Carbon metering method based on low-voltage distributed photovoltaic

Abstract

The invention relates to a carbon metering method based on low-voltage distributed photovoltaic, and the method comprises the steps: obtaining the actual online electric quantity of a plurality of target photovoltaic power generation areas in a preset metering time period, and enabling the target photovoltaic power generation areas to be any power generation area in a low-voltage distributed photovoltaic power generation system; and generating a carbon emission reduction W corresponding to the preset metering time period according to the emission factor corresponding to the regional power grid where each target photovoltaic power generation area is located and the actual online electric quantity of each target photovoltaic power generation area. According to the invention, the acquisition stability of actual online electric quantity data of each transformer area in the low-voltage distributed photovoltaic power generation system and the accuracy of the acquired electric quantity data are ensured. And the accuracy of the finally calculated carbon emission reduction W can be ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid regulation, and in particular to a carbon metering method based on low-voltage distributed photovoltaics. Background Art

[0002] The large-scale development of low-voltage distributed photovoltaics urgently requires the improvement of the grid's holographic perception and flexible control capabilities. The full realization of observable, measurable and controllable low-voltage distributed photovoltaics is a prerequisite for solving the "double high" and "double peak" problems of the power grid, accelerating the clean and low-carbon transformation of energy, and upgrading the power grid to the energy Internet. However, there is currently no carbon measurement method based on low-voltage distributed photovoltaics. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a carbon metering method based on low-voltage distributed photovoltaics. By optimizing and upgrading multiple dimensions as described above, the present invention can ensure the stability of the collection of actual grid-connected power data of each substation in the low-voltage distributed photovoltaic power generation system and the accuracy of the collected power data. This can then ensure the accuracy of the carbon emission reduction W that is finally calculated.

[0004] The present invention solves the technical problem by adopting the following technical solutions:

[0005] A carbon measurement method based on low-voltage distributed photovoltaics comprises the following steps:

[0006] S100: Obtaining the actual grid-connected power A1, A2, ..., A of multiple target photovoltaic power generation stations in a preset metering period i , …, A z Among them, A i A is the actual grid-connected power of the i-th target photovoltaic power station in the preset metering period; z is the total number of target photovoltaic power generation stations; i = 1, 2, ..., z; the target photovoltaic power generation station is any power generation station in the low-voltage distributed photovoltaic power generation system;

[0007] S200: Generate the carbon emission reduction amount W corresponding to the preset metering period according to the emission factor corresponding to the regional power grid where each target photovoltaic power generation station is located and the actual grid-connected power of each target photovoltaic power generation station:

[0008]

[0009] Among them, K i is the emission factor corresponding to the power grid in the area where the i-th target PV power station is located.

[0010] Moreover, the actual grid-connected power in S100 is divided into the case where the installed capacity is 0-30kW and the full amount is connected to the grid, the case where the installed capacity is 0-30kW and the self-generation is for self-use / surplus power is connected to the grid, the case where the installed capacity is above 30kW and the full amount is connected to the grid, and the case where the installed capacity is above 30kW and the self-generation is for self-use / surplus power is connected to the grid.

[0011] Moreover, the actual online power collection method for the case where the installed capacity is 0-30kW and the full amount is online includes the following steps:

[0012] S110: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the power generation of photovoltaic users and monitor harmonic conditions;

[0013] S111: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

[0014] Moreover, the actual online power collection method for the case where the installed capacity is 0-30kW for self-generation and self-use / surplus power is online includes the following steps:

[0015] S120: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users;

[0016] S121: An electric energy meter is installed on the power generation side of the photovoltaic user. The electric energy meter includes a power quality monitoring module, which is used to measure the power generation of the photovoltaic equipment and monitor the harmonic content;

[0017] S122: An intelligent circuit breaker is installed at the rear end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions;

[0018] S123: An electric energy meter with remote fee control and external switch is set at the user's electricity consumption point to measure the user's electricity consumption.

[0019] Moreover, the method for collecting actual online power consumption when the installed capacity is more than 30kW and the full amount is online includes the following steps:

[0020] S130: A three-phase electric energy meter is installed at the boundary point between the power supply and power consumption facilities. The electric energy meter includes a power quality monitoring module. A set of current transformers that meet the accuracy level requirements are configured for the three-phase electric energy meter to measure the power generation of photovoltaic users and monitor the harmonic content.

