A photovoltaic on-grid path switching control method and system considering historical data

Abstract

A photovoltaic grid connection path switching control method considering historical data includes the following steps: Real-time acquisition of voltage waveform data at the photovoltaic grid connection point for the first time period before an overvoltage occurs, as the real-time waveform; retrieval of voltage waveform data from the same time period of the previous day from a historical database, as the historical waveform; alignment of the real-time waveform and the historical waveform along their time axes, and comparison of similarity at preset intervals; if the similarity of all comparison intervals within the first time period is greater than or equal to a first preset threshold, then the overvoltage switching strategy of the same time period of the previous day is directly invoked, controlling the photovoltaic switching device to switch the photovoltaic grid connection path to a dedicated line or load line; otherwise, the switching strategy is adjusted or regenerated according to the type of deviation, and the corresponding switching operation is executed. This method avoids the delay caused by complex calculations each time, and eliminates misjudgments caused by occasional interference or changes in operating conditions through similarity judgment, ensuring the accuracy and adaptability of the strategy.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic grid connection path switching control method and system that takes historical data into account. Background Technology

[0002] Distributed photovoltaic (PV) power generation systems refer to power generation systems built near user sites, operating primarily on a "self-consumption with surplus power fed into the grid" model. Users generate electricity using PV arrays installed on their own land (such as rooftops or yards), prioritizing power for their own electrical equipment. Excess electricity is fed into the public grid through grid-connected devices, and users purchase electricity from the grid when their own power generation is insufficient. This model of developing and utilizing solar energy locally effectively alleviates the spatial mismatch between energy resources and load demand, and has been widely applied and promoted in recent years.

[0003] The typical operating model of distributed photovoltaic (PV) power generation is "self-consumption with surplus power fed into the grid." Users utilize PV arrays installed on their own land (such as rooftops or yards) to generate electricity, prioritizing its use for their own electrical equipment (self-consumption). Excess electricity is fed into the public grid through grid-connected devices (surplus power fed into the grid). Users can also purchase electricity from the grid when their own power generation is insufficient. By developing and utilizing solar energy locally, this effectively alleviates the spatial mismatch between energy resources and load demand. However, as distributed PV penetration into the distribution network increases, its impact on voltage also becomes greater. During periods when user electricity consumption is low and distributed PV output is high, the large daily peak-to-valley difference leads to overvoltage, especially at the end of the line. Therefore, overvoltage is currently a pressing issue that needs to be addressed for PV grid connection. Summary of the Invention

[0004] To address the aforementioned shortcomings, the present invention aims to propose a photovoltaic grid connection path switching control method and system that considers historical data, thereby solving the problem of difficulty in achieving photovoltaic grid connection during overvoltage conditions in the current stage.

[0005] To achieve this objective, the present invention adopts the following technical solution: a photovoltaic grid connection path switching control method considering historical data, comprising the following steps: Real-time acquisition of voltage waveform data at the photovoltaic grid-connected point during the first time before overvoltage occurs, as the real-time waveform; Retrieve voltage waveform data from the same time period of the previous day from the historical database as historical waveforms; The real-time waveform is aligned with the historical waveform on the time axis and the similarity is compared according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first time period, the overvoltage switching strategy of the same time on the previous day is directly called to control the photovoltaic switching device to switch the photovoltaic grid connection path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

[0006] Preferably, the first duration is 1 hour, the preset period is 5 minutes, and the first preset threshold is 90%.

[0007] Preferably, selecting or regenerating the switching strategy based on the type of deviation includes: The deviation between real-time waveforms and historical waveforms is obtained through trend analysis; If the deviation between the real-time waveform and the historical waveform exhibits regularity, then the amplitude of the real-time waveform is corrected using a deviation quantization model to generate the corrected waveform. Determine whether the similarity between the corrected waveform and the historical waveform is greater than or equal to the first preset threshold. If it is greater than or equal to the threshold, directly call the overvoltage switching strategy of the same time the previous day. If it is less than the threshold, notify the staff to regenerate the switching strategy.

[0008] Preferably, the expression for the deviation quantification model is as follows: ; in Let be the Euclidean distance between the i-th data point in the real-time waveform and the j-th data point in the historical waveform. The minimum distance column for matching the (i-1)th data point in the real-time waveform with the jth data point in the historical waveform is accumulated.

