Control method, system and device suitable for photovoltaic inverter power supply

Abstract

The present application relates to photovoltaic power supply technical field, specifically to a kind of control method, system and equipment suitable for photovoltaic inverter power supply, method includes: according to the current and voltage reduction of each photovoltaic panel in photovoltaic system, determine the light receiving degree of each photovoltaic panel;When the total current change speed of photovoltaic system meets the first condition, the light receiving deviation of each photovoltaic panel is determined by the light receiving degree of each photovoltaic panel, and the light receiving fluctuation degree of photovoltaic system is obtained;When light receiving fluctuation degree meets the second condition, according to the change rule of the light receiving degree of each photovoltaic panel, determine the overall light receiving change of photovoltaic system;Initial perturbation step is adjusted by overall light receiving change, can dynamically match the actual situation of photovoltaic power generation, to ensure the accuracy and reliability of perturbation step setting. Subsequently, when using perturbation observation method to control photovoltaic inverter, photovoltaic inverter power supply control reliability can be improved, and photovoltaic power supply stability is ensured.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power supply technology, and specifically to a control method, system and equipment applicable to photovoltaic inverter power supplies. Background Technology

[0002] As a key component of photovoltaic systems, photovoltaic inverters convert direct current (DC) to alternating current (AC) and track the maximum output power of the photovoltaic module array, integrating into the power grid or used in electrical equipment applications with minimal conversion losses and optimal power quality.

[0003] In the process of photovoltaic power generation, many factors affect the power generation efficiency of photovoltaic panels, including the internal structure and characteristics of the photovoltaic panels, as well as external environmental factors such as light intensity and temperature. Regardless of changes in the external environment, there is a unique maximum power point for a photovoltaic panel at any given time. Maximum power point tracking (MPPT) technology can track the maximum power point of the photovoltaic cells based on its control algorithm, enabling the system to maintain high power generation efficiency under different environmental conditions, which can generally increase the system's power generation by 5%-20%.

[0004] The commonly used Maximum Power Point Tracking (MPPT) algorithm is typically the perturbation-observation method. The core idea of ​​this method is to actively perturb the operating point of the photovoltaic (PV) panel (usually voltage), observe the direction of output power change, and thus determine if the perturbation direction is correct. Based on this, the operating point is adjusted to move closer to the maximum power point. Therefore, the perturbation-observation method gradually approaches the maximum power point by slightly adjusting the voltage and relying on the adjusted power feedback. The perturbation step size is a crucial parameter in this method. However, existing perturbation step sizes are fixed and cannot match the actual conditions of PV power generation, leading to inaccurate perturbation step size settings and affecting the stability of PV power supply. Summary of the Invention

[0005] To address the technical problem of inaccurate perturbation step size setting in the perturbation-observation method for photovoltaic inverter control, the present invention aims to provide a control method, system, and device suitable for photovoltaic inverter power supplies. The specific technical solution adopted is as follows:

[0006] In a first aspect of the present invention, a control method suitable for photovoltaic inverter power supplies is provided, comprising:

[0007] The degree of light received by each photovoltaic panel is determined based on the decrease in current and voltage of each photovoltaic panel in the photovoltaic system.

[0008] When the rate of change of the total current of the photovoltaic system meets the first condition, the light reception deviation of each photovoltaic panel is determined by the light reception degree of each photovoltaic panel, and the light reception fluctuation degree of the photovoltaic system is obtained.

[0009] When the degree of light reception fluctuation meets the second condition, the overall light reception change of the photovoltaic system is determined according to the change pattern of the light reception degree of each photovoltaic panel;

[0010] The initial perturbation step size is adjusted based on the overall change in light exposure.

[0011] In an exemplary embodiment, the process of obtaining the light intensity includes:

[0012] Obtain the current of the photovoltaic panel, and determine the first shading performance characteristic represented by the current reduction based on the difference between the current and the preset standard current.

[0013] Obtain the current voltage of the photovoltaic panel, and determine the second shading performance characteristic represented by the voltage reduction based on the difference between the current voltage and the preset standard voltage;

[0014] The light-receiving degree of the photovoltaic panel is obtained by combining the first shading performance feature and the second shading performance feature; the light-receiving degree is inversely correlated with both the first shading performance feature and the second shading performance feature.

[0015] In an exemplary embodiment, the process of obtaining the light reception deviation includes:

[0016] The difference between the light reception level of each photovoltaic panel and the average light reception level is taken as the light reception deviation of each photovoltaic panel; the average light reception level is the average of the light reception levels of all photovoltaic panels.

[0017] In an exemplary embodiment, the process of obtaining the degree of light fluctuation includes:

[0018] The maximum light reception deviation is determined from the light reception deviation of each photovoltaic panel;

[0019] The light reception fluctuation level is obtained from the average light reception level and the maximum light reception deviation; the light reception fluctuation level is positively correlated with the maximum light reception deviation and negatively correlated with the average light reception level.

