WO2023109882A1 - Smart power meter - Google Patents

Abstract

The present invention relates to a smart power meter, which comprises a core module, a first communication module and a second communication module. The core module locally communicates with a photovoltaic grid-connected inverter, the core module remotely communicates with an SEMS platform, and the core module is used for bidirectionally metering electric parameters of a photovoltaic grid-connected system, determining 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, which are sent by the photovoltaic grid-connected inverter, and uploading the electric parameters to the SEMS platform, so as to realize remote load monitoring. The first communication module is used for realizing the local communication between the core module and the photovoltaic grid-connected inverter; and the second communication module is used for realizing the remote communication between the core module and the SEMS platform. The present invention is applicable to a photovoltaic grid-connected end, and realizes, in combination with a photovoltaic grid-connected inverter, various functions such as energy consumption analysis, remote load monitoring and backflow prevention; and the present invention can realize household use and commercial use characteristics and has expandability.

Description

Smart Power Meter technical field

The invention belongs to the technical field of power electronics, and in particular relates to an intelligent power meter for buying and selling electricity that can be used at a photovoltaic grid-connected end for remote load monitoring and local backflow prevention.

Background technique

With the implementation of the development policy of carbon peaking and carbon neutrality vigorously promoted by the country, and the application of various photovoltaic application scenario solutions (household, industrial and commercial, ground power station) vigorously promoted by various photovoltaic inverter manufacturers, it is possible to design a It is particularly important to find a smart meter that is suitable for photovoltaic application scenarios.

In the implementation of specific projects, most of the photovoltaic inverter manufacturers will rely on the products of traditional power meter manufacturers. The meters designed by these traditional power meter manufacturers usually do not have the function of buying and selling electricity, and cannot effectively cooperate with the grid-connected inverter to carry out effective user-side and grid-side energy consumption analysis, specifically including the following aspects:

The traditional power meter does not have the function of judging whether the local communication with the grid-connected inverter is normal, so when performing remote load monitoring, it cannot effectively inform the SEMS platform whether the local communication is normal;

Traditional power meters usually use grid-connected inverters for remote load monitoring, but there will be abnormal local communication. At this time, grid-connected inverters cannot successfully obtain data from traditional power meters, resulting in SEMS The platform cannot obtain the data on the grid side; in addition, the grid-connected inverter does not work at night, so the SEMS platform cannot successfully obtain the electrical parameters on the user side;

Traditional power meters do not have the characteristics of household use and industrial and commercial use;

The maximum current of traditional electric meters is usually only 120A, which is not scalable.

To sum up, it is very important to design 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 backflow prevention.

Contents of the invention

The purpose of the present invention is to provide a multi-functional electric smart power meter suitable for photovoltaic grid-connected terminals, so as to solve the problem that existing smart power meters cannot complete two-way measurement of electrical parameters of photovoltaic grid-connected systems and cannot realize remote load monitoring and local anti-backflow operation technical problems.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A smart power meter is arranged between a photovoltaic grid-connected inverter and a power grid in a photovoltaic grid-connected system, the photovoltaic grid-connected inverter communicates with a SEMS platform, and the smart power meter includes:

A core module, local communication can be realized between the core module and the photovoltaic grid-connected inverter, remote communication can be realized between the core module and the SEMS platform, and the core module is used for two-way metering of the photovoltaic Electric parameters of the grid-connected system, judging whether the local communication with the photovoltaic grid-connected inverter is normal, and receiving the photovoltaic grid-connected inverter when the local communication with the photovoltaic grid-connected inverter is normal The electrical parameters of the photovoltaic grid-connected system sent by the inverter, the electrical parameters of the photovoltaic grid-connected system obtained by uploading its measurement and/or the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter parameters to the SEMS platform to realize remote load monitoring, and upload the measured power amount in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize Anti-backflow function.

The smart power meter also includes:

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

A second communication module, the second communication module is respectively connected to the core module and the SEMS platform, and is used to realize remote communication between the core module and the SEMS platform.

The first communication module is a bus communication module.

The first communication module adopts RS485 bus.

The second communication module is a wireless communication module.

