A power supply control system for an integrated optical storage device

Abstract

The present invention belongs to the technical field of photovoltaic power supply control, and specifically relates to a photovoltaic power supply control system for an integrated photovoltaic storage device, including an inverter input detection module, a light intensity detection module, an inverter input utilization evaluation module, a grid power parameter detection module, an inverter output detection module, an inverter output compliance evaluation module, an inverter adjustment judgment module, a photovoltaic array output power adjustment module, and a reactive power compensation control module. The present invention evaluates the effects of inverter input and inverter output by selecting a specified monitoring period during photovoltaic grid-connected operation, and performs inverter operation adjustment when the evaluation result does not meet the standard. In this process, specific adjustment needs are further identified, and control opportunities are analyzed in a targeted manner. In this way, flexible and precise control of inverter input and output can be achieved, the control effect and comprehensiveness of the inverter are improved, and the overall control efficiency of photovoltaic grid-connected operation is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic power supply control, and in particular relates to a photovoltaic power supply control system for an integrated photovoltaic power supply unit. Background Art

[0002] With the rapid growth of electricity demand and the increase in grid load, traditional reliance on fossil fuels for power generation not only consumes limited resources, but also leads to large amounts of greenhouse gas emissions, exacerbating global warming. Photovoltaic power generation, as a clean energy with zero carbon emissions, has become a mainstream power generation option, but its intermittent and volatile nature (affected by light intensity) poses challenges to stable power supply. To this end, the photovoltaic power generation system is integrated with the energy storage system to form a photovoltaic storage all-in-one machine. In addition, when there is still a surplus of photovoltaic power generation after meeting the energy storage demand, the excess power can be transmitted to the grid through grid-connected operation, achieving efficient energy utilization and maximizing economic benefits.

[0003] In the grid-connected operation, the inverter is used to convert the direct current generated by the photovoltaic system into alternating current compatible with the power grid to achieve effective grid connection. To this end, precise inverter control is required. There are some inverter control schemes for photovoltaic grid connection in the prior art. For example, China Invention Patent Publication No. CN116454958B proposes an inverter grid connection and pre-synchronization control method, which controls the inverter by obtaining the grid connection pre-synchronization signal, inverter current and inverter voltage, ensuring that the inverter voltage stably tracks the grid voltage.

[0004] However, this solution mainly focuses on the control of the inverter output, aiming to ensure that the inverter output voltage stably tracks the grid voltage, while ignoring the input loss that may exist during the inverter input process. When the output power of the photovoltaic array is large, the process of the photovoltaic module converting light energy into electrical energy and inputting it into the inverter may cause the inverter to overload, thereby causing input loss. Ignoring this problem may lead to a decrease in the control accuracy of the inverter, which is likely to cause a large waste of resources and affect the overall efficiency of photovoltaic grid connection.

[0005] Another example is the Chinese invention patent publication number CN108899926B, which discloses a photovoltaic off-grid energy storage inverter power supply system. The control component determines whether the photovoltaic component is working at the maximum power point. If the maximum power point is not reached, the MPPT controller is adjusted to ensure that the energy storage inverter always works at the maximum power point, thereby improving the photovoltaic power generation conversion efficiency and energy utilization rate. However, although this solution reduces the loss during inverter input through MPPT control, it lacks trigger analysis of input loss caused by rapid changes in light intensity, which may cause the MPPT control to run for a long time, resulting in low control efficiency. In addition, continuous MPPT adjustment may increase the energy consumption of the system, especially when the light intensity fluctuates greatly, which is easy to cause unnecessary waste of resources. Summary of the invention

[0006] The purpose of the present invention is to improve the deficiencies in the prior art and to provide a photovoltaic and storage integrated power supply control system, which realizes accurate and effective control of the inverter input and output by adding inverter input control during the photovoltaic grid-connected process and further increasing the analysis of the inverter input and inverter output control timing.

[0007] The purpose of the present invention can be achieved through the following technical solutions: a photovoltaic storage integrated power supply control system, comprising the following modules: an inverter input detection module, which is used to select a specified monitoring period during photovoltaic grid-connected operation to sample the input voltage of the grid-connected inverter to form an inverter input voltage time series.

[0008] The light intensity detection module is used to synchronously collect the light intensity at the location of the photovoltaic power generation equipment during a specified monitoring period to form a light intensity time series.

[0009] The inverter input utilization evaluation module is used to compare the inverter input voltage time series with the light intensity time series to evaluate the inverter input utilization of the inverter.

[0010] The power grid electric energy parameter detection module is used to collect the power grid electric energy parameters in real time within a specified monitoring period to form a power grid electric energy parameter time series.