[0021] S131: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

[0022] Moreover, the actual online power collection method for the case where the installed capacity is more than 30kW and the self-generation and self-use / surplus power is online includes the following steps:

[0023] S140: A three-phase electric energy meter and a set of current transformers that meet the accuracy level requirements are installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users;

[0024] S141: A three-phase energy meter is installed on the power generation side of the photovoltaic user. The energy meter contains a power quality monitoring module to measure the power generation of the photovoltaic equipment and monitor the harmonic content;

[0025] S142: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions;

[0026] S143: An electric energy meter with remote fee control and external switch is installed at the user's electricity consumption point to measure the user's electricity consumption.

[0027] Moreover, the communication networking methods used to obtain the online power in step 1 include: Type I concentrator, energy controller HPLC / dual-mode networking solution; Type II concentrator networking solution; electric energy meter configured with 4G / 5G module networking solution; cloud-to-cloud docking networking solution.

[0028] The advantages and positive effects of the present invention are:

[0029] 1. The present invention obtains the actual grid-connected electricity of multiple target photovoltaic power generation areas in a preset metering period, wherein the target photovoltaic power generation area is any power generation area in a low-voltage distributed photovoltaic power generation system; based on the emission factor corresponding to the regional power grid where each target photovoltaic power generation area is located and the actual grid-connected electricity of each target photovoltaic power generation area, the carbon emission reduction amount W corresponding to the preset metering period is generated. The present invention ensures the stability of the collection of the actual grid-connected electricity data of each area in the low-voltage distributed photovoltaic power generation system in the present invention, as well as the accuracy of the collected electricity data. In addition, the accuracy of the carbon emission reduction amount W finally calculated can be guaranteed.

[0030] 2. The present invention designs different data collection schemes to collect the corresponding photovoltaic power generation and photovoltaic power consumption for the full grid-connected and self-generated and self-used / surplus power grid-connected situations under different installed capacities. Therefore, the actual grid-connected power can be calculated more accurately based on the above values.

[0031] 3. The present invention sets different collection periods, collection frequencies and the number of collected data items according to the richness of the data items to be collected and the real-time requirements for data collection in conventional daily data collection and key data collection. Thus, it can realize the normal collection frequency of conventional data and the real-time collection of key data with high collection frequency.

[0032] 4. The present invention also sets the number of common and three-phase electric energy meters in each substation according to the actual collection capacity of HPLC, so as to realize the collection of the actual grid-connected electricity in each substation in the low-voltage distributed photovoltaic power generation system, and then calculate the corresponding carbon emission reduction according to the collected data. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a flow chart of the present invention;

[0034] Figure 2 This is a 0-30kW full-rate grid-connected metering point setting diagram of the present invention;

[0035] Figure 3 This is a diagram of the metering point setting for 0-30kW self-generation and self-use / surplus power grid connection in the present invention;

[0036] Figure 4 This is a diagram of the setting of full-amount grid-connected metering points above 30kW in the present invention;

[0037] Figure 5 This is a diagram of metering point settings for self-generation and self-use / surplus power grid connection above 30kW in the present invention;

[0038] Figure 6 A communication network structure diagram is collected for the present invention. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below with reference to the accompanying drawings.

[0040] A carbon measurement method based on low voltage distributed photovoltaics, such as Figure 1 As shown, the following steps are included:

[0041] S100: Obtaining the actual grid-connected power A1, A2, ..., A of multiple target photovoltaic power generation stations in a preset metering period i , …, A z Among them, A i A is the actual grid-connected power of the i-th target photovoltaic power station in the preset metering period; z is the total number of target photovoltaic power generation stations; i = 1, 2, ..., z; the target photovoltaic power generation station is any power generation station in the low-voltage distributed photovoltaic power generation system;

[0042] In S100, according to the different low-voltage distributed photovoltaic power grid absorption methods and combined with the installed capacity, the following four actual grid-connected electricity collection plans are formulated: the actual grid-connected electricity is divided into the case where the installed capacity is 0-30kW and the full amount is connected to the grid, the case where the installed capacity is 0-30kW and the self-generation is for self-use / surplus power is connected to the grid, the case where the installed capacity is above 30kW and the full amount is connected to the grid, and the case where the installed capacity is above 30kW and the self-generation is for self-use / surplus power is connected to the grid.

