Smart power meter

Abstract

The application relates to an intelligent power meter which comprises a core module, a first communication module and a second communication module. The core module is in local communication with a photovoltaic grid-connected inverter, the core module is in remote communication with a SEMS platform, the core module is used for bidirectional metering of electric parameters of a photovoltaic grid-connected system, judging whether local communication between the core module and the photovoltaic grid-connected inverter is normal, receiving electric parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter and uploading the electric parameters to the SEMS platform to realize remote load monitoring, and uploading the metered electric parameters of the photovoltaic grid-connected system to the SEMS platform to realize remote load monitoring; the first communication module is used for realizing local communication between the core module and the photovoltaic grid-connected inverter; and the second communication module is used for realizing remote communication between the core module and the SEMS platform. The application is suitable for a photovoltaic grid-connected end, cooperates with the photovoltaic grid-connected inverter to realize multiple functions such as energy consumption analysis, remote load monitoring and anti-backflow, can realize household use and industrial and commercial use, and has scalability.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, specifically relating to a smart power meter for buying and selling electricity that can be used at the photovoltaic grid-connected end for remote load monitoring and local anti-reverse current. Background Technology

[0002] As photovoltaic inverter manufacturers vigorously promote the application of various photovoltaic application scenario solutions (residential, commercial and industrial, ground-mounted power stations), the ability to design a smart meter that meets the requirements of photovoltaic application scenarios is particularly important.

[0003] In the implementation of specific projects, most photovoltaic inverter manufacturers rely on products from traditional power meter manufacturers. These traditional power meter manufacturers typically design meters that lack electricity metering capabilities and cannot effectively cooperate with grid-connected inverters for effective energy consumption analysis on both the user and grid sides. Specifically, this includes the following aspects:

[0004] Traditional power meters do not have the function of judging whether the local communication with the grid-connected inverter is normal. Therefore, when performing remote load monitoring, they cannot effectively inform the SEMS platform whether the local communication is normal.

[0005] Traditional electricity meters typically rely on grid-connected inverters for remote load monitoring. However, this can lead to local communication failures. In such cases, the grid-connected inverter cannot successfully acquire data from the traditional electricity meter, which in turn prevents the SEMS platform from acquiring data from the grid side. Furthermore, grid-connected inverters do not operate at night, causing the SEMS platform to fail to acquire user-side electrical parameters.

[0006] Traditional power meters do not have the characteristics of being usable by both residential and industrial users;

[0007] Traditional electricity meters typically only have a maximum current of 120A and lack scalability.

[0008] In conclusion, it is very important to design a smart power meter for buying and selling electricity that can be used at the photovoltaic grid connection end for remote load monitoring and local anti-reverse current. Summary of the Invention

[0009] The purpose of this invention is to provide a multifunctional intelligent power meter suitable for photovoltaic grid-connected terminals, so as to solve the technical problems that existing intelligent power meters cannot complete bidirectional metering of electrical parameters of photovoltaic grid-connected systems and cannot realize remote load monitoring and local anti-reverse current operation.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A smart power meter is installed between a photovoltaic grid-connected inverter and the power grid in a photovoltaic grid-connected system. The photovoltaic grid-connected inverter communicates with an SEMS platform. The smart power meter includes:

[0012] The core module enables local communication with the photovoltaic grid-connected inverter and remote communication with the SEMS platform. The core module is used for bidirectional metering of the electrical parameters of the photovoltaic grid-connected system, determining whether its local communication with the photovoltaic grid-connected inverter is normal, receiving the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter when the local communication is normal, uploading the metered electrical parameters of the photovoltaic grid-connected system and / or the electrical parameters sent by the photovoltaic grid-connected inverter to the SEMS platform for remote load monitoring, and uploading the power quantity from the metered electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to implement reverse current prevention function.

[0013] The intelligent power meter also includes:

[0014] A first communication module is connected to the core module and the photovoltaic grid-connected inverter respectively, and is used to realize local communication between the core module and the photovoltaic grid-connected inverter;

[0015] The second communication module is connected to both the core module and the SEMS platform, and is used to enable remote communication between the core module and the SEMS platform.

[0016] The first communication module is a bus communication module.

[0017] The first communication module uses an RS485 bus.

[0018] The second communication module is a wireless communication module.