[0020] In an exemplary embodiment, the process of acquiring the overall change in light exposure includes:

[0021] Construct a photovoltaic panel location matrix based on the geographical location of each photovoltaic panel;

[0022] The rate of change of light reception intensity of each row of photovoltaic panels in the photovoltaic panel position matrix is ​​determined, and the lateral light reception intensity change characteristics are obtained by fusion.

[0023] The rate of change of light reception level of each column of photovoltaic panels in the photovoltaic panel position matrix is ​​determined, and the longitudinal light reception level change characteristics are obtained by fusion.

[0024] By integrating the lateral and longitudinal light intensity variation characteristics, the overall light intensity variation is obtained.

[0025] In an exemplary embodiment, the process of obtaining the rate of change of the light received by each row of photovoltaic panels includes:

[0026] The average light reception level of each photovoltaic panel in the candidate row is calculated to obtain the light reception level of the candidate row photovoltaic panels;

[0027] Calculate the rate of change in the light received by the candidate row of photovoltaic panels;

[0028] The process of obtaining the lateral light reception variation characteristics includes: calculating the average value of the rate of change of light reception of each row of photovoltaic panels as the lateral light reception variation characteristics.

[0029] In an exemplary embodiment, adjusting the initial perturbation step size based on the overall change in light exposure includes:

[0030] An adjustment coefficient is obtained from the overall change in light exposure; the adjustment coefficient is positively correlated with the overall change in light exposure.

[0031] The initial perturbation step size is adjusted according to the adjustment coefficient.

[0032] In one exemplary embodiment, the control method for photovoltaic inverter power supplies further includes:

[0033] When the degree of light fluctuation does not meet the second condition, an adjustment coefficient is obtained from the rate of change of the total current; the adjustment coefficient is positively correlated with the rate of change of the total current.

[0034] The initial perturbation step size is adjusted according to the adjustment coefficient.

[0035] In a second aspect of the present invention, a control system suitable for photovoltaic inverter power supplies is provided, comprising: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-described control method suitable for photovoltaic inverter power supplies when the program instructions are executed.

[0036] In a third aspect of the invention, a control device suitable for a photovoltaic inverter power supply is provided, comprising a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in the control method suitable for a photovoltaic inverter power supply described above.

[0037] This invention offers the following advantages: It determines the overall light reception variation of the photovoltaic system based on the changes in current and voltage of each photovoltaic panel. The initial disturbance step size is then adjusted according to this overall light reception variation, ensuring that the adjusted step size is correlated with the overall state of the photovoltaic system. As the overall state of the photovoltaic system changes, the disturbance step size also changes accordingly, achieving adaptive adjustment. Compared to a fixed disturbance step size setting, this method dynamically matches the actual situation of photovoltaic power generation, thus ensuring the accuracy and reliability of the disturbance step size setting. Subsequently, when using the disturbance observation method for photovoltaic inverter control, it can improve the reliability of photovoltaic inverter power supply control and ensure the stability of photovoltaic power supply. Attached Figure Description

[0038] Figure 1 This is a flowchart of the steps of a control method for a photovoltaic inverter power supply provided in one embodiment of the present invention;

[0039] Figure 2 This is a flowchart illustrating the process of obtaining light intensity according to an embodiment of the present invention;

[0040] Figure 3 This is a flowchart illustrating the process of obtaining the degree of light fluctuation provided in one embodiment of the present invention;

[0041] Figure 4 This is a flowchart illustrating the acquisition of overall light exposure changes according to an embodiment of the present invention;

[0042] Figure 5 This is a flowchart illustrating the process of obtaining the rate of change in the light intensity of each row of photovoltaic panels according to an embodiment of the present invention.

[0043] Figure 6 This is a flowchart of adjusting the initial perturbation step size based on the overall change in light exposure, provided by one embodiment of the present invention;

[0044] Figure 7 This is a flowchart illustrating the steps of a control method for photovoltaic inverter power supplies provided in one embodiment of the present invention. Detailed Implementation

[0045] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All data and information collected in this application have been obtained with full consent.

[0047] In a photovoltaic (PV) system, photovoltaic (PV) panels are the core power generation component. The electricity they generate needs to undergo a series of processing steps before it can be successfully connected to the grid and effectively utilized. To achieve better energy output and lower wiring costs, PV panels are typically configured in a mixed series-parallel configuration, that is, multiple sets of PV panels are connected in series and then in parallel to form a PV system. In this embodiment, all PV panels in the PV system are of the same model to achieve perfect matching of electrical parameters.

[0048] When sunlight shines on the surface of a photovoltaic panel, it converts solar energy into direct current (DC) electricity. The DC power is first collected in a combiner box, then centrally processed and protected by a DC distribution cabinet. Subsequently, the photovoltaic inverter undertakes the core task of converting DC to alternating current (AC). The converted AC power must be smoothed by a filter to remove high-frequency harmonics and ensure power quality. The transformer is responsible for voltage regulation to match grid requirements and ensure stable grid connection. In this process, the photovoltaic inverter plays multiple crucial roles, including current control, grid synchronization, MPPT (Multi-Level Photovoltaic) protection, and anti-islanding protection.

