Maximum power point tracking method and device, electronic equipment and storage medium

Abstract

The application relates to the photovoltaic power generation technical field and provides a maximum power point tracking method and device, electronic equipment and a storage medium. The method comprises the following steps: obtaining multiple output powers according to the output voltage and the output current of a photovoltaic module in a target period; generating a scatter plot according to the output powers and the corresponding output voltages; calculating a first slope value after linear fitting between each point on the scatter plot and a target number of points adjacent to the left of the point, and calculating a second slope value after linear fitting between each point on the scatter plot and a target number of points adjacent to the right of the point; generating a slope difference distribution curve according to the slope difference between the first slope value and the second slope value of each point; obtaining an extreme point by derivation on the slope difference distribution curve; and determining a first maximum power point of the photovoltaic module according to the power value of the extreme point determined in the scatter plot. The above method improves the accuracy of determining the maximum power point.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to a maximum power point tracking method and device, an electronic device and a storage medium. BACKGROUND

[0002] Photovoltaic power generation has the characteristics of wide distribution, large reserves, cleanliness and renewable, and has developed rapidly in recent years. The proportion of photovoltaic power generation in the world is increasing, and the improvement of solar utilization rate and efficiency is of great significance to the entire industry, which can greatly improve the utilization rate of resources.

[0003] The output characteristics of photovoltaic components in photovoltaic power generation equipment are nonlinear, and the output characteristics are jointly affected by light intensity and environmental temperature. Under different light conditions and temperatures, the maximum power point of the photovoltaic component is different. In order to improve the power generation efficiency of the entire photovoltaic power generation equipment, the operating voltage of the photovoltaic component needs to be controlled in real time so that it can operate at the maximum power point as much as possible, so accurate tracking of the maximum output power operating point is particularly important. SUMMARY

[0004] In view of the above, it is necessary to provide a maximum power point tracking method, device, electronic device and storage medium, which can solve the problem of affecting the power generation efficiency of the photovoltaic power generation equipment due to the inability to effectively determine the maximum power point.

[0005] The first aspect of the present application provides a maximum power point tracking method, which comprises: calculating a plurality of output powers according to the output voltage and output current of a photovoltaic component in a target period; generating a scatter plot according to each output power and the corresponding output voltage; the horizontal coordinate of the scatter plot is voltage, and the vertical coordinate is power; calculating the first slope value of linear fitting between each point on the scatter plot and the target number of points adjacent to the left of the point, and calculating the second slope value of linear fitting between each point on the scatter plot and the target number of points adjacent to the right of the point; generating a slope difference distribution curve according to the slope difference between the first slope value and the second slope value of each point; deriving the slope difference distribution curve to obtain an extreme point; determining the maximum power point of the photovoltaic component in the target period according to the power value of the extreme point in the scatter plot.

[0006] The slope difference distribution curve is obtained by the slope difference of each point in the scatter plot. Since the slope difference of a point in the scatter plot can be used to represent the degree of probability change of the point relative to surrounding points, the extreme value point obtained by derivation of the slope difference distribution curve can correspond to an output voltage with a relatively large output power change of the photovoltaic module. The extreme value point obtained by derivation of the slope difference distribution curve is based on global points in the target period of the photovoltaic module, and the maximum power point is determined based on the extreme value point. Therefore, the maximum power point can be determined from a global perspective, and the calculation of the maximum power point will not be trapped in a local maximum in the case that the point distribution trend in the scatter plot shows a multi-peak phenomenon. Therefore, the maximum power point can be accurately tracked regardless of the illumination condition of the photovoltaic module.

[0007] The second aspect of the present application provides a maximum power point tracking device, the maximum power point tracking device comprising:

[0008] The first calculation module is configured to calculate a plurality of output powers according to the output voltage and the output current of the photovoltaic module in the target period. The image generation module is configured to generate a scatter plot according to each output power and the corresponding output voltage. The horizontal coordinate of the scatter plot is voltage, and the vertical coordinate is power. The second calculation module is configured to calculate a first slope value obtained by linear fitting between each point on the scatter plot and a target number of points adjacent to the left of the point, and calculate a second slope value obtained by linear fitting between each point on the scatter plot and a target number of points adjacent to the right of the point. The curve generation module is configured to generate a slope difference distribution curve according to the slope difference between the first slope value and the second slope value of each point. The curve derivation module is configured to derive the slope difference distribution curve to obtain an extreme value point. The third calculation module is configured to determine a corresponding power value of the extreme value point in the scatter plot, and determine a first maximum power point of the photovoltaic module in the target period according to the power value.

[0009] The third aspect of the present application provides an electronic device, comprising: a memory storing computer readable instructions; and a processor executing the computer readable instructions stored in the memory to implement the maximum power point tracking method.

[0010] The fourth aspect of the present application provides a computer readable storage medium, the computer readable storage medium stores computer readable instructions, and the computer readable instructions are executed by the processor in the electronic device to implement the maximum power point tracking method. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 FIG. 1 is a structural schematic diagram of a photovoltaic power generation device provided by an embodiment of the present application.

[0012] Figure 2is a flow chart of a maximum power point tracking method provided by an embodiment of the present application.

[0013] Figure 3 is a scene schematic diagram of a scatter plot provided by an embodiment of the present application.

[0014] Figure 4 is a schematic diagram of a slope difference distribution curve provided by an embodiment of the present application.

[0015] Figure 5 is a flow chart of a maximum power point tracking method provided by an embodiment of the present application. Figure 2 is a refinement flow chart of step 230.

[0016] Figure 6 is a refinement flow chart of a method for determining a maximum power point of a photovoltaic module in a target period according to a power value determined by an extreme point in a scatter plot provided by an embodiment of the present application.