[0011] The inverter output detection module is used to synchronously collect the output power parameters of the grid-connected inverter during the specified monitoring period to form an inverter output power parameter time series.

[0012] The inverter output compliance evaluation module is used to compare the grid power parameter time series with the inverter output power parameter time series to evaluate the inverter output compliance of the inverter.

[0013] The inverter adjustment evaluation module is used to judge whether the inverter operation adjustment is needed based on the inverter input utilization and inverter output compliance of the inverter, and if it is judged to be necessary, identify the adjustment direction.

[0014] The photovoltaic array output power adjustment module is used to analyze the light intensity increase trigger point from the light intensity time series when the adjustment direction is the inverter input, and then adjust the photovoltaic array output power in the subsequent photovoltaic grid connection.

[0015] The reactive power compensation control module is used to analyze the grid power fluctuation trigger point from the grid power parameter time series when the adjustment direction is the inverter output, and then perform reactive power compensation control in the subsequent photovoltaic grid connection.

[0016] In combination with all the above technical solutions, the present invention has the following positive effects: 1. The present invention evaluates the effects of inverter input and inverter output by selecting a specified monitoring period during the photovoltaic grid-connected operation, and performs inverter operation adjustment when the evaluation result does not meet the standard. This can avoid unnecessary control when the effect has met the standard, thereby reducing the waste of control resources.

[0017] 2. When evaluating that the inverter input and output effects are not up to standard and the inverter operation needs to be adjusted, the present invention further identifies specific adjustment requirements and analyzes the control timing in a targeted manner. This can achieve flexible and precise control of the inverter input and output, improve the control effect and comprehensiveness of the inverter, and help improve the overall control efficiency of photovoltaic grid-connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0019] Figure 1 It is a schematic diagram of system module connection of the present invention.

[0020] Figure 2 This is a schematic diagram of the photovoltaic grid-connected inverter connection of the present invention.

[0021] Figure 3 This is an operation diagram of the photovoltaic grid-connected inverter control process of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The present invention provides a photovoltaic-storage integrated power supply control system, comprising photovoltaic power generation equipment, an inverter and a power grid, wherein the photovoltaic power generation equipment comprises a photovoltaic array composed of photovoltaic modules.

[0024] It is important to know that photovoltaic modules are composed of solar panels, which are connected in series or in parallel to form photovoltaic arrays. Photovoltaic arrays directly convert sunlight into DC power and input it into inverters. The greater the light intensity, the more DC power the photovoltaic array generates. The inverter is responsible for converting the DC power output by the photovoltaic array into AC power compatible with the power grid, and ultimately realizing grid-connected power supply.

[0025] For specific photovoltaic grid-connected inverter connections, see Figure 2 shown.

[0026] See also Figure 1 As shown, the specific implementation of the above control system includes an inverter input detection module, a light intensity detection module, an inverter input utilization evaluation module, a grid power parameter detection module, an inverter output detection module, an inverter output compliance evaluation module, an inverter adjustment evaluation module, a photovoltaic array output power adjustment module, and a reactive power compensation control module. The inverter input detection module and the light intensity detection module are both connected to the inverter input utilization evaluation module, the grid power parameter detection module and the inverter output detection module are both connected to the inverter output compliance evaluation module, the inverter input utilization evaluation module and the inverter output compliance evaluation module are both connected to the inverter adjustment evaluation module, and the inverter adjustment evaluation module is respectively connected to the photovoltaic array output power adjustment module and the reactive power compensation control module.

[0027] The inverter input detection module is used to select a specified monitoring period during photovoltaic grid-connected operation to sample the input voltage of the grid-connected inverter to form an inverter input voltage time series.

[0028] It should be added that the designated monitoring period should include at least one grid-connected day, which can cover the periodic changes in light intensity (such as morning, noon, and evening), to avoid selecting only local time periods, resulting in small changes in light intensity and unable to provide sufficient and reliable data for inverter input evaluation. It is usually recommended to select a week of grid-connected days to ensure the representativeness and comprehensiveness of the data, which can provide richer data samples and reduce the impact of short-term fluctuations or abnormal conditions on the evaluation results.

[0029] It should be noted that the sampling of the input voltage of the grid-connected inverter is to reflect the DC power generated by the photovoltaic array, because the DC power output by the photovoltaic array is presented in the form of DC voltage when it is input to the inverter. By monitoring the input voltage, the power generation of the photovoltaic array can be evaluated.

[0030] The light intensity detection module is used to synchronously collect the light intensity at the location of the photovoltaic power generation equipment during a specified monitoring period to form a light intensity time series.

