sample size is selected as the backup sample size, which is particularly suitable for the special inspection level of small samples.

[0072] 5. Class B charging facilities indicate low reliability of online calculation results. A more stringent, discriminating sampling scheme employs a higher-level inspection. This approach utilizes a larger sample size for the same batch size compared to a less discriminating inspection scheme. (The acceptance number for a given sample size is determined by the AQL (AQL stands for Acceptance Quality Limit, which refers to the worst-case average quality level of a continuous series of batches submitted for acceptance sampling). Therefore, a more stringent, discriminating sampling scheme can more effectively identify substandard charging facilities, thereby controlling the overall substandard risk of charging facilities in the market.

[0073] 6. Field verification results show that the maximum deviation between the error value derived from the energy conservation algorithm and the field verification value is less than 1%. Blind data testing results demonstrate that the performance verification method of the present invention is highly responsive to error changes, exhibits consistent directionality, and exhibits strong interference suppression capabilities. Overall, the algorithm is suitable for widespread application.

[0074] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0076] Figure 1 Schematic diagram of the framework of the system of the present invention;

[0077] Figure 2 This is a flowchart of the method in Example 1 of the present invention;

[0078] Figure 3 This is a flowchart of the MAP process in an embodiment of the present invention;

[0079] Figure 4 This is a schematic diagram of the structure of the device in Example 2 of the present invention. DETAILED DESCRIPTION

[0080] The technical solutions in the embodiments of this application have the following general principles: A method and system for confirming the metering performance of a group of charging facilities based on the MAP scheme is provided. This system utilizes a multi-mode integrated metering technology solution consisting of "online error calculation + classified sampling verification + metering performance confirmation" and also introduces the MAP scheme. Instead of using a single error calculation result as the basis for classification, the system uses t-tests and F-tests to compare with historical data trends, providing a more reliable mathematical basis for classification. Furthermore, the batch metering performance confirmation of charging facilities in Fujian Province is fully considered, with special distinctions made in the sampling scheme. For island regions, which may have varying degrees of impact on charging facilities due to the specific environmental temperature and humidity, a stricter sampling scheme is adopted within the parent population of the same category. This enables economical, continuous monitoring and dynamic supervision of operational errors in the electricity metering of large-scale charging facilities.

[0081] Example 1

[0082] like Figure 1 and Figure 2 As shown, this embodiment provides a method for confirming the metering performance of a charging facility group based on the MAP solution, including:

[0083] S1. Online calculation of charging facility operation errors, including:

[0084] S11. Obtain relevant data of the charging station in real time through the online platform, establish an online calculation model for operation error, and calculate the operation error of each charging facility in the charging station; the online calculation model can be an energy conservation model, a vehicle-pile comparison model, or a vehicle-pile interaction model.

[0085] The energy conservation model uses an online platform to obtain real-time data from the charging station master meter and the charging data of the charging facilities within the charging station. Based on the law of conservation of energy, an online calculation model for operating errors is established. The operating errors of each charging facility within the charging station are calculated using the charging station master meter data as a standard.

[0086] Charging facilities can be charging piles or charging guns. A charging facility group is a collection of charging facilities aggregated for statistical sampling. This typically involves charging facilities in the same region and operated by the same operator with similar metering characteristics. In special cases, it can also be a combination of smaller groups operated by different operators, referred to as a mixed group.

[0087] The operational error of a charging facility refers to the statistical value of the energy metering error of the charging facility over a period of time under actual conditions at the charging site. The operational error limit for online monitoring of charging facilities should generally not exceed ±3%.

[0088] The online charging facility metering performance evaluation platform is used to centrally monitor and supervise the metering performance of public charging facilities for electric vehicles, realizing a management platform for digital metering and monitoring throughout the entire life cycle of charging facilities. Through a unified information communication interface, it receives information such as charging facility operation service platforms, (charging station electricity) metering automation systems (master stations), and electric vehicle battery management systems (BMS) charging data. It conducts comprehensive verification such as big data model analysis and spot checks, and continuously monitors the metering performance and operational status of charging facilities.

[0089] Data acquisition and processing: The charging station master meter data and the charging data of the charging facilities within the charging station are collected, cleaned, analyzed, and stored by the online evaluation platform for charging facility metering performance. The data is then processed to prevent tampering and loss, and the corresponding relationship between the charging station, master meter account number, transformer file, and comprehensive rate is established before it is provided.