[0017] Figure 7 is a refinement flow chart of a method for determining a maximum power point of a photovoltaic module in a target period according to a power value determined by an extreme point in a scatter plot provided by an embodiment of the present application.

[0018] Figure 8 is a refinement flow chart of a method for determining a maximum power point of a photovoltaic module in a target period based on a first maximum power point and a second maximum power point provided by an embodiment of the present application.

[0019] Figure 9 is a structural schematic diagram of a maximum power point tracking device provided by an embodiment of the present application.

[0020] Figure 10 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0021] Hereinafter, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implying that the indicated technical features are limited to a certain number. Therefore, the features defined with "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the words "exemplary", "or", "for example" are used to mean as an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary", "or", "for example" and the like is intended to present the relevant concept in a specific manner.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be understood that, unless otherwise stated, " / " in this application means "or". For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. "At least one" means one or more. "More than one" means two or more. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, and a, b, and c. It should be understood that the order of steps shown in the flowcharts herein can be changed, and some can be omitted.

[0023] A photovoltaic (PV) module is composed of multiple photovoltaic cells connected in series or parallel. PV modules convert solar energy into electrical energy. Traditional maximum power point tracking (MPPT) algorithms can track the maximum power point (MPP) based on the PV module's output characteristic curve to determine the module's maximum output power. Since each PV cell within a PV module operates in the same environment, its output is equal. Therefore, under constant solar irradiance and operating temperature, the PV module's MPP output characteristic curve exhibits a single peak, and traditional MPPT algorithms are less prone to fluctuations during the tracking process, accurately determining the MPP. However, under unstable sunlight or when the PV module is partially shaded, the current MPP output characteristic curve will exhibit multiple peaks. If the MPP output characteristic curve exhibits multiple peaks, traditional MPPT algorithms are prone to drastic fluctuations during the tracking process, easily stopping at local optima before finding the global optimum, thus becoming trapped in local optima and failing to accurately determine the true maximum power point, resulting in low efficiency in determining the MPP.

[0024] To address the problem that traditional maximum power point tracking algorithms are prone to getting trapped in local optima and failing to accurately determine the maximum power point when photovoltaic modules are under unstable lighting or partial shading, this application provides a maximum power point tracking method to achieve accurate determination of the maximum power point.

[0025] The maximum power point tracking method provided in the embodiments of the present application can be applied to one or more electronic devices. The electronic device can be an energy storage device. The energy storage device can store energy, for example, the energy storage device can store the energy collected by the photovoltaic module. The network in which the electronic device is located includes, but is not limited to, the Internet, a wide area network, a metropolitan area network, a local area network, a virtual private network (VPN), and the like. The embodiments of the present application do not specially limit the specific form of the electronic device.

[0026] In order to better understand the maximum power point tracking method provided in the embodiments of the present application, the implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0027] Figure 1 FIG. 1 is an application scenario diagram of a maximum power point tracking method provided in the embodiments of the present application. As shown in FIG. 1, a photovoltaic module 101 establishes a connection with an electronic device 102. Figure 1 The photovoltaic module 101 is used to convert solar energy into electrical energy. The photovoltaic module 101 can be composed of a plurality of photovoltaic cells in a series or parallel manner. The photovoltaic module 101 can transmit the converted electrical energy to the electronic device 102.

[0028] The photovoltaic module 101 is used to convert solar energy into electrical energy. The photovoltaic module 101 can be composed of a plurality of photovoltaic cells in a series or parallel manner. The photovoltaic module 101 can transmit the converted electrical energy to the electronic device 102.

[0029] The electronic device 102 can be any one of a vehicle-mounted energy storage device, a household energy storage device, a mobile energy storage device, and the like. After receiving the electrical energy transmitted by the photovoltaic module 101, the electronic device 102 stores the received electrical energy. In an embodiment of the present application, the electronic device 102 includes a battery pack, and the battery pack is used to store the electrical energy transmitted by the photovoltaic module 101.

[0030] The electronic device 102 can implement the maximum power point tracking method to determine the maximum power point of the photovoltaic module 101. In an embodiment of the present application, after determining the maximum power point of the photovoltaic module 101, the electronic device 102 can update the output voltage of the photovoltaic module 101 to the output voltage corresponding to the maximum power point of the photovoltaic module 101, so that the photovoltaic module 101 works at the maximum power point. Figure 2 FIG. 2 is a flowchart of a maximum power point tracking method provided in the embodiments of the present application. Figure 2 The method shown in FIG. 2 is applied to an electronic device. According to different requirements, the order of the steps in the flowchart can be changed, and some steps can be omitted. The maximum power point tracking method provided in the embodiments of the present application includes steps 210, 220, 230, 240, 250, and 260.

[0031] At step 210, a plurality of output powers are calculated according to the output voltage and the output current of the photovoltaic module in the target period.

[0032] The target period is the period for which the maximum power point is calculated this time, and can be set according to actual conditions.

[0033] In an embodiment of the present application, the photovoltaic module can be a solar power generation device composed of a plurality of photovoltaic panels or photovoltaic modules in series, parallel or mixed manner.

[0034] Based on the output voltage and the output current output by the photovoltaic module each time, the output power corresponding to the output this time is calculated, thereby obtaining a plurality of output powers in the target period.

[0035] At step 220, a scatter plot is generated according to each output power and the corresponding output voltage.

[0036] In an embodiment of the present application, the scatter plot can be used to represent the relationship between the change of the output power and the change of the output voltage. Specifically, the horizontal coordinate of the scatter plot is the voltage, and the vertical coordinate is the output power.

[0037] At step 230, the first slope value after linear fitting between each point on the scatter plot and the target number of points adjacent to the left of the point is calculated, and the second slope value after linear fitting between each point on the scatter plot and the target number of points adjacent to the right of the point is calculated.

