A photovoltaic string azimuth angle determination method, device and electronic equipment

Abstract

The application provides a photovoltaic string azimuth angle determination method and device and electronic equipment. The method comprises the following steps: acquiring power generation performance data sequence of a photovoltaic string and solar angles at different time points, wherein the power generation performance data sequence comprises power generation performance data of the photovoltaic string at different time points; determining a maximum data time point corresponding to maximum power generation performance data in the power generation performance data sequence, and establishing a target function according to the solar angles at different time points and the power generation performance data; and determining a string azimuth angle of the photovoltaic string according to the maximum data time point and the target function. The technical scheme of the application reduces the workload and labor cost of determining the photovoltaic string azimuth angle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, in particular to a photovoltaic string azimuth angle determination method and device and electronic equipment. BACKGROUND

[0002] In a photovoltaic power station, the azimuth angle of a photovoltaic string has a crucial influence on the power generation of the photovoltaic power station. The azimuth angle refers to the angle between the vertical plane of the photovoltaic string and the direction of due south, due north, due east or due west. Due to the influence of terrain and construction reasons, the azimuth angles of different photovoltaic strings may not be consistent. When photovoltaic strings with different azimuth angles are connected in parallel, parallel mismatch may occur, thereby affecting the power generation of the entire inverter. Therefore, if the azimuth angle of a photovoltaic string can be detected in time, and the optimal solution for connecting the photovoltaic string to a maximum power point tracking system is determined when the azimuth angles of photovoltaic strings are inconsistent, the power generation of the photovoltaic power station can be effectively improved.

[0003] However, the azimuth angle of a photovoltaic string is currently manually measured by a human, which is not only labor-intensive but also inefficient. SUMMARY

[0004] The problem solved by the present application is how to improve the efficiency of determining the azimuth angle of a photovoltaic string and reduce the workload of staff.

[0005] To solve the above problems, the present application provides a photovoltaic string azimuth angle determination method, device and electronic equipment.

[0006] In a first aspect, the present application provides a photovoltaic string azimuth angle determination method, comprising:

[0007] obtaining a power generation performance data sequence of a photovoltaic string and a solar angle at different time points, the power generation performance data sequence comprising power generation performance data of the photovoltaic string at different time points;

[0008] determining a maximum data time point corresponding to maximum power generation performance data in the power generation performance data sequence, and establishing a target function according to the solar angle at each time point and the power generation performance data;

[0009] determining the string azimuth angle of the photovoltaic string according to the maximum data time point and the target function.

[0010] Optionally, the determination of the maximum data time point corresponding to the maximum power generation performance data in the power generation performance data sequence comprises:

[0011] obtaining the temperature of the photovoltaic string at different time points, respectively correcting the power generation performance data at each time point according to the temperature to obtain corrected power generation performance data at each time point;

[0012] determining the maximum data moment corresponding to the maximum power generation performance data in all the modified power generation performance data.

[0013] Optionally, the solar angles include a solar elevation angle, a solar azimuth angle and a solar incident angle, and the obtaining of the power generation performance data sequence of the photovoltaic string and the solar angles at different moments includes:

[0014] obtaining an declination angle and a solar time angle, and determining the solar elevation angle according to the solar time angle and the declination angle;

[0015] determining the solar azimuth angle according to the solar elevation angle and the declination angle;

[0016] determining the solar incident angle according to the solar elevation angle and the solar azimuth angle.

[0017] Optionally, the power generation performance data includes at least one of actual irradiance data, string current and string power of the photovoltaic string.

[0018] Optionally, the obtaining of the power generation performance data sequence of the photovoltaic string and the solar angles at different moments includes:

[0019] obtaining the power generation performance data sequence of the photovoltaic string on a typical sunny day, wherein the typical sunny day is a sunny day in which the power generation performance data meets a preset rule.

[0020] Optionally, the preset rule includes at least one of the following: a correlation between the actual irradiance data and clear sky model irradiance data is higher than a first preset threshold, a correlation between a first order difference of the actual irradiance data and a first order difference of the clear sky model irradiance data is higher than a second preset threshold, a correlation between the string current and a current calculated based on the clear sky model irradiance data is higher than a third preset threshold, and a correlation between the string power and a power calculated based on the clear sky model irradiance data is higher than a third preset threshold.

[0021] Optionally, the solar angles include a solar elevation angle and a solar incident angle, and when the power generation performance data includes the actual irradiance data, the actual irradiance data includes a direct irradiance value of a horizontal plane on which the photovoltaic string is located, and the establishing of the objective function according to the solar angles at different moments and the power generation performance data includes:

[0022] establishing the objective function according to the solar elevation angle, the solar incident angle and the actual irradiance data, the objective function being represented by a fourth formula, and the fourth formula including:

[0023]

[0024] wherein f(t) represents the objective function, represents the direct radiation value of the horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ t represents the solar incident angle at time t.

