Current and voltage characteristic curve generation method and device, electronic equipment and storage medium

Abstract

The invention relates to the technical field of photovoltaic power generation, and discloses a current and voltage characteristic curve generation method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining a historical maximum power point voltage value of a target photovoltaic array; based on the historical maximum power point voltage value, determining a maximum power point current value corresponding to the historical maximum power point at the current moment; determining a scanning upper limit current value based on the maximum power point current value; acquiring a scanning lower limit current value; and performing current scanning on the target photovoltaic array based on the scanning upper limit current value and the scanning lower limit current value to obtain a plurality of current and voltage data pairs of the target photovoltaic array so as to generate a target current and voltage characteristic curve of the target photovoltaic array. The corresponding scanning upper limit current value is determined according to the current working condition of the photovoltaic array, the accuracy of the generated IV characteristic curve is improved, and the safety of the photovoltaic array is improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and specifically to a method, apparatus, electronic device, and storage medium for generating current-voltage characteristic curves. Background Technology

[0002] During the long-term operation of a photovoltaic power plant, its performance will degrade due to various faults. Based on the current-voltage (IV) characteristic curve of the photovoltaic array, in-depth diagnosis of the health status of the photovoltaic array and precise fault location can be achieved. Therefore, obtaining an accurate IV characteristic curve is of great significance for the precise operation and maintenance and performance improvement of photovoltaic power plants.

[0003] In related technologies, the IV characteristic curve of the photovoltaic array is generated according to a fixed current scanning range under different operating conditions. This results in inaccurate IV characteristic curves, which in turn cannot accurately reflect the health status of the photovoltaic array and reduce its safety. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and storage medium for generating current-voltage characteristic curves, in order to solve the problem that the generated IV characteristic curves in related technologies are inaccurate, thus failing to accurately reflect the health status of photovoltaic arrays and reducing the safety of photovoltaic arrays.

[0005] In a first aspect, the present invention provides a method for generating current-voltage characteristic curves, the method comprising: Obtain the historical maximum power point voltage value of the target photovoltaic array; Based on the historical maximum power point voltage value, determine the maximum power point current value corresponding to the historical maximum power point at the current moment; Based on the maximum power point current value, determine the upper limit current value of the target photovoltaic array for scanning; Obtain the lower limit current value of the target photovoltaic array; Based on the upper and lower current values ​​of the scan, the target photovoltaic array is scanned to obtain multiple voltage and current data pairs of the target photovoltaic array. Based on multiple voltage and current data pairs, the target voltage and current characteristic curve of the target photovoltaic array is generated.

[0006] The current-voltage characteristic curve generation method provided in this invention utilizes the historical maximum power point voltage value of the target photovoltaic array to determine the maximum power point current value corresponding to the historical maximum power point at the current moment. Then, based on the maximum power point current value, the upper limit current value of the scan is determined. This realizes the dynamic adjustment of the scan interval according to historical operating information and current operating conditions, improves the accuracy of the generated IV characteristic curve, and enables the generated IV characteristic curve to accurately reflect the health status of the target photovoltaic array, thereby improving the safety of the target photovoltaic array.

[0007] In one optional implementation, determining the maximum power point current value corresponding to the historical maximum power point at the current moment based on the historical maximum power point voltage value includes: If the current output voltage of the target photovoltaic array is less than the historical maximum power point voltage, then the output current of the target photovoltaic array is adjusted downward until the output voltage of the target photovoltaic array is equal to the historical maximum power point voltage. The adjusted output current value is then determined as the maximum power point current value corresponding to the historical maximum power point at the current moment. If the current output voltage of the target photovoltaic array is greater than the historical maximum power point voltage, the output current of the target photovoltaic array is adjusted upward until the output voltage of the target photovoltaic array is equal to the historical maximum power point voltage. The adjusted output current value is then determined as the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0008] The current-voltage characteristic curve generation method provided in this invention determines the maximum power point current value corresponding to the historical maximum power point at the current moment by comparing the current output voltage value of the target photovoltaic array with the historical maximum power point voltage value. This realizes dynamic adjustment of the scanning interval based on historical operating information and current operating conditions, thereby improving the accuracy of the generated IV characteristic curve.

[0009] In one optional implementation, determining the upper limit current value of the target photovoltaic array based on the maximum power point current value includes: Obtain the current short-circuit current estimation coefficient of the target photovoltaic array; Based on the maximum power point current value and the current short-circuit current estimation coefficient, the short-circuit current estimation value of the target photovoltaic array is determined; Based on the short-circuit current estimate, the current exit threshold of the target photovoltaic array is determined; Based on the current exit threshold, the upper limit current value for scanning of the target photovoltaic array is determined.

[0010] The current-voltage characteristic curve generation method provided in this invention uses the historical maximum power point voltage value, the maximum power point current value corresponding to the historical maximum power point at the current moment, and the current short-circuit current estimation coefficient to estimate the short-circuit current of the target photovoltaic array, and sets the upper limit current value for scanning based on this. This allows the IV scanning range to be automatically adjusted according to the actual operating conditions of the target photovoltaic array, avoiding the problem of the scanning range being too large or too small due to the fixed upper limit of the rated current value, and reducing the reliance on hardware protection.

[0011] In one optional implementation, determining the upper limit current value of the target photovoltaic array based on a current exit threshold includes: The current exit threshold is determined as the upper limit current value for scanning the target photovoltaic array; or, Obtain the upper limit value of the current protection of the target photovoltaic array, determine the smaller value between the upper limit value of the current protection and the current exit threshold, and determine the smaller value between the upper limit value of the current protection and the current exit threshold as the upper limit current value of the scan of the target photovoltaic array.

[0012] The current-voltage characteristic curve generation method provided in this invention determines the upper limit current value of the target photovoltaic array based on the current exit threshold and the upper limit value of the current protection, making the determined upper limit current value of the scan more accurate.

[0013] In one optional implementation, a current scan is performed on the target photovoltaic array based on the upper and lower current limits of the scan to obtain multiple current-voltage data pairs of the target photovoltaic array, including: Get the total number of scan points; The total number of scan points is divided equally into the first scan point number and the second scan point number; Based on the first number of scan points and the first current range, the first current step size is determined. The first current range is the current range from the lower limit current value to the maximum power point current value. Based on the second number of scan points and the second current range, the second current step size is determined. The second current range is the current range from the maximum power point current value to the upper limit of the scan current value. Based on the first current step size, multiple current scanning points are determined in the first current range; Based on the second current step size, multiple current scanning points in the second current range are determined; The target photovoltaic array is scanned in ascending order of current scanning points to obtain multiple pairs of current and voltage data.