[0038] In an embodiment of the present application, the target number of points adjacent to the left of a point on the scatter plot is the point obtained by counting the target number of points from the left of the point; the target number of points adjacent to the right of a point on the scatter plot is the point obtained by counting the target number of points from the right of the point. Figure 3 A scene schematic diagram of a scatter plot provided in an embodiment of the present application is shown. Figure 3 Only part of the points in the scatter plot are shown, and other points are not shown. For example, the target number is set to 2, the target number of points adjacent to the left of point C is the point obtained by counting 2 points from the left of point D: points B and A; the target number of points adjacent to the right of point C is the point obtained by counting 2 points from the right of point C: points D and E.

[0039] In an embodiment of the present application, when the first slope value of a point on the scatter plot is calculated, a plurality of linear fitting methods such as least squares method, gradient descent method and Gauss-Newton method can be used. Alternatively, the point and the target number of points adjacent to the left of the point can be substituted into a preset formula for linear fitting, thereby obtaining the first slope value corresponding to the point. For example, the preset formula can be: Y i =aX i +b, wherein X i is the voltage, and Y iwherein, X is the voltage, Y is the power, and i is a positive integer. The values of a and b are obtained by linear fitting of the point and the target number of points adjacent to the left of the point, and the value corresponding to a is determined as the first slope value corresponding to the point.

[0040] In an embodiment of the present application, the second slope value of a point on the scatter plot can be calculated in various linear fitting manners such as the least square method, the gradient descent method, and the Gauss-Newton method. The second slope value corresponding to the point can also be obtained by linear fitting of the point and the target number of points adjacent to the right of the point, respectively, into the preset formula. The preset formula can be Y = cX + d, wherein, X is the voltage, Y is the power, and i is a positive integer. i i i i wherein, X is the voltage, Y is the power, and i is a positive integer. The values of a and b are obtained by linear fitting of the point and the target number of points adjacent to the left of the point, and the value corresponding to a is determined as the first slope value corresponding to the point.

[0041] In an embodiment of the present application, the target number can be set according to actual conditions, or can also be obtained according to other calculation manners, which is not limited herein. For example, the target number can be set as an integer greater than or equal to 2.

[0042] In step 240, a slope difference distribution curve is generated according to the slope difference between the first slope value and the second slope value of each point.

[0043] It can be understood that the slope difference of any point in the scatter plot can be used to represent the degree of change in power of the point relative to the surrounding points. If the slope difference on the left and right sides of the point is greater, it indicates that the power of the point changes more dramatically relative to the surrounding points; and if the slope difference of the point is smaller, it indicates that the power of the point changes more gently relative to the surrounding points.

[0044] Specifically, the slope difference between the first slope value and the second slope value of each point in the scatter plot is obtained, and a data set including the output voltage value corresponding to each point in the scatter plot and the slope difference corresponding to the output voltage value is obtained. Then, data processing and linear fitting of the data in the data set are performed to obtain the slope difference distribution curve. Thus, the abscissa and the ordinate of the slope difference distribution curve are the output voltage and the slope difference, respectively, and the distribution function corresponding to the curve is obtained by fitting the slope difference distribution curve. In this embodiment, the algorithm for linear fitting is not limited, which can be an interpolation method or other fitting algorithm.

[0045] In an embodiment of the present application, the slope difference distribution curve is generated by subtracting the first slope value from the second slope value.

[0046] ​​​In another embodiment of the present application, the first slope value can be subtracted from the second slope value to obtain a slope difference between the first slope value and the second slope value, and a slope difference distribution curve can be generated according to the obtained slope difference.

[0047] Figure 4 is a schematic diagram of a slope difference distribution curve provided by an embodiment of the present application. As shown in Figure 4 , the abscissa of the slope difference distribution curve is voltage, and the ordinate is slope difference.

[0048] In step 250, the slope difference distribution curve is differentiated to obtain an extreme point.

[0049] In an embodiment of the present application, the slope difference distribution curve is first-order differentiated, the derivative of the continuous function corresponding to the slope difference distribution curve is set to 0, and an extreme point is obtained.

[0050] It can be understood that in different embodiments, the number of extreme points calculated by differentiating different slope difference distribution curves also varies.

[0051] Although the scatter plot is discrete points, the distribution of the points in the corresponding coordinate system can show a trend of ups and downs similar to the formation of a wave. In the case that the photovoltaic module is in a stable light condition, the scatter plot in the scatter plot is approximately a single-peak waveform, and when the slope difference distribution curve is differentiated, an extreme point is obtained. In the case that the photovoltaic module is in an unstable light condition or a local shadow condition, the scatter plot in the scatter plot is approximately a waveform with multiple peaks and troughs, and when the slope difference distribution curve is differentiated, multiple extreme points are obtained.

[0052] For example, continuing to refer to Figure 3 , for ease of understanding, the dashed line is used to represent the trend curve of the scatter plot, and it can be seen that the wave formed by the distribution trend of the points can show a multi-peak phenomenon, and multiple peaks and troughs can be formed. The peak of the wave formed by the distribution trend of the points can be the point corresponding to the maximum power value in the scatter plot. Specifically, when the wave formed by the distribution trend of the points shows a single-peak phenomenon, the above-mentioned one extreme point obtained according to the slope difference distribution curve can be used to find the peak, i.e., the point corresponding to the maximum power value in the scatter plot; when the wave formed by the distribution trend of the points shows a multi-peak phenomenon, the above-mentioned multiple extreme points obtained according to the slope difference distribution curve can be used to find the peaks and troughs, and the maximum power value corresponding point can be found according to the maximum value of the power points corresponding to the peaks and troughs. It can be understood that the waveform of the wave formed by the distribution trend of the points in the scatter plot corresponding to a target period of a photovoltaic module is substantially the same as the waveform of the P-U output characteristic curve of the photovoltaic module in the target period.