[0025] Optionally, the solar angle includes the solar elevation angle and the solar incident angle, when the power generation performance data includes the actual irradiance data, the actual irradiance data includes the direct radiation value of the horizontal plane where the photovoltaic string is located, and the target function is established according to the solar angle and the power generation performance data at each time point, including:

[0026] The target function is established according to the solar elevation angle, the solar incident angle and the actual irradiance data, and the target function is represented by a fifth formula, and the fifth formula includes:

[0027]

[0028] Wherein, f(t) represents the target function, represents the direct radiation value of the horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ t represents the solar incident angle at time t, and PR(G, t) represents the system efficiency between the photovoltaic string and the inverter at the azimuth angle of the string at time t.

[0029] Optionally, the determination of the string azimuth angle of the photovoltaic string according to the maximum data time point and the target function includes:

[0030] Solving the target function to determine the string azimuth angle of the photovoltaic string when the target function takes the maximum value at the maximum data time point.

[0031] Optionally, after determining the string azimuth angle of the photovoltaic string according to the maximum data time point and the target function, the method further includes:

[0032] Determining the wiring distance between each photovoltaic string and the corresponding inverter;

[0033] Weighted sum of the wiring distance and the string azimuth angle of the photovoltaic string to determine the eigenvalue of the photovoltaic string;

[0034] For any inverter, all photovoltaic strings connected to the inverter are sorted according to the eigenvalue in a predetermined order;

[0035] According to the sorting result, each photovoltaic string is allocated to the corresponding maximum power point tracking system.

[0036] In a second aspect, the present application provides a photovoltaic string azimuth angle determination device, comprising:

[0037] An acquisition module is configured to acquire a power generation performance data sequence of a photovoltaic string and solar angles at different time points, wherein the power generation performance data sequence comprises power generation performance data of the photovoltaic string at different time points.

[0038] A processing module is configured to determine a maximum data time point corresponding to maximum power generation performance data in the power generation performance data sequence, and to establish a target function according to the solar angles at different time points and the power generation performance data.

[0039] A calculation module is configured to determine a string azimuth angle of the photovoltaic string according to the maximum data time point and the target function.

[0040] In a third aspect, the present application provides an electronic device comprising a memory and a processor.

[0041] The memory is configured to store a computer program.

[0042] The processor is configured to implement the photovoltaic string azimuth angle determination method according to any one of the first aspect when executing the computer program.

[0043] The photovoltaic string azimuth angle determination method, device and electronic device have the following advantages: the power generation performance data sequence of a photovoltaic string to be processed is acquired, each power generation performance data in the power generation performance data sequence is compared with each other to determine maximum power generation performance data, and the time point corresponding to the maximum power generation performance data is a maximum data time point. Moreover, the solar angles at different time points are acquired, a target function is established according to the solar angles at different time points and the power generation performance data, the target function is solved according to the maximum data time point, and the photovoltaic string azimuth angle corresponding to the maximum value of the target function at the maximum data time point is the optimal photovoltaic string azimuth angle to be determined. The photovoltaic string azimuth angle is determined by the electronic device by combining the power generation performance data sequence of each photovoltaic string and the solar angles, which greatly improves the efficiency of determining the photovoltaic string azimuth angle and reduces the workload of the staff, thereby saving labor costs. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 FIG. 1 is a flowchart of a photovoltaic string azimuth angle determination method according to an embodiment of the present application;

[0045] Figure 2 FIG. 3 is a schematic diagram of target function curves at different photovoltaic string azimuth angles according to an embodiment of the present application;

[0046] Figure 3Fig. 1 is a schematic diagram of a photovoltaic array azimuth angle determination device according to an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the above objectives, characteristics and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein, but rather, these embodiments are provided so as to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are merely for illustrative purposes, and are not intended to limit the scope of protection of the present application.

[0048] It should be understood that each of the steps recited in the method embodiments of the present application can be executed in different orders, and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0049] The term "comprising" and variations thereof as used herein are used inclusively, i.e., "comprising but not limited to". The term "based on" is "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optional" means "optional in at least some embodiments". Related definitions will be given in the description below. It should be noted that the concepts "first", "second", etc. mentioned in the present application are merely used to distinguish different devices, modules or units, and are not intended to limit the order or interdependence of the functions performed by these devices, modules or units.

