A method for analyzing environmental adaptability of DC charging piles

Abstract

The present invention discloses an environmental adaptability analysis method for a DC charging pile, comprising the following steps: S1. Analyze and determine the physical structure and electrical structure of the charging pile; S2. Statistically calculate the types and causes of the failures of each physical module constituting the physical structure of the charging pile and each electrical module constituting the electrical structure caused by environmental factors; S3. Perform environmental membership analysis on the physical structure and electrical structure of the charging pile, wherein the membership is respectively expressed as the proportion of each environmental factor causing the failure of each physical module or electrical module, and the sum of the memberships of various environmental factors to the same physical module or electrical module is equal to 1; S4. Perform correlation analysis on the environmental factors of the charging pile and the health of the charging pile by adopting a comprehensive fuzzy evaluation method. According to the analysis results, the charging pile is operated and maintained in a targeted manner to improve its service life.

Description

Technical Field

[0001] The invention relates to an environmental adaptability analysis method for a DC charging pile. Background Art

[0002] As an important facility for providing fast charging for new energy vehicles, DC charging piles have a rapid development. During operation, DC charging piles are easily affected by environmental factors such as temperature, humidity and pollutants. They have more faults than AC charging piles, especially when placed outdoors, they are more susceptible to environmental influences and performance degradation. At present, the research on the environmental reliability of DC charging piles is still in a continuous process of verification. Many scholars have proposed many fault diagnosis theories and judgment methods. For example, the fault diagnosis method based on signal processing has been used for a long time. In essence, it is through signal acquisition, signal model establishment, feature value extraction and fault identification. However, this method can only identify the location of the fault and lacks a real understanding of the root cause of the fault; while the fault diagnosis method based on neural network has functions such as memory, learning, and association, but it needs to be based on a large number of data samples to ensure good learning effects. These methods have their limitations or inaccuracies. The fault diagnosis method based on analytical models only focuses on the study of single faults, and the accuracy of fault judgment is poor. Most researchers focus on the diagnosis and timely maintenance after the fault occurs, but ignore the analysis of the environmental adaptability of DC charging piles, so as to carry out targeted maintenance, thereby reducing the failure rate of DC charging piles.

[0003] Therefore, analyzing the environmental adaptability of DC charging piles, identifying the weak links in the environmental adaptability of DC charging piles, and maintaining them during the operation of DC charging piles are of great significance for extending the life of DC charging piles and improving their operating performance. Summary of the invention

[0004] The present invention provides an environmental adaptability analysis method for a DC charging pile, which can identify weak links in the environmental adaptability of a DC charging pile, provide a basis for operation and maintenance of the charging pile, and help to extend the operation performance and life of the charging pile.

[0005] The environmental adaptability analysis method of a DC charging pile of the present invention fully analyzes the physical structure and electrical structure of the charging pile, investigates the actual service environment of the charging pile, determines the influence of various environmental factors on the physical structure and electrical structure of the DC charging pile, and analyzes the correlation between the health of the charging pile and the service environment. The analysis method of the present invention includes the following steps:

[0006] S1. Analyze and determine the physical and electrical structures that make up the charging pile;

[0007] S2. Statistical analysis of the types and causes of failures of various physical modules that make up the physical structure of the charging pile and various electrical modules that make up the electrical structure due to environmental factors;

[0008] S3. Perform environmental membership analysis on the physical structure and electrical structure of the charging pile, where the membership is expressed as the proportion of each environmental factor causing the failure of each physical module or electrical module, and the sum of the membership of various environmental factors to the same physical module or electrical module is equal to 1. Determine the membership of various environmental factors to each physical module of the physical structure and each electrical module of the electrical structure as the data basis for subsequent comprehensive fuzzy evaluation;

[0009] S4. A comprehensive fuzzy evaluation method is used to analyze the correlation between the environmental factors of the charging pile and the health of the charging pile, that is, a comprehensive evaluation is made on the influence coefficients of various environmental factors on each physical module of the physical structure and each electrical module of the electrical structure.