[0049] Traditional MPPT (Maximum Power Point Tracking) uses a fixed perturbation step size, which is difficult to adapt to rapid changes in sunlight. However, when the sunlight received by a photovoltaic panel changes, its current and voltage data will change. Therefore, the current and voltage data of the photovoltaic panel can reflect its sunlight reception, thus enabling adaptive perturbation step size MPPT.

[0050] The current and voltage of each photovoltaic panel are collected. Inside the junction box of each photovoltaic panel, a voltage sensor, specifically an isolated differential voltage sensor, is installed in parallel. The measurement point is directly connected to the positive and negative output terminals of the photovoltaic panel to collect the voltage data. A current sensor, such as a Hall effect current sensor, is installed on the output line of each photovoltaic panel to collect the current of each panel. Simultaneously, a current sensor is also installed on the total output line of the photovoltaic system to collect the total current of the photovoltaic system. The sampling frequency of each sensor is set according to actual needs; this embodiment uses 1kHz as an example.

[0051] This embodiment provides a control method suitable for photovoltaic inverter power supplies, which adjusts the disturbance step size in the Multi-Performance Testing (MPPT) to control the photovoltaic inverter power supply based on the adjusted disturbance step size. It should be understood that this control method requires the photovoltaic system to be in normal operating condition. If a fault occurs in the photovoltaic system, such as a short circuit or open circuit, the fault diagnosis system installed in the photovoltaic system will perform the fault diagnosis, and the control method provided in this embodiment will not be executed. Therefore, this control method is only executed when the photovoltaic system is in normal operating condition to ensure the accuracy of the results.

[0052] like Figure 1 As shown, the control method for photovoltaic inverter power supplies provided in this embodiment includes the following steps:

[0053] Step 1: Determine the light reception level of each photovoltaic panel based on the decrease in current and voltage of each photovoltaic panel in the photovoltaic system;

[0054] Step 2: When the rate of change of the total current of the photovoltaic system meets the first condition, determine the light reception deviation of each photovoltaic panel based on the light reception level of each photovoltaic panel, and obtain the light reception fluctuation level of the photovoltaic system.

[0055] Step 3: When the light reception fluctuation meets the second condition, determine the overall light reception change of the photovoltaic system based on the change pattern of light reception of each photovoltaic panel;

[0056] Step 4: Adjust the initial perturbation step size based on the overall changes in light exposure.

[0057] The following detailed explanation of each step, in conjunction with the accompanying drawings, is provided.

[0058] Step 1: Determine the light reception level of each photovoltaic panel based on the decrease in current and voltage of each photovoltaic panel in the photovoltaic system.

[0059] Since a photovoltaic system is composed of photovoltaic panels connected in series and parallel, for ease of explanation, the following explanation will use any single photovoltaic panel as an example, and any single photovoltaic panel will be defined as a candidate photovoltaic panel.

[0060] Since the voltage and current of a candidate photovoltaic panel are controlled by the light intensity, the higher the light intensity, the greater the voltage and current. Therefore, the light reception level of the candidate photovoltaic panel is determined based on the decrease in current and voltage. The light reception level refers to the degree of light received, which can also be understood as the light intensity.

[0061] This embodiment presets a time period. Based on the data information of the photovoltaic system within each time period, an adjusted perturbation step size corresponding to that time period is obtained. Then, based on the determined perturbation step size, MPPT is used to control the photovoltaic inverter power supply for one or more subsequent time periods. It should be understood that the duration of the time period is set according to the actual situation. It should also be understood that if the time period consists of several time points, the voltage of the candidate photovoltaic panel is the average voltage at each moment within that time period, and the current of the candidate photovoltaic panel is the average current at each moment within that time period.

[0062] In one exemplary embodiment, such as Figure 2 As shown, the following is a specific process for obtaining the degree of light reception:

[0063] Step 11: Obtain the current of the photovoltaic panel, and determine the first shading performance characteristic represented by the current reduction based on the difference between the current and the preset standard current.

[0064] Obtain the current of the candidate photovoltaic panel, which is the current of the candidate photovoltaic panel in the current time period (i.e., the average current at each moment within the current time period; the same applies to voltage below). It should be understood that if the time period is a time interval, then the current moment is the last moment of the current time period.

[0065] In one exemplary embodiment, the preset standard current can be the current output by the photovoltaic panel under the strongest sunlight intensity in the region, without any obstructions blocking the sunlight. Therefore, the preset standard current can be understood as the maximum current that the photovoltaic panel can output in the region, or directly as the maximum current that the photovoltaic panel can output. In this case, the preset standard current is the same for all photovoltaic panels in the photovoltaic system.