[0019] The method by which the core module determines whether its local communication with the photovoltaic grid-connected inverter is normal includes the following steps:

[0020] S201: Initialize the communication parameters and communication flag bits of the first communication module;

[0021] S202: Determine whether the data frame sent by the photovoltaic grid-connected inverter can be detected. If yes, execute S203; otherwise, execute S206.

[0022] S203: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter is less than the preset t1. If yes, execute S204; otherwise, execute S207.

[0023] S204: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter being less than t1 exceeds the preset t2. If yes, execute S205; otherwise, execute S207.

[0024] S205: Record the communication flag bit, which indicates whether the local communication between the core module and the photovoltaic grid-connected inverter is normal, as 1;

[0025] S206: Wait for the photovoltaic grid-connected inverter to send a data frame;

[0026] S207: Determine that the photovoltaic grid-connected inverter has not sent a data frame to the core module, and then execute S208;

[0027] S208: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter that can be detected reaches or exceeds t1 exceeds t2. If yes, execute S209; otherwise, return to S203.

[0028] S209: Record the communication flag bit, which indicates whether the local communication between the core module and the photovoltaic grid-connected inverter is normal, as 2.

[0029] t1 is preset to 2s, and t2 is preset to 1min.

[0030] The electrical parameters of the photovoltaic grid-connected system include the amount of electricity purchased and sold to the power grid.

[0031] The method for bidirectional metering of the electrical parameters of the photovoltaic grid-connected system by the core module includes the following steps:

[0032] S401: Perform segmented calibration and preset electrical parameter calculations using arithmetic sum or absolute values;

[0033] S402: Calculate electrical parameters based on electrical parameter calculation methods;

[0034] S403: Based on the results of electrical parameter calculations, identify the direction of power to determine whether to buy or sell electricity;

[0035] S404: Check whether the arithmetic sum or absolute value used in the calculation of electrical parameters is consistent with the preset value.

[0036] The method by which the core module uploads the power quantity from the electrical parameters of the photovoltaic grid-connected system it has measured to the photovoltaic grid-connected inverter so that the photovoltaic grid-connected inverter can realize the anti-reverse current function includes the following steps:

[0037] S501: The core module collects the output power of the photovoltaic grid-connected inverter, the power on the grid-connected side, and the input power on the user side through a built-in power acquisition algorithm;

[0038] S502: The collected power from the grid-connected side, the input power from the user side, and the output power of the photovoltaic grid-connected inverter are uploaded to the photovoltaic grid-connected inverter, so that the photovoltaic grid-connected inverter triggers anti-reverse current operation based on the anti-reverse current threshold percentage set internally.

[0039] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art: The present invention is applicable to the photovoltaic grid-connected end, and can effectively cooperate with the photovoltaic grid-connected inverter to realize multiple functions such as energy consumption analysis, remote load monitoring, and anti-reverse current. It can realize the characteristics of residential and industrial and commercial use, and has scalability. Attached Figure Description

[0040] Appendix Figure 1 This is a schematic diagram of a photovoltaic grid-connected system using the intelligent power meter of the present invention.

[0041] Appendix Figure 2 This is a flowchart illustrating the method of the present invention for a smart power meter to determine whether its local communication with a photovoltaic grid-connected inverter is normal.

[0042] Appendix Figure 3 This is a flowchart illustrating how the intelligent power meter of the present invention uploads the electrical parameters of the photovoltaic grid-connected system to the SEMS platform.

[0043] Appendix Figure 4 This is a flowchart of the method for metering electrical parameters of a photovoltaic grid-connected system using an intelligent power meter, as described in this invention.

[0044] Appendix Figure 5 This is a flowchart illustrating the remote load monitoring and local backflow prevention of the intelligent power meter of the present invention. Detailed Implementation