[0009] Preferably, selecting to adjust or regenerate the switching strategy based on the type of deviation also includes: Step A: Obtain the deviation between the real-time waveform and the historical waveform through trend analysis; Step B: If the deviation between the real-time waveform and the historical waveform shows irregularity, the degree of agreement between the two-day curves at the overvoltage moment is calculated. If the degree of agreement is greater than the second preset threshold, the optimal grid connection path switching scheme is calculated based on the current grid operation status and photovoltaic power generation parameters. If the degree of agreement is less than the second threshold, step C is executed. Step C: Start the real-time monitoring program and continuously monitor the voltage for the next 1-3 minutes. If the voltage continues to be overvoltage for 1-3 minutes, notify the staff to regenerate the switching strategy. If there is no continuous overvoltage for 1-3 minutes, no switching operation will be performed.

[0010] Preferably, it also includes a frequent overvoltage switching handling step: Monitor the number of overvoltage switching events per hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

[0011] A photovoltaic grid connection path switching control system that takes into account historical data, and a photovoltaic grid connection path switching control method that takes into account historical data, comprising a first acquisition module, a second acquisition module, and a grid connection control module; The first acquisition module is used to acquire the voltage waveform data of the photovoltaic grid connection point for the first time before the overvoltage occurs, as the real-time waveform. The second acquisition module is used to retrieve voltage waveform data from the historical database for the same period of the previous day as historical waveforms; The Internet access control module is used to align the real-time waveform with the historical waveform on the time axis and perform similarity comparison according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first duration, the overvoltage switching strategy of the same time the previous day is directly invoked to control the photovoltaic switching device to switch the photovoltaic Internet access path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

[0012] Preferably, this also includes frequent switching of monitoring modules; The frequent switching monitoring module is used to monitor the number of overvoltage switching times within one hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

[0013] One of the above technical solutions has the following advantages or beneficial effects: it utilizes the periodic characteristics of photovoltaic power output and load changes to achieve prediction and rapid response to overvoltage, avoiding the delay caused by complex calculations each time, and at the same time, it eliminates misjudgments caused by occasional interference or changes in operating conditions through similarity judgment, thus ensuring the accuracy and adaptability of the strategy. Attached Figure Description

[0014] Figure 1 One example of the method of the present invention is a flowchart in one embodiment; Figure 2 The following is a schematic diagram of the structure of one embodiment of the system of the present invention. Detailed Implementation

[0015] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0016] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0017] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] like Figures 1-2 As shown, a photovoltaic grid connection path switching control method that considers historical data includes the following steps: Real-time acquisition of voltage waveform data at the photovoltaic grid-connected point during the first time before overvoltage occurs, as the real-time waveform; Retrieve voltage waveform data from the same time period of the previous day from the historical database as historical waveforms; The real-time waveform is aligned with the historical waveform on the time axis and the similarity is compared according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first time period, the overvoltage switching strategy of the same time on the previous day is directly called to control the photovoltaic switching device to switch the photovoltaic grid connection path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

[0020] To address the overvoltage problem caused by the mismatch between user load and photovoltaic output time periods under high distributed photovoltaic (PV) penetration, particularly overvoltage at the end of the line, this invention first collects the voltage waveform for the first time period before the overvoltage occurs as the real-time waveform. It then retrieves historical waveforms from the same time period of the previous day for time axis alignment and period similarity comparison. If the similarity of all compared periods is higher than a preset threshold, it indicates that the photovoltaic output and load variation patterns of the current day are highly consistent with the previous day. In this case, the switching strategy successfully implemented the previous day to handle the overvoltage can be directly invoked, controlling the PV switching device to quickly switch the grid connection path to a dedicated line or load line, thereby promptly absorbing excess power or changing the power flow distribution to raise the voltage. If the similarity is insufficient, the switching strategy is dynamically adjusted or regenerated based on the deviation type between the real-time and historical waveforms to ensure that the strategy adapts to the current actual grid conditions. This method relies on the construction of a historical database, the acquisition and processing of real-time data, a similarity algorithm, and the establishment of a strategy library. By comparing real-time data with historical patterns, it not only utilizes the periodic characteristics of photovoltaic power output and load changes to achieve overvoltage prediction and rapid response, avoiding delays caused by complex calculations each time, but also eliminates misjudgments caused by occasional interference or changes in operating conditions through similarity judgment, ensuring the accuracy and adaptability of the strategy. This invention, on the one hand, effectively suppresses overvoltage occurrence through advance prediction and rapid switching, ensuring grid safety and power quality; on the other hand, it reduces the reliance on complex real-time calculations.