[0043] like Figure 2 As shown in the figure, the actual online power collection method for the case where the installed capacity is 0-30kW and the full amount is online includes the following steps:

[0044] S110: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the power generation of photovoltaic users and monitor harmonic conditions;

[0045] S111: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

[0046] When the installed capacity is 0-8kW, a three-phase energy meter should be used. When the installed capacity is 8kW-30kW, a three-phase energy meter must be used.

[0047] like Figure 3 As shown in the figure, the actual online power collection method for the case of self-generation and self-use / surplus power on the grid with an installed capacity of 0-30kW includes the following steps:

[0048] S120: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users;

[0049] S121: An electric energy meter is installed on the power generation side of the photovoltaic user. The electric energy meter includes a power quality monitoring module, which is used to measure the power generation of the photovoltaic equipment and monitor the harmonic content;

[0050] S122: An intelligent circuit breaker is installed at the rear end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions;

[0051] S123: An electric energy meter with remote fee control and external switch is set at the user's electricity consumption point to measure the user's electricity consumption.

[0052] When the installed capacity is 0-8kW, a three-phase energy meter should be used. When the installed capacity is 8kW-30kW, a three-phase energy meter must be used.

[0053] like Figure 4As shown in the figure, the actual online power collection method for the case where the installed capacity is more than 30kW and the full amount is online includes the following steps:

[0054] S130: A three-phase electric energy meter is installed at the boundary point between the power supply and power consumption facilities. The electric energy meter includes a power quality monitoring module. A set of current transformers that meet the accuracy level requirements are configured for the three-phase electric energy meter to measure the power generation of photovoltaic users and monitor the harmonic content.

[0055] S131: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

[0056] like Figure 5 As shown in the figure, the actual online power collection method for the case of self-generation and self-use / surplus power on the grid with an installed capacity of more than 30kW includes the following steps:

[0057] S140: A three-phase electric energy meter and a set of current transformers that meet the accuracy level requirements are installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users;

[0058] S141: A three-phase energy meter is installed on the power generation side of the photovoltaic user. The energy meter contains a power quality monitoring module to measure the power generation of the photovoltaic equipment and monitor the harmonic content;

[0059] S142: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions;

[0060] S143: An electric energy meter with remote fee control and external switch is installed at the user's electricity consumption point to measure the user's electricity consumption.

[0061] According to the above four collection schemes, the corresponding photovoltaic power generation and photovoltaic power consumption can be collected for the full grid-connected and self-generated for self-use / surplus power grid-connected situations under different installed capacities. Therefore, the actual grid-connected power can be calculated more accurately based on the above values. Specifically, the actual grid-connected power = photovoltaic power generation - photovoltaic power consumption.

[0062] Low-voltage distributed photovoltaic collection communication includes remote and local communication methods. Remote communication is mainly based on 4G / 5G and Ethernet. Local communication is mainly based on HPLC / dual mode, RS-485, Bluetooth, CAN bus, M-BUS and other methods. For the communication methods between the various device terminals involved in the above four actual online power collection schemes, such as Figure 6 As shown, the following four communication networking modes can be adopted according to actual needs.

[0063] (I) Type I concentrator, energy controller HPLC (low voltage power line high speed carrier communication) / dual-mode networking solution

[0064] Type I concentrators and energy controllers communicate with the data collection master station remotely via 4G / 5G, Ethernet, etc., and communicate with the energy meter locally via HPLC / dual mode. The energy meter communicates with the circuit breaker via RS-485 / Bluetooth. The energy meter communicates with the data collector via RS-485 / CAN / M-BUS, etc.

[0065] (II) Type II concentrator networking solution

[0066] The Type II concentrator communicates with the data collection master station remotely via 4G / 5G, and communicates with the energy meter locally via RS-485. The energy meter communicates with the circuit breaker via RS-485 / Bluetooth. The energy meter communicates with the data collector via RS-485 / CAN / M-BUS and other methods.

