Remote calibration method for electric energy of alternating current charging pile

Abstract

The invention discloses an AC charging pile electric energy remote calibration method, and relates to the technical field of electric energy metering and calibration. The method comprises the following steps: constructing a calibration system; an error self-diagnosis module is used for carrying out error calculation and electric parameter calculation on the collected signals to obtain electric parameter data and a monitoring error in a calibration signal processing flow, and a reference signal calibration module is used for judging an error source to determine a fault repair scheme during calibration; the collected signals comprise a load signal and a reference signal of a reference signal source; the reference signal source comprises a direct-current reference signal source and an alternating-current reference signal source; and based on the fault repairing scheme, the laboratory is used for remotely calibrating the electric energy of the alternating-current charging pile. According to the invention, electrical parameters can be accurately monitored, errors in a signal processing flow can be calibrated, and the accuracy and stability of the signal processing flow are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy metering and calibration, and in particular to a method for remote calibration of electric energy of an AC charging pile. Background Art

[0002] In the field of electric energy metering, traditional calibration methods mainly rely on on-site calibration or laboratory calibration, that is, transporting the equipment to be calibrated to a site with high-precision standard equipment for comparison and correction. Although this method can ensure the accuracy of calibration, it has many limitations and shortcomings. First, on-site calibration or laboratory calibration requires a lot of time and resources, especially during transportation, which may introduce additional errors. In addition, for large equipment or equipment installed in remote areas, transportation costs are high and risks are relatively high.

[0003] With the development of science and technology and the advancement of remote communication technology, remote calibration technology has gradually become a research hotspot. However, the current application of remote calibration technology in the field of electric energy metering still faces many challenges. On the one hand, electric energy metering involves a variety of electrical parameters (such as voltage, current, power factor, etc.), and the remote transmission and comparison of these parameters are relatively complex, requiring high-precision measurement technology and stable communication links. On the other hand, the remote calibration process may be affected by environmental factors (such as electromagnetic interference, temperature changes, etc.), resulting in unstable calibration results.

[0004] Some research institutions and enterprises have begun to explore remote calibration technology for electric energy metering. For example, some studies have proposed remote calibration systems based on the Internet of Things and cloud computing, which can realize remote monitoring and calibration of metering equipment by establishing calibration databases and servers on network platforms. However, these systems still need to be further improved and optimized in practical applications, especially in terms of calibration accuracy, real-time and security.

[0005] In addition, although some developed countries are relatively advanced in the research and application of remote calibration technology for electric energy metering, for example, the U.S. NIST (National Institute of Standards and Technology) and some European metrology institutions have developed remote calibration systems based on satellite common view technology, using GPS or GNSS satellite signals as high-precision time references to achieve remote comparison and calibration of physical quantities such as voltage and frequency. These methods have significant advantages in improving calibration accuracy and reducing costs, but the comprehensive impact of multiple factors still needs to be considered in the specific implementation and application process. Summary of the invention

[0006] The purpose of the present invention is to provide a remote calibration method for electric energy of an AC charging pile, which can accurately monitor electrical parameters and calibrate errors in a signal processing flow, thereby improving the accuracy and stability of the signal processing flow.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A method for remote calibration of electric energy of an AC charging pile, comprising:

[0009] Constructing a calibration system; the calibration system includes a field end and a laboratory; the field end includes an error self-diagnosis module and a reference signal calibration module connected in sequence; the reference signal calibration module is also connected to the laboratory via wireless communication;

[0010] The error self-diagnosis module is used to perform error calculation and electrical parameter calculation on the collected signal to obtain the monitoring error in the electrical parameter data and calibration signal processing flow, and the reference signal calibration module is used to judge the error source and determine the fault repair plan during calibration; the collected signal includes a load signal and a reference signal of a reference signal source; the reference signal source includes a DC reference signal source and an AC reference signal source;

[0011] Based on the fault repair solution, the laboratory is used to remotely calibrate the power of the AC charging pile.