[0021] Preferably, the first duration is 1 hour, the preset period is 5 minutes, and the first preset threshold is 90%.

[0022] Preferably, selecting or regenerating the switching strategy based on the type of deviation includes: The deviation between real-time waveforms and historical waveforms is obtained through trend analysis; If the deviation between the real-time waveform and the historical waveform exhibits regularity, then the amplitude of the real-time waveform is corrected using a deviation quantization model to generate the corrected waveform. Determine whether the similarity between the corrected waveform and the historical waveform is greater than or equal to the first preset threshold. If it is greater than or equal to the threshold, directly call the overvoltage switching strategy of the same time the previous day. If it is less than the threshold, notify the staff to regenerate the switching strategy.

[0023] This invention introduces a deviation regularity judgment and amplitude correction mechanism to solve the problem of strategy misuse or response delay that may be caused by simple threshold judgment, thereby improving the accuracy and robustness of overvoltage control. When the similarity between the real-time waveform and the historical waveform does not reach the first preset threshold, the system first identifies whether the deviation between the two exhibits regular characteristics through trend analysis. For example, the overall increase in photovoltaic output or the shift of the load baseline due to weather changes usually means that the overvoltage mechanism is similar to that of the previous day but the amplitude is different. In this case, there is no need to regenerate a complex switching strategy. Instead, the amplitude of the real-time waveform is corrected through the deviation quantification model to generate a corrected waveform that reflects the actual operating conditions. Then, the similarity is compared with the historical waveform. If the corrected similarity meets the standard, the successful strategy of the previous day can still be called. Only adaptive adjustments need to be made to the switching timing or parameters. This avoids the computational overhead and response delay caused by frequent strategy reconstruction due to small amplitude differences and ensures the effectiveness of the strategy. If the correction still does not meet the standard, it means that the deviation exhibits irregular or complex characteristics, which may be due to changes in the grid structure, equipment abnormalities, or extreme weather. In this case, the staff is notified to regenerate the strategy. This allows for the use of human experience to handle unconventional operating conditions and prevents automatic control from malfunctioning. This implementation method introduces a fault-tolerant manual review process while ensuring the efficiency of automatic control through a layered processing mechanism.

[0024] The calculation of the similarity between the corrected waveform and the historical waveform is consistent with the calculation of the similarity between the historical waveform and the real-time waveform. It can be obtained by Euclidean distance calculation. The calculation process is existing technology and will not be described in detail here.

[0025] Preferably, the expression for the deviation quantification model is as follows: ; in Let be the Euclidean distance between the i-th data point in the real-time waveform and the j-th data point in the historical waveform. The minimum distance column for matching the (i-1)th data point in the real-time waveform with the jth data point in the historical waveform is accumulated.

[0026] Preferably, selecting to adjust or regenerate the switching strategy based on the type of deviation also includes: Step A: Obtain the deviation between the real-time waveform and the historical waveform through trend analysis; Step B: If the deviation between the real-time waveform and the historical waveform shows irregularity, the degree of agreement between the two-day curves at the overvoltage moment is calculated. If the degree of agreement is greater than the second preset threshold, the optimal grid connection path switching scheme is calculated based on the current grid operation status and photovoltaic power generation parameters. If the degree of agreement is less than the second threshold, step C is executed. Step C: Start the real-time monitoring program and continuously monitor the voltage for the next 1-3 minutes. If the voltage continues to be overvoltage for 1-3 minutes, notify the staff to regenerate the switching strategy. If there is no continuous overvoltage for 1-3 minutes, no switching operation will be performed.