[0010] As a preferred analytical method of the present invention,

[0011] The step S4 includes the following process:

[0012] S41. Determine the fuzzy comprehensive evaluation factor set of the three environmental factors of temperature, humidity and pollutants that affect each physical module and each electrical module of the charging pile,

[0013] The comprehensive evaluation factor set of the physical module U = {charging gun seat size matching problem, charging gun electronic lock failure problem, charging gun contact resistance is too large, charging gun and cable are not firmly fixed, charging pile insulation grounding problem, charging pile shell protection level problem, charging pile electrical safety problem, charging pile metering problem, cable problem},

[0014] Comprehensive evaluation factor set U of the electrical module = {power supply circuit failure, microprocessor failure, detection circuit failure, drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure, high-frequency rectifier circuit failure, touch screen failure, IC card reader failure, electric energy meter failure};

[0015] S42. Determine the comprehensive evaluation set of the three environmental factors of temperature, humidity and pollutants that affect the physical modules and electrical modules of the charging pile.

[0016] The comprehensive evaluation set can be V = {very high, high, medium, low, very low};

[0017] S43. According to the failure causes of each physical module of the charging pile, a single factor evaluation of three environmental factors is performed to obtain three impact evaluation matrices of temperature, humidity and pollutants on the physical structure of the charging pile.

[0018] According to the failure causes of each electrical module of the charging pile, the single factor impact evaluation of three environmental factors is carried out, and three impact evaluation matrices of temperature, humidity and pollutants on the electrical structure of the charging pile are obtained respectively.

[0019] The rows of the evaluation matrix correspond to the elements of the comprehensive evaluation factor set, i.e., the fault types, the columns of the evaluation matrix correspond to the elements of the comprehensive evaluation set, and the elements of the evaluation matrix are the corresponding membership degrees;

[0020] S44. Use the analytic hierarchy process to establish a weight set of the impact of each element on the evaluation target in the comprehensive evaluation factor set of each physical module and each electrical module of the charging pile; to ensure the validity of the weight set, perform a consistency check on the weight set.

[0021] S45. Establish a mathematical model to conduct hierarchical fuzzy comprehensive evaluation of the effects of temperature, humidity and pollutants on the physical structure and electrical structure of the charging pile;

[0022] S46. Obtain quantitative indicators of the impact of three environmental factors, namely temperature, humidity and pollutants, on charging piles.

[0023] The elements of the evaluation factors of each physical module of the physical structure described in the present invention are divided into two-level indicators, among which the first-level indicators are charging gun problems, charging pile problems and cable problems. The charging gun seat size matching problem, charging gun electronic lock failure problem, charging gun contact resistance is too large and the charging gun and cable are not firmly fixed as the second-level indicators of the charging gun problem. The charging pile insulation grounding problem, charging pile shell protection level problem, charging pile electrical safety problem and charging pile metering problem are the second-level indicators of the charging pile problem.

[0024] The elements of the evaluation factors of each electrical module of the electrical structure are divided into two-level indicators, among which the first-level indicators are control module failure, power charging module failure and external equipment failure; the power supply circuit failure, microprocessor failure and detection circuit failure are used as the second-level indicators of the control module failure; the drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure and high-frequency rectifier circuit failure are used as the second-level indicators of the power charging module failure; the touch screen failure, IC card reader failure and electric energy meter failure are used as the second-level indicators of the external equipment failure.

[0025] The present invention has the following significant effects:

[0026] 1. The environmental adaptability analysis method of the DC charging pile of the present invention is based on the monitoring data of the actual service environment conditions of outdoor charging piles in hot and humid climates, analyzes the laws and characteristics of the physical structure and electrical structure of the charging piles affected by environmental factors, studies the environmental load characteristic values ​​of the charging pile component structure, and combines the environmental failure mechanism of the charging pile. Through theoretical analysis, a multi-factor collaborative load test spectrum of charging piles that is more suitable for harsh environments such as outdoor environments can be accurately established, which can be used as the data basis for the operation and maintenance of charging piles in different service environments, providing a theoretical basis for extending the service life of charging piles.