[0012] Optionally, the operation process of the error self-diagnosis module is: using a sampling circuit to collect the load signal and the reference signal of the reference signal source, and superimposing the signals according to Thevenin's theorem and Norton's theorem 4, and then using an analog-to-digital conversion module to separate the signals, the first branch performs electrical parameter calculations, and the second branch performs online error calculations.

[0013] Optionally, the sampling circuit consists of a voltage divider and a current divider.

[0014] Optionally, the error calculation expression is:

[0015]

[0016] Among them, C 监测误差 is the self-diagnosis function monitoring error, %; U 基准电压额定值 is the initial parameter after calibration; U 基准电压还原值 It is a real-time parameter for error self-diagnosis.

[0017] Optionally, the operation process of the reference signal calibration module is as follows: the AC reference voltage of the reference signal source is biased and alternately passed through the voltage-frequency conversion module with the DC reference voltage to convert it into a corresponding frequency signal, and the frequency counter determines the time interval signal and the pulse signal corresponding to the frequency signal, and finally transmits the time interval signal and the pulse signal to the laboratory via wireless communication for calibration; wherein, the voltage-frequency conversion module includes a main voltage-frequency conversion module and a standby voltage-frequency conversion module, and the on and off of the main voltage-frequency conversion module and the standby voltage-frequency conversion module are controlled by a programmable switch.

[0018] Optionally, during the process of alternating conversion by the voltage-frequency conversion module, a fault judgment is made according to data performance, and it is determined that the fault repair solution during the calibration is to enable a spare voltage-frequency converter or to recommend replacing the electric meter.

[0019] Optionally, the fault judgment process is:

[0020] When the voltage-frequency conversion module adopts the main voltage-frequency conversion module, the DC reference signal before conversion is set to U 1 , AC reference signal is U 2 , set the converted DC frequency signal to f 1 , AC frequency signal is f 2 , and set the main circuit voltage-frequency conversion to k 1 ;

[0021] If f 1 The data is normal, f 2 If there is an error in the data, it is judged to be the AC reference signal U 2 Errors occur;

[0022] If f 1 The data has errors, f 2 If the data is normal, it is judged to be a DC reference signal U 1 Errors occur;

[0023] If f 1 、f 2 The data are all wrong, but Then it is judged as voltage-frequency conversion k 1 Errors occur;

[0024] If f 1 、f 2 The data are erroneous, and k 1 , U 1 or k 1 , U 2 or U 1 , U 2 Or k 1 , U 1 , U 2 If an error occurs and the error location cannot be determined, the voltage-frequency conversion module is replaced with a spare voltage-frequency converter, and the converted DC frequency signal is set to f 3 , AC frequency signal is f 4 , and set the alternate voltage-frequency conversion to k 2 ;

[0025] If f 3 The data is normal, f 4 If there is an error in the data, it is judged to be voltage-frequency conversion k 1and AC reference signal U 2 Errors occur;

[0026] If f 4 The data is normal, f 3 If there is an error in the data, it is judged to be voltage-frequency conversion k 1 and DC reference signal U 1 Errors occur;

[0027] If f 3 、f 4 The data are all wrong, but Then it is judged to be a DC reference signal U 1 , AC reference signal U 2 Errors occur;

[0028] If f 3 、f 4 The data are erroneous, and Then it is judged as voltage-frequency conversion k 1 , DC reference signal U 1 , AC reference signal U 2 There are errors, if k 2 It is also unbelievable, it may be k 2 , U 1 , U 2 There are errors, or k 1 , k 2 , U 1 , U 2 If errors occur, it is recommended to replace the meter.

[0029] Optionally, the operation process in the laboratory is: use the time interval counter and the pulse counter in the frequency counter to trace the standard source at the laboratory end, calculate the voltage difference, and bring it into the voltage deviation formula for calculation.

[0030] Optionally, the voltage deviation formula is:

[0031]

[0032] Among them, △t l and △t r are the differences between the adjacent time intervals at the laboratory end and the field end, f l and f r are the frequency values ​​after voltage-frequency conversion at the laboratory end and the field end, respectively, p is the frequency of the satellite synchronization clock source, K l is the conversion factor of the voltage-to-frequency converter at the laboratory end, N l and N r are the number of pulses per unit time at the laboratory end and the field end respectively.