[0066] The difference between the current of a candidate photovoltaic panel and a preset standard current is determined, and the first shading performance characteristic, characterized by the current reduction of the candidate photovoltaic panel, is determined based on this difference. The first shading performance characteristic represents the degree to which the sunlight of the candidate photovoltaic panel is blocked. This difference can be characterized by a ratio, i.e., calculating the ratio of the current of the candidate photovoltaic panel to the preset standard current. It should be understood that this ratio is greater than or equal to 0 and less than or equal to 1. The larger the ratio, the smaller the difference between the current of the candidate photovoltaic panel and the preset standard current, the smaller the current reduction, and the weaker the first shading performance characteristic. Therefore, the first shading performance characteristic is inversely correlated with this ratio. In an exemplary embodiment, a specific quantification method for the first shading performance characteristic is given below:

[0067] ;

[0068] in, This represents the first shading performance characteristic of the i-th photovoltaic panel; Indicates the preset standard current; This represents the current of the i-th photovoltaic panel.

[0069] Step 12: Obtain the current voltage of the photovoltaic panel, and determine the second shading performance characteristic represented by the voltage reduction based on the difference between the current voltage and the preset standard voltage.

[0070] The current voltage of the candidate photovoltaic (PV) panel is obtained, i.e., the voltage of the candidate PV panel in the current time period. In an exemplary embodiment, the preset standard voltage can be the voltage of the PV panel under the strongest sunlight intensity in the region, without any obstructions blocking the sunlight. Therefore, the preset standard voltage can be understood as the maximum voltage that the PV panel can output in the region, or it can be directly understood as the maximum voltage that the PV panel can output. In this case, the preset standard voltage of all PV panels in the photovoltaic system is the same.

[0071] The difference between the current voltage of a candidate photovoltaic panel and a preset standard voltage is determined, and a second shading performance characteristic, characterized by the voltage reduction of the candidate photovoltaic panel, is determined based on this difference. The second shading performance characteristic represents the degree to which sunlight is blocked by the candidate photovoltaic panel. This difference can be characterized by a ratio, i.e., calculating the ratio of the current voltage of the candidate photovoltaic panel to the preset standard voltage. It should be understood that this ratio is greater than or equal to 0 and less than or equal to 1. The larger the ratio, the smaller the difference between the current voltage of the candidate photovoltaic panel and the preset standard voltage, the smaller the voltage reduction, and the weaker the second shading performance characteristic. Therefore, the second shading performance characteristic is inversely correlated with this ratio. In an exemplary embodiment, a specific quantification method for the second shading performance characteristic is given below:

[0072] ;

[0073] in, This represents the second shading performance characteristic of the i-th photovoltaic panel; Indicates the preset standard voltage; This represents the current voltage of the i-th photovoltaic panel.

[0074] Step 13: Combine the first shading performance characteristics and the second shading performance characteristics to obtain the light reception level of the photovoltaic panel.

[0075] The stronger the first shading characteristic of a candidate photovoltaic (PV) panel, the greater the degree of shading on its current and the lower its light reception. Therefore, light reception is inversely correlated with the first shading characteristic. Similarly, the stronger the second shading characteristic of a candidate PV panel, the greater the degree of shading on its voltage and the lower its light reception. Therefore, light reception is inversely correlated with the second shading characteristic. Based on this logic, a specific method for quantifying light reception is given below:

[0076] ;

[0077] in, This represents the light reception level of the i-th photovoltaic panel. Using the above process, the current light reception level of each photovoltaic panel is obtained. The light reception level characterizes the degree of sunlight received by the photovoltaic panel.

[0078] Step 2: When the rate of change of the total current of the photovoltaic system meets the first condition, the light reception deviation of each photovoltaic panel is determined by the light reception degree of each photovoltaic panel, and the light reception fluctuation degree of the photovoltaic system is obtained.

[0079] The main reason for the change in the amount of light received by photovoltaic panels is the obstruction by clouds and buildings. When the amount of light received changes, it can be mainly divided into two situations: one is a sudden change in the overall light intensity of the photovoltaic system, that is, a sudden change in the overall light intensity of the photovoltaic system. In this case, there is no spatial gradient in the change of light intensity, and all photovoltaic panels in the photovoltaic system change synchronously; the other is gradual obstruction by shadows. In this case, the change in the amount of light received by each photovoltaic panel is spatially distributed, and the change in the amount of light received propagates along the space.