[0031] The inverter input utilization evaluation module is used to compare the inverter input voltage time series with the light intensity time series to evaluate the inverter input utilization of the inverter. The specific evaluation is as follows: each light intensity in the constructed light intensity time series is paired with the previous light intensity to form a number of adjacent light intensity groups.

[0032] After respectively obtaining the contrast difference of each adjacent light intensity group, the adjacent light intensity groups with amplification are screened out. Specifically, the adjacent light intensity group in which the subsequent light intensity is greater than the previous light intensity can be selected, and the adjacent time points corresponding to the adjacent light intensity group are recorded as the adjacent time group for power generation amplification.

[0033] It should be explained that by screening out adjacent time groups of power generation increase where light intensity increases from the light intensity time series, it is possible to capture the increasing trend of light intensity, providing key basic data for subsequent evaluation of whether there is a loss in inverter input when light intensity increases significantly.

[0034] The input voltage corresponding to the adjacent time group of power generation increase is captured from the constructed inverter input voltage time series, and the inverter input voltage increase degree is obtained by taking the difference between the subsequent input voltage and the previous input voltage and dividing it by the previous input voltage.

[0035] Substitute the inverter input voltage increase corresponding to the adjacent time groups of power generation increase into the expression Calculate the inverter input utilization of the inverter , where Indicates The inverter input voltage increase corresponding to the adjacent time groups of power generation increase, Indicates the number of the adjacent time group of power generation increase, , Indicates the number of adjacent time groups of power generation increase, Indicates the preset critical increase, where .

[0036] It should be noted that the above inverter input utilization calculation formula reflects the proportion of the inverter input voltage increase reaching the critical increase in the adjacent time group of power generation increase when the light intensity increases, representing the proportion of the inverter input voltage increase when the light intensity increases. The larger the proportion, the more the inverter input voltage can follow the increase when the light intensity increases, indicating that the inverter responds to the light change in a timely and sufficient manner, the inverter input utilization rate is high, and the input loss is small. On the contrary, the smaller the proportion, the more the inverter input voltage fails to follow the increase when the light intensity increases, and even remains unchanged or decreases, indicating that the inverter does not respond enough to the light change, the inverter input utilization rate is low, and there is a large input loss.

[0037] It should be pointed out that in the inverter input utilization calculation formula, the critical increase is a preset auxiliary indicator used to judge whether the inverter input voltage increases. When screening adjacent time groups for power generation increase, the selection is made only based on the fact that the subsequent light intensity in the adjacent light intensity group is greater than the previous light intensity, and the specific light intensity increase is not quantified. Therefore, when presetting the critical increase, it is not advisable to set it too large. An excessively large critical increase may cause some time groups where the inverter input voltage actually increases to be missed, thereby affecting the accuracy of the evaluation. By way of example, the critical increase can be set to 0.05.

[0038] The power grid electric energy parameter detection module is used to collect the power grid electric energy parameters in real time within a specified monitoring period to form a power grid electric energy parameter time series, wherein the electric energy parameters include voltage, frequency, etc.

[0039] The inverter output detection module is used to synchronously collect the output power parameters of the grid-connected inverter during a specified monitoring period to form an inverter output power parameter time series.

[0040] It is important to understand that the power grid will be impacted by load changes, short-circuit faults, equipment start-up and shutdown, and other factors during operation, causing fluctuations in the power supply voltage and frequency. In the photovoltaic grid-connected system, the inverter needs to track the grid voltage and frequency in real time, and dynamically adjust its own output voltage and frequency to ensure synchronization with changes in grid power parameters. This precise tracking and adjustment mechanism can maximize the stability and power quality of the grid and reduce the potential impact of photovoltaic grid connection.

[0041] The inverter output compliance evaluation module is used to compare the grid power parameter time series with the inverter output power parameter time series to evaluate the inverter output compliance of the inverter. The specific evaluation is as follows: the grid power parameter time series is generated into a grid power parameter change curve in a two-dimensional coordinate system constructed with time as the horizontal axis and power parameter as the vertical axis.

[0042] Similarly, the inverter output electric energy parameter time series is used to generate an inverter output electric energy parameter variation curve.

[0043] The above-mentioned generation of electric energy parameter change curves can intuitively display the dynamic changes of power grid and inverter output electric energy parameters, providing a prerequisite for comprehensiveness and accuracy of data analysis to capture key time points.

[0044] Inflection points are marked in the grid power parameter change curve and the inverter output power parameter change curve respectively.

[0045] By marking and numbering the inflection points, the time points at which the power parameters of the power grid and the power parameters of the inverter output change significantly can be accurately identified.

[0046] The inflection points marked on the grid power parameter change curve and the inverter output power parameter change curve are numbered according to their front and back distribution on the curves.

