A method and system for monitoring power generation of photovoltaic panels

Abstract

The present invention relates to the technical field of photovoltaic power generation monitoring, and specifically to a power generation monitoring method and system for photovoltaic panels, the method comprising: real-time collection of electrical parameters and environmental parameters of photovoltaic panels, and determination of a preliminary voltage regulation step length based on the electrical parameters and equivalent impedance characteristics of the photovoltaic panels. An environmental impact factor is constructed based on the amplitude, rate of change, and historical stability of the light intensity and temperature at the current moment, and a nonlinear correction is performed on the preliminary voltage regulation step length through the environmental impact factor, thereby achieving adaptive constraints and relaxed regulation of the step length to drastic environmental changes. On this basis, multiple symmetrical perturbation operations are performed on the voltage at the current moment, the regulation direction is determined by the power difference, and dynamic adjustment is performed in combination with the step length until the maximum power point is determined. This method improves the accuracy, stability, and response sensitivity of photovoltaic power generation monitoring in complex environments.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation monitoring, and more particularly to a method and system for monitoring power generation of photovoltaic panels. Background Art

[0002] As a crucial component of renewable energy applications, photovoltaic (PV) power generation systems rely heavily on their efficiency to ensure that the panels consistently operate close to their maximum power point (MPP). Stable and efficient MPP tracking is crucial for ensuring PV panel efficiency.

[0003] The conductance increment method is a typical maximum power point tracking method. Based on the power-voltage characteristic curve of a photovoltaic panel, this method compares the conductance increment with the instantaneous conductance to determine the relative position of the current operating point and the maximum power point. This determines the voltage regulation direction, and iterative adjustments are made based on this voltage regulation direction and a preset fixed adjustment step size to gradually approach the maximum power point.

[0004] However, the fixed step size strategy has inherent defects: when the step size is large, the system is prone to overshoot and oscillation when approaching the maximum power point, resulting in energy fluctuations and decreased conversion efficiency; when the step size is small, the system response becomes slow, especially in dynamic environments such as drastic changes in light. The tracking ability is obviously insufficient, and obvious deviation from the maximum power point occurs.

[0005] More critically, in actual photovoltaic operating environments, changes in light intensity and ambient temperature often produce a complex, asynchronous, and nonlinear effect on the electrical characteristics of photovoltaic panels. Rapid fluctuations in light intensity can cause dramatic current changes, while slowly rising temperatures can lead to a continuous shift in the maximum power point voltage. Traditional methods fail to model these changes in environmental factors and lack the dynamic adaptability of regulation strategies. They are unable to flexibly adjust step sizes based on the intensity of environmental disturbances, thus limiting the system's stability and tracking accuracy in complex operating scenarios.

[0006] Therefore, there is an urgent need for a maximum power point tracking method that can integrate the dynamic characteristics of the environment and has adaptive adjustment capabilities to improve the power generation efficiency and robustness of the system operation in an environment with fluctuating light and temperature, so as to accurately monitor the power generation of photovoltaic panels. Summary of the Invention

[0007] In order to solve the problems of the traditional conductance increment method in the maximum power point tracking process, such as the fixed step size making it difficult to balance speed and accuracy, and the weak adaptability to environmental disturbances, the present invention proposes a power generation monitoring method and system for photovoltaic panels.

[0008] In a first aspect, the present invention provides a method for monitoring power generation of a photovoltaic panel, comprising:

[0009] Real-time collection of photovoltaic panel voltage, current, temperature and light intensity;

[0010] Taking any moment as the current moment, determining a preliminary voltage regulation step size based on the voltage, current, and power values ​​at the current moment and the previous moment, combined with the equivalent impedance characteristics of the photovoltaic panel, wherein the preliminary voltage regulation step size is used to adjust the rate of tracking the maximum power point;

[0011] Determining an environmental impact factor at the current moment based on the respective change amplitudes, change rates, and historical stability of the light intensity and temperature at the current moment, and performing a nonlinear correction on the preliminary voltage adjustment step size using the environmental impact factor to limit the step size when the environmental change is drastic and increase the step size when the environmental change is stable, thereby obtaining a corrected voltage adjustment step size;

[0012] Based on the corrected voltage regulation step size, multiple symmetrical perturbations are performed on the current voltage. The current voltage adjustment direction is determined based on the power difference after the symmetrical perturbations. The voltage is then updated according to the voltage adjustment direction and the corrected voltage regulation step size until the maximum power point at the current moment is determined.