[0050] It should be noted that the modification of "one" or "multiple" mentioned in the present application is illustrative rather than limiting, and those skilled in the art should understand that, unless otherwise explicitly indicated in the context, it should be understood as "one or more".

[0051] The names of the messages or information exchanged between the multiple devices in the embodiments of the present application are merely for illustrative purposes, and are not intended to limit the scope of the messages or information.

[0052] As shown in FIG. 1, the photovoltaic array azimuth angle determination method provided by the embodiment of the present application comprises the following steps. Figure 1

[0053] In step S110, the power generation performance data sequence of the photovoltaic array and the solar angle at different time points are obtained, wherein the power generation performance data sequence comprises the power generation performance data of the photovoltaic array at different time points.

[0054] ​Specifically, power generation performance data of the photovoltaic string at each time on a typical sunny day can be acquired, and the power generation performance data at each time is combined to form a power generation performance data sequence. Optionally, the power generation performance data includes at least one of actual irradiation data, string current and string power of the photovoltaic string, and the power generation performance data specifically can include the actual irradiation data, or the actual irradiation data and the string current and / or the string power. The solar angle can include a solar elevation angle, a solar azimuth angle and a solar incident angle.

[0055] In step S120, a maximum data time corresponding to maximum power generation performance data in the power generation performance data sequence is determined, and a target function is established according to the solar angle at each time and the power generation performance data.

[0056] Specifically, the time corresponding to the maximum power generation performance data is determined as the maximum data time, and the influence of the temperature of the photovoltaic string on each power generation performance data can be removed in advance when comparing each power generation performance data in the power generation performance data sequence, so as to improve the accuracy of data processing.

[0057] In step S130, a string azimuth angle of the photovoltaic string is determined according to the maximum data time and the target function.

[0058] Specifically, the target function is solved according to the maximum data time, and the string azimuth angle of the photovoltaic string is determined.

[0059] In the embodiment, the power generation performance data sequence of the photovoltaic string to be processed is acquired, each power generation performance data in the power generation performance data sequence is compared with each other to determine the maximum power generation performance data, and the time corresponding to the maximum power generation performance data is the maximum data time. The solar angle at each time is acquired, the target function is established according to the solar angle at each time and the power generation performance data, and the target function is solved according to the maximum data time. The string azimuth angle of the photovoltaic string corresponding to the maximum value of the target function at the maximum data time is the optimal string azimuth angle to be determined. The power generation performance data sequence of each photovoltaic string and the solar angle are processed in combination, the string azimuth angle of the photovoltaic string is determined by an electronic device, the efficiency of determining the string azimuth angle of the photovoltaic string is greatly improved compared with manually measuring the string azimuth angle of each photovoltaic string one by one, the workload of the staff is reduced, and the labor cost can be saved.

[0060] It should be noted that the technical scheme of the present application can be applied in the adjustment process of various photovoltaic supports, including but not limited to fixed supports, rotating supports and tracking supports, and can also be applied in the verification and correction of the azimuth angle sensor of the Maximum Power Point Tracking (MPPT) system, so as to improve the tracking accuracy of the MPPT system and the photovoltaic power generation capacity.

[0061] Optionally, the acquiring the power generation performance data sequence of the photovoltaic string and the solar angle at different time points comprises:

[0062] acquiring the power generation performance data sequence of the photovoltaic string on a typical sunny day, wherein the typical sunny day is a sunny day in which the power generation performance data meets a preset rule.

[0063] In this optional embodiment, the power generation performance data of the photovoltaic string at each time point on a typical sunny day is acquired, and the power generation performance data at each time point forms a power generation performance data sequence. The photovoltaic string has good power generation performance on a typical sunny day, and the output curve of the photovoltaic string is smoother, which is conducive to improving the calculation accuracy of the azimuth of the subsequent photovoltaic string.

[0064] Optionally, the preset rule comprises at least one of the following: a correlation between the actual irradiation data and the clear sky model irradiation data is higher than a first preset threshold, a correlation between the first-order difference of the actual irradiation data and the first-order difference of the clear sky model irradiation data is higher than a second preset threshold, a correlation between the string current and the current calculated based on the clear sky model irradiation data is higher than a third preset threshold, and a correlation between the string power and the power calculated based on the clear sky model irradiation data is higher than a third preset threshold.