The method for the core module to judge whether the local communication between it and the photovoltaic grid-connected inverter is normal includes the following steps:

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

S202: Judging whether the data frame sent by the photovoltaic grid-connected inverter can be detected at present, if so, execute S203, and if not, execute S206;

S203: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the preset first duration threshold t1, if so, execute S204, and if not, execute S207;

S204: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the first duration threshold t1 and whether the duration exceeds the preset second duration threshold t2, if yes, execute S205, otherwise execute S207;

S205: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is normal;

S206: Waiting for the photovoltaic grid-connected inverter to send a data frame;

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

S208: Determine whether it can be detected that the duration of the data frame sent by the photovoltaic grid-connected inverter reaches or exceeds the first duration threshold t1 and exceeds the second duration threshold t2, if yes, perform S209, otherwise Return to S203;

S209: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is abnormal.

The first duration threshold t1 is preset as 2s, and the second duration threshold t2 is preset as 1min.

In the S205, record the communication flag bit as x, in the S209, record the communication flag bit as y, and x≠y.

The electrical parameters of the photovoltaic grid-connected system include the electricity purchased and sold with the grid.

The method for bidirectionally measuring the electrical parameters of the photovoltaic grid-connected system by the core module includes the following steps:

S401: Carry out subsection calibration and preset electric parameter calculation using arithmetic sum or absolute value;

S402: Perform electrical parameter calculation based on the electrical parameter calculation method;

S403: Identify the direction of the power amount according to the result of the electric parameter calculation, and determine whether to buy or sell electricity;

S404: Check whether the arithmetic sum or absolute value adopted in the result of electric parameter calculation is consistent with the preset.

The method that the core module uploads the metered power in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-backflow function includes the following steps :

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 collection algorithm;

S502: Upload the collected grid-connected power, user-side input power, and output power of the photovoltaic grid-connected inverter to the photovoltaic grid-connected inverter, so that the photovoltaic grid-connected inverter is based on its internal settings The anti-reflux threshold percentage triggers the anti-reflux operation.

The working process of the smart power meter cooperating with the SEMS platform to realize remote load monitoring includes the following steps:

S301: Determine whether the photovoltaic grid-connected inverter is working, if the photovoltaic grid-connected inverter is working, execute S302 for further judgment, and if the photovoltaic grid-connected inverter is not working, execute S304;

S302: Determine whether the local communication between the photovoltaic grid-connected inverter and the smart power meter is normal, if the local communication is normal, execute S303, and if the local communication is abnormal, execute S304;

S303: If the photovoltaic grid-connected inverter works normally and the local communication is normal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the photovoltaic grid-connected inverter and The smart electric meter collects data;

S304: If the photovoltaic grid-connected inverter is not working, or the local communication is abnormal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the smart power meter itself.

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 photovoltaic grid-connected terminals, and can effectively cooperate with photovoltaic grid-connected inverters to realize energy consumption analysis, remote load monitoring, anti-backflow, etc. This function can realize the characteristics of household use, industry and commerce, and has scalability.

Description of drawings

Figure 1 is a schematic diagram of a photovoltaic grid-connected system applying the smart power meter of the present invention.

Figure 2 is a flow chart of the method for judging whether the local communication between the smart power meter and the photovoltaic grid-connected inverter is normal according to the present invention.

Accompanying drawing 3 is the flowchart of uploading the electrical parameters of the photovoltaic grid-connected system to the SEMS platform by the smart power meter of the present invention.

Accompanying drawing 4 is the flowchart of the method for measuring the electrical parameters of the photovoltaic grid-connected system by the smart electric meter of the present invention.

Accompanying drawing 5 is the flow chart of remote load monitoring and local anti-backflow by the intelligent power meter of the present invention.