[0013] The maximum power point of the photovoltaic panel at each moment is obtained in real time, and the power generation of the photovoltaic panel is monitored based on the difference between the actual output power and the maximum power point at each moment.

[0014] This technical solution achieves rapid adaptive tracking of the maximum power point (MPP) and refined power generation status monitoring by introducing a dynamic voltage regulation mechanism based on the fusion of electrical state drive and environmental disturbance perception. Specifically, the solution first analyzes the continuous time series of voltage, current, and power, combined with the equivalent impedance model of the photovoltaic panel, to dynamically estimate the degree to which the current operating point deviates from the MPP. Then, by comprehensively analyzing the amplitude, rate, and stability of light intensity and temperature, an environmental disturbance intensity index is constructed. This quantifies the exogenous factors that influence the MPP's shift, and applies this to the initial voltage regulation step size. A nonlinear suppression and relaxation mechanism is implemented on the initial voltage, achieving the dual optimization goals of suppressing oscillations in strong disturbance environments and improving response speed in slowly varying environments. Subsequently, by testing the response of voltage fluctuations to power changes using a symmetrical perturbation method, a feedback closed-loop regulation logic is established, enhancing the ability to quickly lock onto the MPP position. Finally, by analyzing the deviation between the MPP and the actual output power at each moment, accurate monitoring of the photovoltaic panel's power generation is achieved.

[0015] Preferably, the preliminary voltage regulation step is determined based on the following method: obtaining the voltage and power at the current moment and the previous moment, calculating the power change and voltage change at the current moment, and taking the ratio of the power change to the voltage change as the distance factor; based on the current moment's current, power and the equivalent parallel resistance of the photovoltaic panel, calculating the total output current of the photovoltaic panel at the current moment, and taking the inverse of the total output current as the impedance factor; and determining the preliminary voltage regulation step by multiplying the voltage at the current moment by the distance factor and the impedance factor.

[0016] This technical solution introduces distance and impedance factors to construct a preliminary voltage regulation step size, embodying the deep integration of the electrical variation characteristics of photovoltaic panels and their impedance characteristics within the regulation mechanism. This allows the regulation strategy to take into account both the current power response trend and the system's equivalent load characteristics, thereby achieving a physically constrained and adaptive step size regulation mechanism.

[0017] Preferably, the environmental impact factor at the current moment is determined based on the following method: obtaining the historical light intensity and historical temperature at the current moment; taking the product of the change amplitude and change rate of the light intensity at the current moment and the stability of the historical light intensity as the light intensity impact factor at the current moment; taking the product of the change amplitude and change rate of the temperature at the current moment and the stability of the historical temperature as the temperature impact factor at the current moment; and taking the sum of the light intensity impact factor and the temperature impact factor at the current moment as the environmental impact factor at the current moment.

[0018] This technical solution constructs an environmental impact factor by integrating the changing characteristics of two key environmental variables, light intensity and temperature, to accurately quantify the dynamics of environmental disturbances. This effectively incorporates the combined effects of light and temperature on PV panel output performance. This factor serves as a correction weight for the adjustment step size, enabling nonlinear control of the voltage adjustment step size due to environmental changes.

[0019] Preferably, the stability of the historical light intensity and the stability of the historical temperature are determined based on the reciprocal of the standard deviation of the historical light intensity and the reciprocal of the standard deviation of the historical temperature, respectively.