[0014] The current-voltage characteristic curve generation method provided in this invention distributes the current scanning points evenly across the first current range and the second current range, resulting in a relatively balanced density of current scanning points before and after the maximum power point current value. This better reflects the inflection point shape of the IV characteristic curve and the difference in voltage / current change rate on both sides, which is beneficial for subsequent refined MPPT algorithms, health diagnosis, and performance analysis based on the IV characteristic curve.

[0015] In one alternative implementation, the method further includes: After scanning the target photovoltaic array based on any current scanning point, if the actual output voltage value of the target photovoltaic array is less than the preset minimum voltage threshold, the current scanning of the target photovoltaic array is stopped, the reason for exiting is recorded as low voltage, and the number of exit points is determined and recorded based on the sorting number of the current scanning point. If the actual output current value of the target photovoltaic array is greater than the current protection limit of the target photovoltaic array, the current scanning of the target photovoltaic array will be stopped, the reason for exiting will be recorded as current over-limit exit, and the exit point number will be determined and recorded based on the sorting number of the current scanning point. If the actual output current value of the target photovoltaic array or the current scan point is not less than the current exit threshold of the target photovoltaic array, then stop continuing to scan the target photovoltaic array with current, record the exit reason as reaching the current threshold, and determine and record the exit point number based on the sorting number of the current scan point.

[0016] The current-voltage characteristic curve generation method provided in this invention improves the safety of the target photovoltaic array by setting different exit conditions to avoid invalid scanning and potential unstable operation.

[0017] In one alternative implementation, the method further includes: Determine the threshold for determining the number of scan points based on the total number of scan points; If the number of exit points is less than the number of exit points judgment threshold, and the reason for exit is low voltage, then reduce the short-circuit current estimation coefficient of the target photovoltaic array. If the number of exit points is less than the number of points to determine, and the reason for exiting is current over-limit exit, then increase the short-circuit current estimation coefficient of the target photovoltaic array.

[0018] The current-voltage characteristic curve generation method provided in this invention analyzes the reasons for exiting each scan and the number of exit points. When the number of exit points is lower than the point determination threshold, the short-circuit current estimation coefficient is automatically adjusted, so that the short-circuit current estimation value gradually approaches the true value. This improves the adaptability to different conditions such as irradiance, temperature, and component aging, and enhances the robustness of the system.

[0019] Secondly, the present invention provides a current-voltage characteristic curve generation device, the device comprising: The first acquisition module is used to acquire the historical maximum power point voltage value of the target photovoltaic array; The first determining module is used to determine the maximum power point current value corresponding to the historical maximum power point at the current moment based on the historical maximum power point voltage value; The second determining module is used to determine the upper limit current value of the target photovoltaic array based on the maximum power point current value; The second acquisition module is used to acquire the scanning lower limit current value of the target photovoltaic array; The third acquisition module is used to perform current scanning on the target photovoltaic array based on the upper limit current value and the lower limit current value to obtain multiple current-voltage data pairs of the target photovoltaic array. The generation module is used to generate the target current-voltage characteristic curve of the target photovoltaic array based on multiple current-voltage data pairs.

[0020] Thirdly, the present invention provides an electronic device, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of any of the above-described current-voltage characteristic curve generation methods.

[0021] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of any of the above-described current-voltage characteristic curve generation methods.

[0022] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the above-described current-voltage characteristic curve generation methods. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating a method for generating current-voltage characteristic curves provided in an embodiment of this application; Figure 2 A flowchart illustrating another current-voltage characteristic curve generation method provided in this application embodiment; Figure 3 A flowchart for updating the short-circuit current estimation coefficients provided in this application embodiment; Figure 4 A schematic flowchart illustrating another current-voltage characteristic curve generation method provided in this application embodiment; Figure 5 This is a structural block diagram of the current-voltage characteristic curve generation device provided in the embodiments of this application; Figure 6 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] During the long-term operation of a photovoltaic power plant, its performance will degrade due to various faults. Based on the current-voltage (IV) characteristic curve of the photovoltaic array, in-depth diagnosis of the health status of the photovoltaic array and precise fault location can be achieved. Therefore, obtaining an accurate IV characteristic curve is of great significance for the precise operation and maintenance and performance improvement of photovoltaic power plants.

[0029] In related technologies, a fixed current scanning range plus a fixed number of scanning points is typically used to generate the IV characteristic curve of a photovoltaic array. Specifically: 1. The rated current of the current photovoltaic array or the maximum current preset by the controller is used as the upper limit current for scanning. The controller can be the controller in the photovoltaic inverter or the controller in the photovoltaic array IV scanning device of the photovoltaic testing equipment. 2. The scanning starts from 0 current and gradually increases the current reference value (i.e., the current scanning value) in fixed steps until the upper limit current is reached. 3. A fixed number of scanning points (e.g., 256 points) is preset throughout the scanning process, dividing the [0, upper limit current] interval into several current steps. Each step point corresponds to a current scanning value. At each step point, the photovoltaic array outputs the corresponding current scanning value, and the actual voltage and actual output current data of the photovoltaic side (i.e., the photovoltaic array) are collected to obtain a discrete IV characteristic curve.

[0030] The IV characteristic curve generation method in related technologies is simple to implement and easy to embed in the controller, but it has the following disadvantages: 1. The scanning range does not match the actual short-circuit current under different operating conditions. Under varying irradiance, temperature, and module aging conditions, the actual short-circuit current of a photovoltaic (PV) array can change significantly. However, the IV characteristic curve generation method in related technologies always uses the rated current or the controller's preset maximum current as the upper limit of the scan. This results in the current scan value corresponding to the latter half of the scan current range being far beyond the actual operating range when the actual short-circuit current of the PV array is much lower than the rated current or the controller's preset maximum current. Consequently, the controller has to rely on protection logic to prematurely exit when approaching the short-circuit condition of the PV array, leading to a large number of missing or invalid subsequent current scan values. Furthermore, when the actual short-circuit current of the PV array is close to or slightly higher than the rated current or the controller's preset maximum current, the scan current range is insufficient to completely cover the area near the short circuit, resulting in an incomplete tail of the generated IV curve.