[0033] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0034] The present invention discloses a method for remote calibration of electric energy of an AC charging pile, the method comprising constructing a calibration system; using an error self-diagnosis module to perform error calculation and electric parameter calculation on the collected signal, obtaining the monitoring error in the electric parameter data and calibration signal processing flow, and using a reference signal calibration module to judge the source of the error and determine the fault repair scheme during calibration; the collected signal includes a load signal and a reference signal of a reference signal source; the reference signal source includes a DC reference signal source and an AC reference signal source; based on the fault repair scheme, a laboratory is used to remotely calibrate the electric energy of the AC charging pile. The present invention can accurately monitor the errors in the electric parameter and calibration signal processing flow, and improve the accuracy and stability of the signal processing flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 It is a flow chart of the method for remote calibration of electric energy of an AC charging pile of the present invention;

[0037] Figure 2 Schematic diagram of the system structure in this embodiment;

[0038] Figure 3 This is a schematic diagram of signal superposition in this embodiment;

[0039] Figure 4 This is a signal diagram of the main voltage-frequency conversion module used in this embodiment;

[0040] Figure 5 This is a signal diagram of the standby voltage-frequency conversion module used in this embodiment;

[0041] Figure 6 This is a schematic diagram of a remote calibration device in this embodiment;

[0042] Figure 7 This is a logic diagram of remote calibration in this embodiment. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The purpose of the present invention is to provide a remote calibration method for electric energy of an AC charging pile, which can accurately monitor electrical parameters and calibrate errors in a signal processing flow, thereby improving the accuracy and stability of the signal processing flow.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] like Figure 1 As shown, the present invention provides a method for remote calibration of electric energy of an AC charging pile, comprising:

[0047] Step 100: construct a calibration system; the calibration system includes a field end and a laboratory; the field end includes an error self-diagnosis module and a reference signal calibration module connected in sequence; the reference signal calibration module is also connected to the laboratory via wireless communication.

[0048] Step 200: Utilize the error self-diagnosis module to perform error calculation and electrical parameter calculation on the collected signal to obtain the monitoring error in the electrical parameter data and calibration signal processing flow, and utilize the reference signal calibration module to judge the source of the error and determine the fault repair plan during calibration; the collected signal includes a load signal and a reference signal of a reference signal source; the reference signal source includes a DC reference signal source and an AC reference signal source.

[0049] Step 300: Based on the fault repair solution, use the laboratory to remotely calibrate the power of the AC charging pile.

[0050] Based on the above technical solution, the following embodiments are provided.

[0051] As the system structure in step 100, Figure 2 As shown, the field end includes an error self-diagnosis module and a reference signal calibration module. The error self-diagnosis module system includes a sampling circuit, an analog-to-digital conversion module, a signal separation link, an online error calculation module, an electrical parameter calculation module and a reference signal calibration module.

[0052] The system workflow is as follows: the load signal and the reference signal of the reference signal source are sampled simultaneously through the sampling circuit, and are superimposed on the voltage or current load signal according to Thevenin Theorem and Norton Theorem 4. This is similar to connecting a high-precision voltage signal source in series to the voltage input end of an electric energy meter, and connecting a high-precision current signal source in parallel to the current input end. The signal superposition of the load signal and the reference signal is shown in Figure 1. Figure 3 shown.

[0053] After superposition, the signals are converted into digital signals through the analog-to-digital conversion module. These digital signals are then sent to the signal separation link, where the load signal and the reference signal are separated. The reference signal is sent to the online error calculation module for error analysis. The monitoring error is calculated using the monitoring error calculation formula based on the factory calibration parameters and real-time parameters. The formula is calculated by comparing U 基准电压额定值 with U 基准电压还原值 The difference between the self-diagnosis function and the monitoring error C is calculated. 监测误差 The calculation formula is:

[0054]

[0055] Among them, C 监测误差 is the self-diagnosis function monitoring error, %; U 基准电压额定值 is the initial parameter after calibration; U 基准电压还原值 It is a real-time parameter for error self-diagnosis.