Detailed ways

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

Embodiment 1: As shown in Figure 1, the photovoltaic grid-connected system includes a photovoltaic grid-connected inverter S101, a load S102 connected to the output terminal of the photovoltaic grid-connected inverter S101, and the output of the photovoltaic grid-connected inverter S101 connected to the power grid S104. The photovoltaic grid-connected inverter S101 is used to convert the direct current of the photovoltaic panel into alternating current for use by the user-side load S102. The photovoltaic grid-connected system is also equipped with a SEMS platform S107, which is used to acquire, analyze and store relevant electric energy data of the photovoltaic grid-connected system. The photovoltaic grid-connected inverter S101 is inserted into the wireless communication module S109 through its port S110 to connect it The data is uploaded to the SEMS platform 107 through the wireless transmission protocol S108 to complete the remote load detection. On this basis, the photovoltaic grid-connected system further includes a smart power meter S105, which is arranged at the installation point S103 between the photovoltaic grid-connected inverter S101 and the grid S104. The smart power meter S105 is used to measure the power of the photovoltaic grid-connected inverter S101 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 to communicate with the SEMS The platform S107 performs communication and wireless upgrades. The communication unit circuit S111 integrated on the smart power meter S105 can detect whether the current photovoltaic grid-connected inverter S101 communicates with the smart power meter S105. The smart power meter S105 uses the wireless unit circuit S106 The data protocol frame of uploading data to the SEMS platform S107 includes a flag indicating whether the communication of the communication unit circuit S111 is normal or not.

The specific scheme of the smart power meter S105 is as follows:

The smart power meter S105 includes a core module, a first communication module, and a second communication module. Local communication can be realized between the core module and the photovoltaic grid-connected inverter S101, and remote communication can be realized between the core module and the SEMS platform S107. The core module is used to bidirectionally measure the electrical parameters of the photovoltaic grid-connected system, judge whether the local communication with the photovoltaic grid-connected inverter S101 is normal, and receive when the local communication with the photovoltaic grid-connected inverter S101 is normal. The electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter S101, upload the measured electrical parameters of the photovoltaic grid-connected system and/or the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter S101 to SEMS The platform S107 realizes remote load monitoring and uploads the measured power in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-backflow function. Among them, the electrical parameters of the photovoltaic grid-connected system include the electricity purchased and sold (power) with the grid. The first communication module is respectively connected with the core module and the photovoltaic grid-connected inverter S101, and is used to realize local communication between the core module and the photovoltaic grid-connected inverter S101. The second communication module is respectively connected with the core module and the SEMS platform S107, and is used to realize remote communication between the core module and the SEMS platform S107. Wherein, the first communication module is a bus communication module, for example, the first communication module adopts RS485 bus, that is, the communication unit circuit S111; the second communication module is a wireless communication module, that is, the wireless unit circuit S106.

The above scheme is used at the photovoltaic grid-connected end. By judging whether the local communication between the smart power meter S105 and the photovoltaic grid-connected inverter S101 is successful, the day and night are determined. Is it the data of the grid-connected inverter S101 or the data monitored by the smart power meter S105 of this business. That is, when the local communication between it 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 measured electrical parameters of the photovoltaic grid-connected system to SEMS The platform S107, so that the SEMS platform S107 decides whether to use the data of the smart power meter S105 or the data of the photovoltaic grid-connected inverter S101. It mainly includes the following aspects:

1. This solution provides that when the photovoltaic grid-connected inverter S101 is working during the day, the smart power meter S105 records the electricity sold and sold by the photovoltaic grid-connected inverter S101 to the grid S104, and the smart power meter S105 is connected to the photovoltaic grid. In the case that the inverter S101 cannot successfully communicate locally, the electrical parameter data can be uploaded to the SEMS platform S107 through the wireless unit circuit S106 inside the smart power meter S105, or at night, the photovoltaic grid-connected inverter S101 is not working state, through the wireless unit circuit S106 of the smart power meter S105, remote load monitoring can be performed on the electricity purchased at the user side.

As shown in Figure 3, the working process of the smart power meter S105 working with the SEMS platform S107 to realize remote load monitoring includes the following steps:

S301: Determine whether the photovoltaic grid-connected inverter S101 is working, if the photovoltaic grid-connected inverter S101 is working, execute S302 for further judgment, and if the photovoltaic grid-connected inverter S101 is not working, execute S304;

S302: Determine whether the local communication between the photovoltaic grid-connected inverter S101 and the smart power meter S105 (core module) is normal (the determination process will be explained later), if the local communication is normal, execute S303, if the local communication is abnormal (abnormal) , execute S304;

S303: If the photovoltaic grid-connected inverter S101 works 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 smart power meter S105 collects the data;

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 is the data collected by the smart power meter S105 itself.