[0065] Specifically, the clear sky model can predict the ground irradiance on a sunny day, and the ASHRAE model can be used. The correlation between the actual power generation performance data of the photovoltaic string and the power generation performance data obtained by the clear sky model is studied, for example, the Pearson correlation coefficient between the two, and the correlation is compared with a preset threshold, and a typical sunny day is determined according to the comparison result. It should be noted that because the power generation performance data of the photovoltaic string changes over time in a day, for example, the power generation performance data in the daytime is obviously stronger than that at night, the correlation between the power generation performance data at several typical time points (for example, 10 o'clock in the morning and 12 o'clock in the afternoon) and the corresponding data determined by the clear sky model can be calculated, or the average value of the power generation performance data between a typical time period (for example, 10 o'clock in the morning to 2 o'clock in the afternoon) is selected, and the correlation between the average value and the average value determined by the clear sky model is calculated.

[0066] In this optional embodiment, the correlation between the actual power generation performance data of the photovoltaic string and the power generation performance data determined by the clear sky model is calculated, and the higher the correlation is, the closer the corresponding collection day of the actual power generation performance to the typical sunny day. A typical sunny day can be quickly determined among multiple dates, and the efficiency is high.

[0067] Optionally, the determining the maximum data time point corresponding to the maximum power generation performance data in the power generation performance data sequence comprises:

[0068] The temperature of the photovoltaic string at different time is acquired, and the power generation performance data at each time is corrected according to the temperature, so as to obtain the corrected power generation performance data at each time.

[0069] Specifically, the ambient temperature, the photoelectric conversion efficiency of the photovoltaic string and the heat dissipation coefficient are acquired, and the temperature of the photovoltaic string, i.e. the temperature of the PN junction of the cell on the photovoltaic string, is calculated according to the ambient temperature, the photoelectric conversion efficiency and the heat dissipation coefficient by using a first formula, and the first formula comprises:

[0070]

[0071] Wherein, T cell represents the temperature of the PN junction of the cell on the photovoltaic string, Tamb represents the ambient temperature, U represents the heat dissipation coefficient of the photovoltaic string, a is equal to 1 minus the emissivity of the photovoltaic string, Ginc represents the irradiance incident on the photovoltaic string, and Effic represents the photoelectric conversion efficiency of the photovoltaic string.

[0072] Taking the power generation performance data as the string power as an example, the power generation performance data is corrected according to the temperature of the photovoltaic string by using a second formula, and the second formula comprises:

[0073]

[0074] Wherein, P represents the corrected string power at t time, Pat represents the uncorrected string power at t time, which can be understood as the power data at the inverter end or the busbar end of the photovoltaic power plant, J t represents the temperature loss rate at t time, T cell represents the temperature of the PN junction of the cell on the photovoltaic string at t time, and Alpha represents the temperature coefficient of the photovoltaic string power.

[0075] The maximum data time corresponding to the maximum power generation performance data is determined among all the corrected power generation performance data.

[0076] Specifically, the time corresponding to the maximum power generation performance data among all the corrected power generation performance data at different time is found, and the time is the maximum data time.

[0077] In the optional embodiment, the power generation performance data before correction includes the influence of temperature on the power generation performance, the temperature of the photovoltaic string is calculated, and the power generation performance data is corrected according to the temperature, so as to filter out the influence of temperature on the power generation performance, which is beneficial to improve the calculation accuracy of the subsequent azimuth angle of the photovoltaic string.

[0078] Optionally, the solar angle comprises the solar elevation angle, the solar azimuth angle and the solar incident angle, and the acquisition of the power generation performance data sequence of the photovoltaic string and the solar angle at different time comprises:

[0079] obtaining an declination angle and a solar hour angle at different time, determining the solar altitude angle according to the solar hour angle and the declination angle by using a third formula, the third formula comprising:

[0080]

[0081] wherein h represents the solar altitude angle, represents a geographical latitude where the photovoltaic string is located, ε represents the declination angle, and ω represents the solar hour angle.

[0082] determining the solar azimuth angle according to the solar altitude angle and the declination angle by using a fourth formula, the fourth formula comprising:

[0083]

[0084] wherein A represents the solar azimuth angle;

[0085] determining the solar incident angle according to the solar altitude angle and the solar azimuth angle by using a fifth formula, the fifth formula comprising:

[0086] cosθ=cos(A-A PI )*cosh*sinα+cosαsinh, (Formula Five)

[0087] wherein θ represents the solar incident angle, A PI represents a string azimuth angle of the photovoltaic string, and α represents a tilt angle of the photovoltaic string, which can be measured by a tilt sensor installed on a corresponding photovoltaic support.

[0088] Specifically, wherein n represents a day of the year starting from January 1, wherein t represents a time of day, t∈[0, 24h].