[0056] The monitoring error calculated by this formula can intuitively reflect the performance changes of the electric energy meter during the metering process, aiming to observe the stability of the signal in the entire processing flow. At the same time, the separated load signal is sent to the electrical parameter calculation module for necessary electrical parameter calculation. In this process, the calibration parameters provide necessary parameter support for the electrical parameter calculation module and the online error calculation module.

[0057] The error self-diagnosis module generates a large number of error monitoring reports during the monitoring phase. These reports are stored in the electric energy meter through data storage technology for subsequent query and analysis. In addition, the host computer can remotely obtain the above reports through the remote acquisition function for the next step of analysis and processing.

[0058] The function of the reference signal calibration module is to ensure the high precision of the reference signal source in the error self-diagnosis system. Therefore, the present invention proposes a remote calibration method based on satellite common view technology. The reference signal calibration module is connected to the reference signal source of the error self-diagnosis module, and uses a programmable switch to control the on-off relationship between the DC reference signal, the AC reference signal and the main and standby voltage-frequency converter, thereby realizing the accurate calibration of the reference signal. During the calibration process, the system will judge the source of the error according to the data performance of different signal sources. For example, when only the DC reference signal has an error, it can be concluded that there is a problem with the DC signal source itself; and when both the DC and AC reference signals have errors but meet specific conditions, it may be that there is a fault in the voltage-frequency conversion link. Through this logical judgment method, the system can quickly locate and isolate the fault point, thereby ensuring the accuracy and efficiency of the calibration process. When facing complex multiple fault situations, the reference signal calibration module will judge whether it is necessary to enable the standby voltage-frequency converter for further diagnosis based on the specific data performance, or directly recommend replacing the meter to solve the problem. The following is the specific process.

[0059] The method comprises the following steps:

[0060] 1. Signal conversion:

[0061] The reference signal output by the reference signal source of the error self-diagnosis module is connected to the reference signal calibration module, and the on and off of the DC reference signal, AC reference signal and the main and standby voltage-frequency converters are controlled by a programmable switch.

[0062] The voltage-frequency converter (VFC) is used to bias the AC reference voltage output by the reference signal source and then convert it into a frequency signal proportional to the DC reference voltage through the voltage-frequency conversion module alternately. The voltage-to-frequency module uses the LM331 chip, which can generate modules of different frequencies according to the input voltage. It can convert 0-10V voltage into a 0-10KHz frequency pulse signal, with a maximum nonlinear distortion of less than 0.01%. It has good performance even when the operating frequency is as low as 0.1Hz, high conversion accuracy, and a digital resolution of up to 12 bits. The external circuit is simple, and only a few external components need to be connected to easily form a V / F or F / V conversion circuit. Because the biased AC reference voltage and the DC reference voltage themselves cannot be directly used for remote comparison. Through the VFC, the voltage value is indirectly expressed as the frequency of the pulse signal. The following is a detailed introduction:

[0063] like Figure 4 As shown, if f 1 The data is normal, f 2 If there is an error in the data, the AC reference signal U 2 An error occurs, and If f 1 The data has errors, f 2If the data is normal, it is the DC reference signal U 1 An error occurs, and If f 1 、f 2 The data are all wrong, but The voltage-frequency conversion k 1 An error occurs, and If f 1 、f 2 The data are erroneous, and k 1 , U 1 or k 1 , U 2 or U 1 , U 2 Or k 1 , U 1 , U 2 When an error occurs and the location of the error cannot be determined, the DC reference signal and the AC reference signal are connected to the backup voltage-frequency converter.

[0064] like Figure 5 As shown, if f 3 The data is normal, f 4 If there is an error in the data, it is the voltage-frequency conversion k 1 , AC reference signal U 2 An error occurs, and If f 4 The data is normal, f 3 If there is an error in the data, it is the voltage-frequency conversion k 1 , DC reference signal U 1 An error occurs, and If f 3 、f 4 The data are all wrong, but Then it is the DC reference signal U 1 , AC reference signal U 2 An error occurs, and If f 3 、f 4 The data are erroneous, and Then the voltage-frequency conversion k 1 , DC reference signal U 1 , AC reference signal U 2 There are errors, if k 2 It is also unbelievable, it may be k 2 , U 1 , U 2 There are errors, or k 1 , k 2 , U 1 , U 2 If errors occur, it is recommended to replace the meter.