[0027] 2. The comprehensive fuzzy evaluation of the present invention has unique advantages in analyzing DC charging piles. Due to the complexity of the charging pile structure and environmental factors, the ambiguity of the evaluation criteria, etc., it is impossible to absolutely describe the actual impact of temperature, humidity and pollution on the charging pile. Therefore, the use of comprehensive fuzzy evaluation can integrate multiple factors such as the physical and electrical structure of the charging pile, making the evaluation result more objective and reliable. At the same time, by using comprehensive fuzzy evaluation to analyze the environmental adaptability of DC charging piles, experts can timely update and adjust the evaluation criteria through the comprehensive evaluation set, which is convenient for later maintenance and updating. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Figure 1 This is a flow chart of the environmental adaptability analysis method of a DC charging pile of the present invention;

[0030] Figure 2 A hierarchical model diagram of physical structure evaluation factors in the environmental adaptability analysis method of a DC charging pile of the present invention;

[0031] Figure 3 A hierarchical model diagram of electrical structure evaluation factors in the environmental adaptability analysis method of a DC charging pile of the present invention;

[0032] Figure 4 This is a flow chart for verifying the weight set in the environmental adaptability analysis method of a DC charging pile of the present invention. DETAILED DESCRIPTION

[0033] The environmental adaptability analysis method of a DC charging pile of the present invention comprises the following steps:

[0034] S1. Preliminary detailed analysis to determine the physical and electrical structures that make up the charging pile;

[0035] S2. Conduct on-site surveys on the use of DC charging piles, and count the types and causes of failures of various physical modules that make up the physical structure of the charging pile and various electrical modules that make up the electrical structure due to environmental factors;

[0036] Table 1 Various types of faults of charging piles in service caused by environmental factors

[0037]

[0038]

[0039] S3. Perform environmental membership analysis on the physical structure and electrical structure of the charging pile, that is, perform environmental membership analysis on the internal structure of the DC charging pile, and study the environmental load characteristic values ​​of the charging pile component structure. The membership is expressed as the proportion of each environmental factor causing the failure of each physical module or electrical module. The sum of the membership of various environmental factors to the same physical module or electrical module is equal to 1. Determine the membership of various environmental factors to each physical module of the physical structure and each electrical module of the electrical structure as the data basis for subsequent comprehensive fuzzy evaluation;

[0040] The statistical analysis process of the physical structure is as follows: The physical module of the DC charging pile includes the charging pile shell, fixed screws, dust filter cotton, sealing ring, charging gun cable, charging gun shell, charging gun internal terminal and charging gun internal sensor. The expert system is used to score the percentage of the charging pile shell, fixed screws, dust filter cotton, sealing ring, charging gun cable, charging gun shell, charging gun internal terminal and charging gun internal sensor affected by temperature, humidity and pollutants. The total percentage of the charging pile shell, fixed screws, dust filter cotton, sealing ring, charging gun cable, charging gun shell, charging gun internal terminal and charging gun internal sensor to temperature, humidity and pollutants is 1.

[0041] The statistical analysis process of the electrical structure is as follows: According to the nameplate data, working humidity, temperature, etc. of each electrical module, determine the influence of temperature, humidity, and pollution on each electrical module of the DC charging pile. The electrical modules of the DC charging pile include: control module power supply circuit, control module microprocessor, control module detection circuit, drive protection circuit, AC contactor, rectifier filter circuit, power conversion circuit, high-frequency rectifier circuit, touch screen, card reader and electric energy meter. The expert system DC charging pile control module power supply circuit, control module microprocessor, control module detection circuit, drive protection circuit, AC contactor, rectifier filter circuit, power conversion circuit, high-frequency rectifier circuit, touch screen, card reader and electric energy meter are scored by the percentage of the influence of temperature, humidity and pollution. The sum of the percentages of the control module power supply circuit, control module microprocessor, control module detection circuit, drive protection circuit, AC contactor, rectifier filter circuit, power conversion circuit, high-frequency rectifier circuit, touch screen, card reader and electric energy meter with temperature, humidity and pollution is 1.