[0047] The inflection points with the same number on the grid power parameter change curve and the inverter output power parameter change curve are mapped to form a plurality of inflection point mapping groups.

[0048] The time of each inflection point in each inflection point mapping group on the horizontal axis is extracted to calculate the inverter output timeliness. The specific calculation is as follows: the time of each inflection point in each inflection point mapping group on the horizontal axis is compared to obtain the duration of each inflection point mapping group.

[0049] It should be pointed out that the duration of the inflection point mapping group represents the response time of the inverter output power when the power parameters of the power grid fluctuate, that is, the time interval from the change of the power parameters of the power grid to the start of the inverter output power parameter to follow the change. This duration is an important indicator for evaluating the response speed and tracking performance of the inverter, and can reflect the real-time and effectiveness of the inverter in dealing with power grid fluctuations.

[0050] Import the duration of each inflection point mapping group into the calculation formula Get the inverter output time efficiency , where Indicates The duration of the inflection point mapping group, Indicates the number of the inflection point mapping group, , Indicates the duration of the specified monitoring period.

[0051] It should be explained that in the calculation formula of inverter output time efficiency It reflects the timeliness of the inverter output corresponding to each inflection point mapping group. Only when the duration of each inflection point mapping group is small, the overall inverter output timeliness of the photovoltaic grid-connected in the specified monitoring period will be greater.

[0052] The numerical value of each inflection point in each inflection point mapping group on the vertical axis is extracted to calculate the inverter output accuracy.

[0053] The numerical difference of each inflection point in each inflection point mapping group on the vertical axis represents the matching degree between the inverter output power parameter and the grid power parameter, and specifically reflects the tracking accuracy of the inverter at that time point.

[0054] The specific calculation of the above inverter output accuracy is as follows: Substitute the difference of the value of each inflection point on the vertical axis in each inflection point mapping group into the calculation formula Get the inverter output accuracy , where Indicates The numerical difference of the inflection point mapping group on the vertical axis, Indicates The vertical axis value of the inflection point on the grid power parameter change curve in the inflection point mapping group.

[0055] It should be explained that in the inverter output accuracy calculation formula It reflects the inverter output accuracy corresponding to each inflection point mapping group. Only when the numerical difference of each inflection point mapping group on the vertical axis is small, the overall inverter output accuracy of photovoltaic grid connection in the specified monitoring period will be greater.

[0056] The present invention provides specific indicators for quantifying the performance of the inverter output following the power grid by calculating the inverter output timeliness and accuracy, which is not only helpful for evaluating the inverter output effect of the inverter.

[0057] The inverter output timeliness and inverter output accuracy corresponding to each electric energy parameter are weighted averaged to obtain the inverter output compliance.

[0058] As an example of calculating the inverter output compliance, the weight factors of the inverter output timeliness and inverter output accuracy are 0.4 and 0.6. The reason for giving a larger weight to the inverter output accuracy is that the inverter output accuracy directly represents the matching degree between the inverter output power parameters (such as voltage and frequency) and the grid power parameters. High accuracy ensures that the power output of the inverter is consistent with the grid, maintains stable power quality, reduces harmonics and voltage fluctuations, and avoids adverse effects on the grid and other electrical equipment. Although timeliness is also important and reflects the response speed of the inverter, in actual applications, the impact of accuracy on system performance is more significant. Therefore, giving a larger weight to accuracy can more comprehensively evaluate the overall performance of the inverter and ensure its stability and reliability under different working conditions.

[0059] The present invention calculates the inverter output compliance by taking the weighted average of the inverter output timeliness and the inverter output accuracy, and can comprehensively consider the timeliness and accuracy to obtain a comprehensive performance evaluation index. The higher the compliance, the better the inverter performs in terms of response speed and tracking accuracy, and can better adapt to the fluctuations of the power grid and ensure the stability of the system and the power quality.

[0060] The inverter adjustment judging module is used to judge whether the inverter operation adjustment is needed based on the inverter input utilization and inverter output compliance of the inverter, and if it is judged to be necessary, identify the adjustment direction.

[0061] As a way to implement the above scheme, judging whether inverter operation adjustment is needed is implemented as follows: comparing the inverter input utilization and inverter output compliance of the inverter with the corresponding compliance thresholds respectively; if both the inverter input utilization and the inverter output compliance of the inverter reach the compliance thresholds, it is judged that inverter operation adjustment is not needed; otherwise, it is judged that inverter operation adjustment is needed.

[0062] In a specific embodiment of the above method, the inverter input utilization threshold value can be set to 0.7. Since the power parameters of the power grid include voltage, frequency, etc., when performing the inverter output compliance analysis, the inverter output compliance calculated by the weighted average of various power parameters can be compared with the inverter output compliance threshold value set for each power parameter. When the inverter output compliance of any one of the power parameters does not reach the standard threshold, it is judged that the inverter operation needs to be adjusted.