[0090] The charging station master meter data is the frozen data of voltage, current, power, power factor, and power consumption at 96 points per day of the charging station master meter;

[0091] The charging data of the charging facilities in the charging station is required to be that the charging facilities have been in operation for more than 3 months, with no less than m×90 charging order data or more than 1 month of high-frequency data of the charging process, where m is the total number of charging facilities in the station, and the frequency of the high-frequency data is not less than 1 minute / time.

[0092] If there are non-charging power loads in the charging station, such as air conditioning, lighting, etc., they will be metered separately.

[0093] Model calculation: Based on the tree-like topology of the master meter and sub-meters, and according to the characteristics of user-side data collection, the relationship between the master meter and sub-meters is explored. An online calculation model for operating errors is established based on the law of conservation of energy. The operating errors of each charging facility within the charging station are calculated using the master meter data of the charging station as a standard.

[0094] Based on the law of conservation of energy, the online calculation model for operating errors is: "Total power supply of the charging station" = "Sum of actual power consumption of all charging facilities" + "Line loss" + "Fixed loss within the station" + "Power consumption of other equipment within the station". The formula is as follows:

[0095]

[0096] Where:

[0097] E y ——The total power supply of the charging station;

[0098] m——the total number of charging facilities in the charging station;

[0099] E j ——Charging power of each charging facility;

[0100] η——Conversion efficiency of charging facilities, the conversion efficiency of AC charging facilities is 1;

[0101] γ j ——Operational errors of each charging facility;

[0102] E u - line loss;

[0103] E0 - the fixed loss within the charging station, including the power consumption of the display screen of the charging facility;

[0104] E in - The power consumption of other equipment in the charging station except the charging equipment;

[0105] By collecting charging data, a system of equations consisting of no less than m+2 equations is formed. Solving the system of equations can obtain the operating error γ of each charging facility. j , m is the total number of charging facilities in the station.

[0106] S12. Evaluate the uncertainty of the operating error obtained from the online calculation model. Specifically, conduct on-site verification of some charging facilities, and analyze the calculation process of the operating error of each charging facility based on the on-site verification results to accurately evaluate the uncertainty of the operating error obtained from the online calculation model.

[0107] The calculation error uncertainty of the online calculation model for the evaluation error includes the sources of judgment uncertainty, which include the following three sources:

[0108] a) Uncertainty component u1 introduced by algorithm repeatability

[0109] The uncertainty component introduced by the dispersion of the measurement results of the calibrated charging facility mainly includes the influence of quantization errors caused by clock bias, data fluctuation, and data truncation. The uncertainty component is evaluated using the Type A evaluation of measurement uncertainty [JJF 1001, 5.20].

[0110] b) Uncertainty component u2 introduced by on-site verification

[0111] On-site verification was completed according to the current verification procedures for charging facilities, and the selected charging facilities were verified twice. The uncertainty of the on-site verification results is mainly due to the traceability to the standard, the number of digits of the charging facility indication, and the measurement repeatability. The uncertainty components were mainly evaluated using the Type B evaluation of measurement uncertainty [JJF 1001, 5.21].

[0112] c) Uncertainty component u3 introduced by the deviation between the on-site verification error value and the algorithm calculation error value

[0113] The algorithm capability is measured using the deviation level of the on-site verification results and the error value calculated by the algorithm. The uncertainty components are derived based on the statistical law of the deviation. The uncertainty is evaluated using the Type A evaluation of measurement uncertainty [JJF 1001, 5.20].

[0114] The combined uncertainty u can be obtained by combining the uncertainty components from different sources mentioned above. c :

[0115]

[0116] Taking the confidence probability as P = 95% and the coverage factor k = 2, the expanded uncertainty can be obtained as U:

[0117] U=ku c #

[0118] S2. MAP process link. MAP (measurement assurance program) is a new type of measurement value transfer program originating from the United States. It adopts the closed-loop feedback control method in control theory and mathematical statistics, the basic ideas of quality management and quality assurance in modern industrial production, to effectively control the links and factors that affect the quality of detection in the measurement process. It can quantitatively determine the total measurement uncertainty of the measurement process relative to the reference benchmark or other specified standards and verify whether the total uncertainty meets the user's requirements, so that the quality of measurement is guaranteed and not only accurate but also reliable. MAP can be expressed in a popular formula as follows:

[0119] MAP = statistical control of measurement process + closed-loop measurement transmission + uncertainty assessment.