[0089] Optionally, the solar angles include a solar altitude angle, a solar azimuth angle, and a solar incident angle, when the power generation performance data includes the actual irradiance data of the photovoltaic string, the actual irradiance data includes a direct irradiance value of a horizontal plane where the photovoltaic string is located, and the establishing a target function according to the solar angles at each time and the power generation performance data comprises:

[0090] establishing the target function according to the solar altitude angle, the solar incident angle, and the actual irradiance data, the target function being represented by a sixth formula, the sixth formula comprising:

[0091]

[0092] wherein f(t) represents the target function, represents the direct radiation value of the horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ t represents the solar incident angle at time t, represents the geographic latitude where the photovoltaic string is located, ε represents the declination angle, and a represents the inclination angle of the photovoltaic string, A t represents the solar azimuth angle at time t, A PI represents the string azimuth angle of the photovoltaic string at time t.

[0093] Optionally, the target function f(t) can be replaced by a function of the total irradiance of the inclined surface of the photovoltaic string and time.

[0094] I bht in the sixth formula can also be fitted into a polynomial with respect to time t, i.e.:

[0095]

[0096] wherein a, b, …, and c are polynomial coefficients.

[0097] In this optional embodiment, by fitting into a polynomial, the function relationship between the actual irradiance data and time t can be described, which is beneficial to the derivation of the target function and further facilitates the determination of the maximum value of the target function.

[0098] Optionally, the solar angles include the solar elevation angle and the solar incident angle, when the power generation performance data includes the actual irradiance data, the actual irradiance data includes the direct radiation value of the horizontal plane where the photovoltaic string is located, and the target function is established according to the solar angles and the power generation performance data at each time point, which includes:

[0099] The target function is established according to the solar elevation angle, the solar incident angle, and the actual irradiance data, and the target function is represented by a seventh formula, wherein the seventh formula includes:

[0100]

[0101] wherein f(t) represents the target function, represents the direct radiation value of the horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ t represents the solar incident angle at time t, and PR(G, t) represents the system efficiency between the photovoltaic string and the inverter at each string azimuth angle at time t, represents the geographic latitude where the photovoltaic string is located, ε represents the declination angle, and a represents the inclination angle of the photovoltaic string, At A represents the solar azimuth at time t. PI The value represents the azimuth angle of the photovoltaic string at time t.

[0102] Alternatively, the objective function f(t) can be replaced by a function of the total irradiance on the tilted surface of the photovoltaic string versus time.

[0103] The seventh formula can also be used. Fit a polynomial with respect to time t, i.e.:

[0104]

[0105] Where a, b...c are polynomial coefficients.

[0106] In this optional embodiment, fitting the string current and / or string power to multiple similarities can describe the functional relationship between time t, which is beneficial for differentiating the objective function and thus facilitating the determination of the maximum value of the objective function.

[0107] Optionally, determining the string azimuth angle of the photovoltaic string based on the maximum data time and the objective function includes:

[0108] The objective function is solved based on the maximum data time to determine the string azimuth angle of the photovoltaic string when the objective function reaches its maximum value at the maximum data time.

[0109] Specifically, such as Figure 2 As shown, by plotting the objective function curves for different photovoltaic string azimuth angles, it can be seen that the objective value of the objective function reaches its peak at different times under different photovoltaic string azimuth angles. Therefore, among the times when the objective function reaches its maximum value for each different photovoltaic string azimuth angle, the time when the power generation performance data is at its maximum is found, and the photovoltaic string azimuth angle corresponding to that time is the optimal photovoltaic string azimuth angle to be determined.

[0110] Taking the derivative of the objective function f(t) yields f'(t). Substituting the maximum data time ta into f'(t), the string azimuth angle A of the photovoltaic string corresponding to f'(ta) = 0 is determined. PI This azimuth angle is the optimal azimuth angle for the photovoltaic string. The solution process can be expressed using the eighth formula, which includes:

[0111]

[0112] Among them, A ta This represents the solar azimuth angle at the time of the maximum data point ta.

[0113] In the optional embodiment, the azimuth angle of the photovoltaic string is calculated based on the variation trend of the actual irradiation data, and the calculation is performed only in the irradiation dimension, so that the azimuth angle of the photovoltaic string can be quickly calculated, and the calculation efficiency is improved. The azimuth angle of the photovoltaic string is calculated based on the variation trend of the corrected string current and / or string power, and the calculation is performed in the dimension of the string current and / or string power, so that the calculation accuracy is higher.

[0114] Optionally, after the azimuth angle of the photovoltaic string is determined according to the maximum data moment and the target function, the method further comprises:

[0115] The wiring distance between each photovoltaic string and the corresponding inverter is determined.

[0116] The wiring distance and the azimuth angle of the photovoltaic string are weighted and summed to determine the characteristic value of the photovoltaic string.