[0053] In step 260, the first maximum power point of the photovoltaic module in the target period is determined according to the power value of the extreme point determined in the scatter plot.

[0054] Since the slope difference distribution curve is obtained according to the first slope and the second slope of each point in the scatter diagram in the above steps, the abscissa of the slope difference distribution curve is the output voltage, and therefore the extreme point obtained by derivation of the slope difference distribution curve also corresponds to the output power in the scatter diagram. Then, the output voltage corresponding to the extreme point is substituted into the scatter diagram, so as to determine the power value corresponding to the voltage value, that is, the power value of the extreme point.

[0055] As described above, when there are multiple extreme points, the extreme points can find the points corresponding to the peaks and troughs of the wave formed by the point distribution trend in the scatter diagram, but only the point corresponding to the highest peak in the wave formed by the point distribution trend is the point corresponding to the maximum power value in the scatter diagram. The extreme point itself cannot directly determine whether the extreme point is the point corresponding to the highest peak in the wave formed by the point distribution trend, and therefore, the maximum power value is found by finding the maximum power value corresponding to each extreme point, that is, the point corresponding to the maximum power value in the scatter diagram.

[0056] The present application obtains the slope difference distribution curve through the slope difference of each point in the scatter diagram. Since the slope difference of a point in the scatter diagram can be used to represent the degree of change in probability of the point relative to surrounding points, the extreme point obtained by derivation of the slope difference distribution curve can correspond to an output voltage with a large change in output power of the photovoltaic module. The extreme point obtained by derivation of the slope difference distribution curve includes all points of the photovoltaic module in the target period, and the maximum power point is determined based on the obtained extreme point, so that the maximum power point can be determined from a global perspective, and the calculation of the maximum power point will not be trapped in a local maximum when the point distribution trend in the scatter diagram has a multi-peak phenomenon, thereby achieving the technical effect that the maximum power point can be accurately tracked regardless of the illumination condition of the photovoltaic module.

[0057] Figure 5 The present application provides a method for determining a maximum power point of a photovoltaic module. Figure 2 The detailed flowchart of step 230 is applied to an electronic device. The order of steps in the flowchart can be changed according to different requirements, and some steps can be omitted. Step 230 includes step 410, step 420, and step 430.

[0058] Step 410 performs multiple linear fitting on each point in the scatter diagram to obtain a corresponding linear fitting model.

[0059] Specifically, in this embodiment, the points in the scatter plot can be linearly fitted multiple times, and a linear fitting model corresponding to each time of linear fitting can be obtained. In an embodiment of this application, at each time of linear fitting, the points in the scatter plot can be grouped, for example, two points in a group or three points in a group, etc. Taking two points in a group as an example, linear fitting can be performed on the points in the scatter plot two by two, and a plurality of linear fitting sets can be obtained, which are the linear fitting models described above.

[0060] In an embodiment of this application, linear fitting is performed on each point in the scatter plot and its left and right adjacent points of a test number, and a linear fitting model is obtained. By modifying the value of the test number, multiple linear fittings can be performed on each point in the scatter plot, and a linear fitting model corresponding to each time of linear fitting can be obtained, thereby obtaining a plurality of linear fitting models. The values of the test number corresponding to different linear fittings are different. The test numbers corresponding to different linear fitting models are different, and the value range of the test number can be set according to actual conditions, for example, 1-15. For some specific implementations of performing linear fitting, refer to the related description of step 230 of method 200 in the foregoing. Figure 2

[0061] In an embodiment of this application, the test number is sequentially set to 1-15, and 15 linear fittings are performed on each point in the scatter plot, thereby obtaining 15 corresponding linear fitting models.

[0062] In step 420, the goodness of fit of each linear fitting model is calculated according to the scatter plot.

[0063] In an embodiment of this application, the goodness of fit is an index for measuring the fitting degree of a linear fitting model to the data in the scatter plot. The better the goodness of fit of a linear fitting model, the more accurately the linear fitting model can describe the variability or error of each point in the scatter plot.

[0064] In an embodiment of this application, the coefficient of determination of a linear fitting model can be calculated according to the points in the scatter plot, thereby determining the goodness of fit of the linear fitting model. The coefficient of determination is an index for measuring the fitting degree of a fitting model to observed data, and its value is between 0 and 1. The closer the value is to 1, the better the fitting degree of the linear fitting model to the data. In an embodiment of this application, the coefficient of determination of a linear fitting model can be determined as the goodness of fit of the linear fitting model. For example, after 15 linear fittings are performed on each point in the scatter plot to obtain 15 linear fitting models, the coefficient of determination of each linear fitting model in the 15 linear fitting models can be calculated, and the goodness of fit of each linear fitting model can be determined according to the coefficient of determination of the linear fitting model.

[0065] ​Step 430, determining the test number corresponding to the linear fitting model with the largest goodness of fit value as the target number, and calculating the first slope value and the second slope value of each point according to the linear fitting model with the largest goodness of fit value and the target number.

[0066] The linear fitting model with the largest goodness of fit value is the linear fitting model with the largest goodness of fit calculated in step 420.

[0067] In an embodiment of the present application, the linear fitting model with the largest goodness of fit value can be determined as the target linear fitting model, and the test number corresponding to the target linear fitting model can be determined as the target number. Then, the first slope value and the second slope value of each point in the scatter plot are calculated, which will be explained in detail in the corresponding explanation of step S230. For example, the linear fitting model with the largest goodness of fit value among the 15 linear fitting models is determined as the target linear fitting model, and the test number corresponding to the target linear fitting model is determined as the target number. When the test number corresponding to the linear fitting model with the largest goodness of fit value is 2, the target number is set to 2. The first slope value of each point on the scatter plot and the two points adjacent to the left of the point, and the second slope value of each point on the scatter plot and the two points adjacent to the right of the point are calculated.