[0120] The implementation of the present invention in the charging pile group MAP system establishes a new metering management system for charging piles, realizes the self-iterative optimization of the charging pile group error monitoring system, and ensures the economical, continuous monitoring and dynamic supervision of the charging pile group electric energy metering operation error.

[0121] like Figure 3 As shown, the MAP process of the present invention includes the following steps:

[0122] S21. Determine the grouping method of the virtual verification standard value, calculate the running errors M times to form a group, and perform t-test and F-test on each P group;

[0123] If there is a reference pile at the charging station, let the reference pile be the jth pile, then calculate the virtual verification standard value according to the following formula:

[0124]

[0125] Where, The operating error calculated by the online calculation link of the charging facility operating error for the kth time in the i-th group of reference piles; The reference value at this time is the error obtained by manual verification or standard module; if the charging station has a reference pile (set as the jth pile), then the steps S22 to S28 of the MAP process link are correspondingly adjusted to only be performed on the reference pile.

[0126] The t-test is a statistical method used to assess whether there is a significant difference between two or more groups, particularly when the sample size is small or the population variance is unknown. This test is based on the T-distribution, a distribution used in statistics to describe statistics with small samples.

[0127] The t-distribution critical table is an important tool for performing a T-test. It provides critical values ​​for the t-distribution at different degrees of freedom and significance levels. These critical values ​​are used to determine whether the calculated t-statistic is large enough to decide whether to reject the null hypothesis.

[0128] The F test is a hypothesis testing method in statistics, which is mainly used to compare whether the variances of two or more groups are consistent, or to test whether the means of multiple groups are equal in analysis of variance.

[0129] The F-distribution critical value table is a collection of F values ​​generated based on a specific degree of freedom and significance level (usually 0.05 or 0.01), as shown in Table F2. These critical values ​​are used when performing an F-test to determine whether the F-statistic is large enough to conclude that the variances of two groups are significantly different. If the calculated F-statistic is greater than the corresponding critical value in the table, the null hypothesis is generally rejected, indicating that the variances of the two groups are significantly different.

[0130] S22, calculate the k-th running error of the j-th pile group i as its virtual verification standard value

[0131] S23, calculate the mean value of the i-th group of the j-th pile according to the following formula Within-group standard deviation

[0132]

[0133] S24. Perform a gross error test on the i-th group of data for the j-th pile according to the following formula:

[0134]

[0135] Where G 1-α (M) is the critical value of the Grubbs criterion. If the above formula is satisfied, the k-th operation error calculation result passes the gross error test and can form a set of data. Otherwise, it should be eliminated and returned to the online calculation link of the charging facility operation error.

[0136] S25, calculate the inter-group mean A of the first P groups of virtual verification standard values ​​of the j-th pile according to the following formula jC , standard deviation between groups S jB , combined standard deviation S jP :

[0137]

[0138] S26: When the jth pile P+1 group adds the lth running error calculation result, calculate the current virtual verification standard value according to S22 When M calculations are accumulated, a set of virtual verification standard values ​​is formed, and the mean value of the P+1 group is calculated according to S23. Within-group standard deviation And perform gross error inspection according to S24;

[0139] S27. Calculate the t-test value and F-test value of the virtual verification standard value of the P+1th group, and perform the t-test and F-test. The charging facility group MAP verification is considered qualified if and only if the following two equations are satisfied; otherwise, the charging facility group MAP verification is considered unqualified:

[0140]

[0141]

[0142] Where, t p (P-1) represents the critical value of the t distribution with a confidence probability of p and a degree of freedom of P-1;

[0143] F a (M-1, (M-1)P) represents the critical value of the F distribution at the significance level α with degrees of freedom of M-1 and (M-1)P respectively, which can be obtained by looking up the table;

[0144] S28: If the MAP verification is qualified, the next set of data will be entered into the cumulative sum calculation. If the MAP verification is unqualified, the data of this set will be eliminated and the next set of data will be entered into the cumulative sum calculation.

[0145] S3. Classification: Based on the operating errors and uncertainties of each charging facility in the charging station obtained through online calculations, as well as the inspection results of the MAP process, the charging facilities are classified into categories A, B, C, and D, as shown in Table 1.