[0063] As a further implementation method of the above scheme, the identification and adjustment direction refers to the following process: the inverter input utilization and inverter output compliance of the inverter are compared with the corresponding standard thresholds respectively. If the inverter input utilization of the inverter does not reach the threshold, the adjustment direction is to the inverter input, which means that the output power of the photovoltaic array increases too fast during the increase of light intensity, resulting in a large input loss. This is most likely caused by the output power of the photovoltaic array exceeding the processing capacity of the inverter. The output power of the photovoltaic array can be optimized and adjusted; if the inverter output compliance of the inverter does not reach the standard threshold, the adjustment direction is to the inverter output, which means that the output power parameters of the inverter fail to effectively follow the changes in the power grid, which is likely to cause a large impact on the power grid. In order to reduce the impact on the power grid, reactive power compensation control can be performed to improve the inverter's ability to track changes in the power grid.

[0064] The photovoltaic array output power adjustment module is used to analyze the light intensity increase trigger point from the light intensity time series when the adjustment direction is the inverter input, and then adjust the photovoltaic array output power in the subsequent photovoltaic grid connection.

[0065] Preferably, the analysis of the light intensity increase trigger point is performed as follows: based on the comparison result of the inverter input voltage increase corresponding to each power generation increase adjacent time group and the critical increase, the power generation increase adjacent time group that does not reach the critical increase is screened out as the gap adjacent time group.

[0066] This step helps focus on those time points where input loss occurs, providing a basis for further analysis.

[0067] The inverter input voltage increase gap is obtained by subtracting the critical increase from the inverter input voltage increase corresponding to each adjacent time group. This step quantifies the difference between the input voltage increase of each time group and the expected value, and provides a basis for subsequent sorting. Thus, the adjacent time groups with gaps are arranged in order from small to large according to the inverter input voltage increase gap to obtain the first sorting corresponding to the adjacent time groups with gaps.

[0068] The subsequent light intensity in each adjacent time group is compared with the preceding light intensity to calculate the light intensity increase, and then each adjacent time group is arranged in order of light intensity increase from small to large to obtain a second ranking corresponding to the adjacent time group.

[0069] The first sorting and the second sorting corresponding to the adjacent time groups with gaps are overlapped to calculate the overlap. The specific calculation can be performed by counting the proportion of adjacent time groups with overlapping sorting numbers as the overlap, and comparing it with the preset overlap threshold. For example, the overlap threshold is 80%. If the overlap reaches the overlap threshold, it means that there is a significant correlation between the inverter input voltage increase and the light intensity increase. A coordinate system is constructed with the light intensity increase as the horizontal axis and the inverter input voltage increase as the vertical axis, and then the inverter input voltage increase and the light intensity increase corresponding to each adjacent time group are fitted in the constructed coordinate system to generate a power generation increase correlation curve.

[0070] The above-generated power generation increase correlation curve shows the relationship between the light intensity increase and the inverter input voltage increase in a visual manner.

[0071] After the power generation increase correlation curve is generated, a straight line parallel to the horizontal axis is drawn from the correlation curve according to the critical increase degree, and then the horizontal axis corresponding to the intersection of the straight line and the correlation curve is captured as the light intensity increase trigger point.

[0072] It should be noted that since the correlation curve is generated based on the condition that the inverter input has losses, the intersection point indicates that the inverter input voltage increase just reaches the critical increase under a specific light intensity increase, which means that the light intensity increase is the minimum value that causes the inverter input voltage to begin to have input losses, that is, the light intensity increase trigger point.

[0073] If the overlap does not reach the overlap threshold, it means that the relationship between the two is not obvious enough, then the light intensity increase corresponding to each adjacent time group is compared, and the majority is selected as the light intensity increase trigger point.

[0074] It should be understood that the mode refers to frequently occurring data with common characteristics. Selecting the mode as the trigger point can reduce the impact of outliers and ensure that the selection of the trigger point has a certain degree of robustness. Even if the light intensity increase of some time groups is abnormally high or low, the mode can still reflect the common characteristics of most time groups.

[0075] When the present invention determines that the adjustment direction is the inverter input, it is necessary to parse the light intensity increase trigger point from the light intensity time series. The trigger point refers to the minimum light intensity increase that causes the inverter input loss. By parsing this trigger point, it is possible to provide a suitable opportunity for the subsequent photovoltaic array output power adjustment, ensure the pertinence and effectiveness of the adjustment, and thus reduce the inverter input loss in a timely manner.