[0042] S4. A comprehensive fuzzy evaluation method is used to analyze the correlation between the environmental factors of the charging pile and the health of the charging pile, that is, a comprehensive evaluation is made on the influence coefficients of various environmental factors on each physical module of the physical structure and each electrical module of the electrical structure.

[0043] As a preferred embodiment, the analysis process of the present invention is as follows:

[0044] S41. Determine the fuzzy comprehensive evaluation factor set of the three environmental factors of temperature, humidity and pollutants that affect each physical module and each electrical module of the charging pile,

[0045] The comprehensive evaluation factor set of the physical module U = {charging gun seat size matching problem, charging gun electronic lock failure problem, charging gun contact resistance is too large, charging gun and cable are not firmly fixed, charging pile insulation grounding problem, charging pile shell protection level problem, charging pile electrical safety problem, charging pile metering problem, cable problem},

[0046] Comprehensive evaluation factor set U of the electrical module = {power supply circuit failure, microprocessor failure, detection circuit failure, drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure, high-frequency rectifier circuit failure, touch screen failure, IC card reader failure, electric energy meter failure};

[0047] S42. Determine the comprehensive evaluation set of the three environmental factors of temperature, humidity and pollutants that affect the physical modules and electrical modules of the charging pile.

[0048] Comprehensive evaluation set V = {very high, high, medium, low, very low};

[0049] S43. According to the failure causes of each physical module of the charging pile, a single factor evaluation of three environmental factors is performed to obtain three impact evaluation matrices of temperature, humidity and pollutants on the physical structure of the charging pile.

[0050] According to the failure causes of each electrical module of the charging pile, the single factor impact evaluation of three environmental factors is carried out, and three impact evaluation matrices of temperature, humidity and pollutants on the electrical structure of the charging pile are obtained respectively.

[0051] The rows of the evaluation matrix correspond to the elements of the comprehensive evaluation factor set, i.e., the fault types, the columns of the evaluation matrix correspond to the elements of the comprehensive evaluation set, and the elements of the evaluation matrix are the corresponding membership degrees;

[0052] For example: the temperature impact judgment matrix R of the physical structure T , Humidity impact evaluation matrix R D , Pollutant impact evaluation matrix R C

[0053] Rows 1 to 9 correspond to comprehensive evaluation factors affected by the environment: charging gun holder size matching problem, charging gun electronic lock failure, charging gun contact resistance is too large, charging gun and cable are not firmly fixed, charging pile edge grounding problem, charging pile shell protection level problem, charging pile electrical safety problem, charging pile metering problem, and cable problem.

[0054] Columns 1 to 5 correspond to the elements of the comprehensive evaluation set: very low, low, medium, high, and very high. Each element in the matrix is ​​the degree of membership of the row evaluation factor and the column evaluation set. T The first row shows that the membership degree of "charging gun holder size matching problem" is very low and is 0.78; the corresponding membership degree is 0.19; the corresponding membership degree is 0.03; the corresponding membership degree is 0; and the corresponding membership degree is 0.

[0055] The evaluation matrices of the impact of temperature, humidity, and pollutants on physical structures are:

[0056]

[0057]

[0058] Electrical structure:

[0059] The 1st to 11th rows of the matrix correspond to the comprehensive evaluation factors affected by the environment: power supply circuit failure, microprocessor failure, detection circuit failure, drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure, high-frequency rectifier circuit failure, human-computer interaction module touch screen failure, IC card reader failure, and electric energy meter failure.

[0060] The first to fifth columns of the matrix correspond to the elements of the comprehensive evaluation set: very low, low, medium, high, and very high. Each element in the matrix is ​​the degree of membership of the row evaluation factor and the column evaluation set. T The first row "Power circuit failure" has a membership of 0 for very low, 0.13 for low, 0.78 for medium, 0.09 for high, and 0 for very high.