[0068] In the above embodiment, the first slope value and the second slope value are calculated by performing multiple linear fitting on each point on the scatter plot, obtaining a linear fitting model corresponding to each point, and selecting the linear fitting model with the largest goodness of fit value from the obtained multiple linear fitting models, which can make the calculation of the first slope value and the second slope value more accurate and improve the accuracy of the calculation of the first slope value and the second slope value.

[0069] Figure 6 is a detailed flowchart of a method for determining the maximum power point of the photovoltaic module in the target period according to the power value of the extreme point determined in the scatter plot, provided by an embodiment of the present application, applied to an electronic device. According to different needs, the order of steps in the flowchart can be changed, and some steps can be omitted. Among them, determining the maximum power point of the photovoltaic module in the target period according to the power value of the extreme point determined in the scatter plot includes steps 510, 520 and 530.

[0070] Step 510, obtaining the extreme voltage value corresponding to the extreme point.

[0071] In an embodiment of the present application, the output voltage corresponding to each extreme point, i.e. the extreme voltage value, can be determined according to the slope difference distribution curve. It should be noted that the extreme voltage value is one or more of the output voltages.

[0072] Step 520: Determine the power corresponding to the extreme voltage value in the scatter plot based on the extreme voltage value to obtain the power value.

[0073] The scatter plot includes the mapping relationship between output voltage and output power. In one embodiment of this application, the extreme voltage corresponding to each extreme point is substituted into the scatter plot for querying to determine the power corresponding to the extreme voltage, thereby obtaining the power value.

[0074] Step 530: Determine the maximum power value in the power values ​​as the maximum power point of the photovoltaic module in the target period.

[0075] After finding the power value corresponding to the extreme voltage value, the global maximum power value in the scatter plot can be found.

[0076] The above embodiments can determine the corresponding extreme voltage value based on the extreme point, and determine the power corresponding to the extreme voltage value in the scatter plot based on the extreme voltage value, thereby obtaining the power value corresponding to the extreme point. Finally, the maximum power point is obtained based on the determined power value. The method of calculating the maximum power point by the above method can accurately find the global maximum power point.

[0077] Figure 7 This is a detailed flowchart of a method for determining the maximum power point of a photovoltaic module in a target period based on the power values ​​determined by the extreme points in a scatter plot, provided by an embodiment of this application, and applied to electronic devices. The order of the steps in this flowchart can be changed, and some steps can be omitted, depending on different requirements. Specifically, determining the maximum power point of the photovoltaic module in the target period based on the power values ​​determined by the extreme points in the scatter plot includes steps 610 and 620.

[0078] Step 610: Determine the second maximum power point of the photovoltaic module based on the perturbation observation method.

[0079] In this embodiment, maximum power tracking is performed on the output power of the same photovoltaic module for two adjacent periods (the target period and the test period adjacent to the target period). Figure 2 The maximum power point of the photovoltaic module calculated by the method shown in the figure during the target period is called the first maximum power point of the photovoltaic module; the maximum power point of the photovoltaic module calculated using the perturbation observation method during the test period is called the second maximum power point of the photovoltaic module. In one embodiment of this application, the period range of the target period is the same as the period range of the test period, the two periods are adjacent in time, and the illumination conditions of the photovoltaic module during the target period are the same as those during the test period.

[0080] In another embodiment of the present application, the second maximum power point is the maximum power point of another photovoltaic module calculated by using the perturb and observe method in the target period. In this embodiment, the photovoltaic module for calculating the first maximum power point and the photovoltaic module for calculating the second maximum power point are two photovoltaic modules of the same type, and the two photovoltaic modules are under the same light condition in the target period. Since the two photovoltaic modules are of the same type and are under the same light condition in the target period, the second maximum power points calculated by using the perturb and observe method for the two photovoltaic modules are the same, so the second maximum power point of one photovoltaic module calculated by using the perturb and observe method can be directly determined as the second maximum power point of the other photovoltaic module.

[0081] In step 620, the target maximum power point of the photovoltaic module is determined based on the first maximum power point and the second maximum power point.

[0082] In an embodiment of the present application, the target maximum power point of the photovoltaic module can be determined as the average of the first maximum power point and the second maximum power point. In the above embodiment, the second maximum power point of the photovoltaic module is determined by using the perturb and observe method, and then the target maximum power point of the photovoltaic module is determined according to the first maximum power point and the second maximum power point obtained by using two different methods, which can improve the accuracy of determining the maximum power point.

[0083] In an embodiment of the present application, the target maximum power point of the photovoltaic module can be determined as the larger value of the first maximum power point and the second maximum power point. In the above embodiment, since the first maximum power point and the second maximum power point are both calculated maximum power points, selecting the larger value as the target maximum power point of the photovoltaic module can make the determined target maximum power point larger, so that the output power of the photovoltaic module can be larger when the output voltage of the photovoltaic module is adjusted according to the target maximum power point.

[0084] In an embodiment of the present application, the target maximum power point of the photovoltaic module can be determined as the smaller value of the first maximum power point and the second maximum power point. In the above embodiment, in order to avoid the possibility that the larger calculated maximum power point is an error and the actual maximum power point of the photovoltaic module is smaller than the larger calculated maximum power point, the smaller maximum power point is selected as the target maximum power point of the photovoltaic module, which avoids the situation that the output voltage of the photovoltaic module is adjusted according to the maximum power point that the photovoltaic module cannot reach, thereby improving the accuracy of the photovoltaic module control.

[0085] Therefore, the method for determining the target maximum power point of the photovoltaic module based on the first maximum power point and the second maximum power point in the present embodiment can be adjusted according to actual needs to accurately determine the maximum power point of the photovoltaic module.