[0045] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0046] Example 1: As shown in the attached document Figure 1As shown, the photovoltaic grid-connected system includes a photovoltaic grid-connected inverter S101 and a load S102 connected to the output terminal of the photovoltaic grid-connected inverter S101. The output terminal of the photovoltaic grid-connected inverter S101 is connected to the power grid S104. The photovoltaic grid-connected inverter S101 converts the DC power from the photovoltaic panel into AC power for use by the user-side load S102. The photovoltaic grid-connected system also includes an SEMS platform S107, which is used to acquire, analyze, and store relevant power data of the photovoltaic grid-connected system. The photovoltaic grid-connected inverter S101 uploads its data to the SEMS platform S107 via a wireless communication module S109 inserted through its port S110, using a wireless transmission protocol S108, thus completing remote load detection. In addition, the photovoltaic grid-connected system also includes a smart power meter S105, which is installed at point S103 between the photovoltaic grid-connected inverter S101 and the power grid S104. The smart power meter S105 is used to measure the power of surplus electricity from the photovoltaic grid-connected inverter S101 sent to the power grid S104 and the power purchased by the user from the power grid S104. The wireless unit circuit S106 integrated on the smart power meter S105 is used for communication and wireless upgrades with the SEMS platform S107. The communication unit circuit S111 integrated on the smart power meter S105 has a logic mechanism to detect whether the photovoltaic grid-connected inverter S101 is communicating with the smart power meter S105. The data protocol frame that the smart power meter S105 uploads data to the SEMS platform S107 through the wireless unit circuit S106 contains a flag indicating whether the communication unit circuit S111 is working properly.

[0047] The specific solution for the S105 intelligent power meter is as follows:

[0048] The intelligent power meter S105 includes a core module, a first communication module, and a second communication module. The core module enables local communication with the photovoltaic grid-connected inverter S101 and remote communication with the SEMS platform S107. The core module is used for bidirectional metering of the electrical parameters of the photovoltaic grid-connected system, determining the normality of its local communication with the photovoltaic grid-connected inverter S101, receiving the electrical parameters of the photovoltaic grid-connected system sent by the inverter S101 when local communication with the inverter S101 is normal, uploading the metered electrical parameters of the photovoltaic grid-connected system and / or the electrical parameters sent by the inverter S101 to the SEMS platform S107 for remote load monitoring, and uploading the power quantity from the metered electrical parameters of the photovoltaic grid-connected system to the inverter for reverse current prevention. The electrical parameters of the photovoltaic grid-connected system include the amount of electricity purchased and sold (power) to the grid. The first communication module is connected to both the core module and the photovoltaic grid-connected inverter S101, enabling local communication between them. The second communication module is connected to both the core module and the SEMS platform S107, enabling remote communication between them. The first communication module is a bus communication module, for example, using an RS485 bus (communication unit circuit S111); the second communication module is a wireless communication module (wireless unit circuit S106).

[0049] The above scheme is applied to the photovoltaic grid-connected end. It determines daytime and nighttime by judging the success of local communication between the local power meter S105 and the photovoltaic grid-connected inverter S101. The SEMS platform S107 determines whether to use data from the grid-connected inverter S101 or the data monitored by the local power meter S105 for load monitoring. Specifically, when local communication between the local power meter S105 and the photovoltaic grid-connected inverter S101 is normal, it receives the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter S101 and uploads the electrical parameters of the photovoltaic grid-connected system obtained from its metering to the SEMS platform S107. The SEMS platform S107 then decides whether to use data from the smart power meter S105 or the photovoltaic grid-connected inverter S101. This mainly includes the following aspects:

[0050] I. This solution provides that when the photovoltaic grid-connected inverter S101 is working during the day, the intelligent power meter S105 records the electricity purchased and sold by the photovoltaic grid-connected inverter S101 to the power grid S104. In the event that the intelligent power meter S105 and the photovoltaic grid-connected inverter S101 cannot successfully establish local communication, the electrical parameter data is uploaded to the SEMS platform S107 through the wireless unit circuit S106 inside the intelligent power meter S105. At night, when the photovoltaic grid-connected inverter S101 is not working, the wireless unit circuit S106 of the intelligent power meter S105 can be used to remotely monitor the load of electricity purchased by the user side.

[0051] As attached Figure 3 As shown, the working process of the intelligent power meter S105 working with the SEMS platform S107 to achieve remote load monitoring includes the following steps:

[0052] S301: Determine whether the photovoltaic grid-connected inverter S101 is working. If the photovoltaic grid-connected inverter S101 is working, proceed to S302 for further determination. If the photovoltaic grid-connected inverter S101 is not working, proceed to S304.

[0053] S302: Determine whether the local communication between the photovoltaic grid-connected inverter S101 and the smart power meter S105 (core module) is normal (the judgment process will be explained later). If the local communication is normal, proceed to S303. If the local communication is abnormal, proceed to S304.

[0054] S303: If the photovoltaic grid-connected inverter S101 is working normally and the local communication is normal, the data uploaded by the smart power meter S105 to the SEMS platform S107 uses the data collected by the photovoltaic grid-connected inverter S101 and the data collected by the smart power meter S105.