[0027] To address the problem that when real-time waveforms deviate irregularly from historical waveforms, the inability to effectively match historical patterns may lead to decision-making difficulties or operational errors. When trend analysis determines that the deviation exhibits irregular characteristics, the system first calculates the consistency between the two-day curves at the overvoltage moment. If the consistency is higher than the second preset threshold, it indicates that although the overall waveform trend is irregular, the voltage change pattern on the day of the critical overvoltage event still has a high similarity to historical data. At this time, the optimal grid connection path switching scheme can be dynamically calculated based on real-time parameters such as the current grid operation status and photovoltaic power generation. Thus, even when historical strategies cannot be directly applied, precise control can still be achieved through real-time optimization. If the consistency is lower than the second preset threshold, it indicates that the pattern at the overvoltage moment is also seriously inconsistent with historical patterns, possibly due to complex factors such as grid topology changes, extreme weather, or equipment failures. In this case, the system does not rashly execute automatic switching but instead starts a real-time monitoring program to continuously observe voltage changes within 1 to 3 minutes. If the overvoltage persists, the system notifies the staff to regenerate the strategy and handle unconventional operating conditions using manual experience. If the overvoltage dissipates on its own within a short period of time, no operation is performed to avoid unnecessary switching due to instantaneous disturbances or measurement noise. This implementation combines hierarchical judgment of conformity with real-time monitoring, which enables rapid optimization control in scenarios where historical patterns can be referenced, while maintaining a fault-tolerant mechanism of prudent waiting and manual intervention in completely unpredictable scenarios.

[0028] It is worth mentioning that the optimal Internet access path switching scheme can be obtained by constructing a function with the lowest Internet access cost, and then finding the optimal solution through methods such as a variant of the particle swarm optimization algorithm. This optimization calculation scheme can be calculated using existing technology, and will not be explained in detail here.

[0029] Preferably, it also includes a frequent overvoltage switching handling step: Monitor the number of overvoltage switching events per hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

[0030] When addressing the aforementioned persistent overvoltage issue, simply triggering voltage thresholds and optimizing path switching may lead to frequent control equipment actions under specific abnormal scenarios (such as severe load fluctuations or photovoltaic output instability). This not only accelerates the aging and wear of hardware such as photovoltaic switching devices but may also cause oscillations in the distribution network topology, ultimately affecting power supply reliability. To improve the fault tolerance of distributed photovoltaic grid-connected voltage control, a more comprehensive and robust solution to the overvoltage problem is needed.

[0031] When the number of switching operations reaches or exceeds three times within an hour, this invention no longer blindly executes the predetermined control strategy, but instead switches to a diagnostic analysis mode. It performs feature identification on the photovoltaic output curve and load curve during the abnormal period. This data-driven root cause analysis method can effectively distinguish whether the root cause of overvoltage originates from the grid side (abnormal load) or the power source side (abnormal photovoltaic output). If the load curve is determined to be abnormal, it means that the overvoltage is likely caused by transient events such as a sudden load drop rather than continuous high-penetration photovoltaic injection. In this case, pausing the overvoltage switching operation can prevent the control equipment from over-responding to transient disturbances. The optimization process can be restarted after the load curve stabilizes, thereby improving the stability of the control strategy while ensuring voltage safety. Conversely, if the photovoltaic output curve is determined to be abnormal (such as a short-term power surge caused by cloud edge effects), it indicates that the overvoltage does indeed originate from intermittent fluctuations in photovoltaic power generation. In this case, continuing the switching operation can promptly absorb excess power by changing the access topology, preventing voltage exceedances.

[0032] A photovoltaic grid connection path switching control system that takes into account historical data, and a photovoltaic grid connection path switching control method that takes into account historical data, comprising a first acquisition module, a second acquisition module, and a grid connection control module; The first acquisition module is used to acquire the voltage waveform data of the photovoltaic grid connection point for the first time before the overvoltage occurs, as the real-time waveform. The second acquisition module is used to retrieve voltage waveform data from the historical database for the same period of the previous day as historical waveforms; The Internet access control module is used to align the real-time waveform with the historical waveform on the time axis and perform similarity comparison according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first duration, the overvoltage switching strategy of the same time the previous day is directly invoked to control the photovoltaic switching device to switch the photovoltaic Internet access path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

[0033] Preferably, this also includes frequent switching of monitoring modules; The frequent switching monitoring module is used to monitor the number of overvoltage switching times within one hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic grid connection path switching control method considering historical data, characterized in that, Includes the following steps: Real-time acquisition of voltage waveform data at the photovoltaic grid-connected point during the first time before overvoltage occurs, as the real-time waveform; Retrieve voltage waveform data from the same time period of the previous day from the historical database as historical waveforms; The real-time waveform is aligned with the historical waveform on the time axis and the similarity is compared according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first time period, the overvoltage switching strategy of the same time on the previous day is directly called to control the photovoltaic switching device to switch the photovoltaic grid connection path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

2. The photovoltaic grid connection path switching control method considering historical data according to claim 1, characterized in that, The first duration is 1 hour, the preset period is 5 minutes, and the first preset threshold is 90%.