2. As shown in Figure 2, the method for the core module of the smart power meter S105 to judge whether the local communication with the photovoltaic grid-connected inverter S101 is normal includes the following steps:

S201: Initialize the communication parameters and communication flags of the first communication module, where the communication parameters of the first communication module include the baud rate of RS485 of the smart power meter S105;

S202: Determine whether the data frame issued by the photovoltaic grid-connected inverter can be detected at present, if so, that is, the smart power meter S105 can currently detect the data frame issued by the photovoltaic grid-connected inverter S101, then execute S203 for further judgment , if no, that is, the smart power meter S105 cannot currently detect the data frame sent by the photovoltaic grid-connected inverter S101, then execute S206;

S203: Judging whether it can be detected that the duration of the data frame sent by the photovoltaic grid-connected inverter is less than the preset first duration threshold t1, if so, execute S204, otherwise execute S207; in this step, the first duration threshold t1 is preset 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 execute S204 to further judge, if the smart power meter S105 detects that the photovoltaic grid-connected If the time of the data frame is greater than or equal to 2s, execute S207;

S204: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the first duration threshold t1 and the duration exceeds the preset second duration threshold t2, if so, execute S205, and if not, execute S207; this step , the second duration threshold t2 is preset as 1min, if the smart power meter S105 can detect the data frame issued by the photovoltaic grid-connected inverter S101 within 2s, and the duration exceeds 1min, then execute S205, if the smart power The instrument S105 can detect the data frame sent by the photovoltaic grid-connected inverter S101 within 2s, but the duration does not exceed 1min, then execute S207;

S205: Record the communication flag used to indicate whether the local communication between the core module of the smart power meter S105 and the photovoltaic grid-connected inverter S101 is normal as a flag indicating that the local communication is normal, which is recorded as 1 in this embodiment. The communication flag is included in the protocol frame after the smart power meter S105 uploads data to the SEMS platform S107;

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

S207: If the smart power meter S105 cannot receive the data frame sent by the photovoltaic grid-connected inverter S101 within the first duration threshold t1, that is, within 2s, it is determined that the photovoltaic grid-connected inverter S101 has not sent the data frame to the core module , and then perform S208;

S208: Judging whether it can be detected that the duration of the data frame sent by the photovoltaic grid-connected inverter S101 reaches or exceeds the first duration threshold t1 and the duration exceeds the second duration threshold t2, and if so, it is marked that the smart power meter S105 cannot receive it within 2s When the data frame sent by the photovoltaic grid-connected inverter S101 lasts for more than 1 minute, execute S209, otherwise return to S203;

S209: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is abnormal, which is recorded as 2 in this embodiment, and the communication flag is included in Afterwards, the smart power meter S105 uploads data to the protocol frame of the SEMS platform S107.

The communication flag recorded in S205 and S209 may be different, that is, the communication flag is recorded as x in S205, and the communication flag is recorded as y in S209, and x≠y. On the SEMS platform S107 side, it chooses to use the data collected by the photovoltaic grid-connected inverter S101 or the data collected by the smart power meter S105 according to the communication flag and actual needs.

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

3. The smart power meter S105 adds an algorithm for buying and selling electricity calculations. Through this algorithm, accurate electricity buying and selling calculations can be realized.

As shown in Figure 4, the method for bidirectionally measuring the electrical parameters of the photovoltaic grid-connected system by the core module in the smart power meter S105 includes the following steps:

S401: Carry out accurate segmental calibration on the smart power meter S105 to achieve high-precision electric energy measurement, and preset electric parameter calculation to use arithmetic sum or absolute value;

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

S403: Identify the direction of the power amount according to the result of the electric parameter calculation, determine whether to buy or sell electricity, and use the forward and reverse electric energy registers to calculate the buying and selling of electricity;

S404: When performing electricity buying and selling calculations, check whether the calculation results of the current electrical parameters use arithmetic sums or absolute values, and whether they are consistent with presets.