[0065] C 基准电压校准误差 is the deviation between the reference voltage calibrated value and the actual reference voltage value, %; the calibration error calculation formula is:

[0066]

[0067] Where U 基准电压实际值 is the real-time measurement value of the benchmark error; U 基准电压校准值 is the value after calibration of the reference error.

[0068] In order to achieve absolute accuracy of the reference signal source in the error self-diagnosis module, it is necessary to trace the DC voltage source. The clock information on the synchronous GPS satellite is used as a carrier and medium for non-physical standard transmission, which can realize the traceability of DC voltage parameters. After the bias voltage of the error self-diagnosis module passes through the voltage-frequency converter, the frequency converted by the voltage-frequency converter is traced through the satellite second pulse, and the time interval counter and pulse counter are used to trace the standard source at the laboratory end, and the voltage difference is calculated and brought into the voltage deviation formula for calculation, thereby ensuring the accuracy of the reference signal source. The voltage deviation formula is as follows:

[0069]

[0070] Among them, △t l and △t r are the differences between the adjacent time intervals at the laboratory end and the field end, f l and f r are the frequency values ​​after voltage-frequency conversion at the laboratory end and the field end, respectively, p is the frequency of the satellite synchronization clock source (usually 1 Hz), K l is the conversion factor of the voltage-to-frequency converter at the laboratory end, N l and N r They are the number of pulses per unit time (such as one second pulse cycle) at the laboratory end and the field end respectively.

[0071] like Figure 6-Figure 7 As shown, the AC power remote calibration system in this embodiment is deployed in an electric vehicle charging station including multiple AC charging piles. The charging station is located in a relatively remote area where frequent on-site calibration is not easy, so the method of the present invention can significantly improve the calibration efficiency and reduce manpower and logistics costs.

[0072] Error self-diagnosis module: The sampling circuit, analog-to-digital conversion module and signal separation link are integrated inside the AC charging pile. The voltage and current signals of each charging pile are collected through the sampling circuit and converted into digital signals through the analog-to-digital conversion module. The signal separation link is used to separate the load signal from the reference signal to ensure the accuracy of the error self-diagnosis.

[0073] Reference signal calibration module: A reference signal source is set up in the center of the charging station. The reference signal source is synchronized with an external high-precision time reference through satellite common view technology. The reference signal source outputs high-precision AC voltage and current signals as a reference standard for the calibration of the charging piles of the entire charging station.

[0074] Remote calibration server: A remote calibration server is set up near the charging station or in a remote data center to receive the calibration data uploaded by each charging pile and process and analyze the data using a preset calibration algorithm. The server is also responsible for storing calibration records and reports for subsequent audit and traceability.

[0075] Start the calibration process: The system administrator sends a calibration start command to each charging pile through the remote control system. After receiving the command, the charging pile starts the error self-diagnosis module and the reference signal calibration module.

[0076] Error self-diagnosis: The error self-diagnosis module inside the charging pile starts working, collects voltage and current signals in real time, and processes them through the analog-to-digital conversion module and signal separation link. The online error calculation module uses the preset monitoring error calculation formula to calculate and monitor the error of the signal in the processing process in real time.

[0077] Reference signal calibration: The charging pile uses a programmable switch to connect the AC voltage and current signals of the reference signal source to the error self-diagnosis module as a calibration reference. The reference signal calibration module accurately calibrates the metering circuit inside the charging pile based on the difference between the reference signal and the load signal. During the calibration process, the system will record and transmit the relevant calibration data to the remote calibration server.

[0078] Data analysis and reporting: After receiving the calibration data uploaded by each charging pile, the remote calibration server uses the remote calibration algorithm based on satellite common view technology to process and analyze the data. The server generates a detailed calibration report, including key information such as error comparison before and after calibration, calibration time, and calibration results.