[0117] For any inverter, all photovoltaic strings connected to the inverter are sorted according to the characteristic value in a preset order.

[0118] Each photovoltaic string is allocated to a corresponding maximum power point tracking system according to the sorting result.

[0119] Specifically, for any photovoltaic string, the wiring distance of the photovoltaic string is weighted, and the weight is assumed to be K1, and the azimuth angle of the photovoltaic string is weighted, and the weight is assumed to be K2, and the characteristic value of the photovoltaic string is equal to K1*wiring distance+K2*azimuth angle. For any inverter, all photovoltaic strings connected to the inverter can be arranged in order of characteristic value from large to small or from small to large, and each two adjacent photovoltaic strings can be allocated to the same MPPT (Maximum Power Point Tracking) system according to the sorting result, for example, the first photovoltaic string and the second photovoltaic string are put into the same MPPT system according to the sorting result, the third photovoltaic string and the fourth photovoltaic string are put into the same MPPT system, and so on.

[0120] In the optional embodiment, each photovoltaic string is allocated according to the wiring distance and the azimuth angle of the photovoltaic string, and the photovoltaic strings with close wiring distances and close azimuth angles connected to the same inverter are allocated to the same MPPT system, so that the power generation of the entire photovoltaic power station can be improved.

[0121] Optionally, a current actual azimuth angle of the photovoltaic string is acquired, a difference between the current actual azimuth angle and an optimal azimuth angle determined by the eighth formula is calculated, it is judged whether the difference is within a preset range, if yes, no operation is performed; if no, a prompt information is outputted to remind an operation and maintenance personnel to timely adjust the string azimuth angle of the photovoltaic string.

[0122] Alternatively, a current actual azimuth angle of the photovoltaic string collected by the azimuth angle sensor is acquired, a difference between the current actual azimuth angle and an optimal azimuth angle determined by the eighth formula is calculated, it is judged whether the difference is within a preset range, if yes, no operation is performed; if no, a prompt information is outputted to remind an operation and maintenance personnel to check the azimuth angle sensor or to adjust the photovoltaic string according to the difference and / or the optimal azimuth angle.

[0123] As shown in FIG. Figure 3 Another embodiment of the present application provides a photovoltaic string azimuth angle determination device, which comprises:

[0124] An acquisition module is configured to acquire a power generation performance data sequence of a photovoltaic string and solar angles at different time points, wherein the power generation performance data sequence comprises power generation performance data of the photovoltaic string at different time points.

[0125] A processing module is configured to determine a maximum data time point corresponding to maximum power generation performance data in the power generation performance data sequence and establish a target function according to the solar angles at different time points and the power generation performance data.

[0126] A calculation module is configured to determine a string azimuth angle of the photovoltaic string according to the maximum data time point and the target function.

[0127] Optionally, the processing module is specifically configured to acquire temperatures of the photovoltaic string at different time points, correct the power generation performance data at different time points respectively according to the temperatures to obtain corrected power generation performance data at different time points, and determine the maximum data time point corresponding to the maximum power generation performance data in all the corrected power generation performance data.

[0128] Optionally, the solar angles comprise a solar altitude angle, a solar azimuth angle and a solar incident angle, and the acquisition module is specifically configured to acquire declination angles and solar hour angles at different time points, determine the solar altitude angle according to the solar hour angles and the declination angles, determine the solar azimuth angle according to the solar altitude angle and the declination angles, and determine the solar incident angle according to the solar altitude angle and the solar azimuth angle.

[0129] Optionally, the power generation performance data comprises at least one of actual irradiation data, string current and string power of the photovoltaic string.

[0130] Optionally, the obtaining module is specifically configured to: obtain the power generation performance data sequence of the photovoltaic string in a typical sunny day, wherein the typical sunny day is a sunny day in which the power generation performance data meets a preset rule.

[0131] Optionally, the preset rule includes at least one of the following: a correlation between the actual irradiation data and clear sky model irradiation data is higher than a first preset threshold, a correlation between a first order difference of the actual irradiation data and a first order difference of the clear sky model irradiation data is higher than a second preset threshold, a correlation between the string current and a current calculated based on the clear sky model irradiation data is higher than a third preset threshold, and a correlation between the string power and a power calculated based on the clear sky model irradiation data is higher than a third preset threshold.

[0132] Optionally, the solar angle includes a solar elevation angle and a solar incident angle, and when the power generation performance data includes the actual irradiation data, the actual irradiation data includes a direct irradiation value of a horizontal plane where the photovoltaic string is located, and the processing module is specifically further configured to:

[0133] establish the target function according to the solar elevation angle, the solar incident angle and the actual irradiation data, the target function being represented by a fourth formula, and the fourth formula including:

[0134]

[0135] wherein f(t) represents the target function, represents a direct irradiation value of a horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ t represents the solar incident angle at time t.