[0020] Preferably, the change amplitude of the light intensity at the current moment is determined based on the difference between the light intensity at the current moment and the average of the historical light intensities; the change amplitude of the temperature at the current moment is determined based on the difference between the temperature at the current moment and the average of the historical temperatures.

[0021] Preferably, the nonlinear correction of the preliminary voltage regulation step size by the environmental impact factor is performed based on the following relationship:

[0022] ;

[0023] In the formula, for The voltage regulation step after time correction, for Environmental factors at all times, for Initial voltage regulation step size at time is the cosine function, which is used to convert Nonlinear mapping to an angular range.

[0024] This technical solution uses the cosine function to perform nonlinear mapping of environmental influencing factors, realizes dynamic correction of the initial voltage regulation step, and achieves smooth, continuous and controllable voltage regulation. It helps photovoltaic systems achieve efficient and stable maximum power point tracking in complex and changing environments, thereby improving overall power generation performance and system robustness.

[0025] Preferably, judging the voltage adjustment direction at the current moment based on the power difference after the symmetrical disturbance includes: performing forward disturbance and reverse disturbance based on the voltage at the current moment respectively; obtaining the power after the forward disturbance and the power after the reverse disturbance; if the power after the forward disturbance is greater than the power at the current moment, and the power after the forward disturbance is greater than the power after the reverse disturbance, judging that the voltage adjustment direction at the current moment is increasing; if the power after the reverse disturbance is greater than the power at the current moment, and the power after the reverse disturbance is greater than the power after the forward disturbance, judging that the voltage adjustment direction at the current moment is decreasing.

[0026] Preferably, the method for determining the maximum power point at the current moment is: after each symmetrical disturbance operation, the voltage is updated according to the voltage adjustment direction determined by the disturbance operation and the corrected voltage adjustment step, and the power corresponding to the updated voltage is obtained as the power after the symmetrical disturbance operation; if the power after a certain symmetrical disturbance operation is less than the power after the previous symmetrical disturbance operation, and the power after the previous symmetrical disturbance operation is greater than the power after the previous symmetrical disturbance operation, the power after the previous symmetrical disturbance operation is determined as the maximum power point at the current moment.

[0027] This technical solution determines the location of the maximum power point by performing multiple consecutive symmetrical perturbations and analyzing the power trend before and after the perturbations. This trend-based approach, based on local power changes, avoids tracking errors caused by transient fluctuations or errors, effectively improving the accuracy and stability of maximum power point locking.

[0028] Preferably, the method for monitoring power generation based on the difference between the actual output power and the maximum power point at each moment is as follows: if during the monitoring process, the actual output power in a certain continuous time period continuously deviates from the maximum power point and the degree of deviation exceeds the deviation threshold, it is determined that the photovoltaic panel has power generation abnormality in the continuous time period; if during the monitoring process, the actual output power in a certain continuous time period does not continuously deviate from the maximum power point and the degree of deviation exceeds the deviation threshold, it is determined that the photovoltaic panel has no power generation abnormality in the continuous time period.

[0029] In a second aspect, the present invention further provides a power generation monitoring system for photovoltaic panels, the power generation monitoring system comprising a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement any step of the power generation monitoring method.

[0030] The present invention has the following effects:

[0031] This method estimates a preliminary voltage regulation step size based on the changing relationship between voltage and power and the equivalent impedance characteristics of the photovoltaic panel. This step size is then dynamically and nonlinearly corrected based on environmental variations. This allows for adaptive control of the regulation step size to the intensity of environmental disturbances, overcoming the drawback of the traditional conductance increment method, where a fixed step size cannot balance dynamic response speed and steady-state tracking accuracy. By precisely locking the maximum power point through symmetrical perturbations, the photovoltaic panel can operate stably at its optimal power output under varying environmental conditions, improving the accuracy of power generation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic flow chart of the method of the present invention;

[0033] Figure 2 It is a schematic flow chart of the method of step S5 of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] The present invention provides a method and system for monitoring power generation of photovoltaic panels, such as Figure 1 As shown in , including:

[0036] S1: Real-time collection of electrical and environmental parameters of photovoltaic panels.