[0086] Figure 8 is a detailed flowchart of a method for determining a target maximum power point of a photovoltaic module based on a first maximum power point and a second maximum power point, provided by an embodiment of the present application, applied to an electronic device. The order of steps in the flowchart can be changed according to different needs, and some steps can be omitted. The method for determining a target maximum power point of a photovoltaic module based on a first maximum power point and a second maximum power point includes steps 710, 720, 730, and 740.

[0087] Step 710: Calculate the power difference between the first maximum power point and the second maximum power point.

[0088] In an embodiment of the present application, the absolute value of the power difference between the first maximum power point and the second maximum power point can be determined as the power difference between the first maximum power point and the second maximum power point. Alternatively, the absolute value of the power difference between the second maximum power point and the first maximum power point can be determined as the power difference between the first maximum power point and the second maximum power point.

[0089] Step 720: Determine whether the power difference is less than a preset threshold.

[0090] The preset threshold is the maximum difference in power value. When the power difference between the first maximum power point and the second maximum power point is equal to or less than the preset threshold, it is determined that the maximum power points calculated by the two methods are both relatively accurate, and it is determined that the current light is relatively stable; when the power difference between the first maximum power point and the second maximum power point is greater than the preset threshold, it is determined that the light in which the photovoltaic module is currently located is unstable or that the photovoltaic module is partially shaded, and the value calculated by the perturb and observe method may have errors. The preset threshold can be set according to actual conditions.

[0091] If the power difference between the first maximum power point and the second maximum power point is less than the preset threshold, step 730 determines the second maximum power point as the target maximum power point of the photovoltaic module.

[0092] If the power difference between the first maximum power point and the second maximum power point is greater than or equal to the preset threshold, step 740 determines the first maximum power point as the target maximum power point of the photovoltaic module.

[0093] The above embodiment compares the first maximum power point with the second maximum power point to determine whether the second maximum power point determined by the perturb and observe method is abnormal, and in the case where it can be determined that the second maximum power point is abnormal, determines the first maximum power point with higher accuracy as the target maximum power point of the photovoltaic module, thereby improving the accuracy of determining the maximum power point.

[0094] In an embodiment of the present application, when the power difference between the first maximum power point and the second maximum power point is less than the preset threshold, the electronic device uses the perturb and observe method to calculate the maximum power point of the photovoltaic module in a preset time period after the target period. The preset time period after the target period can be set according to actual conditions, such as 1 hour, 2 hours, etc. after the target period.

[0095] Since the perturb and observe method does not need to use many detection sensors, it is relatively cost-saving. Therefore, in the above embodiment, when it is determined that the current illumination is relatively stable and the perturb and observe method can accurately determine the maximum power point, the perturb and observe method is continued to be used to calculate the maximum power point of the photovoltaic array in a preset time period, so as to reduce the cost of calculating the maximum power point while ensuring that the maximum power point is accurately determined.

[0096] Figure 9 FIG. 8 is a structural schematic diagram of a maximum power point tracking device provided in an embodiment of the present application. In some embodiments, the maximum power point tracking device 80 can include a plurality of functional modules composed of computer program segments. The computer programs of each program segment in the maximum power point tracking device 80 can be stored in the memory of the electronic device and executed by at least one processor to perform the maximum power point tracking method in the plurality of embodiments described above.

[0097] In the present embodiment, the maximum power point tracking device 80 can be divided into a plurality of functional modules according to the functions performed thereby. The plurality of divided functional modules can include a first calculation module 810, an image generation module 820, a second calculation module 830, a curve generation module 840, a curve derivation module 850, and a third calculation module 860. The module referred to in the present application refers to a series of computer program segments that can be executed by at least one processor and can complete a fixed function, which are stored in the memory. In the embodiments of the present application, the definition of the maximum power point tracking device 80 can refer to the definition of the maximum power point tracking method described above, and will not be described in detail here.

[0098] The first calculation module 810 is configured to calculate each output power according to the output voltage and the output current of the photovoltaic module in the target period.

[0099] The image generation module 820 is configured to generate a scatter plot according to each output power and the corresponding output voltage; the horizontal coordinate of the scatter plot is voltage, and the vertical coordinate is power.

[0100] The second calculation module 830 is configured to calculate a first slope value after linear fitting between each point on the scatter plot and a target number of points adjacent to the left of the point, and calculate a second slope value after linear fitting between each point on the scatter plot and a target number of points adjacent to the right of the point.

[0101] The curve generation module 840 is configured to generate a slope difference distribution curve according to the slope difference between the first slope value and the second slope value of each point.

[0102] The curve derivation module 850 is configured to derive the slope difference distribution curve to obtain an extreme point.

[0103] The third calculation module 860 is configured to determine a corresponding power value in the scatter plot according to the extreme point, and determine the first maximum power point of the photovoltaic module in the target period according to the power value.

[0104] In an embodiment of the present application, the second calculation module 830 is configured to perform multiple linear fitting on each point on the scatter plot to obtain a corresponding linear fitting model, the number of tests in each linear fitting process is different, the goodness of fit of each linear fitting model is calculated according to the scatter plot, and the first slope value and the second slope value of each point are calculated according to the linear fitting model with the largest goodness of fit.

[0105] In an embodiment of the present application, the third calculation module 860 is configured to obtain an extreme voltage value corresponding to the extreme point, determine a power corresponding to the extreme voltage value in the scatter plot according to the extreme voltage value to obtain a power value, and determine the maximum power value in the power value as the first maximum power point of the photovoltaic module in the target period.

[0106] In an embodiment of the present application, the maximum power point tracking device 80 further comprises a fourth calculation module. The fourth calculation module is configured to determine the second maximum power point of the photovoltaic module in the target period based on the perturb and observe method, and determine the target maximum power point of the photovoltaic module according to the first maximum power point and the second maximum power point.