[0136] Optionally, the solar angle includes the solar elevation angle and the solar incident angle, and when the power generation performance data is the string current and / or the string power, the processing module is specifically further configured to:

[0137] establish the target function according to the solar elevation angle, the solar incident angle and the current and / or the power, the target function being represented by a fifth formula, and the fifth formula including:

[0138]

[0139] wherein f(t) represents the target function, represents a direct irradiation value of a horizontal plane where the photovoltaic string is located at time t, h t represents the solar elevation angle at time t, θ tPR (G, t) represents the system efficiency between the photovoltaic string and the inverter at each string azimuth angle at time t, and the string power is associated with the string current.

[0140] Optionally, the computing module is specifically configured to solve the target function, and determine the string azimuth angle of the photovoltaic string when the target function takes the maximum value at the maximum data time.

[0141] Optionally, the method further comprises a distribution module, which is configured to determine the wiring distance between each photovoltaic string and the corresponding inverter, and to determine the eigenvalue of the photovoltaic string by weighted sum of the wiring distance and the string azimuth angle of the photovoltaic string, and to sort all the photovoltaic strings connected to the inverter according to the eigenvalue in a preset order for any inverter, and to distribute each photovoltaic string to the corresponding maximum power point tracking system according to the sorting result.

[0142] Another embodiment of the present application provides an electronic device including a memory and a processor; the memory is configured to store a computer program; the processor is configured to implement the photovoltaic string azimuth angle determination method as described above when executing the computer program.

[0143] Another embodiment of the present application provides a computer readable storage medium storing a computer program, when the computer program is executed by a processor, the photovoltaic string azimuth angle determination method as described above is implemented.

[0144] An electronic device that can be a server or a client of the present application will now be described, which is an example of a hardware device that can be applied to various aspects of the present application. The electronic device is intended to represent a wide variety of digital electronic computing devices, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computing devices. The electronic device can also represent a variety of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections, and relationships, and their functions, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0145] The electronic device includes a computing unit that can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded into a random access memory (RAM) from a storage unit. In the RAM, various programs and data required for device operation can also be stored. The computing unit, the ROM, and the RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0146] The computer system can include clients and servers. This relationship can be

[0147] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The program can be stored in a computer readable storage medium, and when the program is executed, the processes of the above-mentioned embodiment methods can be included. The storage medium can be a magnetic disc, an optical disc, a read-only memory (ROM), a random access memory (RAM), or the like. In this application, the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present application. In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0148] Although the present application is disclosed as above, the protection scope of the present application is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and these changes and modifications will fall within the protection scope of the present application.

Claims

1. A method for determining the azimuth angle of a photovoltaic string, characterized in that, The method comprises the following steps: obtaining a power generation performance data sequence of a photovoltaic string and solar angles at different times, the power generation performance data sequence comprising power generation performance data of the photovoltaic string at different times, and the solar angles comprising a solar elevation angle and a solar incident angle; determining a maximum data time corresponding to maximum power generation performance data in the power generation performance data sequence, the power generation performance data comprising actual irradiation data of the photovoltaic string; and establishing a target function according to the solar angles and the power generation performance data at different times, comprising: establishing the target function according to the solar elevation angle, the solar incident angle and the actual irradiation data; the solar incident angle is determined by a string azimuth angle of the photovoltaic string, and the target function is used to represent a function of total irradiation of a photovoltaic string inclined surface and time; determining the string azimuth angle of the photovoltaic string according to the maximum data time and the target function, wherein the photovoltaic string azimuth angle corresponding to the maximum value of the target function at the maximum data time is the optimal photovoltaic string azimuth angle to be determined.

2. The photovoltaic string azimuth angle determination method of claim 1, wherein, The determination of the maximum data time corresponding to the maximum power generation performance data in the power generation performance data sequence comprises the following steps: obtaining temperatures of the photovoltaic string at different times, correcting the power generation performance data at different times respectively according to the temperatures to obtain corrected power generation performance data at different times; determining the maximum data time corresponding to the maximum power generation performance data in all the corrected power generation performance data.

3. The photovoltaic string azimuth determination method of claim 1, wherein, The solar angles comprise a solar elevation angle, a solar azimuth angle and a solar incident angle, and the obtaining of the power generation performance data sequence of the photovoltaic string and the solar angles at different times comprises the following steps: obtaining an declination angle and solar time angles at different times, and determining the solar elevation angle according to the solar time angles and the declination angle; determining the solar azimuth angle according to the solar elevation angle and the declination angle; determining the solar incident angle according to the solar elevation angle and the solar azimuth angle.