[0037] When monitoring photovoltaic panel power generation, electrical parameters include voltage and current, which are sampled synchronously with a fixed sampling period of 1 second. Environmental parameters include light intensity and temperature, and the sampling frequency of light intensity and temperature is consistent with that of electrical parameters.

[0038] S2: Determine a preliminary voltage adjustment step size based on the change of the electrical parameters.

[0039] Setting the voltage regulation step size plays a key role in achieving rapid tracking of the maximum power point. At each moment, when adjusting the voltage to track the maximum power point of the photovoltaic panel, if the voltage regulation step size is too large, overshoot and oscillation are likely to occur during tracking. If the step size is too small, the response is slow, and the maximum power point cannot be tracked in time, affecting power generation efficiency.

[0040] Therefore, this step adaptively determines the preliminary voltage adjustment step size according to the electrical operating status at each moment, providing a basis for subsequent dynamic correction and tracking direction judgment.

[0041] Typically, during maximum power point tracking (MPPT), a power-voltage curve is constructed, with the voltage at each moment on the horizontal axis and the power at each moment on the vertical axis. This curve typically exhibits a single peak, with the peak at the maximum power point (MPP), where the slope is zero. To the left of the MPP, power increases with increasing voltage, resulting in a positive slope. To the right of the MPP, power decreases with increasing voltage, resulting in a negative slope. Furthermore, the farther from the MPP, the steeper the curve, meaning the larger the absolute value of the slope. The closer to the MPP, the flatter the curve, and the closer the absolute value of the slope approaches zero.

[0042] In one embodiment, the preliminary voltage adjustment step size is determined based on the following method:

[0043] First, taking any moment as the current moment, obtain the voltage and power at the current moment and the previous moment, calculate the current power change and voltage change, and use the ratio of the power change to the voltage change as the distance factor. Then, based on the current current, power, and the equivalent parallel resistance of the photovoltaic panel, calculate the total output current of the photovoltaic panel at the current moment, and use the reciprocal of the total output current as the impedance factor. Finally, the current voltage is multiplied by the product of the distance factor and the impedance factor to determine the initial voltage adjustment step size.

[0044] Specifically, it can be expressed as:

[0045]

[0046] In this formula, for Initial voltage regulation step size at time for The voltage at the moment, for The voltage at the moment, for The power at the moment (equal to the product of voltage and current), for The power of the moment, for The current at the moment, is the equivalent parallel resistance of the photovoltaic panel, To find the absolute value sign. Calculating the equivalent parallel resistance is a common parameter extraction method for photovoltaic panel equivalent circuit models. Existing technologies typically use the open-circuit voltage decay method and the dark-state IV (current-voltage) curve method to obtain the equivalent parallel resistance. These methods have become standard processes.

[0047] In this formula, Partially calculated by first-order difference operations The ratio of the power change to the voltage change at the moment, which indicates the power-voltage curve at The slope at the moment is used as a distance factor to reflect the distance between the power at the current moment and the maximum power point at the current moment. The larger the value, that is, the larger the absolute value of the slope, the farther the power at the current moment is from the maximum power point at the current moment (because the closer to the maximum power point, the smaller the slope), and the larger the adjustment step size should be to approach the maximum power point faster, and vice versa.

[0048] In this formula, Part of it is the impedance factor, which is used to dynamically adjust the sensitivity of the step size. Reflecting the photovoltaic panels The effective output current at the moment, Reflects the current lost by the photovoltaic panel due to its own impedance, Some of the photovoltaic panels are The total output current at the moment reflects the photovoltaic panel's The power generation state at the moment, the greater the total output current, the more likely the photovoltaic panel is in a high power state, therefore, when tracking the maximum power point, you should be more cautious and the step size should be smaller, so through Reduce the sensitivity of the voltage step to prevent excessive adjustment steps at high power operating points close to the maximum power point, which may cause power oscillation.