[0061] The evaluation matrices of the impact of temperature, humidity, and pollutants on electrical structures are:

[0062]

[0063]

[0064] S44. A hierarchy analysis method is used to establish a weight set of the impact of each element on the evaluation target in the comprehensive evaluation factor set of each physical module and each electrical module of the charging pile; the hierarchy analysis method is referred to as AHP.

[0065] First, we build a hierarchical model.

[0066] like Figure 2 As shown in the figure, the evaluation target is physical structure failure. The first four elements of the comprehensive evaluation factor set belong to charging gun failure, and the last four elements belong to charging pile failure. The evaluation factors are divided into two levels. The first-level indicators are the criterion layer, which includes three factors: charging gun failure, charging pile failure and cable failure. The second-level indicators are the factor layer. The four failure factors of the charging gun are in order: charging gun seat size matching problem, charging gun electronic lock failure, charging gun contact resistance is too large, and the charging gun and cable are not firmly fixed; the four failure factors of the charging pile are in order: charging pile grounding problem, charging pile shell protection level problem, charging pile electrical safety problem, and charging pile metering problem.

[0067] like Figure 3 As shown in the figure, the evaluation target is electrical structure failure. The first three elements of the comprehensive evaluation factor set belong to control module failure, the middle five elements belong to power charging module failure, and the last three elements belong to external equipment failure. Therefore, the evaluation factors of electrical structure failure are also divided into two levels. The first-level indicators are the criterion layer, which has three factors: control module failure, power charging module failure and external equipment failure. The second-level indicators are the factor layer, among which the factors of the three control module failures are in order: power supply circuit failure, microprocessor failure, and detection circuit failure; the five power charging module failures are in order: drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure, and high-frequency rectifier circuit failure; the factors of the three external equipment failures are in order: human-computer interaction module touch screen failure, IC card reader failure, and electric energy meter failure.

[0068] Each factor in the comprehensive evaluation factor set has a different status and role in the evaluation target, that is, different evaluation factors have different weights on the final target evaluation. In order to ensure the effectiveness of the weight set and the reasonableness of the analysis results, a judgment matrix is ​​constructed, and the square root method and MATLAB programming are used to perform consistency checks on the weight set.

[0069] The judgment matrix is ​​constructed using the 1-9 scaling method, which is used to compare the relative importance of two factors i and j.

[0070] Table 2 Judgment matrix scale and its meaning

[0071]

[0072]

[0073] The judgment matrix construction process of physical structure failure as the evaluation target:

[0074] The three elements of the criterion layer are charging gun failure, charging pile failure and cable failure. Charging pile failure has the greatest impact on the physical structure failure of the evaluation target, followed by charging gun failure, and cable failure has the least impact. Compare the row factors and column factors of the matrix. Take the second row factor "charging pile failure" as an example. i corresponds to charging pile failure and j corresponds to charging gun failure. Because charging pile failure is obviously more important than charging gun failure, it can be obtained from Table 2 that the value of the first column of the second row of the judgment matrix is ​​5; similarly, because the charging pile is equally important than the charging pile, the value of the second row and the second column is 1; because the charging pile is more important than the cable, the value of the third column of the second row of the matrix is ​​7.

[0075] Therefore, the judgment matrix of the evaluation target and criterion layer is as follows:

[0076]

[0077] Similarly, the judgment matrix of the second-level indicator factor layer and the first-level indicator criterion layer can be obtained:

[0078]

[0079] The square root method is used to check the consistency of the judgment matrix. The calculation process is shown in Figure 4 , the inspection steps are as follows:

[0080] Calculate the product of each row of the judgment matrix A, which is called Mi;

[0081]

[0082] In formula (1-1), i=1, 2, …, n, where n is the order of the judgment matrix A.