[0031] Understandably, under different operating conditions of the photovoltaic array, the IV characteristic curve of the photovoltaic array is generated according to a fixed current scanning range. It lacks adaptive capability and cannot be dynamically adjusted according to historical operating information, resulting in inaccurate IV characteristic curves. Consequently, it cannot accurately reflect the health status of the photovoltaic array and reduces the safety of the photovoltaic array.

[0032] 2. The distribution of scan points does not match the characteristics of the IV characteristic curve. The IV characteristic curve of a photovoltaic array exhibits a significant change in slope around the Maximum Power Point (MPP), displaying a clear "inflection point" characteristic. The denser the points near the inflection point, the easier it is to accurately locate the MPP.

[0033] The IV characteristic curve generation method in related technologies distributes a fixed number of scan points evenly between 0 and the upper limit current, without distinguishing between the regions before and after MPP. This results in an excessive number of scan points in the region where the current is close to 0, even though this region contributes little to the MPP calculation. It also leads to a relatively insufficient number of scan points in the region between MPP and the upper limit current, making it difficult to accurately characterize the shape of the inflection point and the difference in slope on both sides.

[0034] Understandably, the mismatch between the distribution of scan points and the characteristics of the IV characteristic curve leads to a large number of scan points falling in meaningless areas, resulting in low scanning efficiency. It also results in insufficient scan points in critical areas, unclear curve characteristics, and the generated IV characteristic curve failing to accurately reflect the health status of the photovoltaic array, thus reducing its safety. Furthermore, it leads to over-reliance on passively terminated scanning via current protection and low-voltage protection, placing a heavy burden on system protection.

[0035] Some related technologies use simplistic experience to set the upper limit current for scanning, such as setting it to approximately a fixed multiple of the maximum power point current. However, this multiple is typically hardcoded into the program and is not dynamically adjusted based on actual scanning results. When the setting is too high, scanning will frequently terminate prematurely due to low voltage or protection activation; conversely, when the setting is too low, it will terminate prematurely due to current exceeding limits. In the long run, the system cannot gradually approximate the actual short-circuit current, making it difficult for the scanning strategy to converge to an optimal state, thus reducing the accuracy and robustness of the generated IV characteristic curve.

[0036] To address the aforementioned technical problems, this application provides a method, apparatus, electronic device, and storage medium for generating current-voltage characteristic curves. The method includes: acquiring the historical maximum power point voltage (MPPT) value of a target photovoltaic (PV) array; determining the maximum power point current (MPC) value corresponding to the historical MPPT at the current moment based on the historical MPPT voltage value; determining the upper limit current value for scanning the target PV array based on the MPC current value; acquiring the lower limit current value for scanning the target PV array; performing a current scan on the target PV array based on the upper and lower limit current values ​​to obtain multiple current-voltage data pairs; and generating a target current-voltage characteristic curve for the target PV array based on the multiple current-voltage data pairs. The method provided above utilizes the historical MPPT voltage value of the target PV array to determine the MPC current value corresponding to the historical MPPT at the current moment, and then determines the upper limit current value for scanning based on the MPC current value. This enables dynamic adjustment of the scanning interval based on historical operating information and current operating conditions, improving the accuracy of the generated IV characteristic curve and ensuring that the generated IV characteristic curve accurately reflects the health status of the target PV array, thereby enhancing the safety of the target PV array.

[0037] Embodiments of this application provide a method for generating current-voltage characteristic curves, applicable to a photovoltaic array IV characteristic curve scanning device in a photovoltaic inverter or photovoltaic testing equipment. The following description uses an application to a photovoltaic inverter as an example. Figure 1 This is a schematic flowchart of the current-voltage characteristic curve generation method provided in the embodiments of this application, as shown below. Figure 1 As shown, the method for generating the current-voltage characteristic curve includes the following steps: Step S101: Obtain the historical maximum power point voltage value of the target photovoltaic array.

[0038] Before initiating the current scan of the target photovoltaic array, the control unit in the photovoltaic inverter reads the historical maximum power point voltage value of the target photovoltaic array from the storage unit. It should be noted that this historical maximum power point voltage value can be either the voltage value when the target photovoltaic array successfully locked and stably operated at its maximum power point using the Maximum Power Point Tracking (MPPT) algorithm, or the filtered voltage value after the last successful locking and stable operation at its maximum power point using the MPPT algorithm.

[0039] The target photovoltaic array can be one of the photovoltaic arrays in a photovoltaic system.

[0040] It should be noted that for the first operation or in the absence of historical data, the historical maximum power point voltage value can be determined based on the rated voltage value of the target photovoltaic array, or it can be initialized by technicians based on experience.

[0041] Step S102: Based on the historical maximum power point voltage value, determine the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0042] Specifically, after obtaining the historical maximum power point voltage value, the maximum power point current value corresponding to the historical maximum power point at the current moment is determined based on the historical maximum power point voltage value.

[0043] Step S103: Determine the upper limit current value of the target photovoltaic array based on the maximum power point current value.

[0044] Step S104: Obtain the lower limit current value of the target photovoltaic array.

[0045] On the open-circuit side of the target photovoltaic array, the control unit sets the lower limit current value I_min for scanning the target photovoltaic array according to the actual needs of the system. I_min can be 0 or a minimum operating current value slightly greater than 0 to avoid prolonged stay in the extremely low current range. The specific setting can be determined according to the operating characteristics of the target photovoltaic array. The selection of I_min ensures that the scanning range covers the region from low current to the maximum power point current Impp.

[0046] Step S105: Based on the upper limit current value and the lower limit current value, perform current scanning on the target photovoltaic array to obtain multiple current-voltage data pairs of the target photovoltaic array.

[0047] Step S106: Based on multiple current-voltage data pairs, generate the target current-voltage characteristic curve of the target photovoltaic array.

[0048] The control unit generates the target current-voltage characteristic curve of the target photovoltaic array under the current operating conditions based on multiple current-voltage data pairs of the target photovoltaic array.

[0049] The current-voltage characteristic curve generation method provided in this application uses the historical maximum power point voltage value of the target photovoltaic array to determine the maximum power point current value corresponding to the historical maximum power point at the current moment, and then determines the upper limit current value of the scan based on the maximum power point current value. This realizes the dynamic adjustment of the scan interval according to historical operating information and current operating conditions, improves the accuracy of the generated IV characteristic curve, and enables the generated IV characteristic curve to accurately reflect the health status of the target photovoltaic array, thereby improving the safety of the target photovoltaic array.