[0080] To obtain the rate of change of the total current of the photovoltaic system, in an exemplary embodiment, the average value of the total current at each moment within the current time period is calculated as the total current of the photovoltaic system in the current time period. Similarly, the total current of the photovoltaic system in previous time periods can be obtained, thus obtaining the total current of the previous time period. The absolute value of the difference between the total current of the current time period and the total current of the previous time period is calculated, and the absolute value of the total current difference is divided by the duration of the current time period. The result is the rate of change of the total current of the photovoltaic system in the current time period. It should be understood that if the duration of the time period is taken as a unit of time, then the rate of change of the total current of the photovoltaic system in the current time period is essentially the absolute value of the difference between the total current of the current time period and the total current of the previous time period. Alternatively, if the time period is only a single point in time, the instantaneous rate of change of the total current in the current time period is obtained (for example, by obtaining the total current change curve and taking the absolute value of the slope of the tangent line at each data point of the curve as the instantaneous rate of change) as the rate of change of the total current in the current time period.

[0081] This embodiment presets a first condition, which is used to proceed with the subsequent processing steps when the rate of change of the total current of the photovoltaic system meets the first condition. In an exemplary embodiment, a preset current change rate threshold is set. This preset current change rate threshold is used to compare with the rate of change of the total current of the photovoltaic system in the current time period to determine whether the rate of change of the total current of the photovoltaic system in the current time period is large. The specific value of the preset current change rate threshold is set according to actual needs, such as 30mA / unit time. Therefore, the first condition is: the rate of change of the total current of the photovoltaic system is greater than or equal to the preset current change rate threshold. Thus, when the rate of change of the total current of the photovoltaic system in the current time period is greater than or equal to the preset current change rate threshold, it indicates that the overall light intensity of the photovoltaic system has changed significantly.

[0082] The current type of light received by the photovoltaic system is determined by the overall light received condition of the photovoltaic system. When there are significant differences in the light received by different photovoltaic panels, it is considered to be a sudden change in light intensity caused by shading; otherwise, it is considered to be a sudden change in the overall light intensity of the photovoltaic system.

[0083] When the rate of change of the total current of the photovoltaic system in the current time period is greater than or equal to the preset rate of change threshold, the light reception deviation of each photovoltaic panel is determined by the light reception level of each photovoltaic panel. In an exemplary embodiment, the average value of the current light reception level of all photovoltaic panels in the photovoltaic system is calculated and defined as the average light reception level.

[0084] For candidate photovoltaic (PV) panels, the difference between the current light received by the candidate PV panel and the average light received is obtained. Specifically, the absolute value of the difference between the current light received by the candidate PV panel and the average light received is calculated, and this absolute value is taken as the current light received deviation of the candidate PV panel. This is used to obtain the current light received deviation of each PV panel.

[0085] Then, based on the light reception deviation of each photovoltaic panel, the degree of light reception fluctuation of the photovoltaic system is obtained. In an exemplary embodiment, such as... Figure 3 As shown, the following is a specific process for obtaining the degree of light fluctuation:

[0086] Step 21: Determine the maximum light reception deviation from the light reception deviations of each photovoltaic panel;

[0087] Step 22: Obtain the degree of light fluctuation from the average light intensity and the maximum light intensity deviation.

[0088] The maximum value of the current light reception deviation for each photovoltaic panel is defined as the current maximum light reception deviation. A larger maximum light reception deviation indicates stronger fluctuations in the photovoltaic system's light reception level, thus indicating a higher degree of light reception fluctuation; the two are positively correlated. Conversely, a higher average light reception level indicates a higher overall light reception level for the photovoltaic system, but also a lower reliability of the maximum light reception deviation. Therefore, the average light reception level is used to inversely characterize the reliability of the maximum light reception deviation, and the degree of light reception fluctuation is inversely correlated with the average light reception level. Based on the above logic, a specific quantification method for the degree of light reception fluctuation is given below:

[0089] ;

[0090] in, This indicates the degree of light fluctuation in a photovoltaic system. Indicates the maximum light reception deviation. This represents the average level of light received.

[0091] As another implementation method, the average value of the current light reception deviation of all photovoltaic panels in the photovoltaic system can be used as the current light reception fluctuation of the photovoltaic system.

[0092] The greater the fluctuation in light reception, the more gradually the light is blocked from each photovoltaic panel, meaning that shadows are gradually formed on the photovoltaic panels, and the light reception of each photovoltaic panel is spatially distributed.

[0093] Step 3: When the light reception fluctuation meets the second condition, determine the overall light reception change of the photovoltaic system based on the change pattern of light reception of each photovoltaic panel.

[0094] The greater the fluctuation in light reception, the more gradually the sunlight is blocked from each photovoltaic panel, meaning that shadows are gradually formed on the panels, resulting in a spatial distribution of light reception across the panels. When shadows gradually block the surface of the photovoltaic panels, causing changes in light reception, the blocking object typically moves along a specific angle. Therefore, it is necessary to determine the overall light reception variation of the photovoltaic system based on the changing patterns of light reception within the system.

[0095] This embodiment presets a second condition. When the light reception fluctuation level meets the second condition, it indicates that the sunlight received by each photovoltaic panel is being gradually blocked, and the subsequent processing in this step is then performed. In an exemplary embodiment, a preset light reception fluctuation level threshold is used to compare with the light reception fluctuation level of the photovoltaic system to determine whether the light reception fluctuation level of the photovoltaic system is large in the current time period. The specific value of the preset light reception fluctuation level threshold is set according to actual needs, and here it can be set to 0.1. Therefore, the second condition is: the light reception fluctuation level of the photovoltaic system is greater than or equal to the preset light reception fluctuation level threshold.