[0083] Calculate the nth root of the product Mi of each row

[0084]

[0085] Pair Matrix Perform normalization processing;

[0086]

[0087] At this time, W i Get the feature vector

[0088] Calculate the maximum eigenvalue λmax of the judgment matrix A;

[0089]

[0090] In formula (1-4), (AW) i Represents the i-th element of the matrix obtained by multiplying the judgment matrix A by the eigenvector W.

[0091] Calculate the consistency index CI of the judgment matrix A. The index CI is used to check the consistency of the judgment;

[0092]

[0093] The larger the CI value, the greater the deviation of the judgment matrix A, and the smaller the CI value, the better the consistency.

[0094] The average random consistency index RI is obtained;

[0095] The value of RI is determined by the order n of the judgment matrix A. The specific values ​​of RI are shown in Table 1 below.

[0096] Table 3 Average random consistency index (n = 1, 2, 3...9)

[0097]

[0098] For the first-order judgment matrix and the second-order judgment matrix, the RI value is 0. Because when the order of the judgment matrix A is first-order or second-order, the judgment matrix has complete consistency. That is, the first-order judgment matrix and the second-order judgment matrix can always pass the consistency test, and there is no need to perform a consistency test.

[0099] Calculate the random consistency ratio CR;

[0100]

[0101] When the random consistency index ratio CR is less than 0.1, the consistency test of the judgment matrix A passes, otherwise it fails. The judgment matrix that fails the test needs to be reconstructed and then the above steps are repeated.

[0102] Calculate the eigenvector W and the maximum eigenroot λ of the judgment matrix A max , deviation consistency index CI, and random consistency ratio CR are:

[0103] λ max =3.0649, CI=0.0324, RI=0.58, CR=0.0559;

[0104] The results for the judgment matrix B1 are:

[0105] λ max =4.1169, CI=0.0390, RI=0.90, CR=0.0433;

[0106] The results for the judgment matrix B2 are:

[0107] λ max =4.1169, CI=0.0390, RI=0.90, CR=0.0433;

[0108] Since all CRs were < 0.1, the consistency of each judgment matrix was verified.

[0109] Similarly, a judgment matrix with the evaluation target as electrical structure failure is constructed.

[0110] Judgment matrix for evaluating target electrical structure failures and criterion layer control module failures, power charging module failures, and external equipment failures:

[0111]

[0112] The judgment matrix between the electrical structure fault factor layer and the criterion layer is obtained:

[0113]

[0114]

[0115]

[0116] The eigenvector W and the maximum eigenroot λ of the judgment matrix A are obtained by calculation. max , deviation consistency index CI, and random consistency ratio CR are:

[0117] The consistency test results of the judgment matrix A are:

[0118] λ max =3.039, CI=0.019, RI=0.58, CR=0.033;

[0119] The consistency test results of the judgment matrix B1 are:

[0120] λ max =3.039, CI=0.019, RI=0.58, CR=0.033;

[0121] The consistency test results of the judgment matrix B2 are:

[0122] λ max =5.136, CI=0.034, RI=1.12, CR=0.030;

[0123] The consistency test results of the judgment matrix B3 are:

[0124] λ max=3.039, CI=0.019, RI=0.58, CR=0.033;

[0125] Since all CRs were < 0.1, the consistency of each judgment matrix was verified.

[0126] S45. Establish a mathematical model to conduct hierarchical fuzzy comprehensive evaluation of the effects of temperature, humidity and pollutants on the physical structure and electrical structure of the charging pile;

[0127] Table 4: Mathematical model for judging physical structure (the values ​​in brackets correspond to the weights of the factors)

[0128]

[0129] The influence coefficients of temperature, humidity and pollutants on the physical structure and electrical structure of the charging pile are evaluated hierarchically and fuzzy comprehensively;

[0130] 1) Impact of temperature on the physical module of charging pile

[0131]

[0132]

[0133] B3=R3=(0.15,0.76,0.09,0,0)

[0134]