[0076] Furthermore, when determining the light intensity increase trigger point, the minimum value is not directly selected from the light intensity increase of the adjacent time group, but considering that the light intensity acquisition time range is limited, the number of samples may be insufficient, and the minimum light intensity increase that causes the inverter input loss may not be accurately captured. Therefore, by performing a correlation analysis between the light intensity increase and the inverter input voltage increase difference, if there is a significant correlation between the two, a continuous curve is obtained by fitting the correlation curve, and then the light intensity increase trigger point is accurately captured from the curve. This method can identify the minimum light intensity increase even if it does not appear in the existing samples, ensuring the accuracy of the trigger point. If there is no significant correlation between the light intensity increase and the inverter input voltage increase difference, the mode of the light intensity increase in the adjacent time group is obtained as the trigger point. The mode reflects the tendency and frequency of the light intensity increase that causes the inverter input loss, and the trigger point obtained based on this is more reasonable and reliable.

[0077] The present invention can capture more accurate light intensity increase trigger points based on limited sample data through correlation analysis and curve fitting.

[0078] Further preferably, the output power adjustment of the photovoltaic array refers to the following process: in the subsequent photovoltaic grid-connected operation, the light intensity is collected in real time and the light intensity increase at adjacent collection moments is calculated, and compared with the light intensity increase trigger point. When the light intensity increase trigger point is reached, the output power of the photovoltaic array is adjusted to match the rated power of the inverter.

[0079] In the above preferred operation example, adjusting the output power of the photovoltaic array can be achieved by optimizing the algorithm of the MPPT controller. The MPPT controller dynamically adjusts the working point of the photovoltaic array by monitoring the voltage and current of the photovoltaic array in real time to ensure that it always operates at the maximum power point. The MPPT controller based on the rated power of the inverter can intelligently adjust the output power of the photovoltaic array to ensure that it does not exceed the processing capacity of the inverter, thereby maximizing the efficiency of the system and avoiding inverter overload or input loss.

[0080] In another example of the above preferred operation, the output power of the photovoltaic array may be adjusted by adjusting the electrical connection mode of the photovoltaic array to reduce the maximum output power of the photovoltaic array so as to match the rated power of the inverter.

[0081] In another example of the above preferred operation, the output power of the photovoltaic array can be adjusted by introducing an energy storage battery to store excess electrical energy when the output power of the photovoltaic array exceeds the rated power of the inverter. Through the coordinated control of the energy storage system, the output fluctuations of the photovoltaic array can be smoothed to ensure that the input power of the inverter is stable within the rated range.

[0082] The reactive power compensation control module is used to analyze the grid power fluctuation trigger point from the grid power parameter time series when the adjustment direction is the inverter output, and then perform reactive power compensation control in the subsequent photovoltaic grid connection.

[0083] The analysis of the trigger point of power grid power fluctuation in the above-mentioned process refers to the following: a deviation inflection point mapping group is selected from the inflection point mapping group corresponding to each power parameter, and the slope of the inflection point is obtained from the power grid power parameter change curve where each deviation inflection point mapping group is located as the power grid power fluctuation degree, and at the same time, the inverter output compliance corresponding to each deviation inflection point mapping group is counted.

[0084] Specifically, the deviation inflection point mapping group can be screened by calculating the inverter output timeliness and inverter output accuracy of each inflection point mapping group to calculate the inverter output timeliness by weighted average, and comparing it with the inverter output compliance threshold, and selecting the inflection point mapping group that does not reach the threshold as the deviation inflection point mapping group.

[0085] The grid power fluctuation degree and inverter output compliance corresponding to each deviation inflection point mapping group are similarly analyzed according to the light intensity increase trigger point to obtain the grid power fluctuation trigger point.

[0086] Specifically, the similar process is: subtract the inverter output compliance threshold from the inverter output compliance corresponding to each deviation inflection point mapping group to obtain the inverter output compliance gap, and arrange the deviation inflection point mapping groups in order of the inverter output compliance gap from small to large to obtain the first sorting corresponding to the deviation inflection point mapping group.

[0087] Arrange the deviation inflection point mapping groups in order from small to large according to the power grid power fluctuation degree to obtain a second ranking corresponding to the deviation inflection point mapping groups.