[0096] When the degree of light reception fluctuation meets the second condition, the overall light reception variation of the photovoltaic system is determined based on the variation pattern of light reception degree of each photovoltaic panel. For example... Figure 4 As shown, the following is a specific process for obtaining the overall changes in light exposure:

[0097] Step 31: Construct a photovoltaic panel location matrix based on the geographical location of each photovoltaic panel.

[0098] In this embodiment, the photovoltaic panels are arranged in multiple rows and columns to form a photovoltaic array. The geographical location of each photovoltaic panel is determined, and a two-dimensional coordinate system is constructed on the plane of the ground. The origin of the two-dimensional coordinate system is the position of the photovoltaic panel in the lower left corner, the horizontal arrangement direction of the photovoltaic panels is the X-axis, and the vertical arrangement direction of the photovoltaic panels is the Y-axis. The geographical location of each photovoltaic panel is mapped onto this two-dimensional coordinate system to obtain the two-dimensional coordinate points of each photovoltaic panel. A photovoltaic panel position matrix is ​​constructed based on the two-dimensional coordinate points of each photovoltaic panel. This yields the composition of each row and column of photovoltaic panels in the photovoltaic panel position matrix. For any row of photovoltaic panels, the X-axis coordinate points of the included photovoltaic panels are different, but the Y-axis coordinate points are the same; for any column of photovoltaic panels, the X-axis coordinate points of the included photovoltaic panels are the same, but the Y-axis coordinate points are different.

[0099] Step 32: Determine the rate of change of light intensity of each row of photovoltaic panels in the photovoltaic panel position matrix, and fuse them to obtain the lateral light intensity change characteristics.

[0100] Determine the rate of change in the light reception of each row of photovoltaic panels in the photovoltaic panel location matrix. In an exemplary embodiment, such as... Figure 5 As shown, the following is a specific process for obtaining the rate of change in the light received by each row of photovoltaic panels:

[0101] Step 321: Calculate the average light reception level of each photovoltaic panel in the candidate row to obtain the light reception level of the candidate row photovoltaic panels.

[0102] For ease of explanation, we define the candidate row of photovoltaic panels as any row of photovoltaic panels. We obtain the current light intensity of each photovoltaic panel in the candidate row, and then calculate the average of the current light intensity of each photovoltaic panel in the candidate row as the light intensity of the candidate row for the current time period.

[0103] Step 322: Calculate the rate of change of the light received by the candidate row photovoltaic panels.

[0104] To obtain the rate of change of light intensity for the candidate row of photovoltaic panels, in an exemplary embodiment, the light intensity of the candidate row of photovoltaic panels in the previous time period is obtained. The absolute value of the difference between the light intensity of the candidate row of photovoltaic panels in the current time period and the light intensity of the previous time period is calculated. The absolute value of the difference is divided by the duration of the current time period, and the result is the rate of change of light intensity of the candidate row of photovoltaic panels in the current time period. For ease of data processing, the absolute value of the difference between the light intensity of the candidate row of photovoltaic panels in the current time period and the light intensity of the previous time period is used as the rate of change of light intensity of the candidate row of photovoltaic panels in the current time period, i.e., the time period is a unit of time. Similarly, the rate of change of light intensity for each row of photovoltaic panels is obtained.

[0105] Then, the rate of change of light reception intensity of each row of photovoltaic panels in the photovoltaic panel position matrix is ​​fused to obtain the lateral light reception intensity variation characteristics. Specifically, the average rate of change of light reception intensity of each row of photovoltaic panels is calculated as the lateral light reception intensity variation characteristics.

[0106] Step 33: Determine the rate of change of light intensity of each column of photovoltaic panels in the photovoltaic panel location matrix, and fuse them to obtain the longitudinal light intensity change characteristics.

[0107] Similar to the process of obtaining the rate of change of light intensity for each row of photovoltaic panels in the photovoltaic panel position matrix described above, for ease of explanation, we assume that any column of photovoltaic panels is used as a candidate column. We obtain the current light intensity of each photovoltaic panel in the candidate column, and then calculate the average of the current light intensity of all photovoltaic panels in the candidate column as the light intensity of the candidate column for the current time period. We obtain the light intensity of the candidate column photovoltaic panel in the previous time period, calculate the absolute value of the difference between the light intensity of the candidate column photovoltaic panel in the current time period and the light intensity of the previous time period, and then divide it by the duration of the current time period. The result is the rate of change of light intensity of the candidate column photovoltaic panel in the current time period. For ease of data processing, here we use the absolute value of the difference between the light intensity of the candidate column photovoltaic panel in the current time period and the light intensity of the previous time period as the rate of change of light intensity of the candidate column photovoltaic panel in the current time period, i.e., the time period is a unit of time. Similarly, we obtain the rate of change of light intensity for each column of photovoltaic panels.