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

4. This scheme can not only carry out remote load monitoring, but also carry out local anti-backflow.

As shown in Figure 5, the realization of this function is that the core module uploads the measured power in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-backflow function The method includes the following steps:

S501: The smart power meter S105 can realize high-precision electricity buying and selling detection due to the use of the logic in Figure 4. At the same time, the core module collects the output power of the photovoltaic grid-connected inverter S101, the power of the grid-connected side input power;

S502: The core module of the smart power meter S105 uploads the collected high-precision grid-connected power, user-side input power, and output power of the photovoltaic grid-connected inverter S101 to the photovoltaic grid-connected inverter S101, so that the photovoltaic The grid-connected inverter S101 triggers the anti-backflow operation based on its internally set anti-backflow threshold percentage;

S503: See Figure 2 for the logic of remote load monitoring.

From the above technical solutions, it can be seen that a smart power meter S105 for buying and selling electricity that can perform remote load monitoring and local backflow prevention at the photovoltaic grid-connected end can perform both remote load monitoring and local backflow prevention, and can be effectively based on Whether the local communication between the photovoltaic grid-connected inverter S101 and the smart power meter S105 is normal or not, and when the photovoltaic grid-connected inverter S101 is not working at night, realize accurate remote load monitoring; and, by using the smart power meter The high-precision power acquisition algorithm used inside the S105 detects the high-precision power on the grid-connected side, the high-precision power on the user side, and the output power of the photovoltaic grid-connected inverter S101, as well as the photovoltaic grid-connected inverter The anti-backflow threshold percentage set inside the device S101 is used to realize the anti-backflow operation. In addition, the smart power meter S105 can also perform effective power calculations on the power grid side, combined with pulse constants and pulse counters, by judging the power direction, performing direction identification, and performing power calculations on the forward and reverse power registers. When calculating buying and selling electricity, check whether the current calculation of buying and selling electricity uses an arithmetic sum or an absolute value.

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

It can effectively cooperate with the photovoltaic grid-connected inverter S101 to conduct effective energy consumption analysis on the grid side, user side and inverter side;

It can judge by itself whether the local communication with the photovoltaic grid-connected inverter S101 is normal, so that when performing remote load monitoring, even if the local communication is not normal, the remote load monitoring can be effectively carried out, and the SEMS platform S107 can be notified of the relevant electricity on the grid side. parameter data;

Since the power accuracy of the photovoltaic grid-connected inverter S101 data is not too high, the smart power meter S105 and the current transformer installed at the grid-connected inverter end can detect the photovoltaic grid-connected inverter with higher precision. The output power of the device S101 makes the anti-backflow more accurate;

At night, when the photovoltaic grid-connected inverter S101 is not working, it can also successfully carry out effective remote load monitoring on the data on the grid side;

The smart power meter S105 for buying and selling electricity can realize the characteristics of household use, industry and commerce, and has scalability. This solution has very good commercial value.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (14)