[0050] Embodiments of this application provide a method for generating current-voltage characteristic curves, applicable to a photovoltaic array IV characteristic curve scanning device in a photovoltaic inverter or photovoltaic testing equipment. Figure 2 This is a schematic flowchart of the current-voltage characteristic curve generation method provided in the embodiments of this application, as shown below. Figure 2 As shown, the method for generating the current-voltage characteristic curve includes the following steps: Step S201: Obtain the historical maximum power point voltage value of the target photovoltaic array. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0051] Step S202: Based on the historical maximum power point voltage value, determine the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0052] Specifically, step S202 includes: Step S2021: If the current output voltage of the target photovoltaic array is less than the historical maximum power point voltage, then adjust the output current of the target photovoltaic array downward until the output voltage of the target photovoltaic array is equal to the historical maximum power point voltage. The adjusted output current value is then determined as the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0053] Step S2022: If the current output voltage of the target photovoltaic array is greater than the historical maximum power point voltage, then adjust the output current of the target photovoltaic array upward until the output voltage of the target photovoltaic array is equal to the historical maximum power point voltage. The adjusted output current value is then determined as the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0054] Step S203: Determine the upper limit current value of the target photovoltaic array based on the maximum power point current value.

[0055] Specifically, step S203 includes: Step S2031: Obtain the current short-circuit current estimation coefficient of the target photovoltaic array.

[0056] The initial short-circuit current estimation coefficient k of the target photovoltaic array can be set by technicians based on experience and can be adjusted subsequently.

[0057] Step S2032: Determine the estimated short-circuit current of the target photovoltaic array based on the maximum power point current value and the current short-circuit current estimation coefficient.

[0058] Specifically, the estimated short-circuit current of the target photovoltaic array is determined based on the following formula: I_sc_est=k×Impp Where I_sc_est is the estimated short-circuit current of the target photovoltaic array, k is the current short-circuit current estimation coefficient of the target photovoltaic array, and Imppp is the maximum power point current value.

[0059] Step S2033: Based on the short-circuit current estimate, determine the current exit threshold of the target photovoltaic array.

[0060] To avoid excessively approximating the actual short-circuit condition during the scanning process, the control unit sets a high current exit threshold, i.e., a current exit threshold, based on the short-circuit current estimate.

[0061] Specifically, the current exit threshold of the target photovoltaic array is determined based on the following formula: I_high_exit=α×I_sc_est Where I_high_exit is the current exit threshold of the target photovoltaic array, α is the preset current adjustment coefficient, and I_sc_est is the estimated short-circuit current of the target photovoltaic array, 0 < α < 1. It should be noted that the value of α is selected by technicians based on the hardware safety margin and operating strategy of the photovoltaic inverter.

[0062] Step S2034: Determine the upper limit current value of the target photovoltaic array based on the current exit threshold.

[0063] Step S204: Obtain the scan lower limit current value of the target photovoltaic array. For details, please refer to [link to relevant documentation]. Figure 1 Step S104 of the illustrated embodiment will not be described again here.

[0064] Step S205: Based on the upper and lower current limits of the scan, a current scan is performed on the target photovoltaic array to obtain multiple current-voltage data pairs for the target photovoltaic array. For details, please refer to [link to relevant documentation]. Figure 1 Step S105 of the illustrated embodiment will not be described again here.

[0065] Step S206: Based on multiple current-voltage data pairs, generate the target current-voltage characteristic curve of the target photovoltaic array. For details, please refer to [link to relevant documentation]. Figure 1 Step S106 of the illustrated embodiment will not be described again here.

[0066] The current-voltage characteristic curve generation method provided in this application determines the maximum power point current value corresponding to the historical maximum power point at the current moment by comparing the current output voltage value of the target photovoltaic array with the historical maximum power point voltage value. This realizes dynamic adjustment of the scanning interval based on historical operating information and current operating conditions, thereby improving the accuracy of the generated IV characteristic curve.

[0067] The short-circuit current of the target photovoltaic array is estimated by using the historical maximum power point voltage value, the maximum power point current value corresponding to the historical maximum power point at the current moment, and the current short-circuit current estimation coefficient. The upper limit current value of the scan is then set based on this, so that the IV scan range can be automatically adjusted according to the actual operating conditions of the target photovoltaic array. This avoids the problem of the scan range being too large or too small due to the fixed upper limit of the rated current value, and reduces the reliance on hardware protection.

[0068] In some optional implementations, step S2034 above includes: Step a1: Determine the current exit threshold as the upper limit current value for scanning the target photovoltaic array.

[0069] or, Obtain the upper limit value of the current protection of the target photovoltaic array, determine the smaller value between the upper limit value of the current protection and the current exit threshold, and determine the smaller value between the upper limit value of the current protection and the current exit threshold as the upper limit current value of the scan of the target photovoltaic array.

[0070] The control unit also sets an upper limit for current protection based on the power device capabilities and circuit design of the photovoltaic inverter, which is used for overcurrent protection determination during the scanning process. Generally, the upper limit for current protection is the rated current value of the target photovoltaic array.

[0071] It should be noted that the control unit determines the upper limit current value for short-circuit side scanning, i.e., the scanning upper limit current value, based on the current exit threshold and the current protection upper limit value. This ensures that the scanning upper limit current value does not exceed the current exit threshold and does not exceed the circuit's maximum allowable safe operating current or the current protection upper limit value. The scanning upper limit current value can be directly taken from the current exit threshold, or it can be the smaller value between the current exit threshold and the current protection upper limit value.

[0072] In some optional implementations, step S205 above includes: Step b1: Obtain the total number of scan points.

[0073] For example, the total number of scan points N = 256. In this embodiment of the application, the scan points are divided into 128 points on each side of the maximum power point current value Imppp as the dividing line, so that the IV characteristic curve can be reflected with higher resolution before and after the maximum power point.

[0074] Step b2: Divide the total number of scan points into the first scan point number and the second scan point number.

[0075] Step b3: Based on the first number of scan points and the first current range, determine the first current step size. The first current range is the current range from the lower limit current value to the maximum power point current value.

[0076] After determining the lower limit current value, the maximum power point current value, and the upper limit current value, the control unit calculates the current step size to the left (open circuit side) and the right (short circuit side) of the maximum power point current value, respectively.

[0077] Specifically, the first current step size is determined using the following formula: ΔI_left = (Impp - I_min) / m Where ΔI_left is the first current step size, Impp is the maximum power point current value, I_min is the lower limit current value of the scan, and m is the number of the first scan points.