[0146] Table 1 Online review classification

[0147]

[0148] If both the t-test and the F-test are qualified, the charging facilities in the charging station are evaluated as Class A; the qualified reliability is high, and a relaxed sampling plan can be adopted;

[0149] If the t-test or F-test fails, the unqualified charging facility is classified as Class B and a stricter sampling plan is required; other charging facilities in the same charging station are classified as Class A and a relaxed sampling plan can be used;

[0150] If the t test fails and the F test fails, the charging facility with the unqualified pile is classified as Class C and requires 100% inspection and on-site verification of each unit. Other charging facilities in the same charging station are classified as Class B and require a stricter sampling plan.

[0151] If neither the t-test nor the F-test can be calculated, or if a charging facility is not connected to the platform, all charging facilities within the station will be classified as Class D and require 100% inspection, with each unit being calibrated on-site. Reasons for non-calculation include missing files, discrepancies between files and actual data, inability to match files, lack of or missing master table data, missing charging facility order data, and excessive unmetered electricity consumption (≥3% of the station's total capacity) by other equipment within the station.

[0152] S4. Sampling verification based on online calculation results, including:

[0153] S41. Determine charging facility groups: Determine charging facility groups based on the classification results and group definitions of the charging facilities. Each charging facility group contains only charging facilities of a single category, i.e., charging facility groups of categories A, B, C, and D, respectively.

[0154] S42. Develop a sampling plan and determine the sample size for random inspection and standby inspection; in this application, samples usually refer to charging guns.

[0155] Formulate a sampling plan: For Class A charging facility groups, a relaxed sampling plan will be implemented. For Class B charging facility groups, different sampling plans will be selected based on the geographical characteristics of Fujian or the integrity of the companies. For Class C and D charging facility groups, a full sampling plan will be implemented, and on-site verification will be carried out for each charging facility. Among them, the different sampling plans selected based on the geographical characteristics of Fujian or the integrity of the companies are as follows:

[0156] a) For non-island areas, a single sampling is adopted and the sampling plan is a normal sampling plan. For island areas, a single sampling is adopted and the sampling plan is a tightened sampling plan.

[0157] b) For honest measurement enterprises, regardless of island and non-island areas, the sampling plan is a relaxed sampling plan;

[0158] Table 2 Sampling plan (inspection level S-4, AQL is 2.5)

[0159]

[0160]

[0161] The normal sampling plan, the tightened sampling plan and the relaxed sampling plan are all based on the corresponding strictness of sampling at inspection level S-4 and AQL 2.5;

[0162] When determining the sample size for random inspection and backup inspection, 20% of the sample size for random inspection and backup inspection shall be selected as the sample size for Class A and Class B charging facilities;

[0163] S43. Select sites and samples for sampling. Samples shall be drawn in accordance with the principle of random selection and in accordance with the simple random sampling method in GB / T10111. The sample numbers for random sampling may be generated by random number table method, random number dice method, playing card method, etc.

[0164] S44. Verify the sample and enter the verification results:

[0165] After selecting the charging facility sampling samples, the samples (guns) are inspected on site one by one in accordance with JJG 1148 and JJG 1149, and the qualification is determined. The metrological performance of the gun is confirmed based on the inspection results.

[0166] S45. Determine the test results of the charging facility group:

[0167] According to the on-site verification results of a single sampling, assuming that the number of samples that do not meet the maximum allowable error limit requirements for on-site sampling verification of charging facilities is d, then:

[0168] When d≤Ac, the group is judged as qualified, but the samples that failed the on-site verification are judged as unqualified;

[0169] When d≥rejection number Re, the group is judged as unqualified, the samples that pass the on-site inspection are judged as qualified, and the samples that fail the on-site inspection are judged as unqualified.

[0170] Among them, the allowable error limits for on-site sampling inspection of charging facilities shall meet the requirements of Table 3.

[0171] Table 3 Maximum allowable error limits for sampling and on-site verification of charging facilities

[0172] Accuracy level Level 1 Level 2 Limit (%) ±1.0 ±2.0

[0173] S5. The measurement performance confirmation phase includes: confirming the measurement performance of the charging facilities based on online calculations and sampling verification results, and forming an online evaluation report on the measurement performance of the charging facilities. Specifically:

[0174] Metrological performance confirmation refers to the process of reviewing the metrological performance in the calibration certificate / test report of the charging facility, including factory inspection, initial and periodic calibration, sampling calibration, and online calculation of big data analysis, etc., entering relevant metrological performance, data, conclusions and other information into the online evaluation platform for metrological performance of charging facilities for iterative use of the metrological performance evaluation model of charging facilities, and outputting the online evaluation report on metrological performance of charging facilities.