[0135] Where A1 is the weight row matrix of the second-level indicators (i.e., four factors) corresponding to the first-level indicator charging gun problem u1, and A2 is the weight row matrix of the second-level indicators corresponding to the first-level indicator charging pile problem u2; R1, R2, and R3 are the weight row matrices of the second-level indicators corresponding to the first-level indicator charging pile problem u2. T The number of columns is the same, R1 takes R T The corresponding row in the matrix is ​​the value matrix of "charging gun seat size matching problem, charging gun electronic lock failure, charging gun contact resistance is too large, charging gun and cable are not fixed firmly", R2 takes R T The corresponding row in is the matrix of the values ​​of "the problem of grounding the charging pile edge, the problem of protection level of the charging pile shell, the problem of electrical safety of the charging pile, and the problem of metering of the charging pile". R3 takes R T The corresponding row is the numerical matrix of "cable problem", matrix R = [B1 B2 B3] T Similarly, the impact of humidity and pollutants on the physical module of the charging pile is judged as follows:

[0136] (2) Impact of humidity on the physical module of charging pile

[0137]

[0138]

[0139] B3=R3=(0.15,0.76,0.09,0,0)

[0140]

[0141] (3) Impact of pollutants on the physical module of charging piles

[0142]

[0143]

[0144] B3=R3=(0.15,0.76,0.09,0,0)

[0145]

[0146] Table 5: Mathematical model for judging electrical structure (the values ​​in brackets are the weights corresponding to the factors)

[0147]

[0148] ① Make a comprehensive judgment on the impact of temperature

[0149]

[0150]

[0151]

[0152]

[0153] Where A1 is the weight row matrix of the secondary indicators (i.e., four factors) corresponding to the first-level indicator control module failure u1, A2 is the weight row matrix of the secondary indicators corresponding to the first-level indicator power charging module failure u2; A3 is the weight row matrix of the secondary indicators corresponding to the first-level indicator power charging module failure u3. Matrix R = [B1 B2 B3] T Similarly, the impact of humidity and pollutants on the electrical module of the charging pile is judged as follows:

[0154] ② Make a comprehensive judgment on the impact of humidity

[0155]

[0156]

[0157]

[0158]

[0159] ③ Make a comprehensive assessment of the impact of pollutants

[0160]

[0161]

[0162]

[0163]

[0164] S46. According to the results of the fuzzy comprehensive evaluation mathematical model, the quantitative indicators of the impact of three environmental factors, namely temperature, humidity and pollutants, on the charging pile are obtained. That is, the degree of fit of the impact of temperature, humidity and pollutants on the reliability of the charging pile, that is, the proportion of each value in each matrix obtained by the S45 formula A○R corresponding to the comprehensive evaluation set V = {very high, high, medium, low, very low} of the factor (temperature, humidity and pollution), and the comprehensive judgment result is the proportion of each value in each matrix obtained by the above formula A○R corresponding to the comprehensive evaluation set V = {very high, high, medium, low, very low} of the environmental factor (temperature, humidity and pollution). For example: through the mathematical model of Table 4, the final calculation result of the impact of temperature on the physical module of the charging pile is the row matrix B, in which very high corresponds to 6%, high corresponds to 7.7%, medium corresponds to 7.4%, low corresponds to 12.2%, and very low corresponds to 66.7%.

[0165] Similarly, other quantitative indicators of the charging pile affected by temperature, humidity and pollutants can be obtained.

[0166] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention, and the embodiments of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structures of the present invention based on the above contents of the present invention, according to the common technical knowledge and customary means in this field, without departing from the above basic technical ideas of the present invention, should fall within the scope of protection of the present invention.