[0107] In an embodiment of the present application, the fourth calculation module is configured to calculate the power difference value between the first maximum power point and the second maximum power point, and determine the first maximum power point as the target maximum power point of the photovoltaic module if the power difference value between the first maximum power point and the second maximum power point is greater than or equal to a preset threshold.

[0108] In an embodiment of the present application, the fourth calculation module is configured to determine the second maximum power point as the target maximum power point of the photovoltaic module if the power difference value between the first maximum power point and the second maximum power point is less than the preset threshold.

[0109] It can be understood that the above-described module division is a logical function division, and actual implementation can have another division manner. In addition, each function module in each embodiment of the present application can be integrated in the same processing unit, or each module can be physically present separately, or two or more modules can be integrated in the same unit. The above integrated module can be realized in the form of hardware or in the form of hardware plus software function module.

[0110] In the embodiment, some specific implementations of the functions of each module / unit can be described in the above-described maximum power point tracking method of the plurality of embodiments, and will not be described here.

[0111] As can be seen from the above technical solutions, the maximum power point tracking device obtains a plurality of output powers according to the output voltage and the output current of the photovoltaic module in the target period, and generates a scatter plot based on each output power and the corresponding output voltage. Then, the first slope value corresponding to the linear fitting between each point in the scatter plot and the target number of points adjacent to the left of the point, and the second slope value corresponding to the linear fitting between the point and the target number of points adjacent to the right of the point are calculated, and the slope difference distribution curve is obtained based on the slope difference between the first slope value and the second slope value. Then, the slope difference distribution curve is differentiated to calculate the extreme point.

[0112] In the embodiment, the slope difference distribution curve is obtained by the slope difference of each point in the scatter plot. Since the slope difference of a point in the scatter plot can be used to represent the degree of change in probability of the point relative to the surrounding points, the extreme point obtained by differentiating the slope difference distribution curve can correspond to the output voltage with large output power change of the photovoltaic module. The slope difference distribution curve includes all the points of the photovoltaic module in the target period, and the extreme point obtained by differentiating the slope difference distribution curve and based on the obtained extreme point to determine the maximum power point can determine the maximum power point from a global perspective, and will not fall into the case of local maximum in the calculation of the maximum power point when the point distribution trend in the scatter plot shows a multi-peak phenomenon. The technical effect of accurately tracking the maximum power point regardless of the illumination condition of the photovoltaic module is achieved.

[0113] Please refer to Figure 10 , Figure 10 The structure of the electronic device provided in an embodiment of the present application is shown in a schematic block diagram.

[0114] The network in which the electronic device 102 is located includes but is not limited to the Internet, a wide area network, a metropolitan area network, a local area network, a virtual private network (VPN), etc.

[0115] As Figure 10As shown, the electronic device 102 includes a communication interface 901, a memory 902, a processor 903, an input / output (I / O) interface 904, and a bus 905. The processor 903 is coupled to the communication interface 901, the memory 902, and the I / O interface 904 via the bus 905, respectively.

[0116] The communication interface 901 is configured to perform communication. The communication interface 901 can be an existing interface of the electronic device 102, or a newly built interface of the electronic device 102. The communication interface 901 can be a network interface, such as a wireless local area network (WLAN) interface, a cellular network communication interface, or a combination thereof.

[0117] The memory 902 can be configured to store an operating system and computer programs. For example, the memory 902 stores a program corresponding to the maximum power point tracking method.

[0118] It should be understood that the memory 902 can include a program storage area and a data storage area. The program storage area can be configured to store an operating system, at least one application program (such as the maximum power point tracking method), and the like; and the data storage area can be configured to store data created according to the use of the electronic device 102, and the like. In addition, the memory 902 can include a volatile memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other memory devices.

[0119] The processor 903 provides computing and control capabilities to support the operation of the entire computer device. For example, the processor 903 is configured to execute the computer programs stored in the memory 902 to implement the steps in the maximum power point tracking method, such as the steps in the maximum power point tracking method. Figures 2 to 8

[0120] ​It should be understood that the processor 903 is a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0121] The I / O interface 904 is configured to provide a channel for user input or output. For example, the I / O interface 904 can be configured to connect various input and output devices (such as a mouse, a keyboard, a 3D touch device, etc.), a display, so that a user can input information or visualize the information.

[0122] The bus 905 is configured to provide a channel for communication between the communication interface 901, the memory 902, the processor 903, and the I / O interface 904 in the electronic device 102.

[0123] Those skilled in the art can understand that, Figure 10 The structure shown is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. A specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0124] In one embodiment, the maximum power point tracking method is applied to the electronic device 102. When the processor 903 executes the computer program stored in the memory 902 to implement the maximum power point tracking method, the following steps are implemented:

[0125] According to the output voltage and the output current of the photovoltaic module in the target period, a plurality of output powers are calculated;

[0126] According to each output power and the corresponding output voltage, a scatter plot is generated;

[0127] The first slope value of the linear fitting between each point on the scatter plot and the target number of points adjacent to the left of the point is calculated, and the second slope value of the linear fitting between each point on the scatter plot and the target number of points adjacent to the right of the point is calculated;

[0128] According to the slope difference between the first slope value and the second slope value of each point, a slope difference distribution curve is generated;

[0129] Derivate the slope difference distribution curve to obtain an extreme point;

[0130] According to the power value of the extreme point determined in the scatter plot, the first maximum power point of the photovoltaic module in the target period is determined.

[0131] Specifically, the specific implementation method of the processor 903 to the above instructions can refer to the description of the related steps in the foregoing maximum power point tracking method embodiments, which will not be described here.

[0132] The embodiments of the present application also provide a computer readable storage medium, the computer readable storage medium stores a computer program, the computer program includes program instructions, and the method implemented when the program instructions are executed can refer to the various embodiments of the maximum power point tracking method of the present application.