3. The photovoltaic grid connection path switching control method considering historical data according to claim 2, characterized in that, Based on the type of deviation, the options for adjusting or regenerating the switching strategy include: The deviation between real-time waveforms and historical waveforms is obtained through trend analysis; If the deviation between the real-time waveform and the historical waveform exhibits regularity, then the amplitude of the real-time waveform is corrected using a deviation quantization model to generate the corrected waveform. Determine whether the similarity between the corrected waveform and the historical waveform is greater than or equal to the first preset threshold. If it is greater than or equal to the threshold, directly call the overvoltage switching strategy of the same time the previous day. If it is less than the threshold, notify the staff to regenerate the switching strategy.

4. The photovoltaic grid connection path switching control method considering historical data according to claim 3, characterized in that, The expression for the deviation quantification model is as follows: ； in Let be the Euclidean distance between the i-th data point in the real-time waveform and the j-th data point in the historical waveform. The minimum distance column for matching the (i-1)th data point in the real-time waveform with the jth data point in the historical waveform is accumulated.

5. The photovoltaic grid connection path switching control method considering historical data according to claim 2, characterized in that, Selecting to adjust or regenerate the switching strategy based on the type of deviation also includes: Step A: Obtain the deviation between the real-time waveform and the historical waveform through trend analysis; Step B: If the deviation between the real-time waveform and the historical waveform shows irregularity, the degree of agreement between the two-day curves at the overvoltage moment is calculated. If the degree of agreement is greater than the second preset threshold, the optimal grid connection path switching scheme is calculated based on the current grid operation status and photovoltaic power generation parameters. If the degree of agreement is less than the second threshold, step C is executed. Step C: Start the real-time monitoring program and continuously monitor the voltage for the next 1-3 minutes. If the voltage continues to be overvoltage for 1-3 minutes, notify the staff to regenerate the switching strategy. If there is no continuous overvoltage for 1-3 minutes, no switching operation will be performed.

6. The photovoltaic grid connection path switching control method considering historical data according to claim 2, characterized in that, It also includes steps for handling frequent overvoltage switching: Monitor the number of overvoltage switching events per hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

7. A photovoltaic grid connection path switching control system that considers historical data, using the photovoltaic grid connection path switching control method that considers historical data as described in any one of claims 1 to 6, characterized in that, It includes a first data acquisition module, a second data acquisition module, and an internet access control module; The first acquisition module is used to acquire the voltage waveform data of the photovoltaic grid connection point for the first time before the overvoltage occurs, as the real-time waveform. The second acquisition module is used to retrieve voltage waveform data from the historical database for the same period of the previous day as historical waveforms; The Internet access control module is used to align the real-time waveform with the historical waveform on the time axis and perform similarity comparison according to a preset period. If the similarity of all comparison periods is greater than or equal to the first preset threshold within the first duration, the overvoltage switching strategy of the same time the previous day is directly invoked to control the photovoltaic switching device to switch the photovoltaic Internet access path to the dedicated line or load line. Otherwise, adjust or regenerate the switching strategy based on the type of deviation, and perform the corresponding switching operation.

8. A photovoltaic grid connection path switching control system considering historical data according to claim 7, characterized in that, This also includes frequent switching of monitoring modules; The frequent switching monitoring module is used to monitor the number of overvoltage switching times within one hour; If the number of switching times is greater than or equal to 3, it is judged as a frequent abnormal state; Analyze the photovoltaic output curve and load curve during abnormal periods; If the load curve is abnormal, the overvoltage switching operation will be suspended and restarted after the load curve stabilizes. If the photovoltaic power output curve is abnormal, the switching operation will continue.

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