[0078] Step b4: Based on the second number of scan points and the second current range, determine the second current step size. The second current range is the current range from the maximum power point current value to the upper limit of the scan current value.

[0079] Specifically, the second current step size is determined using the following formula: ΔI_right = (I_max - Imppp) / n Where ΔI_right is the second current step size, Impp is the maximum power point current value, I_max is the upper limit current value of the scan, and n is the number of second scan points.

[0080] Step b5: Based on the first current step size, determine multiple current scanning points within the first current range.

[0081] Specifically, multiple current scanning points within the first current range are determined using the following formula: I_ref1(i)=I_min+(i-1)×ΔI_left Where I_ref1(i) is the i-th current scan point in the first current range. The value of i is determined according to the number of the first scan points; for example, i can be 1 to 128.

[0082] Step b6: Based on the second current step size, determine multiple current scanning points in the second current range.

[0083] Specifically, multiple current scanning points within the second current range are determined using the following formula: I_ref2(i)=Impp+(i-1)×ΔI_right Where I_ref2(i) is the i-th current scan point in the second current range. The value of i is determined according to the number of second scan points; for example, i can be 1 to 128.

[0084] Through steps b5 and b6, the current scanning points are divided into half before and half before the maximum power point current value, so that the IV characteristic curve has a high sampling density on both sides of the MPP. This is beneficial to reflect the different voltage and current change rates in this region, while avoiding the waste of points caused by placing too many points in the extremely low current region.

[0085] Step b7: Perform a current scan on the target photovoltaic array in ascending order of current scan points to obtain multiple current-voltage data pairs of the target photovoltaic array.

[0086] After obtaining multiple current scanning points in the first current range and multiple current scanning points in the second current range, the control unit performs current scanning on the target photovoltaic array in ascending order of the current scanning points to obtain multiple current-voltage data pairs of the target photovoltaic array.

[0087] Specifically, the scanning process includes the following steps: 1. Initialize the scan counter. Set the scan counter value j to 0.

[0088] 2. Output current scan points and sample them. It can be understood that the current scan point is the current scan value.

[0089] The control unit outputs the current j-th current scan value I_ref(j) to the power conversion unit of the photovoltaic inverter. The power conversion unit adjusts the operating point of the target photovoltaic array to the current level corresponding to the j-th current scan value. After the system stabilizes, the actual output voltage value Upv(j) and the actual output current value Ipv(j) of the target photovoltaic array are acquired through the voltage and current sampling circuit of the photovoltaic inverter. It can be understood that a current-voltage data pair corresponds to the actual output voltage value and the actual output current value obtained based on a current scan value, i.e., (Upv(j), Ipv(j)).

[0090] 3. Scan Exit Condition Judgment: After performing a current scan on the target photovoltaic array based on any current scan point, the control unit sequentially judges the following conditions: 1) Low voltage judgment: If the actual output voltage value Upv(j) of the target photovoltaic array is less than the preset minimum voltage threshold U_min (e.g., close to 0V), it is considered that the target photovoltaic array is close to a short-circuit condition. The reason for exiting is recorded as "exit due to low voltage". Based on the number of current scan points already scanned, the exit point number N_real is recorded, and the current IV scan is terminated, i.e., the current scan of the target photovoltaic array is stopped. It can be understood that the number of current scan points already scanned can be determined based on the sorting sequence number of the current scan points.

[0091] 2) Current over-limit judgment: If the actual output current value Ipv(j) of the target photovoltaic array is greater than the current protection limit of the target photovoltaic array, it is considered that the overcurrent protection condition has been triggered, the exit reason is recorded as "current over-limit exit", the exit point number N_real is recorded, and the current IV scan is terminated.

[0092] 3) High current exit threshold judgment: If Ipv(j) or I_ref1(i) or I_ref2(i) is greater than or equal to the current exit threshold, it is considered that the preset high current boundary has been reached, the exit reason is recorded as "exiting after reaching the current threshold", the number of exit points N_real is recorded, and the current IV scan is terminated.

[0093] 4) Count completion judgment: If none of the above three conditions are triggered—that is, the actual output voltage of the target photovoltaic array is not less than the preset minimum voltage threshold, the actual output current of the target photovoltaic array is not greater than the current protection upper limit of the target photovoltaic array, and the actual output current of the target photovoltaic array and the current scan point are less than the current exit threshold of the target photovoltaic array—the control unit determines whether the current j has reached the total number of scan points N (e.g., 256). If j ≥ N, the scan is considered complete, the exit reason is recorded as "normal scan completed", N_real = N is recorded, and the current IV scan is terminated; if j < N, the target step is executed. The target step is to increment the scan count and continue scanning: when the scan is not finished and the maximum number of points has not been reached, the control unit increments j by 1, i.e., j = j + 1, and then returns to the step of executing the above output current scan point and sampling, outputs a new I_ref(j), and continues the subsequent scan.

[0094] Through the above loop, the control unit completes the scanning process of the IV curve and obtains the set of discrete IV data points under the corresponding operating conditions.

[0095] After the scan is complete, the control unit generates the target current-voltage characteristic curve of the target photovoltaic array under the current operating condition based on the obtained discrete IV data point set (current and voltage data) for the corresponding operating condition. When necessary, it further calculates the corresponding power P(j) = Upv(j) × Ipv(j) to obtain characteristic parameters such as the current maximum power point, maximum power point voltage, maximum power point current, and fill factor. The generated IV characteristic curve and characteristic parameters can be saved in the storage unit for subsequent MPPT strategy optimization, module status assessment, or system monitoring.

[0096] The current-voltage characteristic curve generation method provided in this application improves scanning efficiency by adaptively setting the scanning interval and the distribution of the number of scanning points, concentrating a limited number of scanning points in the effective interval related to the MPP and short-circuit regions, reducing the waste of scanning points in the low-current invalid region.

[0097] In some optional embodiments, the above-described method for generating current-voltage characteristic curves further includes: Step c1: After performing a current scan on the target photovoltaic array based on any current scan point, if the actual output voltage value of the target photovoltaic array is less than the preset minimum voltage threshold, then stop continuing to perform a current scan on the target photovoltaic array, record the exit reason as "exit due to low voltage", and determine and record the exit point number based on the sorting number of the current scan point.

[0098] Step c2: If the actual output current value of the target photovoltaic array is greater than the current protection limit of the target photovoltaic array, then stop continuing to scan the target photovoltaic array for current, record the exit reason as current over-limit exit, and determine and record the exit point number based on the sorting number of the current scan point.