[0133] The computer readable storage medium can be an internal storage unit of the electronic device, such as a hard disk or a memory of the electronic device. The computer readable storage medium can also be an external storage device of the electronic device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc.

[0134] Further, the computer readable storage medium can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function, etc.; and the data storage area can store data created according to the use of the electronic device, etc.

[0135] The electronic device and the computer readable storage medium provided by the foregoing embodiments can obtain the slope difference distribution curve from the slope difference of each point in the scatter plot. Since the slope difference of a point in the scatter plot can be used to represent the degree of change in probability of the point relative to surrounding points, the extreme point obtained by deriving the slope difference distribution curve can correspond to an output voltage with a relatively large change in output power of the photovoltaic module. Moreover, the slope difference distribution curve includes all points of the photovoltaic module in the target period. The extreme point obtained by deriving the slope difference distribution curve and the maximum power point determined based on the obtained extreme point can achieve the technical effect of accurately tracking the maximum power point regardless of the illumination conditions of the photovoltaic module.

[0136] It should also be understood that the terms used herein are for the purpose of describing particular embodiments and are not intended to limit the application. As used in this specification and the appended claims, the singular forms "a," "an" and "the" are intended to include plural referents unless the context clearly dictates otherwise.

[0137] It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items, and that the term "at least one of' as used herein means one or more. It is further noted that the use of "a" or "an", that is, a singular form, is intended to include one or more than one, unless explicitly stated otherwise. It is further noted that the use of "comprise", "comprises", "comprising", "contain", "contains", "containing", "include", "includes", "including" or "has" or "having" or "have" or "having", or variants thereof, is intended to be open-ended, and to encompass the stated item or items and equivalents thereof and additional items or items.

[0138] The above-mentioned embodiment serial numbers of the present application are only for description, and do not represent advantages or disadvantages of the embodiments. The above describes only the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A maximum power point tracking method, characterized in that, The method includes: Multiple output powers are calculated based on the output voltage and output current of the photovoltaic module within the target period; A scatter plot is generated based on the output power and corresponding output voltage of each item; Calculate the first slope value of the linear fit between each point on the scatter plot and the number of target points adjacent to it on its left, and calculate the second slope value of the linear fit between each point on the scatter plot and the number of target points adjacent to it on its right. Based on the slope difference between the first slope value and the second slope value at each point, a slope difference distribution curve is generated; Differentiating the slope difference distribution curve yields the extreme points; Determining the first maximum power point of the photovoltaic module in the target period based on the power value determined by the extreme point in the scatter plot includes: determining the power corresponding to the extreme voltage value in the scatter plot based on the extreme voltage value corresponding to the extreme point, and obtaining the power value; and determining the maximum power value among the power values ​​as the first maximum power point of the photovoltaic module in the target period.

2. The maximum power point tracking method as described in claim 1, characterized in that, The calculation of the first slope value after linear fitting between each point and the number of target points adjacent to its left, and the calculation of the second slope value after linear fitting between each point on the scatter plot and the number of target points adjacent to its right, include: Multiple linear fitting operations are performed on each point on the scatter plot to obtain the corresponding linear fitting model; the number of tests is different in each linear fitting process. The goodness of fit of each of the linear fitting models is calculated based on the scatter plot; The number of tests corresponding to the linear fitting model with the largest goodness-of-fit value is determined as the target number, and the first slope value and the second slope value of each point are calculated based on the linear fitting model with the largest goodness-of-fit value and the target number.

3. The maximum power point tracking method as described in claim 1, characterized in that, The method further includes: The second maximum power point of the photovoltaic module is determined based on the perturbation observation method. The target maximum power point of the photovoltaic module is determined based on the first maximum power point and the second maximum power point.

4. The maximum power point tracking method as described in claim 3, characterized in that, Determining the target maximum power point of the photovoltaic module based on the first maximum power point and the second maximum power point includes: Calculate the power difference between the first maximum power point and the second maximum power point; If the power difference between the first maximum power point and the second maximum power point is greater than or equal to a preset threshold, then the first maximum power point is determined as the target maximum power point of the photovoltaic module.

5. The maximum power point tracking method as described in claim 4, characterized in that, The method further includes: If the power difference between the first maximum power point and the second maximum power point is less than the preset threshold, the second maximum power point is determined as the target maximum power point of the photovoltaic module.

6. The maximum power point tracking method as described in any one of claims 1 to 5, characterized in that, The target quantity is an integer value greater than or equal to 2.

7. A maximum power point tracking device, characterized in that, The maximum power point tracking device includes: The first calculation module is used to calculate the output power based on the output voltage and output current of the photovoltaic module within the target period; The image generation module is used to generate a scatter plot based on each output power and the corresponding output voltage; The second calculation module is used to calculate the first slope value after linear fitting between each point on the scatter plot and the number of target points adjacent to its left, and to calculate the second slope value after linear fitting between each point on the scatter plot and the number of target points adjacent to its right. The curve generation module is used to generate a slope difference distribution curve based on the slope difference between the first slope value and the second slope value at each point; The curve differentiation module is used to differentiate the slope difference distribution curve to obtain the extreme points; The third calculation module is used to determine the corresponding power value in the scatter plot based on the extreme point; and to determine the first maximum power point of the photovoltaic module in the target period based on the power value; wherein, the third calculation module is used to determine the power corresponding to the extreme voltage value in the scatter plot based on the extreme voltage value corresponding to the extreme point, and to obtain the power value; and to determine the maximum power value among the power values ​​as the first maximum power point of the photovoltaic module in the target period.

8. An electronic device, characterized in that, The electronic device includes: Memory, which stores computer-readable instructions; and The processor executes computer-readable instructions stored in the memory to implement the maximum power point tracking method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-readable instructions that are executed by a processor in an electronic device to implement the maximum power point tracking method as described in any one of claims 1 to 6.

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