Photovoltaic array loss quantification method based on spatiotemporal distribution characteristics of data

Abstract

The application relates to photovoltaic operation and maintenance management technology, and relates to a photovoltaic array loss quantification method based on data space-time distribution characteristics, which comprises the following steps: acquiring a measurement value, calculating photovoltaic power station theoretical power generation and loss power, calculating a photovoltaic array output without temperature loss, calculating the overall loss of the photovoltaic array, constructing an upper line of the temperature loss point, obtaining a first loss power, obtaining a second loss power, constructing a second analysis model, taking a maximum irradiance value, calculating the maximum theoretical power generation in each time period, calculating the efficiency value of each time period, calculating the average value of the efficiency value of the time period, obtaining a shadow loss coefficient and obtaining a maximum power tracking loss coefficient, and the like. The shadow loss coefficient and the maximum power tracking loss coefficient are obtained by analyzing the data through the construction of the analysis model, the loss power is accurately quantified, and the operation and maintenance of the photovoltaic power station are provided with a basis.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic operation and maintenance management technology, specifically to a method for quantifying photovoltaic array losses based on the spatiotemporal distribution characteristics of data. Background Technology

[0002] Photovoltaic power generation, as an important component of renewable energy, has developed rapidly in recent years. A photovoltaic power station consists of several photovoltaic arrays, and a photovoltaic array is composed of several photovoltaic modules connected in series and parallel. In the actual operation of a photovoltaic (PV) power plant, environmental factors such as shading of PV module panels, panel contamination, the angle of incidence of sunlight on the PV module panels, and temperature all affect the power generation efficiency of the PV power plant. In addition, the power generation efficiency of a PV power plant is also closely related to the DC circuit from the PV array to the inverter, the inverter's operating status, and the line from the inverter to the booster station. This results in the actual output of the PV power plant always being less than its theoretical output. This portion of electricity that could have been generated but was not is defined as lost electricity. Currently, the analysis of lost electricity is generally divided into array losses, inverter losses, collector line losses, and booster station losses. Array losses include DC circuit losses, shading losses, temperature rise losses, contamination losses, and angle of incidence losses. These array losses can be managed through operation and maintenance to reduce the losses in PV power generation. However, there is currently no accurate method for quantifying array losses, which cannot provide a basis for the operation and maintenance of PV power plants. Summary of the Invention

[0003] This invention provides a method for quantifying photovoltaic array losses based on the spatiotemporal distribution characteristics of data. By acquiring measured values ​​of solar irradiance on the tilted surface of the photovoltaic array, photovoltaic panel temperature, photovoltaic array output, and photovoltaic power station output, an analysis model is constructed to analyze the data and obtain the shading loss coefficient and maximum power tracking loss coefficient. This enables accurate quantification of the lost electricity, providing a basis for the operation and maintenance of photovoltaic power stations.

[0004] A photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics includes the following steps:

[0005] Step 1: Obtain the measured values, including the tilt angle of the photovoltaic array, the solar irradiance on the tilted surface, the temperature of the photovoltaic cell panel, the power output of the photovoltaic array, and the power output of the photovoltaic power station.

[0006] Step 2: Calculate the theoretical power generation and power loss of the photovoltaic power station. Based on the measured values ​​obtained in Step 1, calculate the theoretical power generation, temperature loss, voltage boosting loss, and inverter loss of the photovoltaic power station. Calculate the tilt angle correction coefficient based on the tilt angle of the photovoltaic array and the design data of the photovoltaic power station, and calculate the incident angle loss. Obtain the correction coefficient of the DC circuit from the power station design data and calculate the DC circuit power loss.

[0007] Step 3: Calculate the output of the photovoltaic array without temperature loss. The output of the photovoltaic array obtained in Step 1 and the output of the photovoltaic array without temperature loss obtained in Step 2 are used to obtain the output of the photovoltaic array without temperature loss. The first analysis model is constructed with the solar radiation intensity as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. The distribution of the output of the photovoltaic array without temperature loss is obtained in the first analysis model.

[0008] Step 4: Calculate the total loss of the photovoltaic array. The total power loss is obtained by comparing the theoretical power output of the photovoltaic power station obtained in Step 2 with the power loss without temperature loss obtained in Step 3.