[0079] Expected effect: Through the application of this embodiment, the accuracy of electric energy measurement of AC charging piles has been significantly improved. The remote calibration method not only reduces the manpower and logistics costs of on-site calibration, but also avoids additional errors that may be introduced during transportation. At the same time, the integrated application of the error self-diagnosis module and the reference signal calibration module ensures the stability and reliability of the charging pile during long-term use.

[0080] Therefore, it can be seen from the above that the present invention realizes real-time monitoring and high-precision calibration of errors in the electric energy metering process by integrating the error self-diagnosis module and the reference signal calibration module. This design reduces the error accumulation caused by environmental factors and equipment aging, and ensures the high precision and stability of the calibration process by adopting a remote calibration method based on satellite common view technology, thereby improving the accuracy of electric energy metering. Compared with the traditional electric energy calibration method, the present invention does not need to transport the calibrated equipment to a laboratory or calibration center, which greatly saves time and transportation costs and reduces risks. Especially for equipment in large or remote areas, the advantages of remote calibration are more significant, shortening the calibration cycle, speeding up the speed of equipment commissioning, reducing manual intervention through automated and intelligent calibration processes, and improving calibration efficiency. At the same time, the real-time monitoring function of the error self-diagnosis module ensures that the equipment can be calibrated at any time during operation, ensuring the real-time accuracy of the measurement results.

[0081] In addition, the error self-diagnosis module and the reference signal calibration module of the present invention can ensure the long-term stability and consistency of the measurement results. The proposal and implementation of the present invention promote the application of remote calibration technology in the field of electric energy measurement.

[0082] When using the AC power remote calibration solution, special attention should be paid to several key aspects to ensure the accuracy and reliability of the calibration. First, the accuracy and stability of the reference signal are the core of the calibration process. Since the reference signal is used as the reference point for calibration, any slight deviation may cause significant errors in the entire calibration system. Therefore, the reference signal source must be calibrated regularly and its stability must be continuously monitored to ensure the accuracy of remote calibration.

[0083] Secondly, the installation location and method of the equipment have a direct impact on the calibration results. When installing the error self-diagnosis module and the reference signal calibration module, the influence of environmental factors during the installation process must be avoided. In particular, the installation of the reference signal module requires full consideration of factors such as electromagnetic interference and ambient temperature changes to ensure the purity and stability of the signal. Therefore, during use, it is necessary to monitor the temperature and humidity of the calibration environment in real time to maintain the stability of the environment to reduce interference with the calibration results.

[0084] Real-time monitoring and maintenance of the system is also the key to ensure the accuracy of calibration data. During the calibration process, it is necessary to regularly check the working status of the error self-diagnosis module to ensure that it can detect and correct errors in a timely manner. At the same time, the reference signal calibration module also needs to be calibrated and maintained regularly to ensure its long-term stability and accuracy, thereby ensuring accurate and correct energy measurement.

[0085] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0086] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for remote calibration of electric energy of an AC charging pile, characterized in that: include: Constructing a calibration system; the calibration system includes a field end and a laboratory; the field end includes an error self-diagnosis module and a reference signal calibration module connected in sequence; The reference signal calibration module is also connected to the laboratory via wireless communication; The error self-diagnosis module is used to perform error calculation and electrical parameter calculation on the collected signal to obtain the monitoring error in the electrical parameter data and calibration signal processing flow, and the reference signal calibration module is used to determine the error source and determine the fault repair plan during calibration; The collected signals include a load signal and a reference signal of a reference signal source; The reference signal source includes a DC reference signal source and an AC reference signal source; Based on the fault repair solution, the laboratory is used to remotely calibrate the power of the AC charging pile.

2. The AC charging pile electric energy remote calibration method according to claim 1, characterized in that: The operation process of the error self-diagnosis module is as follows: using a sampling circuit to collect the load signal and the reference signal of the reference signal source, and superimposing the signals according to Thevenin theorem and Norton theorem 4, and then using an analog-to-digital conversion module to separate the signals, the first branch to calculate the electrical parameters, and the second branch to calculate the online errors.