[0099] Step c3: If the actual output current value of the target photovoltaic array or the current scanning point is not less than the current exit threshold of the target photovoltaic array, then stop continuing to scan the target photovoltaic array for current, record the exit reason as reaching the current threshold, and determine and record the exit point number based on the sorting number of the current scanning point.

[0100] The current-voltage characteristic curve generation method provided in this application, by setting a current exit threshold and a current protection upper limit, and combining it with low voltage exit judgment, ensures the acquisition of a complete IV characteristic curve while avoiding the photovoltaic array being in extreme operating point for a long time, reducing the electrical stress of components, and improving system safety and reliability.

[0101] In some optional embodiments, the above-described method for generating current-voltage characteristic curves further includes: Step d1: Determine the point count threshold based on the total number of scan points.

[0102] To make the short-circuit current estimate of the target photovoltaic array closer to the actual short-circuit condition, this application adaptively updates the short-circuit current estimation coefficients based on the exit reason and exit point of this scan.

[0103] Specifically, the control unit sets the expected number of scan points N_req, i.e., the total number of scan points N (preferably 256), and sets the point count determination threshold N_th. The point count determination threshold is determined based on the expected number of scan points.

[0104] For example, N_th = 0.9 × N_req. When the number of exited points N_real is less than N_th, it is considered that the current scan has not covered the expected 90% of the points, and the short-circuit current estimation coefficient k needs to be adjusted according to the reason for exiting; when N_real is greater than or equal to N_th, it is considered that the scan coverage is sufficient, and the current short-circuit current estimation coefficient k can be considered to be reasonably estimated.

[0105] Step d2: If the number of exit points is less than the number of points to determine, and the reason for exiting is low voltage, then reduce the short-circuit current estimation coefficient of the target photovoltaic array.

[0106] Step d3: If the number of exit points is less than the number of points to determine the threshold, and the exit reason is current over-limit exit, then increase the short-circuit current estimation coefficient of the target photovoltaic array.

[0107] The control unit performs the following actions based on different exit scenarios: a) Cases where the voltage is too low and the number of points is insufficient If the exit reason is "exit due to low voltage" and N_real < N_th, it indicates that the voltage has dropped to near short-circuit level before the expected 90% of the points have been completed. The current short-circuit current estimate I_sc_est is too large, and the scanning range has been extended too far towards the high-current side. In this case, the control unit will appropriately reduce the short-circuit current estimation coefficient k. For example, the adjusted short-circuit current estimation coefficient is determined by the following formula: k_new = k_old × β Where k_new is the adjusted short-circuit current estimation coefficient, k_old is the original short-circuit current estimation coefficient, and β is the preset adjustment coefficient, 0<β<1, which is used to reduce I_sc_est in the next scan, so that the upper limit current value of the scan is lowered.

[0108] b) Cases where current exceeds limits and the number of points is insufficient If the exit reason is "current over-limit exit" and N_real < N_th, it indicates that current protection was triggered before the expected 90% of the points were completed, the current short-circuit current estimate I_sc_est is too small, and the upper limit current setting is insufficient. In this case, the control unit will appropriately increase the short-circuit current estimation coefficient k. For example, the adjusted short-circuit current estimation coefficient is determined using the following formula: k_new=k_old×γ Where γ > 1, it is used to increase I_sc_est for the next scan, thereby increasing the upper limit current value of the scan.

[0109] c) Normal completion or sufficient points If the reason for exiting is "scan completed normally" or "exiting after reaching the current threshold", and N_real ≥ N_th, it indicates that the current short-circuit current estimation coefficient k is reasonable, and the control unit can keep the current short-circuit current estimation coefficient unchanged, that is: k_new=k_old It should be noted that k can be fine-tuned according to specific implementation needs.

[0110] The control unit writes the updated short-circuit current estimation coefficient k_new into the storage unit for use in subsequent IV scans of the target photovoltaic array. Through multiple scan iterations, the short-circuit current estimation coefficient k will gradually converge, making the short-circuit current estimation value I_sc_est closer to the actual short-circuit current, thus achieving adaptive matching between the scan range and the characteristics of the actual IV curve.

[0111] Figure 3 A flowchart for updating the short-circuit current estimation coefficients provided in the embodiments of this application is shown below. Figure 3 As shown, the process includes: Read the number of exit points, the reason for exit, the current short-circuit current estimation coefficient, and the point determination threshold.

[0112] Determine if the number of exit points is less than the number of exit points judgment threshold. If the number of exit points is less than the number of exit points judgment threshold, determine if the exit reason is low voltage. If the exit reason is low voltage, reduce the short circuit current estimation coefficient.

[0113] If the number of exit points is not less than the point determination threshold, the current short-circuit current estimation coefficient remains unchanged.

[0114] If the reason for termination is excessive current, then increase the short-circuit current estimation factor.

[0115] Save the updated short-circuit current estimation coefficients.

[0116] Embodiments of this application provide a method for generating current-voltage characteristic curves, applicable to a photovoltaic array IV characteristic curve scanning device in a photovoltaic inverter or photovoltaic testing equipment. Figure 4 This is a schematic flowchart of the current-voltage characteristic curve generation method provided in the embodiments of this application, as shown below. Figure 4 As shown, the method for generating the current-voltage characteristic curve includes the following steps: Obtain the historical maximum power point voltage value of the target photovoltaic array to determine the maximum power point current value corresponding to the historical maximum power point at the current moment; obtain the current short-circuit current estimation coefficient.

[0117] Calculate the estimated short-circuit current and the current exit threshold; obtain the upper limit value of current protection.

[0118] Based on the current exit threshold and the current protection upper limit value, determine the upper limit current value for scanning; set the lower limit current value for scanning; and calculate the first current step size and the second current step size.

[0119] Based on the first current step size and the second current step size, multiple current scanning points are determined; the current scanning point is determined in ascending order of the current scanning points; and the target photovoltaic array is scanned based on the current scanning point. Determine whether the currently acquired actual output voltage value is less than the preset minimum voltage threshold. If the currently acquired actual output voltage value is less than the preset minimum voltage threshold, record the exit reason as "exit due to low voltage" and record the exit point number.

[0120] If the currently acquired actual output voltage value is not less than the preset minimum voltage threshold, then determine whether the currently acquired actual output current value is greater than the current protection upper limit. If the currently acquired actual output current value is greater than the current protection upper limit, then record the exit reason as "current over-limit exit" and record the exit point number.