[0009] Step 5: Construct the upper edge line of the no-temperature-loss point, obtain the maximum value of the photovoltaic array output no-temperature-loss point corresponding to the horizontal axis in the first analysis model in Step 3, and fit it into a straight line, which is the upper edge line of the no-temperature-loss point.

[0010] Step 6: Obtain the first power loss. The first power loss is obtained by subtracting the value corresponding to the theoretical power generation output of the photovoltaic power station obtained in Step 2 from the value of the horizontal axis corresponding to the horizontal axis in the first analysis model in Step 3, and the value corresponding to the line along the point without temperature loss obtained in Step 5.

[0011] Step 7: Obtain the second power loss by subtracting the value of the vertical coordinate corresponding to the photovoltaic array output without temperature loss from the value of the vertical coordinate along the line of the point with no temperature loss on the horizontal axis in the first analysis model in step 3.

[0012] Step 8: Construct a second analysis model. Construct a second analysis model with the time dimension as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. Input the theoretical power generation of the photovoltaic power station obtained in Step 2, the photovoltaic array output without temperature loss obtained in Step 3, and the upper line of the point without temperature loss obtained in Step 5 into the second analysis model.

[0013] Step 9: Obtain the maximum irradiance value. In step 8, the data is divided into hours to obtain the maximum irradiance value for each time period.

[0014] Step 10: Calculate the maximum theoretical power generation in each time period. The maximum theoretical power generation in each time period is obtained based on the installed capacity, maximum irradiance, and standard irradiance.

[0015] Step 11: Calculate the efficiency value for each time period;

[0016] Step 12: Calculate the average efficiency value over the time period;

[0017] Step 13, obtain the shadow loss coefficient;

[0018] Step 14: Obtain the maximum power tracking loss coefficient.

[0019] Furthermore, the first loss of electricity is the loss of electricity due to pollution of the photovoltaic cell panels.

[0020] Furthermore, in step 7, the second power loss is the power loss due to shadowing and maximum power tracking.

[0021] Furthermore, the time range of the time dimension in step 8 is determined by calculation based on the geographical location of the photovoltaic power station and the date.

[0022] Furthermore, in step 10, the calculation formula is: installed capacity × maximum irradiance / standard irradiance.

[0023] Furthermore, in step 11, the efficiency value for each time period is equal to the point at which the photovoltaic array outputs without temperature loss, divided by the maximum theoretical power generation of the photovoltaic array.

[0024] Furthermore, in step 12, the six highest efficiency values ​​across all time periods are taken, and the average value is calculated.

[0025] Furthermore, in step 13, the shading loss coefficient is calculated as: sum((average efficiency value of the time period / efficiency value of each time period - 1) × no temperature loss).

[0026] Furthermore, in step 14, the maximum power tracking loss coefficient is calculated as: second power loss - shadow loss.

[0027] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0028] This invention obtains measurements of solar irradiance on the tilted surface of a photovoltaic array, photovoltaic panel temperature, photovoltaic array output, and photovoltaic power station output. By constructing an analysis model to analyze the data, it obtains the shading loss coefficient and maximum power point tracking loss coefficient, thereby accurately quantifying this part of the lost electricity and providing a basis for the operation and maintenance of photovoltaic power stations.

[0029] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0032] Figure 1 This is a schematic diagram of the first analysis model disclosed in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the second analysis model disclosed in an embodiment of the present invention;

[0034] Figure 3 This is a flowchart illustrating the photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics disclosed in an embodiment of the present invention. Detailed Implementation

[0035] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0036] like Figure 1-3 As shown, this embodiment of the invention provides a method for quantifying the loss of a photovoltaic array based on the spatiotemporal distribution characteristics of data, including the following steps:

[0037] Step 1: Obtain the measured values, including the tilt angle of the photovoltaic array, the solar irradiance on the tilted surface, the temperature of the photovoltaic cell panel, the power output of the photovoltaic array, and the power output of the photovoltaic power station.

[0038] Step 2: Calculate the theoretical power generation and power loss of the photovoltaic power station. Based on the measured values ​​obtained in Step 1, calculate the theoretical power generation, temperature loss, voltage boosting loss, and inverter loss of the photovoltaic power station. Calculate the tilt angle correction coefficient based on the tilt angle of the photovoltaic array and the design data of the photovoltaic power station, and calculate the incident angle loss. Obtain the correction coefficient of the DC circuit from the power station design data and calculate the DC circuit power loss.