3. The AC charging pile electric energy remote calibration method according to claim 2, characterized in that: The sampling circuit is composed of a voltage divider and a current divider.

4. The AC charging pile electric energy remote calibration method according to claim 1, characterized in that: The expression for the error calculation is: Among them, C 监测误差 is the self-diagnosis function monitoring error, %; U 基准电压额定值 is the initial parameter after calibration; U 基准电压还原值 It is a real-time parameter for error self-diagnosis.

5. The AC charging pile electric energy remote calibration method according to claim 1, characterized in that: The operation process of the reference signal calibration module is as follows: the AC reference voltage of the reference signal source is biased and alternately passed through the voltage-frequency conversion module with the DC reference voltage to convert it into a corresponding frequency signal, and the frequency counter determines the time interval signal and the pulse signal corresponding to the frequency signal, and finally transmits the time interval signal and the pulse signal to the laboratory via wireless communication for calibration; wherein, the voltage-frequency conversion module includes a main voltage-frequency conversion module and a standby voltage-frequency conversion module, and the on and off of the main voltage-frequency conversion module and the standby voltage-frequency conversion module are controlled by a programmable switch.

6. The AC charging pile electric energy remote calibration method according to claim 5, characterized in that: During the alternating conversion by the voltage-frequency conversion module, a fault is determined based on the data performance, and a fault repair solution during the calibration is determined to be to enable a spare voltage-frequency converter or to recommend replacement of the electric meter.

7. The AC charging pile electric energy remote calibration method according to claim 6, characterized in that: The process of fault judgment is as follows: When the voltage-frequency conversion module adopts the main voltage-frequency conversion module, the DC reference signal before conversion is set to U1, the AC reference signal is set to U2, the DC frequency signal after conversion is set to f1, the AC frequency signal is set to f2, and the voltage-frequency conversion of the main circuit is set to k1; If the f1 data is normal and the f2 data has an error, it is determined that the AC reference signal U2 has an error; If the f1 data has an error and the f2 data is normal, it is determined that the DC reference signal U1 has an error; If both f1 and f2 data have errors, but It is judged that there is an error in the voltage-frequency conversion k1; If both f1 and f2 data have errors, and Then there is an error in k1, U1 or k1, U2 or U1, U2 or k1, U1, U2, and the location of the error cannot be determined. At this time, the voltage-frequency conversion module is replaced with a spare voltage-frequency converter, and the converted DC frequency signal is set to f3, the AC frequency signal is set to f4, and the spare voltage-frequency converter is set to k2; If the f3 data is normal and the f4 data has an error, it is determined that there is an error in the voltage-frequency conversion k1 and the AC reference signal U2; If the f4 data is normal and the f3 data has an error, it is determined that there is an error in the voltage-frequency conversion k1 and the DC reference signal U1; If both f3 and f4 data have errors, but It is determined that errors occur in the DC reference signal U1 and the AC reference signal U2; If both f3 and f4 data have errors, and It is judged that errors occur in the voltage-frequency conversion k1, the DC reference signal U1, and the AC reference signal U2. If k2 is also unreliable, it may be that errors occur in k2, U1, and U2, or in k1, k2, U1, and U2. In this case, it is recommended to replace the meter.

8. The AC charging pile electric energy remote calibration method according to claim 5, characterized in that: The operation process in the laboratory is: use the time interval counter and pulse counter in the frequency counter to trace the standard source at the laboratory end, calculate the voltage difference, and bring it into the voltage deviation formula for calculation.

9. The AC charging pile electric energy remote calibration method according to claim 8, characterized in that: The voltage deviation formula is: Among them, △t l and △t r are the differences between the adjacent time intervals at the laboratory end and the field end, f l and f r are the frequency values ​​after voltage-frequency conversion at the laboratory end and the field end, respectively, p is the frequency of the satellite synchronization clock source, K l is the conversion factor of the voltage-to-frequency converter at the laboratory end, N l and N r are the number of pulses per unit time at the laboratory end and the field end respectively.

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