[0088] The first sorting and the second sorting corresponding to the deviation inflection point mapping group are overlapped to calculate the overlap degree, and compared with the preset overlap degree threshold. If the overlap degree reaches the overlap degree threshold, a coordinate system is constructed with the grid power fluctuation degree as the horizontal axis and the inverter output compliance degree as the vertical axis, and then the grid power fluctuation degree and the inverter output compliance degree corresponding to each deviation inflection point mapping group are fitted in the constructed coordinate system to generate an inverter output association curve, thereby drawing a straight line parallel to the horizontal axis from the association curve according to the inverter output compliance threshold, and then capturing the horizontal axis corresponding to the intersection of the straight line and the association curve as the grid power fluctuation trigger point. If the overlap degree does not reach the overlap degree threshold, the grid power fluctuation degrees corresponding to each deviation inflection point mapping group are compared, and the majority is selected as the grid power fluctuation trigger point.

[0089] Specifically, the reactive power compensation control is implemented as follows: in the subsequent photovoltaic grid-connected operation, the grid power parameter detection and the grid power fluctuation calculation at adjacent collection times are performed in real time, and compared with the grid power fluctuation trigger point. When the grid power fluctuation trigger point is reached, the reactive power compensator is automatically switched on and off.

[0090] The present invention can provide or absorb reactive power by switching on and off the reactive compensator when the inverter output control cannot completely follow the grid, thereby helping to maintain the stability of the grid voltage, reducing the control burden of the inverter, and further ensuring that the frequency of the inverter output is synchronized with the grid frequency.

[0091] The control operation of inverter input and inverter output in the above photovoltaic grid-connected control is shown in Figure 3 shown.

[0092] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A power supply control system for an integrated optical storage device, characterized in that: include: The inverter input detection module samples the input voltage of the grid-connected inverter during a specified monitoring period to form an inverter input voltage time series; The light intensity detection module synchronously collects the light intensity at the location of the photovoltaic power generation equipment to form a light intensity time series; The inverter input utilization evaluation module compares the inverter input voltage time series with the light intensity time series to evaluate the inverter input utilization of the inverter ; In the formula For the The inverter input voltage increase corresponding to the adjacent time groups of power generation increase, is the number of the adjacent time group of power generation increase, , is the number of adjacent time groups of power generation increase, is the preset critical increase. ; The power grid electric energy parameter detection module collects the power grid electric energy parameters within a specified monitoring period to form a power grid electric energy parameter time series; The inverter output detection module synchronously collects the output power parameters of the grid-connected inverter to form the inverter output power parameter time series; The inverter output compliance evaluation module compares the grid power parameter time series with the inverter output power parameter time series to evaluate the inverter output compliance of the inverter; Inverter adjustment evaluation module, based on And the inverter output compliance judgement whether the inverter operation adjustment is needed, if the judgment is necessary, identify the adjustment direction; The photovoltaic array output power adjustment module is used to analyze the light intensity increase trigger point from the light intensity time series when the adjustment direction is the inverter input, and then adjust the photovoltaic array output power in the subsequent photovoltaic grid connection; The reactive power compensation control module is used to analyze the grid power fluctuation trigger point from the grid power parameter time series when the adjustment direction is the inverter output, and then perform reactive power compensation control in the subsequent photovoltaic grid connection; The power grid power parameter time series is used to generate a power grid power parameter variation curve in a two-dimensional coordinate system with time as the horizontal axis and power parameter as the vertical axis; Similarly, the inverter output power parameter time series is used to generate the inverter output power parameter change curve; Mapping the inflection points with the same number on the power grid power parameter change curve and the inverter output power parameter change curve to form a plurality of inflection point mapping groups; Import the duration of each inflection point mapping group into the formula Get the inverter output time efficiency , where For the The duration of the inflection point mapping group, and , is the duration of the specified monitoring period; Substitute the difference between the values ​​of each inflection point on the vertical axis in each inflection point mapping group into the formula Get the inverter output accuracy , where For the The numerical difference of the inflection point mapping group on the vertical axis, For the The vertical axis value of the inflection point on the power grid electric energy parameter change curve in the inflection point mapping group; The inverter output timeliness and inverter output accuracy corresponding to each electric energy parameter are weighted averaged to obtain the inverter output compliance.

2. A power supply control system for an integrated photovoltaic and storage device as claimed in claim 1, characterized in that: The evaluation of the inverter input utilization of the inverter refers to the following process: Pair each light intensity in the constructed light intensity time series with the previous light intensity to form a number of adjacent light intensity groups; After respectively obtaining the contrast difference of each adjacent light intensity group, the adjacent light intensity group with an increase is screened out, and the adjacent time points corresponding to the adjacent light intensity group are recorded as the power generation increase adjacent time group; The input voltage corresponding to the adjacent time group of power generation increase is captured from the constructed inverter input voltage time series, and the inverter input voltage increase degree is obtained by taking the difference between the subsequent input voltage and the previous input voltage and dividing it by the previous input voltage.