[0175] For Class A charging facility groups, metering performance confirmation is performed as follows:

[0176] The samples that have passed the on-site verification in the group are confirmed as qualified by measurement and a verification certificate is issued; other Class A charging facilities are evaluated as qualified online;

[0177] For samples in the group that fail on-site verification, they will be confirmed as unqualified by metrology and a verification result notice will be issued; other Class A samples at the charging station where the samples that failed on-site verification are located will be downgraded to Class B, and other Class A charging facilities other than the charging station where the samples that failed on-site verification are located will be qualified by online evaluation;

[0178] For Class B charging facilities, the metering performance confirmation is carried out as follows:

[0179] For groups that pass on-site verification, the samples in the group that pass on-site verification are metrologically confirmed as qualified, and a verification certificate is issued, and they are qualified in the online evaluation; the samples in the group that fail on-site verification are metrologically confirmed as unqualified, and a verification result notice is issued; the other samples outside the charging station where the unqualified samples are located in the group are metrologically confirmed as qualified and are qualified in the online evaluation report; the other Class B samples in the charging station where the samples that fail on-site verification are located are downgraded to Class C, and 100% random inspection is implemented;

[0180] For the group that fails the on-site verification, the samples that pass the on-site verification in the group will be confirmed as qualified by metrology, and a verification certificate will be issued, and they will be qualified in the online evaluation report; the samples that fail the on-site verification in the group will be confirmed as unqualified by metrology, and a verification result notice will be issued, and they will be unqualified in the online evaluation report; other Class B samples in the group will be downgraded to Class C, and 100% random inspection will be implemented;

[0181] For Class C charging facility groups, metering performance confirmation is performed as follows:

[0182] After on-site verification in accordance with JJG 1148 and JJG 1149, metrological confirmation is carried out based on the verification results. If the on-site verification is qualified, the metrological confirmation is qualified, a verification certificate is issued, and it is qualified in the online evaluation report; if the on-site verification is unqualified, the metrological confirmation is unqualified, a verification result notice is issued, and it is unqualified in the online evaluation report;

[0183] For Class D charging facility groups, metering performance confirmation is performed as follows:

[0184] On-site calibration is carried out in accordance with JJG 1148 and JJG 1149. A calibration certificate will be issued for qualified products, and a calibration result notice will be issued for unqualified products.

[0185] The cycle for online calculation of charging facility operation errors is 1 month, the sampling verification cycle is 1 year, and the measurement confirmation and online evaluation cycle is 1 year; for charging facilities classified as Class D, the calibration cycle shall be handled in accordance with JJG 1148 and JJG 1149.

[0186] Example 2

[0187] Based on the same inventive concept, this application also provides a device corresponding to the method in Example 1, see Example 2 for details. Figure 4 As shown, in this embodiment, a device is provided, including an online calculation module for charging facility operation errors, a MAP process module, a classification processing module, a sampling verification module based on online calculation results, and a metering performance confirmation module.

[0188] The charging facility operation error online calculation module is used to execute the charging facility operation error online calculation process in the first embodiment, and the details are not described in detail.

[0189] The MAP process module is used to execute the process of the MAP process link in the first embodiment, and the details are not repeated here;

[0190] The classification processing module is used to execute the process of the classification processing link in Example 1, and the details are not detailed here;

[0191] The sampling verification module based on online calculation results is used to execute the process of the sampling verification link based on online calculation results in Example 1, and the details are not repeated here;

[0192] The measurement performance confirmation module is used to execute the process of the measurement performance confirmation link in Example 1, and the details are not repeated here.

[0193] Since the device described in the second embodiment of the present invention is used to implement the method of the first embodiment of the present invention, those skilled in the art will be able to understand the specific structure and variations of the device based on the method described in the first embodiment of the present invention, and therefore will not be described in detail here. All devices used in the method of the first embodiment of the present invention fall within the scope of protection of the present invention.