4. A photovoltaic string azimuth determination method according to any one of claims 1 to 3, characterized in that, The power generation performance data further comprises at least one of a string current and a string power of the photovoltaic string.

5. The photovoltaic string azimuth determination method of claim 4, wherein, The obtaining of the power generation performance data sequence of the photovoltaic string and the solar angles at different times comprises the following steps: obtaining the power generation performance data sequence of the photovoltaic string at a typical sunny day, wherein the typical sunny day is a sunny day in which the power generation performance data meets a preset rule.

6. The photovoltaic string azimuth determination method of claim 5, wherein, The preset rule comprises at least one of the following: a correlation between the actual irradiation data and clear sky model irradiation data is higher than a first preset threshold, a correlation between a first-order difference of the actual irradiation data and a first-order difference of the clear sky model irradiation data is higher than a second preset threshold, a correlation between the string current and a current calculated based on the clear sky model irradiation data is higher than a third preset threshold, and a correlation between the string power and a power calculated based on the clear sky model irradiation data is higher than a third preset threshold.

7. The photovoltaic string azimuth determination method of claim 4, wherein, The actual irradiation data comprises a direct irradiation value of a horizontal plane where the photovoltaic string is located, and the establishment of the target function according to the solar angles and the power generation performance data at different times comprises the following steps: The target function is established according to the solar elevation angle, the solar incident angle and the actual irradiation data, the target function is represented by a fourth formula, and the fourth formula comprises: ， wherein, denotes the objective function, denotes the direct irradiance value of the horizontal plane where the photovoltaic string is located at time t, denotes the solar elevation angle at time t, denotes the solar incidence angle at time t.

8. The photovoltaic string azimuth determination method of claim 4, wherein, The actual irradiation data comprises a direct irradiation value of a horizontal plane where the photovoltaic string is located, and the target function is established according to the solar angle and the power generation performance data at each time point, which comprises: The target function is established according to the solar elevation angle, the solar incident angle and the actual irradiation data, the target function is represented by a fifth formula, and the fifth formula comprises: ， wherein, represents the objective function, represents the direct irradiance value of the horizontal plane where the photovoltaic string is located at time t, represents the solar altitude angle at time t, represents the solar incidence angle at time t, represents the system efficiency between the photovoltaic string and the inverter at the azimuth angle of the photovoltaic string at time t.

9. The photovoltaic string azimuth determination method of any of claims 1 to 3, wherein, The string azimuth angle of the photovoltaic string is determined according to the maximum data time point and the target function, which comprises: The string azimuth angle of the photovoltaic string is determined when the target function takes the maximum value at the maximum data time point.

10. The photovoltaic string azimuth determination method of any of claims 1 to 3, wherein, After the string azimuth angle of the photovoltaic string is determined according to the maximum data time point and the target function, the method further comprises: A wiring distance between each photovoltaic string and a corresponding inverter is determined; A characteristic value of the photovoltaic string is determined by performing a weighted summation on the wiring distance and the string azimuth angle of the photovoltaic string; For any inverter, all photovoltaic strings connected to the inverter are sorted according to the characteristic value in a preset order; Each photovoltaic string is allocated to a corresponding maximum power point tracking system according to the sorting result.

11. A photovoltaic string azimuth determination device, characterized by, Comprise: An acquisition module is configured to acquire power generation performance data sequence of a photovoltaic string and solar angles at different time points, the power generation performance data sequence comprises power generation performance data of the photovoltaic string at different time points, and the solar angles comprise a solar elevation angle and a solar incident angle; A processing module is configured to determine a maximum data time point corresponding to maximum power generation performance data in the power generation performance data sequence, the power generation performance data comprises actual irradiation data of the photovoltaic string; and a target function is established according to the solar angles at different time points and the power generation performance data, which comprises: the target function is established according to the solar elevation angle, the solar incident angle and the actual irradiation data; the solar incident angle is determined by a string azimuth angle of the photovoltaic string, and the target function is used to represent a function of total irradiation of a photovoltaic string inclined plane and time; A calculation module is configured to determine the string azimuth angle of the photovoltaic string according to the maximum data time point and the target function, wherein the string azimuth angle of the photovoltaic string corresponding to the maximum value of the target function at the maximum data time point is the best photovoltaic string azimuth angle to be determined.

12. An electronic device, comprising: Comprise a memory and a processor; The memory is configured to store a computer program; The processor is configured to implement the photovoltaic string azimuth angle determination method in any one of claims 1 to 10 when the computer program is executed.

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