3. The power supply control system of the integrated photovoltaic and storage device according to claim 1, characterized in that: The analysis process of the inverter output timeliness and inverter output accuracy is as follows: Marking inflection points in the power grid power parameter change curve and the inverter output power parameter change curve respectively; The inflection points marked on the grid power parameter change curve and the inverter output power parameter change curve are numbered according to their front and back distribution on the curves; The time of each inflection point on the horizontal axis in each inflection point mapping group is extracted to calculate the inverter output timeliness; The numerical value of each inflection point in each inflection point mapping group on the vertical axis is extracted to calculate the inverter output accuracy.

4. The power supply control system of the integrated photovoltaic and storage device according to claim 1, characterized in that: The judgment of whether the inverter operation adjustment is required is implemented as follows: The inverter input utilization and inverter output compliance of the inverter are compared with the corresponding standard thresholds respectively. If the inverter input utilization and inverter output compliance of the inverter both reach the standard thresholds, it is judged that no inverter operation adjustment is required, otherwise it is judged that inverter operation adjustment is required.

5. The power supply control system of the integrated optical storage device according to claim 4, characterized in that: The identification and adjustment direction refers to the following process: The inverter input utilization and inverter output compliance of the inverter are compared with the corresponding standard thresholds respectively. If the inverter input utilization of the inverter does not reach the standard threshold, the adjustment direction is to the inverter input. If the inverter output compliance of the inverter does not reach the standard threshold, the adjustment direction is to the inverter output.

6. The power supply control system for an integrated photovoltaic and storage device according to claim 1, characterized in that: The analysis of the light intensity increase trigger point is as follows: Based on the comparison result of the inverter input voltage increase degree corresponding to each power generation increase adjacent time group and the critical increase degree, the power generation increase adjacent time group that does not reach the critical increase degree is screened out as the gap adjacent time group; Difference is made between the critical increase and the increase of the inverter input voltage corresponding to each gap adjacent time group to obtain the inverter input voltage increase difference, and the gap adjacent time groups are arranged in the order of the inverter input voltage increase difference from small to large to obtain the first sorting corresponding to the gap adjacent time groups; Compare the subsequent light intensity with the preceding light intensity in each adjacent time group to calculate the light intensity increase, and then arrange each adjacent time group in the order of light intensity increase from small to large to obtain a second ranking corresponding to the adjacent time group; The first sorting and the second sorting corresponding to the adjacent time groups are overlapped to calculate the overlap degree, and compared with the preset overlap degree threshold. If the overlap degree reaches the overlap degree threshold, a coordinate system is constructed with the light intensity increase degree as the horizontal axis and the inverter input voltage increase degree as the vertical axis. Then, the inverter input voltage increase degree and the light intensity increase degree corresponding to each adjacent time group are fitted in the constructed coordinate system to generate a power generation increase correlation curve. Thus, a straight line parallel to the horizontal axis is drawn in the correlation curve according to the critical increase degree, and then the horizontal axis corresponding to the intersection of the straight line and the correlation curve is captured as the light intensity increase trigger point. If the overlap degree does not reach the overlap degree threshold, the light intensity increase degrees corresponding to each adjacent time group are compared, and the majority is selected as the light intensity increase trigger point.

7. A power supply control system for an integrated photovoltaic and storage device as claimed in claim 6, characterized in that: The photovoltaic array output power adjustment is as follows: In the subsequent photovoltaic grid-connected operation, the light intensity is collected in real time and the light intensity increase at adjacent collection moments is calculated and compared with the light intensity increase trigger point. When the light intensity increase trigger point is reached, the output power of the photovoltaic array is adjusted to match the rated power of the inverter.

8. The power supply control system of the integrated photovoltaic and storage device according to claim 6, characterized in that: The analysis of the trigger point of power grid power fluctuation refers to the following process: The deviation inflection point mapping groups are selected from the inflection point mapping groups corresponding to the various electric energy parameters, and the slope of the inflection point is obtained from the electric energy parameter change curve of the power grid where each deviation inflection point mapping group is located as the power grid power fluctuation degree, and the inverter output compliance corresponding to each deviation inflection point mapping group is counted; The grid power fluctuation degree and inverter output compliance corresponding to each deviation inflection point mapping group are similarly analyzed according to the light intensity increase trigger point to obtain the grid power fluctuation trigger point.

9. The power supply control system of the integrated photovoltaic and storage device according to claim 8, characterized in that: The reactive power compensation control is implemented as follows: In the subsequent photovoltaic grid-connected operation, the grid power parameter detection and grid power fluctuation calculation at adjacent collection times are carried out in real time, and compared with the grid power fluctuation trigger point. When the grid power fluctuation trigger point is reached, the reactive power compensator is automatically switched on and off.

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