[0039] Step 3: Calculate the output of the photovoltaic array without temperature loss. The output of the photovoltaic array obtained in Step 1 and the output of the photovoltaic array without temperature loss obtained in Step 2 are used to obtain the output of the photovoltaic array without temperature loss. The first analysis model is constructed with the solar radiation intensity as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. The distribution of the output of the photovoltaic array without temperature loss is obtained in the first analysis model.

[0040] Step 4: Calculate the total loss of the photovoltaic array. The total power loss is obtained by comparing the theoretical power output of the photovoltaic power station obtained in Step 2 with the power loss without temperature loss obtained in Step 3.

[0041] Step 5: Construct the upper edge line of the no-temperature-loss point, obtain the maximum value of the photovoltaic array output no-temperature-loss point corresponding to the horizontal axis in the first analysis model in Step 3, and fit it into a straight line, which is the upper edge line of the no-temperature-loss point.

[0042] Step 6: Obtain the first power loss. The first power loss is obtained by subtracting the value corresponding to the theoretical power generation output of the photovoltaic power station obtained in Step 2 from the value of the horizontal axis corresponding to the horizontal axis in the first analysis model in Step 3, and the value corresponding to the line along the point without temperature loss obtained in Step 5.

[0043] It should be noted that the first loss of electricity is the loss of electricity due to pollution of the photovoltaic panel. Based on the obtained loss of electricity due to pollution of the photovoltaic panel, reasonable operation and maintenance measures can be implemented for the photovoltaic panel to minimize the loss of electricity due to pollution of the photovoltaic panel and improve the efficiency of operation and maintenance.

[0044] Step 7: Obtain the second power loss by subtracting the value of the vertical coordinate corresponding to the photovoltaic array output without temperature loss from the value of the vertical coordinate along the line of the point with no temperature loss on the horizontal axis in the first analysis model in step 3.

[0045] It should be noted that the second power loss is the power loss due to shading and maximum power tracking. Based on the obtained power loss due to shading and maximum power tracking, the location of the photovoltaic system and surrounding obstructions can be dynamically adjusted to minimize the power loss due to shading. At the same time, the power loss due to maximum power tracking can be adaptively adjusted to reduce its loss.

[0046] Step 8: Construct a second analysis model. Construct a second analysis model with the time dimension as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. Input the theoretical power generation of the photovoltaic power station obtained in Step 2, the photovoltaic array output without temperature loss obtained in Step 3, and the upper line of the point without temperature loss obtained in Step 5 into the second analysis model.

[0047] Specifically, the time range of the time dimension in step 8 is determined by calculation based on the geographical location of the photovoltaic power station and the date.

[0048] In a preferred embodiment, the time dimension can be set to a range of 06:00-19:00.

[0049] Step 9: Obtain the maximum irradiance value. In step 8, the data is divided into hours to obtain the maximum irradiance value for each time period.

[0050] Step 10: Calculate the maximum theoretical power generation in each time period. The maximum theoretical power generation in each time period is obtained based on the installed capacity, maximum irradiance, and standard irradiance.

[0051] The calculation formula is: Maximum theoretical power generation = Installed capacity × Maximum irradiance / Standard irradiance.

[0052] Step 11: Calculate the efficiency value for each time period;

[0053] Specifically, the efficiency value for each time period = the point at which the photovoltaic array outputs without temperature loss / the maximum theoretical power generation of the photovoltaic array.

[0054] Step 12: Calculate the average efficiency value over the time period;

[0055] Specifically, in step 12, the six highest efficiency values ​​across all time periods are taken, and the average value is calculated.

[0056] Step 13, obtain the shadow loss coefficient;

[0057] The shading loss coefficient is calculated as follows: Shading loss coefficient = sum((average efficiency value of the time period / efficiency value of each time period - 1) × no temperature loss).

[0058] Step 14: Obtain the maximum power tracking loss coefficient;

[0059] The maximum power tracking loss coefficient is calculated as follows: Maximum power tracking loss coefficient = Second loss power - Shadow loss power.

[0060] This embodiment obtains measurements of the irradiance on the tilted surface of the photovoltaic array, the temperature of the photovoltaic cell panel, the output of the photovoltaic array, and the output of the photovoltaic power station. By constructing an analysis model to analyze the data, the shading loss coefficient and the maximum power tracking loss coefficient are obtained, thus accurately quantifying this part of the power loss. This provides a basis for the operation and maintenance of the photovoltaic power station. During the operation and maintenance process, corresponding operation and maintenance measures can be formulated based on the quantification results to reduce power loss and improve the overall power generation.