Claims

1. A method for analyzing the environmental adaptability of a DC charging pile, characterized in that: The following steps are involved: S1. Analyze and determine the physical and electrical structures that make up the charging pile; S2. Statistical analysis of the types and causes of failures of various physical modules that make up the physical structure of the charging pile and various electrical modules that make up the electrical structure due to environmental factors; S3. Perform environmental membership analysis on the physical structure and electrical structure of the charging pile, wherein the membership is expressed as the proportion of each environmental factor causing each physical module or electrical module failure, and the sum of the memberships of various environmental factors to the same physical module or electrical module is equal to 1; S4. A comprehensive fuzzy evaluation method is used to analyze the correlation between the environmental factors of the charging pile and the health of the charging pile, that is, a comprehensive evaluation is made on the influence coefficients of various environmental factors on each physical module of the physical structure and each electrical module of the electrical structure, including the following process: S41. Determine the fuzzy comprehensive evaluation factor set of the three environmental factors of temperature, humidity and pollutants that affect each physical module and each electrical module of the charging pile, The comprehensive evaluation factor set of the physical module U = {charging gun seat size matching problem, charging gun electronic lock failure problem, charging gun contact resistance is too large, charging gun and cable are not firmly fixed, charging pile insulation grounding problem, charging pile shell protection level problem, charging pile electrical safety problem, charging pile metering problem, cable problem}, Comprehensive evaluation factor set U of the electrical module = {power supply circuit failure, microprocessor failure, detection circuit failure, drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure, high-frequency rectifier circuit failure, touch screen failure, IC card reader failure, electric energy meter failure}; S42. Determine the comprehensive evaluation set of the three environmental factors of temperature, humidity and pollutants that affect each physical module and each electrical module of the charging pile, Comprehensive evaluation set V = {very high, high, medium, low, very low}; S43. According to the failure causes of each physical module of the charging pile, a single factor evaluation of three environmental factors is performed to obtain three impact evaluation matrices of temperature, humidity and pollutants on the physical structure of the charging pile. According to the failure causes of each electrical module of the charging pile, the single factor impact evaluation of three environmental factors is carried out, and three impact evaluation matrices of temperature, humidity and pollutants on the electrical structure of the charging pile are obtained respectively. The rows of the evaluation matrix correspond to the elements of the comprehensive evaluation factor set, i.e., the fault types, the columns of the evaluation matrix correspond to the elements of the comprehensive evaluation set, and the elements of the evaluation matrix are the corresponding membership degrees; S44. Using the analytic hierarchy process to establish the weight set of each element's impact on the evaluation target in the comprehensive evaluation factor set of each physical module and each electrical module of the charging pile; S45. Establish a mathematical model to conduct hierarchical fuzzy comprehensive evaluation of the effects of temperature, humidity and pollutants on the physical structure and electrical structure of the charging pile; S46. Obtain quantitative indicators of the impact of three environmental factors, namely temperature, humidity and pollutants, on charging piles.

2. The environmental adaptability analysis method of a DC charging pile according to claim 1, characterized in that: The elements of the evaluation factors of each physical module of the physical structure are divided into two-level indicators, among which the first-level indicators are charging gun problems, charging pile problems and cable problems. The charging gun seat size matching problem, charging gun electronic lock failure problem, charging gun contact resistance is too large and the charging gun and cable are not firmly fixed as the second-level indicators of the charging gun problem. The charging pile insulation grounding problem, charging pile shell protection level problem, charging pile electrical safety problem and charging pile metering problem are the second-level indicators of the charging pile problem.

3. The environmental adaptability analysis method of a DC charging pile according to claim 2, characterized in that: The elements of the evaluation factors of each electrical module of the electrical structure are divided into two-level indicators, among which the first-level indicators are control module failure, power charging module failure and external equipment failure; the power supply circuit failure, microprocessor failure and detection circuit failure are used as the second-level indicators of the control module failure; the drive protection circuit failure, AC contactor failure, full-bridge rectifier filter circuit failure, power conversion circuit failure and high-frequency rectifier circuit failure are used as the second-level indicators of the power charging module failure; the touch screen failure, IC card reader failure and electric energy meter failure are used as the second-level indicators of the external equipment failure.

4. The environmental adaptability analysis method of a DC charging pile according to claim 3 is characterized in that: The weight sets of the physical modules of the physical structure and the weight sets of the electrical modules of the electrical structure are checked for consistency.

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