[0121] If the current actual output current value is not greater than the current protection upper limit, then determine whether the current actual output current value or the current current scanning point is greater than or equal to the current exit threshold. If the current actual output current value or the current current scanning point is greater than or equal to the current exit threshold, then record the exit reason as "exiting after reaching the current threshold" and record the exit point number.

[0122] If the actual output current value or the current current scan point is less than the current exit threshold, determine whether the current current scan point is the last current scan point. If so, record the exit reason as "scan completed normally" and record the exit point number. If not, update the current current scan point as the next current scan point and continue scanning the target photovoltaic array.

[0123] The short-circuit current estimation coefficients are updated based on the exit reason and exit point, and the updated short-circuit current estimation coefficients are written into the storage unit to generate the IV characteristic curve for this test.

[0124] It should be noted that the current-voltage characteristic curve generation method provided in this application embodiment can be applied to a single photovoltaic array input, or it can be applied to each photovoltaic array in a multi-channel photovoltaic array input system. Each photovoltaic array maintains independent Vmpp, Impp and k, thereby achieving independent adaptive IV scan optimization among multiple photovoltaic arrays.

[0125] It should be further noted that the current-voltage characteristic curve generation method provided in this application embodiment can also be applied to photovoltaic modules according to actual conditions.

[0126] This embodiment also provides a current-voltage characteristic curve generation device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0127] This embodiment provides a current-voltage characteristic curve generation device, such as... Figure 5 As shown, it includes: The first acquisition module 501 is used to acquire the historical maximum power point voltage value of the target photovoltaic array.

[0128] The first determining module 502 is used to determine the maximum power point current value corresponding to the historical maximum power point at the current moment based on the historical maximum power point voltage value.

[0129] The second determining module 503 is used to determine the upper limit current value of the target photovoltaic array based on the maximum power point current value.

[0130] The second acquisition module 504 is used to acquire the scanning lower limit current value of the target photovoltaic array.

[0131] The third acquisition module 505 is used to perform current scanning on the target photovoltaic array based on the upper limit current value and the lower limit current value to obtain multiple voltage and current data pairs of the target photovoltaic array.

[0132] The generation module 506 is used to generate the target current-voltage characteristic curve of the target photovoltaic array based on multiple voltage-current data pairs.

[0133] In some alternative implementations, the first determining module 502 includes: The first adjustment unit is used to adjust the output current value of the target photovoltaic array downwards until the output voltage value of the target photovoltaic array is equal to the historical maximum power point voltage value if the current output voltage value of the target photovoltaic array is less than the historical maximum power point voltage value, and to determine the adjusted output current value as the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0134] The second adjustment unit is used to adjust the output current value of the target photovoltaic array upwards until the output voltage value of the target photovoltaic array is equal to the historical maximum power point voltage value if the current output voltage value of the target photovoltaic array is greater than the historical maximum power point voltage value, and to determine the adjusted output current value as the maximum power point current value corresponding to the historical maximum power point at the current moment.

[0135] In some alternative implementations, the second determining module 503 includes: The first acquisition unit is used to acquire the current short-circuit current estimation coefficient of the target photovoltaic array.

[0136] The first determining unit is used to determine the estimated short-circuit current of the target photovoltaic array based on the maximum power point current value and the current short-circuit current estimation coefficient.

[0137] The second determining unit is used to determine the current exit threshold of the target photovoltaic array based on the short-circuit current estimate.

[0138] The third determining unit is used to determine the upper limit current value of the target photovoltaic array based on the current exit threshold.

[0139] In some optional implementations, the third determining unit includes: The third determining subunit is used to determine the current exit threshold as the upper limit current value for scanning of the target photovoltaic array. Alternatively, it is used to obtain the upper limit current protection value of the target photovoltaic array, determine the smaller value between the upper limit current protection value and the current exit threshold, and determine the smaller value between the upper limit current protection value and the current exit threshold as the upper limit current value for scanning of the target photovoltaic array.

[0140] In some optional implementations, the third acquisition module 505 includes: The second acquisition unit is used to acquire the total number of scan points.

[0141] The division unit is used to divide the total number of scan points into a first scan point and a second scan point.

[0142] The fourth determining unit is used to determine the first current step size based on the first number of scan points and the first current range, wherein the first current range is the current range from the lower limit current value of the scan to the maximum power point current value.

[0143] The fifth determining unit is used to determine the second current step size based on the second number of scan points and the second current range, wherein the second current range is the current range from the maximum power point current value to the upper limit current value of the scan.

[0144] The sixth determining unit is used to determine multiple current scanning points in the first current range based on the first current step size.

[0145] The seventh determining unit is used to determine multiple current scanning points in the second current range based on the second current step size.

[0146] The third acquisition unit is used to perform current scanning on the target photovoltaic array in ascending order of current scanning points to obtain multiple current-voltage data pairs of the target photovoltaic array.

[0147] In some optional embodiments, the above-mentioned current-voltage characteristic curve generation device further includes: The first recording unit is used to stop scanning the target photovoltaic array after performing a current scan on the target photovoltaic array based on any current scan point. If the actual output voltage value of the target photovoltaic array is less than a preset minimum voltage threshold, the unit records the exit reason as "exit due to low voltage" and determines and records the exit point number based on the sorting number of the current scan point.

[0148] The second recording unit is used to stop scanning the target photovoltaic array if the actual output current value of the target photovoltaic array is greater than the current protection limit of the target photovoltaic array, record the exit reason as current over-limit exit, and determine and record the exit point number based on the sorting number of the current scanning point.

[0149] The third recording unit is used to stop scanning the target photovoltaic array if the actual output current value of the target photovoltaic array or the current scanning point is not less than the current exit threshold of the target photovoltaic array, record the exit reason as reaching the current threshold, and determine and record the exit point number based on the sorting number of the current scanning point.

[0150] In some optional embodiments, the above-mentioned current-voltage characteristic curve generation device further includes: The eighth determining unit is used to determine the point count threshold based on the total number of scan points.

[0151] The reduction unit is used to reduce the short-circuit current estimation coefficient of the target photovoltaic array if the number of exit points is less than the number of exit points determination threshold and the exit reason is low voltage.

[0152] The "Increase Unit" is used to increase the short-circuit current estimation coefficient of the target photovoltaic array if the number of exit points is less than the number of points to be determined and the exit reason is current over-limit exit.