A smart power meter is arranged between a photovoltaic grid-connected inverter and a power grid in a photovoltaic grid-connected system, and the photovoltaic grid-connected inverter communicates with an SEMS platform, wherein the smart power meter includes: A core module, local communication can be realized between the core module and the photovoltaic grid-connected inverter, remote communication can be realized between the core module and the SEMS platform, and the core module is used for two-way metering of the photovoltaic Electric parameters of the grid-connected system, judging whether the local communication with the photovoltaic grid-connected inverter is normal, and receiving the photovoltaic grid-connected inverter when the local communication with the photovoltaic grid-connected inverter is normal The electrical parameters of the photovoltaic grid-connected system sent by the inverter, the electrical parameters of the photovoltaic grid-connected system obtained by uploading its measurement and/or the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter parameters to the SEMS platform to realize remote load monitoring, and upload the measured power amount in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize Anti-backflow function; A first communication module, the first communication module is respectively connected with the core module and the photovoltaic grid-connected inverter, and is used to realize local communication between the core module and the photovoltaic grid-connected inverter ; The first communication module is a bus communication module; The second communication module, the second communication module is connected with the core module and the SEMS platform respectively, and is used to realize the remote communication between the core module and the SEMS platform; the second communication module is wireless communication module; The method for the core module to judge whether the local communication between it and the photovoltaic grid-connected inverter is normal includes the following steps: S201: Initialize communication parameters and communication flag bits of the first communication module; S202: Judging whether the data frame sent by the photovoltaic grid-connected inverter can be detected at present, if so, execute S203, and if not, execute S206; S203: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the preset first duration threshold t1, if so, execute S204, and if not, execute S207; S204: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the first duration threshold t1 and whether the duration exceeds the preset second duration threshold t2, if yes, execute S205, otherwise execute S207; S205: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is normal; S206: Waiting for the photovoltaic grid-connected inverter to send a data frame; S207: Determine that the photovoltaic grid-connected inverter has not sent a data frame to the core module, and then perform S208; S208: Determine whether it can be detected that the duration of the data frame sent by the photovoltaic grid-connected inverter reaches or exceeds the first duration threshold t1 and exceeds the second duration threshold t2, if yes, perform S209, otherwise Return to S203; S209: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is abnormal; The electrical parameters of the photovoltaic grid-connected system include the electricity purchased and sold with the grid; the method for bidirectionally measuring the electrical parameters of the photovoltaic grid-connected system by the core module includes the following steps: S401: Carry out subsection calibration and preset electric parameter calculation using arithmetic sum or absolute value; S402: Perform electrical parameter calculation based on the electrical parameter calculation method; S403: Identify the direction of the power amount according to the result of the electric parameter calculation, and determine whether to buy or sell electricity; S404: Check whether the arithmetic sum or absolute value adopted in the result of electric parameter calculation is consistent with the preset; The method that the core module uploads the metered power in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize the anti-backflow function includes the following steps : 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 collection algorithm; S502: Upload the collected grid-connected power, user-side input power, and output power of the photovoltaic grid-connected inverter to the photovoltaic grid-connected inverter, so that the photovoltaic grid-connected inverter is based on its internal settings The anti-reflux threshold percentage triggers the anti-reflux operation. The smart power meter according to claim 1, characterized in that: the working process of the smart power meter cooperating with the SEMS platform to realize remote load monitoring includes the following steps: S301: Determine whether the photovoltaic grid-connected inverter is working, if the photovoltaic grid-connected inverter is working, execute S302 for further judgment, and if the photovoltaic grid-connected inverter is not working, execute S304; S302: Determine whether the local communication between the photovoltaic grid-connected inverter and the smart power meter is normal, if the local communication is normal, execute S303, and if the local communication is abnormal, execute S304; S303: If the photovoltaic grid-connected inverter works normally and the local communication is normal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the photovoltaic grid-connected inverter and The smart electric meter collects data; S304: If the photovoltaic grid-connected inverter is not working, or the local communication is abnormal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the smart power meter itself. A smart power meter is arranged between a photovoltaic grid-connected inverter and a power grid in a photovoltaic grid-connected system, and the photovoltaic grid-connected inverter communicates with an SEMS platform, wherein the smart power meter includes: A core module, local communication can be realized between the core module and the photovoltaic grid-connected inverter, remote communication can be realized between the core module and the SEMS platform, and the core module is used for two-way metering of the photovoltaic Electric parameters of the grid-connected system, judging whether the local communication with the photovoltaic grid-connected inverter is normal, and receiving the photovoltaic grid-connected inverter