[0049] In summary, the formula is Based on The initial voltage regulation step size is calculated based on the current operating point's distance from the maximum power point and the photovoltaic panel's impedance characteristics. If the current operating point is far from the maximum power point, the step size is increased to improve tracking speed. When the current operating point is close to the maximum power point, the step size is reduced to improve positioning accuracy, meeting voltage regulation requirements.

[0050] S3: Determine environmental impact factors based on changes in environmental parameters.

[0051] Since the electrical parameters of photovoltaic panels are also affected by the environment, when the light intensity or temperature changes, the open-circuit voltage, short-circuit current, internal resistance and other parameters of the photovoltaic panels will change, causing the overall shape of the power-voltage curve to shift.

[0052] Therefore, this step further analyzes the changing characteristics of the environment and evaluates the environmental impact factors at each moment to quantify the degree of interference of environmental factors on the adjustment step length.

[0053] In one embodiment, the environmental impact factor is determined based on the following method:

[0054] Get all the light intensities and temperatures within the 1 minute before the current moment (experience value) as the historical light intensities and historical temperatures at the current moment, and calculate the mean and standard deviation of the historical light intensities.

[0055] The environmental impact factor is determined according to the following relationship:

[0056]

[0057] In this formula, for Environmental factors at all times, for The light intensity at the moment, for The light intensity at the moment, for The average of all historical light intensities at time , is the normalization function. for The standard deviation of all historical light intensities at the moment, for The temperature of the moment, for The temperature of the moment, for The average of all historical temperatures at time , for The standard deviation of all historical temperatures at a given moment. The standard deviation is used to reflect the degree of data fluctuation.

[0058] In this formula, Part of The light intensity factor at the moment. The larger the value of this part, the The greater the light intensity at the moment, the greater the impact on voltage regulation. for The change in light intensity at each moment, reflect The rate of change of light intensity at time reflect The stability of the historical light intensity at the moment. The greater the change in the light intensity at a given moment, the faster the rate of change, and the better the stability of the historical light intensity. The more obvious the change in light intensity at a given moment, the greater the impact on the voltage step adjustment, and vice versa.

[0059] In this formula, Part of The temperature influence factor at the moment, the larger the value of this part, the The temperature at any moment has a greater impact on voltage regulation. for The temperature change at that moment, reflect The rate of change of temperature at a moment, reflect The stability of the historical temperature at time . The greater the temperature change amplitude at a certain moment, the faster the change rate, and the better the stability of the historical temperature. The more dramatic the temperature change at a given moment is, and the more obvious it is relative to the historical temperature change, the greater the impact on the voltage step adjustment, and vice versa.

[0060] In short, The bigger, the The more unstable the environment is at the moment, the more likely it is that a sudden change in temperature or light has occurred. In an unstable environment, the voltage step should be adjusted carefully to reduce the impact of environmental factors. The smaller, the The more stable the environment is at the moment, the smaller the environmental impact will be when adjusting the voltage step, and the voltage can be adjusted stably according to the conventional step size.

[0061] S4: Adaptively modify the initial voltage regulation step size using the environmental impact factor.

[0062] During the power generation monitoring process of photovoltaic panels, changes in environmental light intensity and temperature often have nonlinear and uncertain characteristics, which can easily cause rapid fluctuations or slow drifts in the output characteristics of photovoltaic panels. If the adjustment strategy cannot adapt to the changes in the strength of environmental disturbances, it can easily lead to oscillations or lags in the maximum power point tracking process.

[0063] Therefore, this step performs nonlinear scaling of the preliminary voltage regulation step size through the environmental influencing factor, so that the interference of environmental factors is fully considered during voltage regulation, the step size is converged to suppress overshoot when the environment changes drastically, and the step size is relaxed to improve tracking efficiency when the environment is stable, thereby realizing adaptive dynamic control of the voltage regulation rate and effectively improving the stability and accuracy of maximum power point locking.