[0067] (III) Networking solution for electric energy meter configuration with 4G / 5G module

[0068] The energy meter is equipped with a 4G / 5G module, communicates with the data collection master station via 4G / 5G, and communicates with the circuit breaker locally via RS-485 / Bluetooth. The energy meter communicates with the data collector via RS-485 / CAN / M-BUS and other methods.

[0069] (IV) “Cloud-to-Cloud Connection” Networking Solution

[0070] The data collection master station and the PV manufacturer's master station communicate with the PV inverter through a "cloud-to-cloud connection" method.

[0071] The above four communication networking schemes can realize stable communication between various devices in the above actual online power collection scheme, so as to ensure the stability and reliability of data transmission.

[0072] When collecting data from distributed photovoltaic user electricity meters, different collection frequencies can be set according to the characteristics of photovoltaic power generation period and the importance of data to ensure the real-time collection of important data and the real-time nature of the overall data. The specific plan is as follows:

[0073] S150: In daily monitoring, during the distributed photovoltaic power generation period (such as 7:00-19:00), the data in the distributed photovoltaic user's electric energy meter is collected regularly at a frequency of 15 minutes to achieve the normal collection frequency of routine data.

[0074] S160: According to business needs, the voltage, current, active power and reactive power data of key users and key time periods are monitored at high frequency, and multiple corresponding data in the electric energy meter of distributed photovoltaic users are collected regularly at a frequency of 1 minute to achieve high frequency collection of key data.

[0075] Due to the obvious characteristics of distributed photovoltaic power generation time periods, the data required for high-frequency collection can be configured according to time periods (such as 7:00-19:00), and other time periods are executed according to the basic collection frequency requirements. The 15-minute curve data can be obtained by collecting the 15-minute frozen curve of the electric energy meter every day through the collection terminal. Specifically, the collection data items and collection frequency can be configured according to the contents shown in the table below.

[0076] Table 1 Data collection items and collection frequency

[0077]

[0078]

[0079]

[0080]

[0081] Table 2 PV inverter data collection items

[0082]

[0083]

[0084] In the above steps S150 and S160, different collection periods, collection frequencies and numbers of collected data items are set according to the richness of the data items to be collected and the real-time requirements for data collection in the conventional daily data collection and the key data collection, respectively. Thus, both the normal collection frequency of the conventional data and the high collection frequency of the key data in real time can be realized.

[0085] In addition, when the local area communicates with the electric energy meter through HPLC, in order to ensure that data collection can be carried out normally in accordance with the methods in Table 1 and Table 2 above, it is necessary to configure the ratio of the number of ordinary user electric energy meters and photovoltaic user electric energy meters in each substation, as shown in Table 3 below:

[0086] Table 3 Ratio of the number of ordinary user electricity meters and photovoltaic user electricity meters in the substation area

[0087]

[0088] According to theoretical calculations, field tests and application experience, HPLC has the ability to collect at least 100 meters per minute, with 4 data items per meter. When collecting data in accordance with the methods in Tables 1 and 2 above, specifically, ordinary users collect 4 data items at the 15-minute level, and three-phase photovoltaic users are configured according to the tasks in Tables 1 and 2 (14 data items are collected at the 1-minute level, and 20 data items are collected at the 15-minute level). In order to meet the above requirements, it is necessary to set the number of ordinary and three-phase electricity meters in each substation according to the ratio of the number of ordinary user electricity meters and photovoltaic user electricity meters in Table 3. In this way, it can be ensured that the data is collected normally in accordance with the methods in Tables 1 and 2 above.

[0089] S200: Generate the carbon emission reduction amount W corresponding to the preset metering period according to the emission factor corresponding to the regional power grid where each target photovoltaic power generation station is located and the actual grid-connected power of each target photovoltaic power generation station:

[0090]

[0091] Among them, K i is the emission factor corresponding to the power grid in the region where the i-th target photovoltaic power generation station is located. Among them, the emission factor can be obtained from the latest notice of "Annual National Power Grid Average Emission Factor" issued by the Ministry of Ecology and Environment. The average power grid emission factor is one of the most important data in the dual-carbon industry, and there are many types of average power grid emission factors, which can be selected according to the actual usage scenario.

[0092] According to the different low-voltage distributed photovoltaic power grid consumption methods and combined with the installed capacity, the following four actual grid-connected electricity collection plans are formulated.