[0055] S304: If the photovoltaic grid-connected inverter S101 is not working, or the local communication is abnormal, the data uploaded by the smart power meter S105 to the SEMS platform S107 will be the data collected by the smart power meter S105 itself.

[0056] II. As attached Figure 2 As shown, the method by which the core module of the smart power meter S105 determines whether its local communication with the photovoltaic grid-connected inverter S101 is normal includes the following steps:

[0057] S201: Initialize the communication parameters and communication flags of the first communication module. The communication parameters of the first communication module include the baud rate of the RS485 of the smart power meter S105.

[0058] S202: Determine whether the data frame sent by the photovoltaic grid-connected inverter can be detected at present. If yes, that is, the smart power meter S105 can detect the data frame sent by the photovoltaic grid-connected inverter S101 at present, then execute S203 for further judgment. If no, that is, the smart power meter S105 cannot detect the data frame sent by the photovoltaic grid-connected inverter S101 at present, then execute S206.

[0059] S203: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter is less than the preset t1. If yes, proceed to S204; otherwise, proceed to S207. In this step, t1 is preset to 2s. If the smart power meter S105 can detect that the time for the data frame sent by the photovoltaic grid-connected inverter S101 is less than 2s, then proceed to S204 for further determination. If the smart power meter S105 detects that the time for the data frame sent by the photovoltaic grid-connected inverter S101 is greater than or equal to 2s, then proceed to S207.

[0060] S204: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter that can be detected is less than t1 and exceeds the preset t2. If yes, proceed to S205; otherwise, proceed to S207. In this step, t2 is preset to 1 minute. If the smart power meter S105 can detect the data frame sent by the photovoltaic grid-connected inverter S101 within 2 seconds and the duration exceeds 1 minute, then proceed to S205. If the smart power meter S105 can detect the data frame sent by the photovoltaic grid-connected inverter S101 within 2 seconds but the duration does not exceed 1 minute, then proceed to S207.

[0061] S205: Record the communication flag bit, which indicates whether the local communication between the core module of the smart power meter S105 and the photovoltaic grid-connected inverter S101 is normal, as 1. This communication flag bit is included in the protocol frame in which the smart power meter S105 uploads data to the SEMS platform S107.

[0062] S206: If the smart power meter S105 cannot detect the data frame sent by the photovoltaic grid-connected inverter S101, then wait for the photovoltaic grid-connected inverter S101 to send the data frame.

[0063] S207: If the smart power meter S105 cannot receive the data frame sent by the photovoltaic grid-connected inverter S101 within t1, i.e. 2s, it is determined that the photovoltaic grid-connected inverter S101 has not sent the data frame to the core module, and then S208 is executed.

[0064] S208: Determine whether the duration of the data frame sent by the photovoltaic grid-connected inverter S101 reaches or exceeds t1 and the duration exceeds t2. If so, indicate that the smart power meter S105 cannot receive the data frame sent by the photovoltaic grid-connected inverter S101 within 2 seconds and the duration exceeds 1 minute. Then execute S209. Otherwise, return to S203.

[0065] S209: Record the communication flag bit, which indicates whether the local communication between the core module and the photovoltaic grid-connected inverter is normal, as 2. This communication flag bit is included in the protocol frame in which the smart power meter S105 uploads data to the SEMS platform S107.

[0066] The communication flags recorded in S205 and S209 need to be different; that is, the communication flag is recorded as x in S205 and as y in S209, and x ≠ y. Then, on the SEMS platform S107, it selects whether to use the data collected by the photovoltaic grid-connected inverter S101 or the data collected by the smart power meter S105 based on the communication flags and actual needs.

[0067] In S204, data frames sent from the photovoltaic grid-connected inverter S101 to the smart power meter S105 can be continuously acquired.

[0068] Third, this intelligent power meter S105 has an internal algorithm for calculating electricity buying and selling. Through this algorithm, accurate calculation of electricity buying and selling can be achieved.