[0061] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0062] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0063] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for quantifying the loss of a photovoltaic array based on the spatiotemporal distribution characteristics of data, characterized in that, Includes the following steps: Step 1: Obtain the measured values, including the tilt angle of the photovoltaic array, the solar irradiance on the tilted surface, the temperature of the photovoltaic cell panel, the power output of the photovoltaic array, and the power output of the photovoltaic power station. Step 2: Calculate the theoretical power generation and power loss of the photovoltaic power station. Based on the measured values ​​obtained in Step 1, calculate the theoretical power generation, temperature loss, voltage boosting loss, and inverter loss of the photovoltaic power station. Calculate the tilt angle correction coefficient based on the tilt angle of the photovoltaic array and the design data of the photovoltaic power station, and calculate the incident angle loss. Obtain the correction coefficient of the DC circuit from the power station design data and calculate the DC circuit power loss. Step 3: Calculate the output of the photovoltaic array without temperature loss. The output of the photovoltaic array obtained in Step 1 and the output of the photovoltaic array without temperature loss obtained in Step 2 are used to obtain the output of the photovoltaic array without temperature loss. The first analysis model is constructed with the solar radiation intensity as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. The distribution of the output of the photovoltaic array without temperature loss is obtained in the first analysis model. Step 4: Calculate the total loss of the photovoltaic array. The total power loss is obtained by comparing the theoretical power output of the photovoltaic power station obtained in Step 2 with the power loss without temperature loss obtained in Step 3. Step 5: Construct the upper edge line of the no-temperature-loss point, obtain the maximum value of the photovoltaic array output no-temperature-loss point corresponding to the horizontal axis in the first analysis model in Step 3, and fit it into a straight line, which is the upper edge line of the no-temperature-loss point. Step 6: Obtain the first power loss. The first power loss is obtained by subtracting the value corresponding to the theoretical power generation output of the photovoltaic power station obtained in Step 2 from the value of the horizontal axis corresponding to the horizontal axis in the first analysis model in Step 3, and the value corresponding to the line along the point without temperature loss obtained in Step 5. Step 7: Obtain the second power loss by subtracting the value of the vertical coordinate corresponding to the photovoltaic array output without temperature loss from the value of the vertical coordinate along the line of the point with no temperature loss on the horizontal axis in the first analysis model in step 3. Step 8: Construct a second analysis model. Construct a second analysis model with the time dimension as the horizontal axis and the output of the photovoltaic array without considering temperature loss as the vertical axis. Input the theoretical power generation of the photovoltaic power station obtained in Step 2, the photovoltaic array output without temperature loss obtained in Step 3, and the upper line of the point without temperature loss obtained in Step 5 into the second analysis model. Step 9: Obtain the maximum irradiance value. In step 8, the data is divided into hours to obtain the maximum irradiance value for each time period. Step 10: Calculate the maximum theoretical power generation in each time period. The maximum theoretical power generation in each time period is obtained based on the installed capacity, maximum irradiance, and standard irradiance. Step 11: Calculate the efficiency value for each time period; Step 12: Calculate the average efficiency value over the time period; Step 13, obtain the shadow loss coefficient; Step 14: Obtain the maximum power tracking loss coefficient.

2. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, The primary source of lost electricity is the electricity lost due to pollution of the photovoltaic cell panels.

3. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 7, the second power loss is the power loss due to shadowing and maximum power tracking.

4. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, The time range of the time dimension in step 8 is determined by calculation based on the geographical location of the photovoltaic power station and the date.

5. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 10, the calculation formula is: installed capacity × maximum irradiance / standard irradiance.

6. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 11, the efficiency value for each time period is equal to the point at which the photovoltaic array outputs without temperature loss, divided by the maximum theoretical power generation of the photovoltaic array.

7. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 12, the six highest efficiency values ​​across all time periods are taken, and the average value is calculated.

8. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 13, the shading loss coefficient is calculated as: sum((average efficiency value of the time period / efficiency value of each time period - 1) × no temperature loss).

9. The photovoltaic array loss quantification method based on data spatiotemporal distribution characteristics as described in claim 1, characterized in that, In step 14, the maximum power tracking loss coefficient is calculated as: second power loss - shadow loss.

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