[0153] The current-voltage characteristic curve generation device provided in this embodiment of the invention can execute the current-voltage characteristic curve generation method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0154] Embodiments of the present invention also provide an electronic device, such as... Figure 6 As shown, it includes a processor 601 and a memory 602, the memory 602 storing a computer program, and the processor 601 is configured to run the computer program to perform the steps in any of the above embodiments of the current-voltage characteristic curve generation method.

[0155] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above embodiments of the current-voltage characteristic curve generation method when running.

[0156] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0157] Embodiments of the present invention also provide a computer program product, which includes a computer program that, when executed by a processor, implements the steps in any of the above embodiments of the current-voltage characteristic curve generation method.

[0158] Embodiments of the present invention also provide another computer program product, including a non-volatile computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in any of the above embodiments of the current-voltage characteristic curve generation method.

[0159] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0160] The present application provides a detailed description of a method, apparatus, electronic device, and storage medium for generating current-voltage characteristic curves. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of these embodiments are only intended to aid in understanding the method and core concepts of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A method for generating current-voltage characteristic curves, characterized in that, The method includes: Obtain the historical maximum power point voltage value of the target photovoltaic array; Based on the historical maximum power point voltage value, determine the maximum power point current value corresponding to the historical maximum power point at the current moment; Based on the maximum power point current value, the upper limit current value for scanning of the target photovoltaic array is determined; Obtain the lower limit current value of the target photovoltaic array; Based on the upper limit current value and the lower limit current value, the target photovoltaic array is current scanned to obtain multiple current-voltage data pairs of the target photovoltaic array; Based on the multiple current-voltage data pairs, the target current-voltage characteristic curve of the target photovoltaic array is generated.

2. The method according to claim 1, characterized in that, The step of determining the maximum power point current value corresponding to the historical maximum power point at the current moment based on the historical maximum power point voltage value includes: If the current output voltage of the target photovoltaic array is less than the historical maximum power point voltage value, then the output current value of the target photovoltaic array is adjusted downward until the output voltage value of the target photovoltaic array is equal to the historical maximum power point voltage value, and the adjusted output current value is determined as the maximum power point current value corresponding to the historical maximum power point at the current moment. If the current output voltage of the target photovoltaic array is greater than the historical maximum power point voltage, the output current of the target photovoltaic array is adjusted upward until the output voltage of the target photovoltaic array is equal to the historical maximum power point voltage. The adjusted output current value is then determined as the maximum power point current value corresponding to the historical maximum power point at the current moment.

3. The method according to claim 1, characterized in that, Determining the upper limit current value of the target photovoltaic array based on the maximum power point current value includes: Obtain the current short-circuit current estimation coefficient of the target photovoltaic array; Based on the maximum power point current value and the current short-circuit current estimation coefficient, the short-circuit current estimation value of the target photovoltaic array is determined; Based on the short-circuit current estimate, the current exit threshold of the target photovoltaic array is determined; Based on the current exit threshold, the upper limit current value of the target photovoltaic array is determined.

4. The method according to claim 3, characterized in that, Determining the upper limit current value of the target photovoltaic array based on the current exit threshold includes: The current exit threshold is determined as the upper limit current value for scanning the target photovoltaic array; or, Obtain the upper limit value of the current protection of the target photovoltaic array, determine the smaller value between the upper limit value of the current protection and the current exit threshold, and determine the smaller value between the upper limit value of the current protection and the current exit threshold as the upper limit current value of the scan of the target photovoltaic array.

5. The method according to claim 1, characterized in that, The step of performing a current scan on the target photovoltaic array based on the upper and lower current limits of the scan to obtain multiple current-voltage data pairs of the target photovoltaic array includes: Get the total number of scan points; The total number of scan points is divided equally into a first number of scan points and a second number of scan points; Based on the first number of scan points and the first current range, a first current step size is determined, wherein the first current range is the current range from the lower limit current value of the scan to the maximum power point current value; Based on the second number of scan points and the second current range, a second current step size is determined, wherein the second current range is the current range from the maximum power point current value to the upper limit current value of the scan. Based on the first current step size, multiple current scanning points are determined within the first current range; Based on the second current step size, multiple current scanning points in the second current range are determined; The target photovoltaic array is scanned in ascending order of the current scanning points to obtain multiple pairs of current and voltage data for the target photovoltaic array.

6. The method according to claim 5, characterized in that, The method further includes: After performing a current scan on the target photovoltaic array based on any current scan point, if the actual output voltage value of the target photovoltaic array is less than the preset minimum voltage threshold, the current scan on the target photovoltaic array is stopped, the reason for exiting is recorded as low voltage, and the number of exit points is determined and recorded based on the sorting number of the current scan point. If the actual output current value of the target photovoltaic array is greater than the current protection limit of the target photovoltaic array, then stop the current scanning of the target photovoltaic array, record the exit reason as current over-limit exit, and determine and record the exit point number based on the sorting number of the current scanning point; If the actual output current value of the target photovoltaic array or the current scan point is not less than the current exit threshold of the target photovoltaic array, then the current scan of the target photovoltaic array is stopped, the exit reason is recorded as reaching the current threshold, and the exit point number is determined and recorded based on the sorting number of the current scan point.

7. The method according to claim 6, characterized in that, The method further includes: Determine the threshold for determining the number of scan points based on the total number of scan points; If the number of exit points is less than the number of points determination threshold, and the reason for exit is low voltage, then the short-circuit current estimation coefficient of the target photovoltaic array is reduced. If the number of exit points is less than the number of points determination threshold, and the exit reason is current over-limit exit, then the short-circuit current estimation coefficient of the target photovoltaic array is increased.

8. A current-voltage characteristic curve generation device, characterized in that, The device includes: The first acquisition module is used to acquire the historical maximum power point voltage value of the target photovoltaic array; The first determining module is used to determine the maximum power point current value corresponding to the historical maximum power point at the current moment based on the historical maximum power point voltage value; The second determining module is used to determine the upper limit current value of the target photovoltaic array based on the maximum power point current value; The second acquisition module is used to acquire the scan lower limit current value of the target photovoltaic array; The third acquisition module is used to perform current scanning on the target photovoltaic array based on the upper limit current value and the lower limit current value to obtain multiple current-voltage data pairs of the target photovoltaic array; The generation module is used to generate the target current-voltage characteristic curve of the target photovoltaic array based on the multiple current-voltage data pairs.

9. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the current-voltage characteristic curve generation method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein when the computer program is executed by a processor, it implements the steps of the current-voltage characteristic curve generation method as described in any one of claims 1 to 7.

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