[0069] As attached Figure 4 As shown, the method for bidirectional metering of electrical parameters of a photovoltaic grid-connected system in the core module of the intelligent power meter S105 includes the following steps:

[0070] S401: Perform accurate segmented calibration on this intelligent power meter S105 to achieve high-precision power metering, and preset the calculation of electrical parameters to use arithmetic sum or absolute value;

[0071] S402: For the electrical energy on the grid side, the effective electrical energy is calculated based on the electrical parameter calculation method, combined with the pulse constant and pulse calculator;

[0072] S403: Based on the results of electrical parameter calculations, the power quantity is identified in direction to determine whether to buy or sell electricity, and the electricity buying and selling calculations are performed using forward and reverse energy registers.

[0073] S404: When performing electricity purchase and sale calculations, check whether the result of the current electricity parameter calculation uses an arithmetic sum or absolute value, and whether it is consistent with the preset.

[0074] The method for measuring the electrical parameters of the photovoltaic grid-connected system in the core module of the S105 smart power meter can be selected and set according to the actual situation.

[0075] Fourth, this solution can perform both remote load monitoring and local anti-backflow measures.

[0076] As attached Figure 5 As shown, the implementation of this function, namely, the method by which the core module uploads the power quantity from the electrical parameters of the photovoltaic grid-connected system obtained by its metering to the photovoltaic grid-connected inverter so that the photovoltaic grid-connected inverter can realize the anti-reverse current function, includes the following steps:

[0077] S501: This intelligent power meter S105 adopts... Figure 4 The logic enables high-precision detection of electricity buying and selling. At the same time, the core module collects the output power of the photovoltaic grid-connected inverter S101, the power on the grid-connected side, and the input power on the user side through the built-in power acquisition algorithm.

[0078] S502: The core module of this smart power meter S105 will collect high-precision power from the grid-connected side, input power from the user side, and output power from the photovoltaic grid-connected inverter S101 and upload them to the photovoltaic grid-connected inverter S101, so that the photovoltaic grid-connected inverter S101 will trigger anti-reverse current operation based on the anti-reverse current threshold percentage set internally.

[0079] S503: See the logic for remote load monitoring. Figure 2 .

[0080] As can be seen from the above technical solutions, a smart power meter S105 for buying and selling electricity, which can perform remote load monitoring and local reverse current prevention at the photovoltaic grid-connected end, can perform both remote load monitoring and local reverse current prevention. It can effectively achieve accurate remote load monitoring based on whether the local communication between the photovoltaic grid-connected inverter S101 and the smart power meter S105 is normal, and when the photovoltaic grid-connected inverter S101 is not working at night. Furthermore, it can achieve reverse current prevention operation by using the high-precision power acquisition algorithm used inside the smart power meter S105 to detect the high-precision power on the grid-connected side, the high-precision power on the user side, the output power of the photovoltaic grid-connected inverter S101, and the reverse current prevention threshold percentage set inside the photovoltaic grid-connected inverter S101. In addition, this intelligent power meter S105 can also perform effective power calculation on the grid side by combining pulse constant and pulse counter. It can also perform direction recognition by judging the power direction and perform buying and selling calculations by forward and reverse power registers. When performing buying and selling calculations, it checks whether the current calculation of buying and selling power is using arithmetic sum or absolute value.

[0081] In summary, the present invention can solve the following technical problems:

[0082] It can be effectively used in conjunction with the S101 photovoltaic grid-connected inverter to perform effective energy consumption analysis on the grid side, user side, and inverter side.

[0083] It can determine whether the local communication with the photovoltaic grid-connected inverter S101 is normal, so that even if the local communication is not normal, it can still effectively perform remote load monitoring and inform the SEMS platform S107 of the relevant electrical parameter data on the grid side.

[0084] Since the power accuracy of the photovoltaic grid-connected inverter S101 data is not very high, the output power of the photovoltaic grid-connected inverter S101 can be detected with higher accuracy through this electric power trading smart meter S105 and the current transformer installed at the grid-connected inverter end, making the reverse current prevention more accurate.

[0085] Even at night, when the photovoltaic grid-connected inverter S101 is not working, it can still successfully perform effective remote load monitoring of grid-side data;

[0086] The S105 smart power meter can be used by both residential and commercial users, and is scalable. This solution has great commercial value.