[0108] Then, the rate of change of light intensity of each column of photovoltaic panels in the photovoltaic panel location matrix is ​​fused to obtain the longitudinal light intensity variation characteristics. Specifically, the average rate of change of light intensity of each column of photovoltaic panels is calculated as the longitudinal light intensity variation characteristics.

[0109] Step 34: Combine the lateral and longitudinal light intensity variation characteristics to obtain the overall light intensity variation.

[0110] The average values ​​of the lateral and longitudinal light intensity variation characteristics are calculated to obtain the overall light intensity variation of the photovoltaic system in the current time period.

[0111] Step 4: Adjust the initial perturbation step size based on the overall changes in light exposure.

[0112] By considering the overall light reception variation of the photovoltaic system over the current time period, an adaptive perturbation step size is adjusted to achieve maximum power point tracking. In an exemplary embodiment, such as... Figure 6 As shown, the specific process of adjusting the initial perturbation step size based on the overall change in light intensity is given below:

[0113] Step 41: Obtain the adjustment coefficient from the overall change in light exposure.

[0114] The adjustment coefficient for the current time period is obtained based on the overall change in sunlight received by the photovoltaic system during the current time period. This adjustment coefficient is positively correlated with the overall change in sunlight received; in one exemplary embodiment, the overall change in sunlight received is directly used as the adjustment coefficient.

[0115] Step 42: Adjust the initial disturbance step size according to the adjustment coefficient.

[0116] This embodiment sets an initial perturbation step size, which can be a preset maximum perturbation step size. The adjustment coefficient is multiplied by the initial perturbation step size, and the resulting product is the perturbation step size adjusted for the current time period of the photovoltaic system. Using this adaptive perturbation step size, MPPT tracking is performed for several subsequent time periods using the perturbation-observation method, thereby achieving a more effective tracking result.

[0117] In one exemplary embodiment, such as Figure 7 As shown, the control method for photovoltaic inverter power supplies provided in this embodiment further includes the following steps:

[0118] Step 5: When the degree of light fluctuation does not meet the second condition, obtain the adjustment coefficient from the rate of change of the total current.

[0119] When the degree of light fluctuation does not meet the second condition, i.e., the rate of change of the total current of the photovoltaic system in the current time period is less than the preset current change rate threshold, it indicates that the rate of change of the total current of the photovoltaic system in the current time period is not significant. Therefore, an adjustment coefficient for the current time period is obtained based on the rate of change of the total current of the photovoltaic system in the current time period, and the adjustment coefficient is positively correlated with the rate of change of the total current. In an exemplary embodiment, the rate of change of the total current is normalized, for example, using the tanh function; the normalized result is the adjustment coefficient.

[0120] Step 6: Adjust the initial disturbance step size according to the adjustment coefficient.

[0121] The adjustment factor is multiplied by the initial perturbation step size, and the product is the perturbation step size adjusted for the current time period of the photovoltaic system. Using this adaptive perturbation step size, MPPT tracking is performed for several subsequent time periods using the perturbation-observation method, thus achieving a more effective tracking result.

[0122] This embodiment provides a control method for photovoltaic inverter power supplies based on the perturbation-observation method, but improves upon it to address issues such as misjudgment during rapid changes in illumination and oscillations near the maximum power point. By collecting electrical data (voltage and current) from the photovoltaic panel, the system assesses the panel's light reception, thereby adaptively adjusting the control step size of the perturbation-observation method, improving the adaptability and efficiency of the MPPT control strategy. Based on the light reception conditions and predicted changes in light reception, the adaptive step size for the MPPT tracking time point is calculated to achieve more effective maximum power point tracking.

[0123] The control method for photovoltaic inverter power supplies provided in this embodiment has the following specific technical effects: Improved power generation efficiency: Through an adaptive step-size MPPT control strategy, the maximum power point of the photovoltaic cells can be tracked more effectively, increasing the system's power generation by 5%-20%; Enhanced adaptability: The system can accurately determine the photovoltaic panel's light reception and adaptively adjust the MPPT disturbance step size according to the light reception, improving the system's adaptability under different environmental conditions and avoiding getting trapped in local optima; Reduced losses: Oscillations near the maximum power point are reduced, lowering energy loss; Extended equipment lifespan: By optimizing the MPPT control strategy, unnecessary system adjustments and oscillations are reduced, helping to extend the lifespan of the photovoltaic inverter and related equipment; Improved power quality: Optimized MPPT control helps improve power quality and ensure the stability of grid-connected power; Intelligent judgment and response: The system can intelligently judge the photovoltaic panel's light reception and the type of light reception changes, providing more precise control basis for the system and improving the system's intelligence level; Reduced maintenance costs: More accurate judgment and prediction of light reception helps to promptly identify potential problems and reduce maintenance costs.