[0093] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A carbon metering method based on low-voltage distributed photovoltaics, characterized in that: The following steps are involved: S100: Obtaining the actual grid-connected power A1, A2, ..., A of multiple target photovoltaic power generation stations in a preset metering period i , …, A z ; Among them, A i A is the actual grid-connected power of the i-th target photovoltaic power station in the preset metering period; z is the total number of target photovoltaic power generation stations; i = 1, 2, ..., z; the target photovoltaic power generation station is any power generation station in the low-voltage distributed photovoltaic power generation system; S200: Generate the carbon emission reduction amount W corresponding to the preset metering period according to the emission factor corresponding to the regional power grid where each target photovoltaic power generation station is located and the actual grid-connected power of each target photovoltaic power generation station: Among them, K i is the emission factor corresponding to the power grid in the area where the i-th target PV power station is located.

2. According to claim 1, a carbon metering method based on low-voltage distributed photovoltaics is characterized in that: The actual grid-connected power in S100 is divided into the case where the installed capacity is 0-30kW and the full amount is connected to the grid, the case where the installed capacity is 0-30kW and the self-generation is for self-use / surplus power is connected to the grid, the case where the installed capacity is more than 30kW and the full amount is connected to the grid, and the case where the installed capacity is more than 30kW and the self-generation is for self-use / surplus power is connected to the grid.

3. A carbon metering method based on low-voltage distributed photovoltaics according to claim 2, characterized in that: The actual online power collection method for the case where the installed capacity is 0-30kW and the full amount is online includes the following steps: S110: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the power generation of photovoltaic users and monitor harmonic conditions; S111: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

4. The carbon metering method based on low-voltage distributed photovoltaic according to claim 2 is characterized in that: The actual online power collection method for the case where the installed capacity is 0-30kW for self-generation and self-use / surplus power is online includes the following steps: S120: An electric energy meter is installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users; S121: An electric energy meter is installed on the power generation side of the photovoltaic user. The electric energy meter includes a power quality monitoring module, which is used to measure the power generation of the photovoltaic equipment and monitor the harmonic content; S122: An intelligent circuit breaker is installed at the rear end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions; S123: An electric energy meter with remote fee control and external switch is set at the user's electricity consumption point to measure the user's electricity consumption.

5. The carbon metering method based on low-voltage distributed photovoltaic according to claim 2 is characterized in that: The actual online power collection method for the case where the installed capacity is more than 30kW and the full amount is online includes the following steps: S130: A three-phase electric energy meter is installed at the boundary point between the power supply and power consumption facilities. The electric energy meter includes a power quality monitoring module. A set of current transformers that meet the accuracy level requirements are configured for the three-phase electric energy meter to measure the power generation of photovoltaic users and monitor the harmonic content. S131: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid-connection and off-grid instructions issued by the master station, and implement grid-connection and off-grid control according to the grid-connection and off-grid instructions.

6. A carbon metering method based on low-voltage distributed photovoltaics according to claim 2, characterized in that: The actual online power collection method for the case where the installed capacity is above 30kW for self-generation and self-use / surplus power is online includes the following steps: S140: A three-phase electric energy meter and a set of current transformers that meet the accuracy level requirements are installed at the boundary between the power supply and power consumption facilities. The electric energy meter contains a power quality monitoring module to measure the online and offline power consumption of photovoltaic users; S141: A three-phase energy meter is installed on the power generation side of the photovoltaic user. The energy meter contains a power quality monitoring module to measure the power generation of the photovoltaic equipment and monitor the harmonic content; S142: An intelligent circuit breaker is installed at the back end of the electric energy meter to receive the grid connection and disconnection instructions issued by the master station, and implement grid connection and disconnection control according to the grid connection and disconnection instructions; S143: An electric energy meter with remote fee control and external switch is installed at the user's electricity consumption point to measure the user's electricity consumption.

7. The carbon metering method based on low-voltage distributed photovoltaic according to claim 1 is characterized in that: The communication networking methods used to obtain the online power consumption in step 1 include: Type I concentrator, energy controller HPLC / dual-mode networking solution; Type II concentrator networking solution; electric energy meter configured with 4G / 5G module networking solution; cloud-to-cloud docking networking solution.

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