[0064] In one embodiment, the adaptive correction of the preliminary voltage regulation step size is performed based on the following formula:

[0065]

[0066] In the formula, for The voltage regulation step after time correction, for Environmental factors at all times, for Initial voltage regulation step size at time is the cosine function, which is used to convert Nonlinear mapping to an angular range.

[0067] In this formula, due to , belong , exist is a monotonically decreasing function. If The smaller, the The less interference the environmental changes have on voltage regulation, the At minimum, , indicating that the environment is stable and will not interfere with voltage regulation. , , which means that the initial voltage regulation step size can be directly maintained to perform the maximum power point tracking operation. The bigger, the The greater the interference of the environmental changes at the moment on the voltage regulation, the At maximum, , indicating that the environment is changing drastically, causing great interference to voltage regulation, and requiring a larger suppression of the adjustment step. Setting the maximum suppression of half the adjustment step to avoid over-suppression. , , which means that the maximum power point tracking operation is performed with half the initial voltage regulation step size.

[0068] In summary, this regulation formula uses environmental influencing factors to perform nonlinear adaptive correction on the initial voltage regulation step. Its core significance lies in: utilizing the monotonically decreasing characteristics of the cosine function, the severity of environmental changes is mapped into the suppression coefficient of step adjustment. When the environment is stable, the initial voltage regulation step is slightly corrected to ensure tracking efficiency; when the environment changes drastically, the initial voltage regulation step is significantly corrected to suppress the regulation overshoot caused by environmental disturbances.

[0069] This adaptive correction mechanism can dynamically balance tracking speed and anti-interference capabilities, effectively reducing power oscillations when the environment fluctuates, and quickly locking the maximum power point when the environment is stable, thereby improving the adaptability and tracking accuracy of the photovoltaic panel power generation monitoring system to complex working conditions.

[0070] S5: Perform a symmetrical perturbation operation based on the corrected voltage regulation step size to determine the maximum power point.

[0071] Symmetrical perturbation involves adjusting the PV panel voltage in both forward and reverse directions to detect the maximum power point. This is an anti-interference strategy that uses voltage perturbations and observation of power changes to verify whether the current voltage is near the maximum power point and make adjustments accordingly. The goal is to test the validity of the current voltage by perturbing it, ensuring system stability near the maximum power point, reducing power fluctuations, and improving tracking accuracy.

[0072] Specifically, the voltage at the current moment is symmetrically disturbed multiple times, and the voltage adjustment direction at the current moment is determined based on the power difference after each symmetrical disturbance. The voltage is updated based on the voltage adjustment direction and the corrected voltage adjustment step size (updated once for each symmetrical disturbance) until the maximum power point at the current moment is determined.

[0073] like Figure 2 Shown, including:

[0074] S51: Perform a symmetric perturbation.

[0075] Perform the first symmetrical perturbation on the voltage at the current moment, including:

[0076] Perform forward perturbations and reverse perturbation ;

[0077] The power value after forward disturbance is ;

[0078] The power value after reverse disturbance is ;

[0079] in, represents the output current of the photovoltaic panel after the forward disturbance, Represents the output current of the photovoltaic panel after reverse disturbance, for The voltage at the moment, for The voltage at the moment is adjusted by the corrected adjustment step.

[0080] S52: Determine the voltage adjustment direction at the current moment according to the power difference after the symmetrical disturbance.

[0081] Set the symbolic function Indicates the voltage adjustment direction:

[0082]

[0083] if , indicating that after the first symmetrical disturbance, the power of the photovoltaic panel changes positively, and the output power of the photovoltaic panel increases, which means that the system is approaching the maximum power point. Therefore, the voltage needs to be increased appropriately, and it is determined that the voltage adjustment direction at the current moment is increasing.