[0124] In one exemplary embodiment, this embodiment also provides a control system suitable for photovoltaic inverter power supplies, including: a memory and a processor; the memory is connected to the processor, and the memory is used to store program instructions; the processor is used to implement the steps in the above-described control method embodiment suitable for photovoltaic inverter power supplies when the program instructions are executed.

[0125] In one exemplary embodiment, this embodiment also provides a control device suitable for photovoltaic inverter power supplies, comprising: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps described in the above-described embodiment of the control method suitable for photovoltaic inverter power supplies.

[0126] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0127] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A control method applicable to photovoltaic inverter power supplies, characterized in that, include: The degree of light received by each photovoltaic panel is determined based on the decrease in current and voltage of each photovoltaic panel in the photovoltaic system. When the rate of change of the total current of the photovoltaic system meets the first condition, the light reception deviation of each photovoltaic panel is determined by the light reception degree of each photovoltaic panel, and the light reception fluctuation degree of the photovoltaic system is obtained. When the degree of light reception fluctuation meets the second condition, the overall light reception change of the photovoltaic system is determined according to the change pattern of the light reception degree of each photovoltaic panel; The initial perturbation step size is adjusted based on the overall change in light exposure. The process of obtaining the light reception deviation is as follows: the difference between the light reception degree of each photovoltaic panel and the average light reception degree is taken as the light reception deviation of each photovoltaic panel; the average light reception degree is the average value of the light reception degree of all photovoltaic panels. The process for obtaining the degree of light reception fluctuation is as follows: The maximum light reception deviation is determined from the light reception deviations of each photovoltaic panel; the degree of light reception fluctuation is obtained from the average light reception degree and the maximum light reception deviation; the formula for calculating the degree of light reception fluctuation is: ;in, Indicates the degree of light fluctuation in a photovoltaic system. Indicates the maximum light reception deviation. This represents the average level of light received.

2. The control method for photovoltaic inverter power supplies as described in claim 1, characterized in that, The process of obtaining the light intensity includes: Obtain the current of the photovoltaic panel, and determine the first shading performance characteristic represented by the current reduction based on the difference between the current and the preset standard current. Obtain the current voltage of the photovoltaic panel, and determine the second shading performance characteristic represented by the voltage reduction based on the difference between the current voltage and the preset standard voltage; The light-receiving degree of the photovoltaic panel is obtained by combining the first shading performance feature and the second shading performance feature; the light-receiving degree is inversely correlated with both the first shading performance feature and the second shading performance feature.

3. The control method for photovoltaic inverter power supplies as described in claim 1, characterized in that, The process of obtaining the overall change in light exposure includes: Construct a photovoltaic panel location matrix based on the geographical location of each photovoltaic panel; The rate of change of light reception intensity of each row of photovoltaic panels in the photovoltaic panel position matrix is ​​determined, and the lateral light reception intensity change characteristics are obtained by fusion. The rate of change of light reception level of each column of photovoltaic panels in the photovoltaic panel position matrix is ​​determined, and the longitudinal light reception level change characteristics are obtained by fusion. By integrating the lateral and longitudinal light intensity variation characteristics, the overall light intensity variation is obtained.

4. The control method for photovoltaic inverter power supplies as described in claim 3, characterized in that, The process of obtaining the rate of change in the light received by each row of photovoltaic panels includes: The average light reception level of each photovoltaic panel in the candidate row is calculated to obtain the light reception level of the candidate row photovoltaic panels; Calculate the rate of change in the light received by the candidate row of photovoltaic panels; The process of obtaining the lateral light reception variation characteristics includes: calculating the average value of the rate of change of light reception of each row of photovoltaic panels as the lateral light reception variation characteristics.

5. The control method for photovoltaic inverter power supplies as described in claim 1, characterized in that, The adjustment of the initial perturbation step size based on the overall change in light exposure includes: An adjustment coefficient is obtained from the overall change in light exposure; the adjustment coefficient is positively correlated with the overall change in light exposure. The initial perturbation step size is adjusted according to the adjustment coefficient.

6. The control method for photovoltaic inverter power supply as described in claim 1, characterized in that, The control method applicable to photovoltaic inverter power supplies also includes: When the degree of light fluctuation does not meet the second condition, an adjustment coefficient is obtained from the rate of change of the total current; the adjustment coefficient is positively correlated with the rate of change of the total current. The initial perturbation step size is adjusted according to the adjustment coefficient.

7. A control system suitable for photovoltaic inverter power supplies, characterized in that it includes: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is configured to implement, when program instructions are executed, the control method applicable to photovoltaic inverter power supplies as described in any one of claims 1-6.

8. A control device suitable for photovoltaic inverter power supplies, characterized in that, The invention includes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the control method for a photovoltaic inverter power supply as described in any one of claims 1-6.

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