[0087] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An intelligent power meter, which is arranged between a photovoltaic grid-connected inverter and a power grid in a photovoltaic grid-connected system, wherein the photovoltaic grid-connected inverter communicates with a SEMS platform, characterized in that: The intelligent electric power meter comprises: a core module, which can realize local communication with the photovoltaic grid-connected inverter and can realize remote communication with the SEMS platform, is used for bidirectional metering of electric parameters of the photovoltaic grid-connected system, judging whether the local communication between the core module and the photovoltaic grid-connected inverter is normal, receiving the electric parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter when the local communication between the core module and the photovoltaic grid-connected inverter is normal, uploading the electric parameters of the photovoltaic grid-connected system obtained by metering and / or the electric parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter to the SEMS platform to realize remote load monitoring, and uploading the power amount in the electric parameters of the photovoltaic grid-connected system obtained by metering to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-backflow function; If it is judged that the photovoltaic grid-connected inverter is working normally and the local communication between the photovoltaic grid-connected inverter and the intelligent electric power meter is normal, the data uploaded by the intelligent electric power meter to the SEMS platform adopts the data collected by the photovoltaic grid-connected inverter and the data collected by the intelligent electric power meter. If it is judged that the photovoltaic grid-connected inverter is not working or the local communication between the photovoltaic grid-connected inverter and the intelligent electric power meter is not normal, the data uploaded by the intelligent electric power meter to the SEMS platform adopts the data collected by the intelligent electric power meter itself.

2. The intelligent power meter of claim 1, wherein: The intelligent electric power meter further comprises: a first communication module, which is connected with the core module and the photovoltaic grid-connected inverter respectively and is used for realizing the local communication between the core module and the photovoltaic grid-connected inverter; a second communication module, which is connected with the core module and the SEMS platform respectively and is used for realizing the remote communication between the core module and the SEMS platform.

3. The intelligent power meter of claim 2, wherein: The first communication module is a bus communication module.

4. The intelligent power meter of claim 3, wherein: The first communication module adopts RS485 bus.

5. The intelligent power meter of claim 2, wherein: The second communication module is a wireless communication module.

6. The intelligent power meter of claim 2, wherein: The method for the core module to judge whether the local communication between the core module and the photovoltaic grid-connected inverter is normal comprises the following steps: S201: initializing the communication parameters and the communication flag bit of the first communication module; S202: judging whether the data frame issued by the photovoltaic grid-connected inverter is currently detected, if yes, executing S203, and if not, executing S206; S203: judging whether the duration that the data frame issued by the photovoltaic grid-connected inverter can be detected is less than a preset t1, if yes, executing S204, and if not, executing S207; S204: judging whether the duration that the duration that the data frame issued by the photovoltaic grid-connected inverter can be detected is less than t1 exceeds a preset t2, if yes, executing S205, and if not, executing S207; S205: recording the communication flag bit used for representing whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as 1; S206: waiting for the photovoltaic grid-connected inverter to issue a data frame; S207: determining whether the photovoltaic grid-connected inverter has not issued a data frame to the core module, and then performing S208; S208: determining whether the duration of the photovoltaic grid-connected inverter issuing a data frame is longer than t2 if the duration reaches or exceeds t1, and if so, performing S209, and if not, returning to S203; S209: recording a communication flag bit indicating whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as 2.

7. The intelligent power meter of claim 6, wherein: t1 is preset as 2s, and t2 is preset as 1min.

8. The intelligent power meter of claim 1, wherein: The electrical parameters of the photovoltaic grid-connected system include the electricity buying and selling amounts between the photovoltaic grid-connected system and the power grid.

9. The intelligent power meter of claim 1, wherein: The method for the core module to bidirectionally measure the electrical parameters of the photovoltaic grid-connected system includes the following steps: S401: performing segmented calibration and presetting the arithmetic sum or absolute value for electrical parameter calculation; S402: performing electrical parameter calculation based on the electrical parameter calculation method; S403: identifying the direction of power based on the result of electrical parameter calculation, and determining whether the electricity is bought or sold; S404: checking whether the arithmetic sum or absolute value used in the result of electrical parameter calculation is consistent with the preset value.

10. The intelligent power meter of claim 1, wherein: The method for the core module to upload the power amount in the electrical parameters of the photovoltaic grid-connected system measured by the core module to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-reverse flow function includes the following steps: S501: the core module collects the output power of the photovoltaic grid-connected inverter, the power on the grid side, and the input power on the user side through the built-in power collection algorithm; S502: uploading the collected power on the grid side, the input power on the user side, and the output power of the photovoltaic grid-connected inverter to the photovoltaic grid-connected inverter, so that the photovoltaic grid-connected inverter triggers the anti-reverse flow operation based on the internally set anti-reverse flow threshold percentage.

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