[0084] if , indicating that after the first symmetrical disturbance, the power of the photovoltaic panel changes negatively, and the output power of the photovoltaic panel decreases, which means that the system is moving away from the maximum power point. Therefore, the voltage needs to be appropriately reduced. It is determined that the voltage adjustment direction at the current moment is decreasing.

[0085] In summary, the use of the sign function shows that the direction of voltage update is closely related to the direction of power change. By comparing the power at the current moment The power after the first perturbation is calculated using the sign function to determine whether the power changes in the expected direction. If the power changes in a positive direction, the voltage should increase; if the power changes in a negative direction, the voltage should decrease.

[0086] S53: After each symmetrical disturbance, the voltage is updated according to the voltage adjustment direction and the voltage correction adjustment step size.

[0087] Specifically, the voltage update strategy is set as:

[0088]

[0089] In this formula, for The updated voltage corresponding to the first symmetrical perturbation is: for The voltage at the moment, is a symbolic function, for The voltage at the moment is adjusted by the corrected adjustment step.

[0090] S54: Obtain the power of the updated voltage, and use the updated voltage as the new voltage at the current moment, and repeat steps S51 to S53 until the maximum power point at the current moment is determined.

[0091] Specifically, continue to for The new voltage at time t, repeating the symmetric perturbation-update strategy of this step, is obtained , and so on, repeat continuously, and after each symmetrical disturbance, judge whether the maximum power point at the current moment can be determined once. If the maximum power point at the current moment can be determined, stop repeating and the disturbance operation ends.

[0092] The method for determining the maximum power point at the current moment is:

[0093] If the power of the updated voltage corresponding to a certain symmetrical disturbance is less than the power of the updated voltage corresponding to the previous symmetrical disturbance, and the power of the updated voltage corresponding to the previous symmetrical disturbance is greater than the power of the updated voltage corresponding to the previous symmetrical disturbance, the power after the previous symmetrical disturbance operation is determined as the maximum power point at the current moment.

[0094] For example, when the After the disturbance, the output power Start to decrease, that is , and after the last disturbance, the output power is increased, that is , then the last disturbance As the optimal voltage of the photovoltaic panel at the current moment, at this voltage, the photovoltaic panel is at the maximum power point, and the output power is .

[0095] In summary, through steps S51 to S54, the maximum power point at the current moment is obtained.

[0096] S6: Power generation monitoring is performed based on the difference between the real-time output power and the maximum power point.

[0097] During the photovoltaic panel power generation monitoring process, the maximum power point at each moment is obtained in real time according to the operations of steps S2-S5. If the actual output power at all moments deviates from the respective maximum power point by more than 20% (empirical value) within any consecutive one-minute period (empirical value), the photovoltaic panel is determined to have a power generation anomaly within this one-minute period. If this does not occur, the photovoltaic panel is determined to have no power generation anomaly. This method can ensure that the photovoltaic panel can always operate near the maximum power point under different lighting, temperature, and weather conditions, and can also identify and handle potential anomalies.

[0098] A power generation monitoring system for photovoltaic panels of the present invention includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement operations of steps S1 to S6 to monitor power generation of the photovoltaic panels.

[0099] While various embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only.