[0194] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for confirming the metering performance of a charging facility group based on the MAP solution, characterized by: include: S1. Online calculation of charging facility operation errors, including: S11. Obtain relevant data of the charging station in real time through the online platform, establish an online calculation model for operation error, and calculate the operation error of each charging facility in the charging station; S12. Evaluate the uncertainty of the operating error obtained by the online calculation model; S2, MAP process, includes the following steps: S21. Determine the grouping method of the virtual verification standard value, calculate the running errors M times to form a group, and perform t-test and F-test on each P group; S22, calculate the k-th running error of the j-th pile group i as its virtual verification standard value S23, calculate the mean value of the i-th group of the j-th pile according to the following formula Within-group standard deviation S24. Perform a gross error test on the i-th group of data for the j-th pile according to the following formula: Where G 1-α (M) is the critical value of the Grubbs criterion. If the above formula is satisfied, the k-th operation error calculation result passes the gross error test and can form a set of data. Otherwise, it should be eliminated and returned to the online calculation link of the charging facility operation error. S25, calculate the inter-group mean A of the first P groups of virtual verification standard values ​​of the j-th pile according to the following formula jC , standard deviation between groups S jB , combined standard deviation S jP : S26: When the jth pile P+1 group adds the lth running error calculation result, calculate the current virtual verification standard value according to S22 When M calculations are accumulated, a set of virtual verification standard values ​​is formed, and the mean value of the P+1 group is calculated according to S23. Within-group standard deviation And perform gross error inspection according to S24; S27. Calculate the t-test value and F-test value of the virtual verification standard value of the P+1th group, and perform the t-test and F-test. The charging facility group MAP verification is considered qualified if and only if the following two equations are satisfied; otherwise, the charging facility group MAP verification is considered unqualified: Where, t p (P-1) represents the critical value of the t distribution with a confidence probability of p and a degree of freedom of P-1; F a (M-1, (M-1)P) represents the critical value of the F distribution at the significance level α with degrees of freedom of M-1 and (M-1)P respectively, which can be obtained by looking up the table; S28: If the MAP verification is qualified, the next set of data will be entered into the cumulative sum calculation. If the MAP verification is unqualified, the data of this set will be eliminated and the next set of data will be entered into the cumulative sum calculation. S3. Classification and processing: Based on the operating errors and uncertainties of each charging facility in the charging station obtained through online calculations, as well as the inspection results of the MAP process, the charging facilities are classified into categories A, B, C, and D, where: If both the t-test and the F-test are qualified, the charging facilities in the charging station are evaluated as Class A; If the t-test or F-test fails, the unqualified charging facility is classified as Class B, and other charging facilities in the same charging station are classified as Class A; If the t test fails and the F test fails, the charging facility of the unqualified pile is classified as Class C, and other charging facilities in the same charging station are classified as Class B; If the t-test and F-test are both unaccountable or the charging facilities are not connected to the platform, all charging facilities in the station will be classified as Class D; S4. Sampling verification based on online calculation results, including: S41. Determine charging facility groups: Determine charging facility groups based on the classification results and group definitions of the charging facilities. Each charging facility group contains only charging facilities of a single category, i.e., charging facility groups of categories A, B, C, and D, respectively. S42. Develop a sampling plan and determine the sample size for random inspection and standby inspection; Formulate a sampling plan: For Class A charging facility groups, a relaxed sampling plan will be implemented. For Class B charging facility groups, different sampling plans will be selected based on the geographical characteristics of Fujian or the integrity of the companies. For Class C and D charging facility groups, a full sampling plan will be implemented, and on-site verification will be carried out for each charging facility. Among them, the different sampling plans selected based on the geographical characteristics of Fujian or the integrity of the companies are as follows: a) For non-island areas, a single sampling is adopted and the sampling plan is a normal sampling plan. For island areas, a single sampling is adopted and the sampling plan is a tightened sampling plan. b) For honest measurement enterprises, regardless of island and non-island areas, the sampling plan is a relaxed sampling plan; The sampling of samples shall follow the principle of random sampling, and the normal sampling plan, the tightened sampling plan and the relaxed sampling plan shall all be based on the corresponding strictness of sampling at the inspection level S-4 and AQL 2.5; When determining the sample size for random inspection and backup inspection, 20% of the sample size for random inspection and backup inspection shall be selected as the sample size for Class A and Class B charging facilities; S43. Select sites and samples for sampling: S44. Verify the sampled items and enter the verification results; verify the samples on site one by one in accordance with JJG 1148 and JJG 1149, make conformity assessments, and confirm the metrological performance based on the verification results; S45. Determine the verification result of the charging facility group; S5. The measurement performance confirmation link includes: confirming the measurement performance of the charging facilities based on online calculations and sampling verification results, and forming an online evaluation report on the measurement performance of the charging facilities.