when the local communication with the photovoltaic grid-connected inverter is normal The electrical parameters of the photovoltaic grid-connected system sent by the inverter, the electrical parameters of the photovoltaic grid-connected system obtained by uploading its measurement and/or the electrical parameters of the photovoltaic grid-connected system sent by the photovoltaic grid-connected inverter parameters to the SEMS platform to realize remote load monitoring, and upload the measured power amount in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the photovoltaic grid-connected inverter to realize Anti-backflow function. The smart power meter according to claim 3, characterized in that: the smart power meter further comprises: a first communication module, the first communication module communicates with the core module and the photovoltaic grid-connected inverter respectively connection, for realizing local communication between the core module and the photovoltaic grid-connected inverter; A second communication module, the second communication module is respectively connected to the core module and the SEMS platform, and is used to realize remote communication between the core module and the SEMS platform. The smart power meter according to claim 4, wherein the first communication module is a bus communication module. The smart power meter according to claim 5, characterized in that: said first communication module adopts RS485 bus. The smart power meter according to claim 4, wherein the second communication module is a wireless communication module. The smart power meter according to claim 4, wherein the method for the core module to judge whether the local communication between it and the photovoltaic grid-connected inverter is normal comprises the following steps: S201: Initialize communication parameters and communication flag bits of the first communication module; S202: Judging whether the data frame sent by the photovoltaic grid-connected inverter can be detected at present, if so, execute S203, and if not, execute S206; S203: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the preset first duration threshold t1, if so, execute S204, and if not, execute S207; S204: Judging whether it can be detected that the duration of the data frame delivered by the photovoltaic grid-connected inverter is less than the first duration threshold t1 and whether the duration exceeds the preset second duration threshold t2, if yes, execute S205, otherwise execute S207; S205: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is normal; S206: Waiting for the photovoltaic grid-connected inverter to send a data frame and then end; S207: Determine that the photovoltaic grid-connected inverter has not sent a data frame to the core module, and then perform S208; S208: Determine whether it can be detected that the duration of the data frame sent by the photovoltaic grid-connected inverter reaches or exceeds the first duration threshold t1 and exceeds the second duration threshold t2, if yes, perform S209, otherwise Return to S203; S209: Record the communication flag used to indicate whether the local communication between the core module and the photovoltaic grid-connected inverter is normal as a flag indicating that the local communication is abnormal. The smart power meter according to claim 8, wherein the first duration threshold t1 is preset as 2s, and the second duration threshold t2 is preset as 1min. The smart power meter according to claim 8, wherein the communication flag is recorded as x in S205, and the communication flag is recorded as y in S209, and x≠y. The smart power meter according to claim 3, characterized in that: the electrical parameters of the photovoltaic grid-connected system include the purchased electricity and the sold electricity with the grid. The smart power meter according to claim 3, wherein the method for bidirectionally measuring the electrical parameters of the photovoltaic grid-connected system by the core module comprises the following steps: S401: Carry out subsection calibration and preset electric parameter calculation using arithmetic sum or absolute value; S402: Perform electrical parameter calculation based on the electrical parameter calculation method; S403: Identify the direction of the power amount according to the result of the electric parameter calculation, and determine whether to buy or sell electricity; S404: Check whether the arithmetic sum or absolute value adopted in the result of electric parameter calculation is consistent with the preset. The smart power meter according to claim 3, characterized in that: the core module uploads the measured power in the electrical parameters of the photovoltaic grid-connected system to the photovoltaic grid-connected inverter for the The method for realizing the anti-backflow function of the photovoltaic grid-connected inverter includes the following steps: 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 collection algorithm; S502: Upload the collected grid-connected power, user-side input power, and output power of the photovoltaic grid-connected inverter to the photovoltaic grid-connected inverter, so that the photovoltaic grid-connected inverter is based on its internal settings The anti-reflux threshold percentage triggers the anti-reflux operation. The smart power meter according to claim 3, characterized in that: the working process of the smart power meter cooperating with the SEMS platform to realize remote load monitoring includes the following steps: S301: Determine whether the photovoltaic grid-connected inverter is working, if the photovoltaic grid-connected inverter is working, execute S302 for further judgment, and if the photovoltaic grid-connected inverter is not working, execute S304; S302: Determine whether the local communication between the photovoltaic grid-connected inverter and the smart power meter is normal, if the local communication is normal, execute S303, and if the local communication is abnormal, execute S304; S303: If the photovoltaic grid-connected inverter works normally and the local communication is normal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the photovoltaic grid-connected inverter and The smart electric meter collects data; S304: If the photovoltaic grid-connected inverter is not working, or the local communication is abnormal, the data uploaded by the smart power meter to the SEMS platform adopts the data collected by the smart power meter itself.

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