Claims

1. A method for monitoring power generation of a photovoltaic panel, characterized in that: include: Real-time collection of photovoltaic panel voltage, current, temperature and light intensity; Taking any moment as the current moment, determining a preliminary voltage regulation step size based on the voltage, current, and power values ​​at the current moment and the previous moment, combined with the equivalent impedance characteristics of the photovoltaic panel, wherein the preliminary voltage regulation step size is used to adjust the rate of tracking the maximum power point; The environmental impact factor at the current moment is determined based on the respective change amplitudes, change rates, and historical stability of the light intensity and temperature at the current moment. The preliminary voltage adjustment step size is nonlinearly corrected using the environmental impact factor to limit the step size when the environmental change is drastic and increase the step size when the environmental change is stable, thereby obtaining a corrected voltage adjustment step size. The corrected voltage adjustment step size satisfies: ； for The voltage regulation step after time correction, for Environmental factors at all times, for Initial voltage regulation step size at time is the cosine function, which is used to convert Nonlinear mapping to an angular range; Environmental impact factors meet the following requirements: for The light intensity at the moment, for The light intensity at the moment, for The average of all historical light intensities at time , is the normalization function, for The standard deviation of all historical light intensities at the moment, for The temperature of the moment, for The temperature of the moment, for The average of all historical temperatures at time , for The standard deviation of all historical temperatures at a given moment. The standard deviation is used to reflect the degree of data fluctuation; Based on the corrected voltage regulation step size, multiple symmetrical perturbations are performed on the current voltage. The current voltage adjustment direction is determined based on the power difference after the symmetrical perturbations. The voltage is then updated according to the voltage adjustment direction and the corrected voltage regulation step size until the maximum power point at the current moment is determined. The maximum power point of the photovoltaic panel at each moment is obtained in real time, and the power generation of the photovoltaic panel is monitored based on the difference between the actual output power and the maximum power point at each moment.

2. The method for monitoring power generation of photovoltaic panels according to claim 1, characterized in that: The initial voltage regulation step size is determined based on the following: Obtain the voltage and power at the current moment and the previous moment, calculate the power change and voltage change at the current moment, and use the ratio of the power change to the voltage change as the distance factor; Based on the current, power and equivalent parallel resistance of the photovoltaic panel at the current moment, the total output current of the photovoltaic panel at the current moment is calculated, and the reciprocal of the total output current is used as the impedance factor; The product of the voltage at the current moment, the distance factor, and the impedance factor is determined as the preliminary voltage adjustment step length.

3. The method for monitoring power generation of photovoltaic panels according to claim 1, characterized in that: The current voltage adjustment direction can be determined based on the power difference after the symmetrical disturbance: Perform forward disturbance and reverse disturbance based on the voltage at the current moment; Obtain the power after forward disturbance and the power after reverse disturbance; If the power after the forward disturbance is greater than the power at the current moment, and the power after the forward disturbance is greater than the power after the reverse disturbance, it is determined that the voltage adjustment direction at the current moment is increasing; If the power after the reverse disturbance is greater than the power at the current moment, and the power after the reverse disturbance is greater than the power after the forward disturbance, it is determined that the voltage adjustment direction at the current moment is decreasing.

4. The method for monitoring power generation of photovoltaic panels according to claim 1, characterized in that: The method to determine the maximum power point at the current moment is: After each symmetrical perturbation operation, the voltage is updated according to the voltage adjustment direction determined by the perturbation operation and the corrected voltage adjustment step size, and the power corresponding to the updated voltage is obtained as the power after the symmetrical perturbation operation; If the power after a certain symmetrical perturbation operation is less than the power after the previous symmetrical perturbation operation, and the power after the previous symmetrical perturbation operation is greater than the power after the previous symmetrical perturbation operation, the power after the previous symmetrical perturbation operation is determined as the maximum power point at the current moment.

5. The method for monitoring power generation of photovoltaic panels according to claim 1, characterized in that: The method for power generation monitoring based on the difference between the actual output power and the maximum power point at each moment is: If, during the monitoring process, the actual output power continuously deviates from the maximum power point within a certain continuous time period and the degree of deviation exceeds the deviation threshold, it is determined that the photovoltaic panel has power generation abnormality within the continuous time period; If, during the monitoring process, the actual output power does not continuously deviate from the maximum power point within a certain continuous time period and the degree of deviation exceeds the deviation threshold, it is determined that there is no power generation abnormality of the photovoltaic panel within the continuous time period.

6. A power generation monitoring system for photovoltaic panels, characterized in that: The power generation monitoring system includes a memory and a processor, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the steps of the power generation monitoring method according to any one of claims 1 to 5.

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