2. The method according to claim 1, wherein: In S21, if there is a reference pile in the charging station, assuming the reference pile is the jth pile, the virtual verification standard value is calculated according to the following formula: Where, The operating error calculated by the online calculation link of the charging facility operating error for the kth time in the i-th group of reference piles; This is the error of the reference value obtained through manual verification or standard module; If the charging station has a reference pile, which is set as the jth pile, then steps S22 to S28 of the MAP process are correspondingly adjusted to be performed only on the reference pile.

3. The method according to claim 1, wherein: In S43, the sample is selected according to the principle of random selection, and the sample is selected according to the simple random sampling method in GB / T 10111. The sample number of the random sampling is generated by a random number table method, a random number dice method or a playing card method; In S44, after selecting the charging facility sampling samples, the samples are individually inspected on-site in accordance with JJG 1148 and JJG 1149, and the qualification is determined based on the on-site inspection results of the single sampling samples; In S45, assuming that the number of samples that do not meet the maximum allowable error limit requirement for on-site sampling verification of charging facilities is d, then: When d≤Ac, the group is judged as qualified, but the samples that failed the on-site verification are judged as unqualified; When d≥rejection number Re, the group is judged as unqualified, the samples that pass the on-site inspection are judged as qualified, and the samples that fail the on-site inspection are judged as unqualified.

4. The method according to claim 3, wherein: The S5 is specifically: For Class A charging facility groups, metering performance confirmation is performed as follows: The samples that have passed the on-site verification in the group are confirmed as qualified by measurement and a verification certificate is issued; other Class A charging facilities are evaluated as qualified online; For samples in the group that fail on-site verification, they will be confirmed as unqualified by metrology and a verification result notice will be issued; other Class A samples at the charging station where the samples that failed on-site verification are located will be downgraded to Class B, and other Class A charging facilities other than the charging station where the samples that failed on-site verification are located will be qualified by online evaluation; For Class B charging facilities, the metering performance confirmation is carried out as follows: For groups that pass on-site verification, the samples in the group that pass on-site verification are metrologically confirmed as qualified, and a verification certificate is issued, and they are qualified in the online evaluation; the samples in the group that fail on-site verification are metrologically confirmed as unqualified, and a verification result notice is issued; the other samples outside the charging station where the unqualified samples are located in the group are metrologically confirmed as qualified and are qualified in the online evaluation report; the other Class B samples in the charging station where the samples that fail on-site verification are located are downgraded to Class C, and 100% random inspection is implemented; For groups that fail on-site verification, samples that pass on-site verification in the group will be metrologically confirmed as qualified, and a verification certificate will be issued, and they will be qualified in the online evaluation report; Samples that fail on-site verification in the group will be metrologically confirmed as unqualified, and a verification result notice will be issued, and they will be listed as unqualified in the online evaluation report; other Class B samples in the group will be downgraded to Class C and 100% random inspection will be implemented; For Class C charging facility groups, metering performance confirmation is performed as follows: After on-site verification in accordance with JJG 1148 and JJG 1149, metrological confirmation is carried out based on the verification results. If the on-site verification is qualified, the metrological confirmation is qualified, a verification certificate is issued, and it is qualified in the online evaluation report; if the on-site verification is unqualified, the metrological confirmation is unqualified, a verification result notice is issued, and it is unqualified in the online evaluation report; For Class D charging facility groups, metering performance confirmation is performed as follows: On-site calibration is carried out in accordance with JJG 1148 and JJG 1149. A calibration certificate will be issued for qualified products, and a calibration result notice will be issued for unqualified products.

5. The method according to claim 1, wherein: The cycle for online calculation of charging facility operation errors is 1 month, the sampling verification cycle is 1 year, and the measurement confirmation and online evaluation cycle is 1 year; for charging facilities classified as Class D, the calibration cycle shall be handled in accordance with JJG 1148 and JJG 1149.

6. A system for confirming the metering performance of a charging facility group based on the MAP solution, characterized by: Used to implement the method according to any one of claims 1 to 5.

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